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-% \iffalse meta-comment
-%
-%% File: l3prop.dtx
-%
-% Copyright (C) 1990-2024 The LaTeX Project
-%
-% It may be distributed and/or modified under the conditions of the
-% LaTeX Project Public License (LPPL), either version 1.3c of this
-% license or (at your option) any later version. The latest version
-% of this license is in the file
-%
-% https://www.latex-project.org/lppl.txt
-%
-% This file is part of the "l3kernel bundle" (The Work in LPPL)
-% and all files in that bundle must be distributed together.
-%
-% -----------------------------------------------------------------------
-%
-% The development version of the bundle can be found at
-%
-% https://github.com/latex3/latex3
-%
-% for those people who are interested.
-%
-%<*driver>
-\documentclass[full,kernel]{l3doc}
-\begin{document}
- \DocInput{\jobname.dtx}
-\end{document}
-%</driver>
-% \fi
-%
-% \title{^^A
-% The \pkg{l3prop} module\\ Property lists^^A
-% }
-%
-% \author{^^A
-% The \LaTeX{} Project\thanks
-% {^^A
-% E-mail:
-% \href{mailto:latex-team@latex-project.org}
-% {latex-team@latex-project.org}^^A
-% }^^A
-% }
-%
-% \date{Released 2024-03-14}
-%
-% \maketitle
-%
-% \begin{documentation}
-%
-% \pkg{expl3} implements a \enquote{property list} data type, which contain
-% an unordered list of entries each of which consists of a \meta{key} (string)
-% and an associated \meta{value} (token list). The \meta{key} and \meta{value}
-% may both be given as any balanced text, and the \meta{key} is processed using
-% \cs{tl_to_str:n}, meaning that category codes are ignored. Entries can be
-% manipulated individually, as well as collectively by applying a function to
-% every key--value pair within the list.
-%
-% Each entry in a property list must have a unique \meta{key}: if an entry is
-% added to a property list which already contains the \meta{key} then the new
-% entry overwrites the existing one. The \meta{keys} are compared on a
-% string basis, using the same method as \cs{str_if_eq:nnTF}.
-%
-% Property lists are intended for storing key-based information for use within
-% code. They can be converted from and to key--value lists, which are a form of
-% \emph{input} parsed by the \pkg{l3keys} module. If a key--value list contains
-% a \meta{key} multiple times, only the last \meta{value} associated to it will
-% be kept in the conversion to a property list.
-%
-% Internally, property lists can use two distinct implementations with different
-% data storage, which are decided when declaring the property list variable
-% using \cs{prop_new:N} (\enquote{flat} storage) or \cs{prop_new_linked:N}
-% (\enquote{linked} storage). After a property list is declared with
-% \cs{prop_new:N} or \cs{prop_new_linked:N}, the type of internal data storage
-% can be changed by \cs{prop_make_flat:N} or \cs{prop_make_linked:N}, but only
-% at the outermost group level. All other \pkg{l3prop} functions transparently
-% manipulate either storage method and convert as needed.
-% \begin{itemize}
-% \item
-% The (default) \enquote{flat} storage method is suited for a relatively
-% small number of entries, or when the property list is likely to be
-% manipulated (copied, mapped) as a whole rather than entry-wise. It is
-% significantly faster for \cs{prop_set_eq:NN}, and only slightly faster for
-% \cs{prop_clear:N}, \cs{prop_concat:NNN}, and mapping functions
-% \cs[no-index]{prop_map_\ldots{}}.
-%
-% \item
-% The \enquote{linked} storage method is meant for property lists with a
-% large numbers of entries. It takes up more of \TeX{}'s memory during a run, but is
-% significantly faster (for long lists) when accessing or modifying
-% individual entries using functions such as \cs{prop_if_in:Nn},
-% \cs{prop_item:Nn}, \cs{prop_put:Nnn}, \cs{prop_get:NnN},
-% \cs{prop_pop:NnN}, \cs{prop_remove:Nn}, as it takes a constant
-% time for these operations (rather than the number of items for a
-% \enquote{flat} property list). A technical drawback is that
-% memory is permanently used\footnote{Until the end of the run, that
-% is.} by \meta{keys} stored in a \enquote{linked} property list,
-% even after they are removed and the property list is deleted.
-% \end{itemize}
-%
-% \section{Creating and initialising property lists}
-%
-% \begin{function}{\prop_new:N, \prop_new:c}
-% \begin{syntax}
-% \cs{prop_new:N} \meta{property list}
-% \end{syntax}
-% Creates a new \enquote{flat} \meta{property list} or raises an error if the
-% name is already taken. The declaration is global. The \meta{property list}
-% initially contains no entries. See also \cs{prop_new_linked:N}.
-% \end{function}
-%
-% \begin{function}[added = 2024-02-12]{\prop_new_linked:N, \prop_new_linked:c}
-% \begin{syntax}
-% \cs{prop_new_linked:N} \meta{property list}
-% \end{syntax}
-% Creates a new \enquote{linked} \meta{property list} or raises an error if
-% the name is already taken. The declaration is global. The \meta{property
-% list} initially contains no entries. The internal data storage differs from
-% that produced by \cs{prop_new:N} and it is optimized for property lists with
-% a large number of entries.
-% \end{function}
-%
-% \begin{function}
-% {\prop_clear:N, \prop_clear:c, \prop_gclear:N, \prop_gclear:c}
-% \begin{syntax}
-% \cs{prop_clear:N} \meta{property list}
-% \end{syntax}
-% Clears all entries from the \meta{property list}.
-% \end{function}
-%
-% \begin{function}
-% {
-% \prop_clear_new:N, \prop_clear_new:c,
-% \prop_gclear_new:N, \prop_gclear_new:c
-% }
-% \begin{syntax}
-% \cs{prop_clear_new:N} \meta{property list}
-% \end{syntax}
-% Ensures that the \meta{property list} exists globally by applying
-% \cs{prop_new:N} if necessary, then applies
-% \cs[index=prop_clear:N]{prop_(g)clear:N} to leave the list empty.
-% \begin{texnote}
-% If the property list exists and is of \enquote{linked} type, it
-% is cleared but not made into a flat property list.
-% \end{texnote}
-% \end{function}
-%
-% \begin{function}[added = 2024-02-12]
-% {
-% \prop_clear_new_linked:N, \prop_clear_new_linked:c,
-% \prop_gclear_new_linked:N, \prop_gclear_new_linked:c
-% }
-% \begin{syntax}
-% \cs{prop_clear_new_linked:N} \meta{property list}
-% \end{syntax}
-% Ensures that the \meta{property list} exists globally by applying
-% \cs{prop_new_linked:N} if necessary, then applies
-% \cs[index=prop_clear:N]{prop_(g)clear:N} to leave the list empty.
-% \begin{texnote}
-% If the property list exists and is of \enquote{flat} type, it
-% is cleared but not made into a linked property list.
-% \end{texnote}
-% \end{function}
-%
-% \begin{function}
-% {
-% \prop_set_eq:NN, \prop_set_eq:cN, \prop_set_eq:Nc, \prop_set_eq:cc,
-% \prop_gset_eq:NN, \prop_gset_eq:cN, \prop_gset_eq:Nc, \prop_gset_eq:cc
-% }
-% \begin{syntax}
-% \cs{prop_set_eq:NN} \meta{property list_1} \meta{property list_2}
-% \end{syntax}
-% Sets the content of \meta{property list_1} equal to that of \meta{property
-% list_2}. This converts as needed between the two storage types.
-% \end{function}
-%
-% \begin{function}[added = 2017-11-28, updated = 2021-11-07]
-% {
-% \prop_set_from_keyval:Nn, \prop_set_from_keyval:cn,
-% \prop_gset_from_keyval:Nn, \prop_gset_from_keyval:cn,
-% }
-% \begin{syntax}
-% \cs{prop_set_from_keyval:Nn} \meta{property list}
-% \{
-% \meta{key1} |=| \meta{value1} |,|
-% \meta{key2} |=| \meta{value2} |,| \ldots{}
-% \}
-% \end{syntax}
-% Sets \meta{property list} to contain key--value pairs given in the second
-% argument. If duplicate keys appear only the last of the values is kept.
-% In contrast to most keyval lists (\emph{e.g.}~those in \pkg{l3keys}), each
-% key here \emph{must} be followed with an \texttt{=} sign even to specify an
-% empty \meta{value}.
-%
-% Spaces are trimmed around every \meta{key} and every \meta{value},
-% and if the result of trimming spaces consists of a single brace
-% group then a set of outer braces is removed. This enables both the
-% \meta{key} and the \meta{value} to contain spaces, commas or equal
-% signs. The \meta{key} is then processed by \cs{tl_to_str:n}.
-% This function correctly detects the |=| and |,| signs provided they
-% have the standard category code~$12$ or they are active.
-% \end{function}
-%
-% \begin{function}[added = 2017-11-28, updated = 2021-11-07]
-% {\prop_const_from_keyval:Nn, \prop_const_from_keyval:cn}
-% \begin{syntax}
-% \cs{prop_const_from_keyval:Nn} \meta{property list}
-% \{
-% \meta{key1} |=| \meta{value1} |,|
-% \meta{key2} |=| \meta{value2} |,| \ldots{}
-% \}
-% \end{syntax}
-% Creates a new constant \enquote{flat} \meta{property list} or raises
-% an error if the
-% name is already taken. The \meta{property list} is set globally to
-% contain key--value pairs given in the second argument, processed in
-% the way described for \cs{prop_set_from_keyval:Nn}. If duplicate
-% keys appear only the last of the values is kept.
-% This function correctly detects the |=| and |,| signs provided they
-% have the standard category code~$12$ or they are active.
-% \end{function}
-%
-% \begin{function}[added = 2024-02-12]
-% {\prop_const_linked_from_keyval:Nn, \prop_const_linked_from_keyval:cn}
-% \begin{syntax}
-% \cs{prop_const_linked_from_keyval:Nn} \meta{prop~var}
-% \{
-% \meta{key1} |=| \meta{value1} |,|
-% \meta{key2} |=| \meta{value2} |,| \ldots{}
-% \}
-% \end{syntax}
-% Creates a new constant \enquote{linked} \meta{prop~var} or raises an
-% error if the
-% name is already taken. The \meta{prop~var} is set globally to
-% contain key--value pairs given in the second argument, processed in
-% the way described for \cs{prop_set_from_keyval:Nn}. If duplicate
-% keys appear only the last of the values is kept.
-% This function correctly detects the |=| and |,| signs provided they
-% have the standard category code~$12$ or they are active.
-% \end{function}
-%
-% \begin{function}[added = 2024-02-12]{\prop_make_flat:N, \prop_make_flat:c}
-% \begin{syntax}
-% \cs{prop_make_flat:N} \meta{property list}
-% \end{syntax}
-% Changes the internal storage type of the \meta{property list} to be
-% the same \enquote{flat} storage as \cs{prop_new:N}. The key--value
-% pairs of the \meta{property list} are preserved by the change. If
-% the property list was already flat then nothing is done. This
-% function can only be used at the outermost group level.
-% \end{function}
-%
-% \begin{function}[added = 2024-02-12]{\prop_make_linked:N, \prop_make_linked:c}
-% \begin{syntax}
-% \cs{prop_make_linked:N} \meta{property list}
-% \end{syntax}
-% Changes the internal storage type of the \meta{property list} to be
-% the same \enquote{linked} storage as \cs{prop_new_linked:N}. The
-% key--value pairs of the \meta{property list} are preserved by the
-% change. If the property list was already linked then nothing is
-% done. This function can only be used at the outermost group level.
-% \end{function}
-%
-% \section{Adding and updating property list entries}
-%
-% \begin{function}[updated = 2012-07-09]
-% {
-% \prop_put:Nnn, \prop_put:NnV, \prop_put:Nnv, \prop_put:Nne,
-% \prop_put:NVn, \prop_put:NVV, \prop_put:NVv, \prop_put:NVe,
-% \prop_put:Nvn, \prop_put:NvV, \prop_put:Nvv, \prop_put:Nve,
-% \prop_put:Nen, \prop_put:NeV, \prop_put:Nev, \prop_put:Nee,
-% \prop_put:Nno, \prop_put:Non, \prop_put:Noo,
-% \prop_put:cnn, \prop_put:cnV, \prop_put:cnv, \prop_put:cne,
-% \prop_put:cVn, \prop_put:cVV, \prop_put:cVv, \prop_put:cVe,
-% \prop_put:cvn, \prop_put:cvV, \prop_put:cvv, \prop_put:cve,
-% \prop_put:cen, \prop_put:ceV, \prop_put:cev, \prop_put:cee,
-% \prop_put:cno, \prop_put:con, \prop_put:coo,
-% \prop_gput:Nnn, \prop_gput:NnV, \prop_gput:Nnv, \prop_gput:Nne,
-% \prop_gput:NVn, \prop_gput:NVV, \prop_gput:NVv, \prop_gput:NVe,
-% \prop_gput:Nvn, \prop_gput:NvV, \prop_gput:Nvv, \prop_gput:Nve,
-% \prop_gput:Nen, \prop_gput:NeV, \prop_gput:Nev, \prop_gput:Nee,
-% \prop_gput:Nno, \prop_gput:Non, \prop_gput:Noo,
-% \prop_gput:cnn, \prop_gput:cnV, \prop_gput:cnv, \prop_gput:cne,
-% \prop_gput:cVn, \prop_gput:cVV, \prop_gput:cVv, \prop_gput:cVe,
-% \prop_gput:cvn, \prop_gput:cvV, \prop_gput:cvv, \prop_gput:cve,
-% \prop_gput:cen, \prop_gput:ceV, \prop_gput:cev, \prop_gput:cee,
-% \prop_gput:cno, \prop_gput:con, \prop_gput:coo
-% }
-% \begin{syntax}
-% \cs{prop_put:Nnn} \meta{property list} \Arg{key} \Arg{value}
-% \end{syntax}
-% Adds an entry to the \meta{property list} which may be accessed
-% using the \meta{key} and which has \meta{value}. If the \meta{key}
-% is already present in the \meta{property list}, the existing entry
-% is overwritten by the new \meta{value}. Both the \meta{key} and
-% \meta{value} may contain any \meta{balanced text}. The \meta{key} is
-% stored after processing with \cs{tl_to_str:n}, meaning that category
-% codes are ignored.
-% \end{function}
-%
-% \begin{function}
-% {
-% \prop_put_if_new:Nnn, \prop_put_if_new:NVn, \prop_put_if_new:NnV,
-% \prop_put_if_new:cnn, \prop_put_if_new:cVn, \prop_put_if_new:cnV,
-% \prop_gput_if_new:Nnn, \prop_gput_if_new:NVn, \prop_gput_if_new:NnV,
-% \prop_gput_if_new:cnn, \prop_gput_if_new:cVn, \prop_gput_if_new:cnV
-% }
-% \begin{syntax}
-% \cs{prop_put_if_new:Nnn} \meta{property list} \Arg{key} \Arg{value}
-% \end{syntax}
-% If the \meta{key} is present in the \meta{property list} then no
-% action is taken. Otherwise, a new entry is added as described for
-% \cs{prop_put:Nnn}.
-% \end{function}
-%
-% \begin{function}[added = 2021-05-16]
-% {
-% \prop_concat:NNN, \prop_concat:ccc,
-% \prop_gconcat:NNN, \prop_gconcat:ccc
-% }
-% \begin{syntax}
-% \cs{prop_concat:NNN} \meta{property list_1} \meta{property list_2} \meta{property list3}
-% \end{syntax}
-% Combines the key--value pairs of \meta{property list_2} and
-% \meta{property list_3}, and saves the result in \meta{property list_1}. If a
-% key appears in both \meta{property list_2} and \meta{property list_3} then the
-% last value, namely the value in \meta{property list_3} is kept.
-% This converts as needed between the two storage types.
-% \end{function}
-%
-% \begin{function}[added = 2021-05-16, updated = 2021-11-07]
-% {
-% \prop_put_from_keyval:Nn, \prop_put_from_keyval:cn,
-% \prop_gput_from_keyval:Nn, \prop_gput_from_keyval:cn,
-% }
-% \begin{syntax}
-% \cs{prop_put_from_keyval:Nn} \meta{property list}
-% \{
-% \meta{key1} |=| \meta{value1} |,|
-% \meta{key2} |=| \meta{value2} |,| \ldots{}
-% \}
-% \end{syntax}
-% Updates the \meta{property list} by adding entries for each key--value
-% pair given in the second argument. The addition is done through
-% \cs{prop_put:Nnn}, hence if the \meta{property list} already contains
-% some of the keys, the corresponding values are discarded and
-% replaced by those given in the key--value list. If duplicate keys
-% appear in the key--value list then only the last of the values is kept.
-%
-% The function is equivalent to storing the key--value pairs in a
-% temporary property list using \cs{prop_set_from_keyval:Nn}, then
-% combining \meta{property list} with the temporary variable using
-% \cs{prop_concat:NNN}. In particular, the \meta{keys} and
-% \meta{values} are space-trimmed and unbraced as described in
-% \cs{prop_set_from_keyval:Nn}.
-% This function correctly detects the |=| and |,| signs provided they
-% have the standard category code~$12$ or they are active.
-% \end{function}
-%
-% \section{Recovering values from property lists}
-%
-% \begin{function}[updated = 2011-08-28]
-% {
-% \prop_get:NnN, \prop_get:NVN, \prop_get:NvN, \prop_get:NeN,
-% \prop_get:NoN,
-% \prop_get:cnN, \prop_get:cVN, \prop_get:cvN, \prop_get:ceN,
-% \prop_get:coN,
-% \prop_get:cnc
-% }
-% \begin{syntax}
-% \cs{prop_get:NnN} \meta{property list} \Arg{key} \meta{tl var}
-% \end{syntax}
-% Recovers the \meta{value} stored with \meta{key} from the
-% \meta{property list}, and places this in the \meta{token list
-% variable}. If the \meta{key} is not found in the
-% \meta{property list} then the \meta{token list variable} is set
-% to the special marker \cs{q_no_value}. The \meta{token list
-% variable} is set within the current \TeX{} group. See also
-% \cs{prop_get:NnNTF}.
-% \end{function}
-%
-% \begin{function}[updated = 2011-08-18]
-% {
-% \prop_pop:NnN, \prop_pop:NVN,
-% \prop_pop:NoN,
-% \prop_pop:cnN, \prop_pop:cVN,
-% \prop_pop:coN
-% }
-% \begin{syntax}
-% \cs{prop_pop:NnN} \meta{property list} \Arg{key} \meta{tl var}
-% \end{syntax}
-% Recovers the \meta{value} stored with \meta{key} from the
-% \meta{property list}, and places this in the \meta{token list
-% variable}. If the \meta{key} is not found in the
-% \meta{property list} then the \meta{token list variable} is set
-% to the special marker \cs{q_no_value}. The \meta{key} and
-% \meta{value} are then deleted from the property list. Both
-% assignments are local. See also \cs{prop_pop:NnNTF}.
-% \end{function}
-%
-% \begin{function}[updated = 2011-08-18]
-% {
-% \prop_gpop:NnN, \prop_gpop:NVN,
-% \prop_gpop:NoN,
-% \prop_gpop:cnN, \prop_gpop:cVN,
-% \prop_gpop:coN
-% }
-% \begin{syntax}
-% \cs{prop_gpop:NnN} \meta{property list} \Arg{key} \meta{tl var}
-% \end{syntax}
-% Recovers the \meta{value} stored with \meta{key} from the
-% \meta{property list}, and places this in the \meta{token list
-% variable}. If the \meta{key} is not found in the
-% \meta{property list} then the \meta{token list variable} is set
-% to the special marker \cs{q_no_value}. The \meta{key} and
-% \meta{value} are then deleted from the property list.
-% The \meta{property list} is modified globally, while the assignment of
-% the \meta{token list variable} is local. See also \cs{prop_gpop:NnNTF}.
-% \end{function}
-%
-% \begin{function}[EXP, added = 2014-07-17]
-% {
-% \prop_item:Nn, \prop_item:NV, \prop_item:Ne, \prop_item:No,
-% \prop_item:cn, \prop_item:cV, \prop_item:ce, \prop_item:co
-% }
-% \begin{syntax}
-% \cs{prop_item:Nn} \meta{property list} \Arg{key}
-% \end{syntax}
-% Expands to the \meta{value} corresponding to the \meta{key} in
-% the \meta{property list}. If the \meta{key} is missing, this has
-% an empty expansion.
-% \begin{texnote}
-% For \enquote{flat} property lists, this expandable function iterates
-% through every key--value pair and is therefore slower than a
-% non-expandable approach based on \cs{prop_get:NnN}.
-% (For \enquote{linked} property lists both functions are fast.)
-%
-% The result is returned within the \tn{unexpanded}
-% primitive (\cs{exp_not:n}), which means that the \meta{value}
-% does not expand further when appearing in an \texttt{e}-type
-% or \texttt{x}-type argument expansion.
-% \end{texnote}
-% \end{function}
-%
-% \begin{function}[EXP]{\prop_count:N, \prop_count:c}
-% \begin{syntax}
-% \cs{prop_count:N} \meta{property list}
-% \end{syntax}
-% Leaves the number of key--value pairs in the \meta{property list} in
-% the input stream as an \meta{integer denotation}.
-% \end{function}
-%
-% \begin{function}[EXP]{\prop_to_keyval:N}
-% \begin{syntax}
-% \cs{prop_to_keyval:N} \meta{property list}
-% \end{syntax}
-% Expands to the \meta{property list} in a key--value notation. Keep in mind
-% that a \meta{property list} is \emph{unordered}, while key--value interfaces
-% are not necessarily, so this cannot be used for arbitrary interfaces.
-% \begin{texnote}
-% The result is returned within the \tn{unexpanded} primitive
-% (\cs{exp_not:n}), which means that the key--value list does not expand
-% further when appearing in an \texttt{e}-type or \texttt{x}-type argument expansion.
-% It also needs exactly two steps of expansion.
-% \end{texnote}
-% \end{function}
-%
-% \section{Modifying property lists}
-%
-% \begin{function}[added = 2012-05-12]
-% {
-% \prop_remove:Nn, \prop_remove:NV, \prop_remove:Ne,
-% \prop_remove:cn, \prop_remove:cV, \prop_remove:ce,
-% \prop_gremove:Nn, \prop_gremove:NV, \prop_gremove:Ne,
-% \prop_gremove:cn, \prop_gremove:cV, \prop_gremove:ce,
-% }
-% \begin{syntax}
-% \cs{prop_remove:Nn} \meta{property list} \Arg{key}
-% \end{syntax}
-% Removes the entry listed under \meta{key} from the
-% \meta{property list}. If the \meta{key} is
-% not found in the \meta{property list} no change occurs,
-% \emph{i.e}~there is no need to test for the existence of a key before
-% deleting it.
-% \end{function}
-%
-% \section{Property list conditionals}
-%
-% \begin{function}[EXP, pTF, added = 2012-03-03]
-% {\prop_if_exist:N, \prop_if_exist:c}
-% \begin{syntax}
-% \cs{prop_if_exist_p:N} \meta{property list}
-% \cs{prop_if_exist:NTF} \meta{property list} \Arg{true code} \Arg{false code}
-% \end{syntax}
-% Tests whether the \meta{property list} is currently defined. This does not
-% check that the \meta{property list} really is a property list variable.
-% \end{function}
-%
-% \begin{function}[EXP, pTF]{\prop_if_empty:N, \prop_if_empty:c}
-% \begin{syntax}
-% \cs{prop_if_empty_p:N} \meta{property list}
-% \cs{prop_if_empty:NTF} \meta{property list} \Arg{true code} \Arg{false code}
-% \end{syntax}
-% Tests if the \meta{property list} is empty (containing no entries).
-% \end{function}
-%
-% \begin{function}[EXP, pTF, updated = 2011-09-15]
-% {
-% \prop_if_in:Nn, \prop_if_in:NV, \prop_if_in:Ne, \prop_if_in:No,
-% \prop_if_in:cn, \prop_if_in:cV, \prop_if_in:ce, \prop_if_in:co
-% }
-% \begin{syntax}
-% \cs{prop_if_in_p:Nn} \meta{property list} \Arg{key}
-% \cs{prop_if_in:NnTF} \meta{property list} \Arg{key} \Arg{true code} \Arg{false code}
-% \end{syntax}
-% Tests if the \meta{key} is present in the \meta{property list},
-% making the comparison using the method described by \cs{str_if_eq:nnTF}.
-% \begin{texnote}
-% For \enquote{flat} property lists, this expandable function iterates
-% through every key--value pair and is therefore slower than a
-% non-expandable approach based on \cs{prop_get:NnNTF}.
-% (For \enquote{linked} property lists both functions are fast.)
-% \end{texnote}
-% \end{function}
-%
-% \section{Recovering values from property lists with branching}
-%
-% The functions in this section combine tests for the presence of a key
-% in a property list with recovery of the associated valued. This makes them
-% useful for cases where different code follows depending on the presence
-% or absence of a key in a property list. They offer increased readability
-% and performance over separate testing and recovery phases.
-%
-% \begin{function}[TF, updated = 2012-05-19]
-% {
-% \prop_get:NnN, \prop_get:NVN, \prop_get:NvN, \prop_get:NeN,
-% \prop_get:NoN,
-% \prop_get:cnN, \prop_get:cVN, \prop_get:cvN, \prop_get:ceN,
-% \prop_get:coN,
-% \prop_get:cnc
-% }
-% \begin{syntax}
-% \cs{prop_get:NnNTF} \meta{property list} \Arg{key} \meta{token list variable} \\
-% ~~\Arg{true code} \Arg{false code}
-% \end{syntax}
-% If the \meta{key} is not present in the \meta{property list}, leaves
-% the \meta{false code} in the input stream. The value of the
-% \meta{token list variable} is not defined in this case and should
-% not be relied upon. If the \meta{key} is present in the
-% \meta{property list}, stores the corresponding \meta{value} in the
-% \meta{token list variable} without removing it from the
-% \meta{property list}, then leaves the \meta{true code} in the input
-% stream. The \meta{token list variable} is assigned locally.
-% \end{function}
-%
-% \begin{function}[TF, added = 2011-08-18, updated = 2012-05-19]
-% {
-% \prop_pop:NnN, \prop_pop:NVN,
-% \prop_pop:NoN,
-% \prop_pop:cnN, \prop_pop:cVN,
-% \prop_pop:coN
-% }
-% \begin{syntax}
-% \cs{prop_pop:NnNTF} \meta{property list} \Arg{key} \meta{token list variable} \\
-% ~~\Arg{true code} \Arg{false code}
-% \end{syntax}
-% If the \meta{key} is not present in the \meta{property list}, leaves
-% the \meta{false code} in the input stream. The value of the
-% \meta{token list variable} is not defined in this case and should
-% not be relied upon. If the \meta{key} is present in
-% the \meta{property list}, pops the corresponding \meta{value}
-% in the \meta{token list variable}, \emph{i.e.}~removes the item from
-% the \meta{property list}.
-% Both the \meta{property list} and the \meta{token list variable}
-% are assigned locally.
-% \end{function}
-%
-% \begin{function}[TF, added = 2011-08-18, updated = 2012-05-19]
-% {
-% \prop_gpop:NnN, \prop_gpop:NVN,
-% \prop_gpop:NoN,
-% \prop_gpop:cnN, \prop_gpop:cVN,
-% \prop_gpop:coN
-% }
-% \begin{syntax}
-% \cs{prop_gpop:NnNTF} \meta{property list} \Arg{key} \meta{token list variable} \\
-% ~~\Arg{true code} \Arg{false code}
-% \end{syntax}
-% If the \meta{key} is not present in the \meta{property list}, leaves
-% the \meta{false code} in the input stream. The value of the
-% \meta{token list variable} is not defined in this case and should
-% not be relied upon. If the \meta{key} is present in
-% the \meta{property list}, pops the corresponding \meta{value}
-% in the \meta{token list variable}, \emph{i.e.}~removes the item from
-% the \meta{property list}.
-% The \meta{property list} is modified globally, while the
-% \meta{token list variable} is assigned locally.
-% \end{function}
-%
-% \section{Mapping over property lists}
-%
-% All mappings are done at the current group level, \emph{i.e.}~any
-% local assignments made by the \meta{function} or \meta{code} discussed
-% below remain in effect after the loop.
-%
-% \begin{function}[rEXP, updated = 2013-01-08]
-% {\prop_map_function:NN, \prop_map_function:cN}
-% \begin{syntax}
-% \cs{prop_map_function:NN} \meta{property list} \meta{function}
-% \end{syntax}
-% Applies \meta{function} to every \meta{entry} stored in the
-% \meta{property list}. The \meta{function} receives two arguments for
-% each iteration: the \meta{key} and associated \meta{value}.
-% The order in which \meta{entries} are returned is not defined and
-% should not be relied upon.
-% To pass further arguments to the \meta{function}, see
-% \cs{prop_map_inline:Nn} (non-expandable) or \cs{prop_map_tokens:Nn}.
-% \end{function}
-%
-% \begin{function}[updated = 2013-01-08]
-% {\prop_map_inline:Nn, \prop_map_inline:cn}
-% \begin{syntax}
-% \cs{prop_map_inline:Nn} \meta{property list} \Arg{inline function}
-% \end{syntax}
-% Applies \meta{inline function} to every \meta{entry} stored
-% within the \meta{property list}. The \meta{inline function} should
-% consist of code which receives the \meta{key} as |#1| and the
-% \meta{value} as |#2|.
-% The order in which \meta{entries} are returned is not defined and
-% should not be relied upon.
-% \end{function}
-%
-% \begin{function}[rEXP]
-% {\prop_map_tokens:Nn, \prop_map_tokens:cn}
-% \begin{syntax}
-% \cs{prop_map_tokens:Nn} \meta{property list} \Arg{code}
-% \end{syntax}
-% Analogue of \cs{prop_map_function:NN} which maps several tokens
-% instead of a single function. The \meta{code} receives each
-% key--value pair in the \meta{property list} as two trailing brace
-% groups. For instance,
-% \begin{verbatim}
-% \prop_map_tokens:Nn \l_my_prop { \str_if_eq:nnT { mykey } }
-% \end{verbatim}
-% expands to the value corresponding to \texttt{mykey}: for each
-% pair in |\l_my_prop| the function \cs{str_if_eq:nnT} receives
-% \texttt{mykey}, the \meta{key} and the \meta{value} as its three
-% arguments. For that specific task, \cs{prop_item:Nn} is faster.
-% \end{function}
-%
-% \begin{function}[rEXP, updated = 2012-06-29]{\prop_map_break:}
-% \begin{syntax}
-% \cs{prop_map_break:}
-% \end{syntax}
-% Used to terminate a \cs[no-index]{prop_map_\ldots} function before all
-% entries in the \meta{property list} have been processed. This
-% normally takes place within a conditional statement, for example
-% \begin{verbatim}
-% \prop_map_inline:Nn \l_my_prop
-% {
-% \str_if_eq:nnTF { #1 } { bingo }
-% { \prop_map_break: }
-% {
-% % Do something useful
-% }
-% }
-% \end{verbatim}
-% Use outside of a \cs[no-index]{prop_map_\ldots} scenario leads to low
-% level \TeX{} errors.
-% \begin{texnote}
-% When the mapping is broken, additional tokens may be inserted
-% before further items are taken
-% from the input stream. This depends on the design of the mapping
-% function.
-% \end{texnote}
-% \end{function}
-%
-% \begin{function}[rEXP, updated = 2012-06-29]{\prop_map_break:n}
-% \begin{syntax}
-% \cs{prop_map_break:n} \Arg{code}
-% \end{syntax}
-% Used to terminate a \cs[no-index]{prop_map_\ldots} function before all
-% entries in the \meta{property list} have been processed, inserting
-% the \meta{code} after the mapping has ended. This
-% normally takes place within a conditional statement, for example
-% \begin{verbatim}
-% \prop_map_inline:Nn \l_my_prop
-% {
-% \str_if_eq:nnTF { #1 } { bingo }
-% { \prop_map_break:n { <code> } }
-% {
-% % Do something useful
-% }
-% }
-% \end{verbatim}
-% Use outside of a \cs[no-index]{prop_map_\ldots} scenario leads to low
-% level \TeX{} errors.
-% \begin{texnote}
-% When the mapping is broken, additional tokens may be inserted
-% before the \meta{code} is
-% inserted into the input stream.
-% This depends on the design of the mapping function.
-% \end{texnote}
-% \end{function}
-%
-% \section{Viewing property lists}
-%
-% \begin{function}[updated = 2021-04-29]{\prop_show:N, \prop_show:c}
-% \begin{syntax}
-% \cs{prop_show:N} \meta{property list}
-% \end{syntax}
-% Displays the entries in the \meta{property list} in the terminal,
-% and specifies its storage type.
-% \end{function}
-%
-% \begin{function}[added = 2014-08-12, updated = 2021-04-29]{\prop_log:N, \prop_log:c}
-% \begin{syntax}
-% \cs{prop_log:N} \meta{property list}
-% \end{syntax}
-% Writes the entries in the \meta{property list} in the log file,
-% and specifies its storage type.
-% \end{function}
-%
-% \section{Scratch property lists}
-%
-% There is no need to include both flat and linked property lists as
-% scratch variables. We arbitrarily pick the older implementation.
-%
-% \begin{variable}[added = 2012-06-23]{\l_tmpa_prop, \l_tmpb_prop}
-% Scratch \enquote{flat} property lists for local assignment.
-% These are never used by
-% the kernel code, and so are safe for use with any \LaTeX3-defined
-% function. However, they may be overwritten by other non-kernel
-% code and so should only be used for short-term storage.
-% \end{variable}
-%
-% \begin{variable}[added = 2012-06-23]{\g_tmpa_prop, \g_tmpb_prop}
-% Scratch \enquote{flat} property lists for global assignment.
-% These are never used by
-% the kernel code, and so are safe for use with any \LaTeX3-defined
-% function. However, they may be overwritten by other non-kernel
-% code and so should only be used for short-term storage.
-% \end{variable}
-%
-% \section{Constants}
-%
-% \begin{variable}{\c_empty_prop}
-% A permanently-empty property list used for internal comparisons.
-% \end{variable}
-%
-% \end{documentation}
-%
-% \begin{implementation}
-%
-% \section{\pkg{l3prop} implementation}
-%
-% \TestFiles{m3prop001, m3prop002, m3prop003, m3prop004, m3show001}
-%
-% \begin{macrocode}
-%<*package>
-% \end{macrocode}
-%
-% \begin{macrocode}
-%<@@=prop>
-% \end{macrocode}
-%
-% With the (default) flat data storage, a property list is a macro whose
-% top-level expansion is of the form
-% \begin{quote}
-% \cs{s_@@} \cs{@@_chk:w}
-% \cs{@@_pair:wn} \meta{key_1} \cs{s_@@} \Arg{value_1} \\
-% \ldots{} \\
-% \cs{@@_pair:wn} \meta{key_n} \cs{s_@@} \Arg{value_n} \\
-% \end{quote}
-% where \cs{s_@@} is a scan mark (equal to \cs{scan_stop:}), \cs{@@_chk:w}
-% produces a suitable error if the property list is used directly in the input
-% stream, and \cs{@@_pair:wn} can be used to map through the property list.
-%
-% With the linked data storage, each property list entry
-% \meta{key_i}--\meta{value_i} is stored into a token list
-% \cs[no-index]{@@~\meta{prefix}~\meta{key_i}}. The \meta{prefix} is one or
-% more characters (no spaces), constructed automatically only once, when the
-% property list is initially declared. The control sequence name does not
-% conform to standard naming for variables because (1) this is an internal
-% control sequence, not really a \pkg{expl3} variable; (2) keeping track of the
-% scope |l| or~|g| throughout all functions would be a pretty big mess,
-% especially if users accidentally mix local and global use (we would have to
-% always check for such mistakes, rather than only checking when suitable debug
-% options are set); (3) shorter control sequence names use less memory and are
-% quicker in case of hash collisions, which may matter since we are using many
-% control sequences.
-%
-% We need to enable mapping through such a property list, but without storing a
-% list of all entries anywhere: this is achieved by making each of these token
-% lists also store a pointer to the next entry. To enable efficient deletion,
-% the token lists also store a pointer to the previous entry. This means we
-% have a doubly-linked list. To avoid having to special-case the two ends of
-% the doubly-linked list when deleting entries, we include as a zeroth entry in
-% the doubly-linked list the property list variable itself, and we include as an
-% $(n+1)$-th entry in the doubly-linked list an end-pointer
-% \cs{@@~\meta{prefix}} (no trailing space, so it differs from an empty key).
-% The space before \meta{prefix} ensures there is no collision with
-% other \pkg{l3prop} internal functions, even if we have very many
-% linked property lists being defined.
-%
-% The property list variable itself is a token list of the form
-% \begin{quote}
-% \cs{@@_flatten:w} \cs{@@~\meta{prefix}} \cs{s_@@} \Arg{prefix}
-% \cs[no-index]{@@~\meta{prefix}~\meta{key_1}}
-% \end{quote}
-% Here, \cs{@@_flatten:w} serves as an efficiently recognized marker, and when
-% \texttt{f}-expanded it is tasked with fully unpacking the property list into
-% the same form as the default data storage so as to ease conversion. The
-% \meta{prefix} is used when looking up an entry. The token list
-% \cs{@@~\meta{prefix}} (see below) contains a pointer to the last key to help
-% insert a new entry. The pointer to \meta{key_1} is needed to start a mapping.
-% The token list labeled by \meta{key_i} is of the form
-% \begin{quote}
-% \cs{use_none:n} \cs[no-index]{@@~\meta{prefix}~\meta{key$_{i-1}$}}
-% \cs{@@_pair:wn} \meta{key_i} \cs{s_@@} \Arg{value_i}
-% \cs[no-index]{@@~\meta{prefix}~\meta{key$_{i+1}$}}
-% \end{quote}
-% where the pointer to \meta{key$_{i-1}$} is needed when deleting the
-% \meta{key_i}. Expanding this will run \cs{@@_pair:wn} on the
-% \meta{key_i}--\meta{value_i} pair (for speed, \meta{key_i} is kept as explicit
-% tokens rather than slowly extracting it from a control sequence name), then
-% move on to the next key, thus mapping through the whole list. The mapping is
-% ended upon expanding \cs{@@~\meta{prefix}}, which is the token list
-% \begin{quote}
-% \cs{use_none:n} \cs[no-index]{@@~\meta{prefix}~\meta{key_n}}
-% \end{quote}
-% Let us think about deleting the \meta{key_i}. We need to update the
-% \meta{key$_{i-1}$} and \meta{key$_{i+1}$} to point to each other
-% instead of \meta{key_i}. To edit the corresponding token lists, it is
-% important that \cs[no-index]{@@~\meta{prefix}~\meta{key_i}} be at the
-% \enquote{same place} in the token lists also in the boundary cases
-% $i=1$ or $i=n$, namely as the second token, or as the second argument
-% after \cs{s_@@}.
-%
-% \subsection{Internal auxiliaries}
-%
-% \begin{macro}{\@@_tmp:w}
-% Scratch macro, defined as needed, for instance to save \cs{@@_pair:wn} when
-% concatenating.
-% \begin{macrocode}
-\cs_new_eq:NN \@@_tmp:w ?
-% \end{macrocode}
-% \end{macro}
-%
-% \begin{variable}{\l_@@_internal_tl}
-% Token list used in various places: for the prefix; when converting from flat
-% to linked props; and to store the new key--value pair inserted by
-% \cs{prop_put:Nnn}.
-% \begin{macrocode}
-\tl_new:N \l_@@_internal_tl
-% \end{macrocode}
-% \end{variable}
-%
-% \begin{variable}{\s_@@_mark,\s_@@_stop}
-% Internal scan marks.
-% \begin{macrocode}
-\scan_new:N \s_@@_mark
-\scan_new:N \s_@@_stop
-% \end{macrocode}
-% \end{variable}
-%
-% \begin{variable}{\q_@@_recursion_tail,\q_@@_recursion_stop}
-% Internal recursion quarks.
-% \begin{macrocode}
-\quark_new:N \q_@@_recursion_tail
-\quark_new:N \q_@@_recursion_stop
-% \end{macrocode}
-% \end{variable}
-%
-% \begin{macro}[EXP]{\@@_if_recursion_tail_stop:n}
-% \begin{macro}[EXP]{\@@_if_recursion_tail_stop:o}
-% Functions to query recursion quarks.
-% \begin{macrocode}
-\__kernel_quark_new_test:N \@@_if_recursion_tail_stop:n
-\cs_generate_variant:Nn \@@_if_recursion_tail_stop:n { o }
-% \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \subsection{Structure of a property list}
-%
-% \begin{macro}{\s_@@}
-% A private scan mark is used as a marker after each key, and at the
-% very beginning of the property list.
-% \begin{macrocode}
-\scan_new:N \s_@@
-% \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_chk:w, \@@_chk_loop:nw, \@@_chk_get:nw}
-% This removes the flat property list from the input stream and complains
-% about a bad use of a property list. Since property lists do not have an
-% end-marker, we slowly peek ahead in a loop. Speed does not matter since
-% this is for an error situation. While \cs{@@_pair:wn} does not keep a fixed
-% definition, it always includes the internal \cs{s_@@} in its argument
-% specification, so that there is no risk of accidentally picking up a public
-% token instead of \cs{@@_pair:wn} when doing a meaning test. We collect the
-% keys and values to produce a more useful error message.
-% \begin{macrocode}
-\cs_new_protected:Npn \@@_chk:w { \@@_chk_loop:nw { } }
-\cs_new_protected:Npn \@@_chk_loop:nw #1
- {
- \peek_meaning:NTF \@@_pair:wn
- { \@@_chk_get:nw {#1} }
- { \msg_error:nne { prop } { misused } {#1} }
- }
-\cs_new_protected:Npn \@@_chk_get:nw #1 \@@_pair:wn #2 \s_@@ #3
- { \@@_chk_loop:nw { #1 , ~ {#2} = { \tl_to_str:n {#3} } } }
-% \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_pair:wn}
-% Used as \cs{@@_pair:wn} \meta{key} \cs{s_@@} \Arg{item} for both storage
-% types, this internal token starts each key--value pair in the property list.
-% This default definition is changed globally by any mapping function, so
-% there is not much point trying to make it an error. Instead, the error is
-% produced by \cs{@@_chk:w}.
-% \begin{macrocode}
-\cs_new:Npn \@@_pair:wn #1 \s_@@ #2 { }
-% \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_flatten:w}
-% We implement here the fact that \texttt{f}-expanding a linked property list
-% gives a flat property list.
-% Leaving a linked property list in the input stream will turn it into a flat
-% property list so that the error implemented by \cs{@@_chk:w} will correctly
-% be triggered.
-% \begin{macrocode}
-\cs_new_protected:Npn \@@_flatten:w #1 \s_@@ #2#3
- { \use:e { \@@_flatten_aux:N #3 } }
-% \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}[rEXP]
-% {\@@_flatten:N, \@@_flatten_aux:w, \@@_flatten_aux:N, \@@_flatten_loop:w}
-% The main function \cs{@@_flatten:N} receives a linked property list and
-% flattens it. The auxiliary \cs{@@_flatten_aux:N} receives a pointer to the
-% first key and flattens the linked property list into a flat property list.
-% This is only restricted-expandable as it involves mapping through all of the
-% property list's entries starting from \meta{key_1}. The looping function
-% \cs{@@_flatten_loop:w} removes \cs{use_none:n} and a backwards pointer~|#2|,
-% leaves the key--value pair for \cs{use:e} to receive, and calls itself
-% again after expanding the next key's token list. Its argument |#3| is
-% empty, except at the end where it is the \cs{use_none:nnnn} appearing in the
-% definition of~\cs{@@_flatten_aux:N}, which ends the loop.
-% \begin{macrocode}
-\cs_new:Npn \@@_flatten:N #1
- { \exp_after:wN \@@_flatten_aux:w #1 }
-\cs_new:Npn \@@_flatten_aux:w #1 \s_@@ #2 { \@@_flatten_aux:N }
-\cs_new:Npn \@@_flatten_aux:N #1
- {
- \s_@@ \@@_chk:w
- \exp_after:wN \@@_flatten_loop:w #1
- \use_none:nnnn \@@_pair:wn \s_@@ { }
- }
-\cs_new:Npn \@@_flatten_loop:w #1#2#3 \@@_pair:wn #4 \s_@@ #5
- {
- #3
- \exp_not:n { \@@_pair:wn #4 \s_@@ {#5} }
- \exp_after:wN \@@_flatten_loop:w
- }
-% \end{macrocode}
-% \end{macro}
-%
-% \begin{variable}{\g_@@_prefix_int, \c_@@_basis_int}
-% Used to assign prefixes for each linked property list. It is converted to
-% base \cs{c_@@_basis_int}, then each digit is converted to a character,
-% starting at |!| (the character after space).
-% \begin{macrocode}
-\int_new:N \g_@@_prefix_int
-\int_const:Nn \c_@@_basis_int { \c_max_char_int - `\! }
-% \end{macrocode}
-% \end{variable}
-%
-% \begin{macro}{\@@_next_prefix:, \@@_to_prefix:n}
-% Store in \cs{l_@@_internal_tl} the conversion of \cs{g_@@_prefix_int} to
-% characters, and increment this integer for use in the next linked property
-% list. No need to optimize since this is only used when declaring the
-% property list the first time.
-% The aim here is to make this string as short as we can, given the
-% range of distinct characters available. This speeds up the work of
-% \cs{cs:w} \ldots{} \cs{cs_end:} that looks up keys in the hash table.
-% \begin{macrocode}
-\cs_new_protected:Npn \@@_next_prefix:
- {
- \tl_set:Ne \l_@@_internal_tl
- { \@@_to_prefix:n { \g_@@_prefix_int } }
- \int_gincr:N \g_@@_prefix_int
- }
-\cs_new:Npn \@@_to_prefix:n #1
- {
- \int_compare:nNnTF {#1} > \c_@@_basis_int
- {
- \exp_args:Nf \@@_to_prefix:n
- { \int_div_truncate:nn {#1} \c_@@_basis_int }
- \exp_args:Nf \@@_to_prefix:n
- { \int_mod:nn {#1} \c_@@_basis_int }
- }
- { \char_generate:nn { `\! + #1 } { 12 } }
- }
-% \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_if_flat:NTF, \@@_if_flat_aux:w}
-% We could either test for the presence of \cs{@@_chk:w} (flat
-% property list) or of \cs{@@_flatten:w} (linked property list). We
-% make the second choice; this way props that are accidentally
-% \tn{relax} are treated as they were before. The auxiliary receives
-% \cs{use_i:nn} or \cs{use_ii:nn} as~|#3|.
-% As a transitional fix we avoid erroring in case the prop is undefined (the \cs{exp_after:wN} is omitted in that case, taking the flat branch).
-% \begin{macrocode}
-\cs_new:Npn \@@_if_flat:NTF #1
- {
- \prop_if_exist:NT #1
- \exp_after:wN \@@_if_flat_aux:w #1
- \s_@@_mark \use_ii:nn
- \@@_flatten:w \s_@@_mark \use_i:nn \s_@@_stop
- }
-\cs_new:Npn \@@_if_flat_aux:w
- #1 \@@_flatten:w #2 \s_@@_mark #3 #4 \s_@@_stop {#3}
-% \end{macrocode}
-% \end{macro}
-%
-% \subsection{Allocation and initialisation}
-%
-% \begin{variable}[tested = m3prop004]{\c_empty_prop}
-% An empty flat prop.
-% \begin{macrocode}
-\tl_const:Nn \c_empty_prop { \s_@@ \@@_chk:w }
-% \end{macrocode}
-% \end{variable}
-%
-% \begin{macro}[tested = m3prop001]{\prop_new:N, \prop_new:c}
-% Flat property lists are initialized with the value \cs{c_empty_prop}.
-% \begin{macrocode}
-\cs_new_protected:Npn \prop_new:N #1
- {
- \__kernel_chk_if_free_cs:N #1
- \cs_gset_eq:NN #1 \c_empty_prop
- }
-\cs_generate_variant:Nn \prop_new:N { c }
-% \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}[tested = m3prop001]{\prop_new_linked:N, \prop_new_linked:c}
-% \begin{macro}{\@@_new_linked:N}
-% The auxiliary is used in \cs{prop_make_linked:N}.
-% For linked property lists, get a new prefix in \cs{l_@@_internal_tl}, then
-% use it to set up the internal structure: the last token in~|#1| is usually a
-% pointer to the first key, which is here the end-pointer. That end-pointer
-% has a pointer to the previous key (usually the last key), which is the
-% variable~|#1| itself that begins the doubly-linked list.
-% \begin{macrocode}
-\cs_new_protected:Npn \prop_new_linked:N #1
- {
- \__kernel_chk_if_free_cs:N #1
- \@@_new_linked:N #1
- }
-\cs_new_protected:Npn \@@_new_linked:N #1
- {
- \@@_next_prefix:
- \cs_gset_nopar:Npe #1
- {
- \@@_flatten:w
- \exp_not:c { @@ ~ \l_@@_internal_tl }
- \s_@@ { \l_@@_internal_tl }
- \exp_not:c { @@ ~ \l_@@_internal_tl }
- }
- \cs_gset_nopar:cpe { @@ ~ \l_@@_internal_tl }
- {
- \exp_not:N \use_none:n
- \exp_not:N #1
- }
- }
-\cs_generate_variant:Nn \prop_new_linked:N { c }
-% \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[tested = m3prop001]{\prop_clear:N, \prop_clear:c}
-% \begin{macro}[tested = m3prop001]{\prop_gclear:N, \prop_gclear:c}
-% \begin{macro}{\@@_clear:NNN, \@@_clear:wNNN, \@@_clear_loop:Nw}
-% Clearing a flat property list is like declaring it anew, simply setting it
-% equal to \cs{c_empty_prop}. For linked property lists we must clear all of
-% the variables storing individual keys, which requires a loop. At each step
-% of the loop, \cs{@@_clear_loop:Nw} receives
-% \cs[index=cs_set_eq:NN]{cs_(g)set_eq:NN}, \cs{use_none:n}, the backwards
-% pointer, an empty~|#4| (except at the end of the loop), and the key--value
-% pair |#5=#6| which we disregard. The looping auxiliary undefines the
-% previous key's token list (this includes the main token list, but that is
-% fine because it is restored at the end) and calls itself after expanding the
-% next key's token list. The loop ends when |#4| is \cs{use_none:nnnn}.
-% After the loop, \cs{@@_clear:wNNN} correctly sets up the main variable~|#6|
-% and the end-pointer~|#1|. Importantly, this is done using
-% \cs[index=cs_set_nopar:Npe]{cs_(g)set_nopar:Npe} and \cs{exp_not:n} because
-% the almost-equivalent \cs{tl_set:Nn} would complain in debug mode about the
-% fact that the main variable is undefined at this stage. Importantly,
-% \cs{@@_clear_entries:NN} is used in the implementation of
-% \cs{prop_set_eq:NN}.
-% \begin{macrocode}
-\cs_new_protected:Npn \prop_clear:N
- { \@@_clear:NNN \cs_set_eq:NN \cs_set_nopar:Npe }
-\cs_generate_variant:Nn \prop_clear:N { c }
-\cs_new_protected:Npn \prop_gclear:N
- { \@@_clear:NNN \cs_gset_eq:NN \cs_gset_nopar:Npe }
-\cs_generate_variant:Nn \prop_gclear:N { c }
-\cs_new_protected:Npn \@@_clear:NNN #1#2#3
- {
- \@@_if_flat:NTF #3
- { #1 #3 \c_empty_prop }
- { \exp_after:wN \@@_clear:wNNN #3 #1 #2 #3 }
- }
-\cs_new_protected:Npn \@@_clear:wNNN
- \@@_flatten:w #1 \s_@@ #2#3#4#5#6
- {
- \@@_clear_entries:NN #4 #3
- #5 #6 { \exp_not:n { \@@_flatten:w #1 \s_@@ {#2} #1 } }
- #5 #1 { \exp_not:n { \use_none:n #6 } }
- }
-\cs_new_protected:Npn \@@_clear_entries:NN #1#2
- {
- \exp_after:wN \@@_clear_loop:Nw \exp_after:wN #1 #2
- \use_none:nnnn \@@_pair:wn \s_@@ { }
- }
-\cs_new_protected:Npn \@@_clear_loop:Nw
- #1#2#3#4 \@@_pair:wn #5 \s_@@ #6
- {
- #1 #3 \tex_undefined:D
- #4
- \exp_after:wN \@@_clear_loop:Nw
- \exp_after:wN #1
- }
-% \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[tested = m3prop001]
-% {
-% \prop_clear_new:N, \prop_clear_new:c,
-% \prop_gclear_new:N, \prop_gclear_new:c,
-% \prop_clear_new_linked:N, \prop_clear_new_linked:c,
-% \prop_gclear_new_linked:N, \prop_gclear_new_linked:c
-% }
-% A simple variation of the token list functions.
-% \begin{macrocode}
-\cs_new_protected:Npn \prop_clear_new:N #1
- { \prop_if_exist:NTF #1 { \prop_clear:N #1 } { \prop_new:N #1 } }
-\cs_generate_variant:Nn \prop_clear_new:N { c }
-\cs_new_protected:Npn \prop_gclear_new:N #1
- { \prop_if_exist:NTF #1 { \prop_gclear:N #1 } { \prop_new:N #1 } }
-\cs_generate_variant:Nn \prop_gclear_new:N { c }
-\cs_new_protected:Npn \prop_clear_new_linked:N #1
- { \prop_if_exist:NTF #1 { \prop_clear:N #1 } { \prop_new_linked:N #1 } }
-\cs_generate_variant:Nn \prop_clear_new_linked:N { c }
-\cs_new_protected:Npn \prop_gclear_new_linked:N #1
- { \prop_if_exist:NTF #1 { \prop_gclear:N #1 } { \prop_new_linked:N #1 } }
-\cs_generate_variant:Nn \prop_gclear_new_linked:N { c }
-% \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}[tested = m3prop001]
-% {\prop_set_eq:NN, \prop_set_eq:cN, \prop_set_eq:Nc, \prop_set_eq:cc}
-% \begin{macro}[tested = m3prop001]
-% {\prop_gset_eq:NN, \prop_gset_eq:cN, \prop_gset_eq:Nc, \prop_gset_eq:cc}
-% \begin{macro}
-% {
-% \@@_set_eq:NNNN, \@@_set_eq:wNNNN, \@@_set_eq:nNnNN,
-% \@@_set_eq_loop:NNnw, \@@_set_eq_end:w
-% }
-% If both variables are accidentally the same variable (or equal flat property
-% lists, as it turns out) we do nothing, otherwise the following code would
-% lose all entries. If the target variable~|#3| is a flat prop, either copy
-% directly or flatten before copying. If it is a linked prop, we must clear
-% it, then go through the entries in~|#4| to add them to~|#3|.
-% \begin{macrocode}
-\cs_new_protected:Npn \prop_set_eq:NN
- { \@@_set_eq:NNNN \cs_set_eq:NN \cs_set_nopar:Npe }
-\cs_generate_variant:Nn \prop_set_eq:NN { Nc , cN , cc }
-\cs_new_protected:Npn \prop_gset_eq:NN
- { \@@_set_eq:NNNN \cs_gset_eq:NN \cs_gset_nopar:Npe }
-\cs_generate_variant:Nn \prop_gset_eq:NN { Nc , cN , cc }
-\cs_new_protected:Npn \@@_set_eq:NNNN #1#2#3#4
- {
- \cs_if_eq:NNF #3#4
- {
- \@@_if_flat:NTF #3
- {
- \@@_if_flat:NTF #4
- { #1 #3 #4 }
- { #2 #3 { \@@_flatten:N #4 } }
- }
- { \exp_after:wN \@@_set_eq:wNNNN #3 #1#2#3#4 }
- }
- }
-\cs_new_protected:Npn \@@_set_eq:wNNNN
- \@@_flatten:w #1 \s_@@ #2#3#4#5#6#7
- {
- \@@_clear_entries:NN #4 #3
- \exp_args:Nf \@@_set_eq:nNnNN {#7} #1 {#2} #5 #6
- }
-% \end{macrocode}
-% We have used that |f|-expanding either type of prop gives a flat prop. At
-% this stage \cs{@@_set_eq:nNnNN} receives the second variable as a flat prop,
-% the end-pointer, the prefix, the suitable
-% \cs[index=cs_set_nopar:Npe]{cs_(g)set_nopar:Npe} assignment, and the first
-% variable itself. Remove the leading \cs{s_@@} and \cs{@@_chk:w} with
-% \cs{use_i:nnn}, then start the loop.
-% \begin{macrocode}
-\cs_new_protected:Npn \@@_set_eq:nNnNN #1#2#3#4#5
- {
- \use_i:nnn
- {
- \@@_set_eq_loop:NNnw #5 #4 {#3}
- \@@_flatten:w #2 \s_@@ {#3}
- }
- #1
- \use_none:n \@@_pair:wn ? \s_@@
- }
-% \end{macrocode}
-% The looping function receives the current pointer~|#1| (initially the
-% variable itself), the defining function~|#2| and the prefix~|#3|, then a
-% partial definition~|#4| (which in later stages includes the backwards
-% pointer), followed by the current value as \cs{s_@@} |{#5}|. It seeks the
-% next key~|#7| to construct in \cs{l_@@_internal_tl} the next pointer
-% \cs[no-index]{@@~\meta{prefix}~\meta{next key}} (the
-% argument~|#6| is empty, except at the end of the loop, where it is
-% \cs{use_none:n} in such a way as to delete the \meta{space} and \meta{next
-% key}). Then the token list (current pointer)~|#1| is set-up to contain the
-% partial definition and current value, as well as the newly constructed next
-% pointer. After a line responsible for correctly ending the loop with
-% \cs{@@_set_eq_end:w}, we loop, setting up the next definition, which starts
-% with \cs{use_none:n} and a backwards pointer to~|#1| followed by the
-% \meta{next key}~|#7| and so on.
-% \begin{macrocode}
-\cs_new_protected:Npn \@@_set_eq_loop:NNnw
- #1#2#3#4 \s_@@ #5#6 \@@_pair:wn #7 \s_@@
- {
- \tl_set:Ne \l_@@_internal_tl { \exp_not:c { @@ ~ #3 #6 ~ #7 } }
- #2 #1 { \exp_not:n { #4 \s_@@ {#5} } \exp_not:o \l_@@_internal_tl }
- \use_none:n #6 \@@_set_eq_end:w
- \exp_after:wN \@@_set_eq_loop:NNnw \l_@@_internal_tl #2 {#3}
- \use_none:n #1 \@@_pair:wn #7 \s_@@
- }
-% \end{macrocode}
-% The end-code picks up what is needed to correctly assign the last token
-% list (the end pointer), which is simply \cs{use_none:n}
-% \cs[no-index]{@@_\meta{prefix}\meta{space}\meta{key_n}}.
-% \begin{macrocode}
-\cs_new_protected:Npn \@@_set_eq_end:w
- \exp_after:wN \@@_set_eq_loop:NNnw #1#2#3
- \use_none:n #4#5 \s_@@
- {
- \exp_after:wN #2 \l_@@_internal_tl { \exp_not:n { \use_none:n #4 } }
- }
-% \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}{\prop_make_flat:N, \prop_make_flat:c \@@_make_flat:Nn}
-% The only interesting case is when given a linked prop. Clear the
-% linked property list using \cs{@@_clear:wNNN} with local assignments
-% (it does not matter since we are at the outermost group level, and
-% \cs{cs_set_eq:NN} is very slightly faster than its global version.
-% Then store the contents (expanded preventively by \cs{exp_args:NNf})
-% with an assignment \cs{cs_set_nopar:Npe} that does not perform
-% \pkg{l3debug} checks.
-% \begin{macrocode}
-\cs_new_protected:Npn \prop_make_flat:N #1
- {
- \int_compare:nNnTF { \tex_currentgrouplevel:D } = 0
- {
- \@@_if_flat:NTF #1 { }
- { \exp_args:NNf \@@_make_flat:Nn #1 {#1} }
- }
- {
- \msg_error:nnee { prop } { inner-make }
- { \token_to_str:N \prop_make_flat:N } { \token_to_str:N #1 }
- }
- }
-\cs_generate_variant:Nn \prop_make_flat:N { c }
-\cs_new_protected:Npn \@@_make_flat:Nn #1#2
- {
- \exp_after:wN \@@_clear:wNNN #1 \cs_set_eq:NN \cs_set_nopar:Npe #1
- \cs_set_nopar:Npe #1 { \exp_not:n {#2} }
- }
-% \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\prop_make_linked:N, \prop_make_linked:c, \@@_make_linked:Nn}
-% The only interesting case is when given a flat prop. We expand the
-% contents for later use. Then \cs{@@_new_linked:N} disregards that
-% previous value of~|#1| and initializes the linked prop. We can then
-% use an auxiliary \cs{@@_set_eq:wNNNN} underlying
-% \cs{prop_set_eq:NN}, with the prop contents saved as
-% \cs{l_@@_internal_tl}. That step is a bit unsafe, as
-% \cs{l_@@_internal_tl} (really, a flat prop here) is used within
-% \cs{@@_set_eq:wNNNN} itself, but it is in fact expanded early enough
-% to be ok.
-% \begin{macrocode}
-\cs_new_protected:Npn \prop_make_linked:N #1
- {
- \int_compare:nNnTF { \tex_currentgrouplevel:D } = 0
- {
- \@@_if_flat:NTF #1
- { \exp_args:NNo \@@_make_linked:Nn #1 {#1} } { }
- }
- {
- \msg_error:nnee { prop } { inner-make }
- { \token_to_str:N \prop_make_linked:N } { \token_to_str:N #1 }
- }
- }
-\cs_generate_variant:Nn \prop_make_linked:N { c }
-\cs_new_protected:Npn \@@_make_linked:Nn #1#2
- {
- \@@_new_linked:N #1
- \tl_set:Nn \l_@@_internal_tl {#2}
- \exp_after:wN \@@_set_eq:wNNNN #1
- \cs_set_eq:NN \cs_set_nopar:Npe #1 \l_@@_internal_tl
- }
-% \end{macrocode}
-% \end{macro}
-%
-% \begin{variable}[tested = m3prop004]{\l_tmpa_prop, \l_tmpb_prop}
-% \begin{variable}[tested = m3prop004]{\g_tmpa_prop, \g_tmpb_prop}
-% We can now initialize the scratch variables.
-% \begin{macrocode}
-\prop_new:N \l_tmpa_prop
-\prop_new:N \l_tmpb_prop
-\prop_new:N \g_tmpa_prop
-\prop_new:N \g_tmpb_prop
-% \end{macrocode}
-% \end{variable}
-% \end{variable}
-%
-% \begin{macro}
-% {
-% \prop_concat:NNN, \prop_concat:ccc,
-% \prop_gconcat:NNN, \prop_gconcat:ccc,
-% \@@_concat:NNNNN, \@@_concat:nNNN
-% }
-% The basic strategy is to copy the first variable into the target,
-% then loop through the second variable, calling
-% \cs[index=prop_put:Nnn]{prop_(g)put:Nnn} on each item. To avoid
-% running the \pkg{l3debug} scope checks on each of these steps, we
-% use the auxiliaries that underly \cs{prop_set_eq:NN} and
-% \cs{prop_put:Nnn}, whose syntax is a bit unwieldy.
-% We work directly with the target prop |#3| as a scratch space,
-% because copying over from a temporary variable to |#3| would be slow
-% in the linked case. If |#5| is |#3| itself we have to be careful
-% not to lose the data, and we even take the opportunity to skip the
-% copying step completely. To keep the correct version of the
-% duplicate keys we use the code underlying \cs{prop_put_if_new:Nnn},
-% which involves passing \cs{use_none:nnn} to the auxiliary instead of
-% nothing.
-% There is no need to check for the case where |#3| is equal to~|#4|
-% because in that case \cs[index=prop_set_eq:NN]{prop_(g)set_eq:NN}
-% |#3| |#4| (or rather the underlying auxiliary) is correctly set up
-% to do no needless work.
-% \begin{macrocode}
-\cs_new_protected:Npn \prop_concat:NNN
- { \@@_concat:NNNNN \cs_set_eq:NN \cs_set_nopar:Npe }
-\cs_generate_variant:Nn \prop_concat:NNN { ccc }
-\cs_new_protected:Npn \prop_gconcat:NNN
- { \@@_concat:NNNNN \cs_gset_eq:NN \cs_gset_nopar:Npe }
-\cs_generate_variant:Nn \prop_gconcat:NNN { ccc }
-\cs_new_protected:Npn \@@_concat:NNNNN #1#2#3#4#5
- {
- \cs_if_eq:NNTF #3 #5
- { \@@_concat:nNNN \use_none:nnn #2 #3 #4 }
- {
- \@@_set_eq:NNNN #1 #2 #3 #4
- \@@_concat:nNNN { } #2 #3 #5
- }
- }
-\cs_new_protected:Npn \@@_concat:nNNN #1#2#3#4
- {
- \cs_gset_eq:NN \@@_tmp:w \@@_pair:wn
- \cs_gset_protected:Npn \@@_pair:wn ##1 \s_@@
- { \@@_put:nNNnn {#1} #2 #3 {##1} }
- \exp_last_unbraced:Nf \use_none:nn #4
- \cs_gset_eq:NN \@@_pair:wn \@@_tmp:w
- }
-% \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}
-% {
-% \prop_put_from_keyval:Nn, \prop_put_from_keyval:cn,
-% \prop_gput_from_keyval:Nn, \prop_gput_from_keyval:cn,
-% \@@_from_keyval:nn, \@@_from_keyval:Nnn,
-% \@@_missing_eq:n
-% }
-% The core is a call to \cs{keyval_parse:nnn}, with an error message
-% \cs{@@_missing_eq:n} for entries without~|=|, and a call to (essentially)
-% \cs[index=prop_put:Nnn]{prop_(g)put:Nnn} for valid key--value pairs.
-% To avoid repeated scope checks (and errors) when \pkg{l3debug} is
-% active, we instead use the auxiliary underlying \cs{prop_put:Nnn}.
-% Because blank keys are valid here, in contrast to \pkg{l3keys}, we set and
-% restore \cs{l__kernel_keyval_allow_blank_keys_bool}.
-% The key--value argument may be quite large so we avoid reading it until it
-% is really necessary.
-% \begin{macrocode}
-\cs_new_protected:Npn \prop_put_from_keyval:Nn #1
- { \@@_from_keyval:nn { \@@_put:nNNnn { } \cs_set_nopar:Npe #1 } }
-\cs_generate_variant:Nn \prop_put_from_keyval:Nn { c }
-\cs_new_protected:Npn \prop_gput_from_keyval:Nn #1
- { \@@_from_keyval:nn { \@@_put:nNNnn { } \cs_gset_nopar:Npe #1 } }
-\cs_generate_variant:Nn \prop_gput_from_keyval:Nn { c }
-\cs_new_protected:Npn \@@_from_keyval:nn
- {
- \bool_if:NTF \l__kernel_keyval_allow_blank_keys_bool
- { \@@_from_keyval:Nnn \c_true_bool }
- { \@@_from_keyval:Nnn \c_false_bool }
- }
-\cs_new_protected:Npn \@@_from_keyval:Nnn #1#2#3
- {
- \bool_set_eq:NN \l__kernel_keyval_allow_blank_keys_bool \c_true_bool
- \keyval_parse:nnn \@@_missing_eq:n {#2} {#3}
- \bool_set_eq:NN \l__kernel_keyval_allow_blank_keys_bool #1
- }
-\cs_new_protected:Npn \@@_missing_eq:n
- { \msg_error:nnn { prop } { prop-keyval } }
-% \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}
-% {
-% \prop_set_from_keyval:Nn, \prop_set_from_keyval:cn,
-% \prop_gset_from_keyval:Nn, \prop_gset_from_keyval:cn,
-% }
-% Just empty the prop (with the auxiliary underlying
-% \cs{prop_clear:N} to avoid \pkg{l3debug} problems) and push
-% key--value entries using
-% \cs[index=prop_put_from_keyval:Nn]{prop_(g)put_from_keyval:Nn}.
-% \begin{macrocode}
-\cs_new_protected:Npn \prop_set_from_keyval:Nn #1
- {
- \@@_clear:NNN \cs_set_eq:NN \cs_set_nopar:Npe #1
- \prop_put_from_keyval:Nn #1
- }
-\cs_generate_variant:Nn \prop_set_from_keyval:Nn { c }
-\cs_new_protected:Npn \prop_gset_from_keyval:Nn #1
- {
- \@@_clear:NNN \cs_gset_eq:NN \cs_gset_nopar:Npe #1
- \prop_gput_from_keyval:Nn #1
- }
-\cs_generate_variant:Nn \prop_gset_from_keyval:Nn { c }
-% \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}
-% {
-% \prop_const_from_keyval:Nn, \prop_const_from_keyval:cn,
-% \prop_const_linked_from_keyval:Nn, \prop_const_linked_from_keyval:cn
-% }
-% For both flat and linked constant props, we create |#1| then use the
-% same auxiliary as for \cs{prop_gput_from_keyval:Nn}. It is most
-% natural to use the already packaged \cs{prop_gput:Nnn}, but that
-% would mean doing an assignment on a supposedly constant property
-% list. To avoid errors when \pkg{l3debug} is activated, we use the
-% auxiliary underlying \cs{prop_gput:Nnn}.
-% \begin{macrocode}
-\cs_new_protected:Npn \prop_const_from_keyval:Nn #1
- {
- \prop_new:N #1
- \@@_from_keyval:nn { \@@_put:nNNnn { } \cs_gset_nopar:Npe #1 }
- }
-\cs_generate_variant:Nn \prop_const_from_keyval:Nn { c }
-\cs_new_protected:Npn \prop_const_linked_from_keyval:Nn #1
- {
- \prop_new_linked:N #1
- \@@_from_keyval:nn { \@@_put:nNNnn { } \cs_gset_nopar:Npe #1 }
- }
-\cs_generate_variant:Nn \prop_const_linked_from_keyval:Nn { c }
-% \end{macrocode}
-% \end{macro}
-%
-% \subsection{Accessing data in property lists}
-%
-% Accessing/deleting/adding entries is mostly done by \cs{@@_split:NnTFn}, which
-% must be fast because it is used in many \pkg{l3prop} functions. Its syntax is
-% as follows.
-% \begin{quote}
-% \cs{@@_split:NnTFn} \meta{property list} \Arg{key} \\
-% ~~\Arg{true code} \Arg{false code} \Arg{link code}
-% \end{quote}
-% If the \meta{property list} uses the linked data storage, then it runs
-% the \meta{link code}, otherwise it does as follows.
-%
-% It splits the \meta{property list} at the \meta{key}, giving three
-% token lists: the \meta{entries before} the \meta{key}, the
-% \meta{value} associated with the \meta{key} and the \meta{entries
-% after} the \meta{key}. Both the \meta{entries before} and the
-% \meta{entries after} can be empty or consist of some number of
-% consecutive entries \cs{@@_pair:wn} \meta{key_i} \cs{s_@@}
-% \Arg{value_i}. If the \meta{key} is present in the \meta{property
-% list} then the \meta{true code} is left in the input stream, with
-% |#1|, |#2|, and |#3| replaced by the \meta{entries before},
-% \meta{value}, and \meta{entries after}. If the \meta{key} is not
-% present in the \meta{property list} then the \meta{false code} is left
-% in the input stream. Only the \meta{true code} is used in the
-% replacement text of a macro defined internally, which requires
-% |##|~doubling.
-%
-% \begin{macro}
-% {
-% \@@_split:NnTFn, \@@_split_aux:nNTFn, \@@_split_test:wn,
-% \@@_split_flat:w, \@@_split_linked:w, \@@_split_wrong:Nw
-% }
-% The aim is to distinguish four cases: a flat prop that contains the
-% given \meta{key}, a flat prop that does not contain it, a linked
-% prop, and an invalid prop. The last case includes those that are
-% set to \tn{relax} by \texttt{c}-expansion, as well as unrelated
-% token list variables since these unfortunately used to
-% \enquote{work} in earlier implementations.
-% In the first three cases we run the \texttt{T}, \texttt{F}, and
-% \texttt{n} arguments, and in the last case we raise an error, set
-% the variable to a known state (empty prop), and run the \texttt{F}
-% code (some conditionals such as \cs{prop_pop:NnNTF} otherwise blow
-% up pretty badly).
-%
-% The first distinction between these cases is done by
-% \cs{@@_split_test:wn}, which looks for the argument after \cs{s_@@}.
-% For a flat prop it will be \cs{@@_chk:w}, which leads to running
-% \cs{@@_split_flat:w}, explained below. For a linked prop it is the
-% prefix, consisting of characters, so we end up running
-% \cs{@@_split_linked:w}, which cleans up and selects the
-% aforementioned \texttt{n} argument. For invalid props, or rather,
-% variables that do not contain \cs{s_@@}, the argument includes
-% \cs{fi:}, and we end up calling \cs{@@_split_wrong:Nw}, which calls
-% \cs{prop_show:N} to raise a detailed error stating how the variable
-% is wrong.
-%
-% Let us return to \cs{@@_split_flat:w}. This function is defined
-% dynamically as
-% \begin{quote}
-% \cs{cs_set:Npn} \cs{@@_split_flat:w} \cs{@@_split_linked:w} |#1| \\
-% \quad \cs{@@_pair:wn} \meta{key} \cs{s_@@} |#2| \\
-% \quad |#3| \cs{s_@@_mark} |#4| |#5| \cs{s_@@_stop} \\
-% \quad |{| |#4| \Arg{true code} |}|
-% \end{quote}
-% Its job is to seek the \meta{key} in the property list (known to be
-% flat at this stage) by using an argument |#1| delimited essentially
-% by that key. If indeed the variable contained the \meta{key}, then
-% |#1|~is the \meta{extract_1} before the key--value pair, |#2|~is the
-% \meta{value} associated with the \meta{key}, |#3|~is the
-% \meta{extract_2} after the key--value pair, |#4|~is \cs{use_i:nnn},
-% and we run \cs{use_i:nnn} \Arg{true code} \Arg{false code} \Arg{link
-% code}, selecting the \meta{true code}. Otherwise, the whole
-% property list together with \cs{s_@@_mark} \cs{use_i:nnn} is taken
-% in as |#1|, then |#2| is some tokens |?| \cs{fi:}
-% \cs{@@_split_wrong:Nw} \meta{variable} that were only useful in the
-% case of invalid props, |#3|~is empty, and most importantly |#4| is
-% \cs{use_ii:nnn}. This command selects the \meta{false code}.
-%
-% Note that we define \cs{@@_split_flat:w} in all cases even though it
-% is only used in the flat case. Indeed, to avoid taking in the whole
-% property list (which may be large) as an argument more than strictly
-% necessary, we would have to keep the \meta{true code} positioned
-% before the expansion of the prop variable in order to use it in the
-% definition. The only way to do that is to store it using an
-% assignment so we might as well just perform the assignment that we
-% can actually use in the flat case.
-% \begin{macrocode}
-\cs_new_protected:Npn \@@_split:NnTFn #1#2
- {
- \exp_after:wN \@@_split_aux:nNTFn
- \exp_after:wN { \tl_to_str:n {#2} } #1
- }
-\cs_new_protected:Npn \@@_split_aux:nNTFn #1#2#3
- {
- \cs_set:Npn \@@_split_flat:w \@@_split_linked:w ##1
- \@@_pair:wn #1 \s_@@ ##2 ##3 \s_@@_mark ##4 ##5 \s_@@_stop
- { ##4 {#3} }
- \exp_after:wN \@@_split_test:wn #2 \s_@@_mark \use_i:nnn
- \@@_pair:wn #1 \s_@@ { ? \fi: \@@_split_wrong:Nw #2 }
- \s_@@_mark \use_ii:nnn
- \s_@@_stop
- }
-\cs_new:Npn \@@_split_flat:w { }
-\cs_new_protected:Npn \@@_split_test:wn #1 \s_@@ #2
- {
- \if_meaning:w \@@_chk:w #2 \exp_after:wN \@@_split_flat:w \fi:
- \@@_split_linked:w
- }
-\cs_new_protected:Npn \@@_split_linked:w #1 \s_@@_stop #2#3 {#3}
-\cs_new_protected:Npn \@@_split_wrong:Nw #1#2 \s_@@_stop #3#4
- {
- \prop_show:N #1
- \cs_gset_eq:NN #1 \c_empty_prop
- #3
- }
-% \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}[tested = m3prop002]
-% {
-% \prop_get:NnN, \prop_get:NVN, \prop_get:NvN, \prop_get:NeN,
-% \prop_get:NoN, \prop_get:NxN,
-% \prop_get:cnN, \prop_get:cVN, \prop_get:cvN, \prop_get:ceN,
-% \prop_get:coN, \prop_get:cxN,
-% \prop_get:cnc
-% }
-% \begin{macro}[TF, tested = m3prop004]
-% {
-% \prop_get:NnN, \prop_get:NVN, \prop_get:NvN, \prop_get:NeN,
-% \prop_get:NoN, \prop_get:NxN,
-% \prop_get:cnN, \prop_get:cVN, \prop_get:cvN, \prop_get:ceN,
-% \prop_get:coN, \prop_get:cxN,
-% \prop_get:cnc
-% }
-% \begin{macro}{\@@_get:NnnTF}
-% \begin{macro}[EXP]{\@@_get_linked:w, \@@_get_linked_aux:w}
-% Here we implement both \cs{prop_get:NnN} and its branching version through
-% \cs{@@_get:NnnTF}. It receives the prop and key, followed by an assignment
-% used when the value is found, \meta{true code} to run after the assignment,
-% and some fall-back \meta{false code} for absent values. It relies on
-% \cs{@@_split:NnTFn}. For a flat prop, the first four arguments of
-% \cs{@@_split:NnTFn} are used, and run either the assignment~|#3{##3}| and
-% \meta{true code}~|#4|, or the \meta{false code}~|#5|.
-% \begin{macrocode}
-\cs_new_protected:Npn \prop_get:NnN #1#2#3
- {
- \@@_get:NnnTF #1 {#2}
- { \tl_set:Nn #3 } { } { \tl_set:Nn #3 { \q_no_value } }
- }
-\cs_generate_variant:Nn \prop_get:NnN { NV , Nv , Ne , c , cV , cv , ce }
-\cs_generate_variant:Nn \prop_get:NnN { No , Nx , co , cx }
-\cs_generate_variant:Nn \prop_get:NnN { cnc }
-\prg_new_protected_conditional:Npnn \prop_get:NnN #1#2#3 { T , F , TF }
- {
- \@@_get:NnnTF #1 {#2}
- { \tl_set:Nn #3 } \prg_return_true: \prg_return_false:
- }
-\prg_generate_conditional_variant:Nnn \prop_get:NnN
- { NV , Nv , Ne , c , cV , cv , ce } { T , F , TF }
-\prg_generate_conditional_variant:Nnn \prop_get:NnN
- { No , Nx , co , cx } { T , F , TF }
-\prg_generate_conditional_variant:Nnn \prop_get:NnN
- { cnc } { T , F , TF }
-\cs_new_protected:Npn \@@_get:NnnTF #1#2#3#4#5
- {
- \@@_split:NnTFn #1 {#2}
- { #3 {##2} #4 }
- {#5}
- { \exp_after:wN \@@_get_linked:w #1 {#2} {#3} {#4} {#5} }
- }
-% \end{macrocode}
-% For a linked prop we must work a bit: \cs{@@_get_linked:w} is followed by
-% the expansion of the prop, then by four brace groups: the key~|#4|, the
-% assignment code~|#5|, \meta{true code}~|#6|, and \meta{false code}~|#7|. If
-% the key is present, its value is stored in the token list
-% \cs[no-index]{@@_}|#2~#4|. If that token list exists,
-% \cs{@@_get_linked_aux:w} gets called followed by the expansion of that token
-% list and we grab as~|#2| the value associated to that key, which we feed to
-% the assignment code and follow-up code. If the key is absent the token list
-% can be \tn{undefined} or \tn{relax}. In both cases \cs{@@_get_linked_aux:w}
-% finds an empty brace group as~|#2|, \cs{use_none:n} as~|#4| and the
-% \meta{false code} as~|#5|.
-% Note that we made \cs{@@_get_linked:w} and subsequent auxiliaries
-% expandable, because they are also used in \cs{prop_item:Nn}.
-% \begin{macrocode}
-\cs_new:Npn \@@_get_linked:w
- \@@_flatten:w #1 \s_@@ #2#3#4#5#6#7
- {
- \if_cs_exist:w @@ ~ #2 ~ \tl_to_str:n {#4} \cs_end:
- \exp_after:wN \exp_after:wN \exp_after:wN \@@_get_linked_aux:w
- \cs:w @@ ~ #2 ~ \tl_to_str:n {#4} \exp_after:wN \cs_end:
- \else:
- \exp_after:wN \@@_get_linked_aux:w
- \fi:
- \s_@@_mark {#5} {#6}
- \s_@@ { } \s_@@_mark \use_none:n {#7}
- \s_@@_stop
- }
-\cs_new:Npn \@@_get_linked_aux:w
- #1 \s_@@ #2 #3 \s_@@_mark #4 #5 #6 \s_@@_stop { #4 {#2} #5 }
-% \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[EXP]
-% {
-% \prop_item:Nn, \prop_item:NV, \prop_item:No, \prop_item:Ne,
-% \prop_item:cn, \prop_item:cV, \prop_item:co, \prop_item:ce
-% }
-% \begin{macro}[EXP]{\@@_item:nnn}
-% Getting the value corresponding to a key in a flat property list in an
-% expandable fashion simply uses \cs{prop_map_tokens:Nn} to go through
-% the property list. The auxiliary \cs{@@_item:nnn} receives the
-% search string~|#1|, the key~|#2| and the value~|#3| and returns as
-% appropriate.
-% \begin{macrocode}
-\cs_new:Npn \prop_item:Nn #1#2
- {
- \@@_if_flat:NTF #1
- {
- \exp_args:NNo \prop_map_tokens:Nn #1
- {
- \exp_after:wN \@@_item:nnn
- \exp_after:wN { \tl_to_str:n {#2} }
- }
- }
- { \exp_after:wN \@@_get_linked:w #1 {#2} \use:n { } { } }
- }
-\cs_new:Npn \@@_item:nnn #1#2#3
- {
- \str_if_eq:eeT {#1} {#2}
- { \prop_map_break:n { \exp_not:n {#3} } }
- }
-\cs_generate_variant:Nn \prop_item:Nn { NV , No , Ne , c , cV , co , ce }
-% \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \subsection{Removing data from property lists}
-%
-% \begin{macro}
-% {
-% \@@_pop:NnNNnTF,
-% \@@_pop_linked:wnNNnTF, \@@_pop_linked:NNNn,
-% \@@_pop_linked:w,
-% \@@_pop_linked_prev:w, \@@_pop_linked_next:w
-% }
-% This auxiliary is used by both the \cs[no-index]{prop_pop} family and
-% the \cs[no-index]{prop_remove} family of functions.
-% It receives a \meta{prop} and a \Arg{key}, three assignment functions
-% (\cs{tl_set:Nn} \cs{cs_set_eq:NN} \cs{cs_set_nopar:Npe} or their global
-% versions), then \Arg{code} \Arg{true code} \Arg{false code}.
-%
-% For a flat prop, split it. If the \meta{key} is there, reconstruct the rest
-% of the prop from the two extracts |##2| |##4| and assign using
-% \cs[index=tl_set:Nn]{tl_(g)set:Nn}, then run \meta{code} \Arg{value} with
-% the \meta{value} found, and run the \meta{true code}. If the \meta{key} is
-% absent, run the \meta{false code}.
-%
-% For a linked prop, the removal is done by \cs{@@_pop_linked:wnNNnTF}, which
-% removes the key--value pair from the doubly-linked list and runs its last
-% three arguments \Arg{code} \Arg{true code} \Arg{false code} depending on
-% whether the key--value is found, in the same way as for flat props.
-% \begin{macrocode}
-\cs_new_protected:Npn \@@_pop:NnNNnTF #1#2#3#4#5#6#7
- {
- \@@_split:NnTFn #1 {#2}
- {
- #4 #1 { \exp_not:n { \s_@@ \@@_chk:w ##1 ##3 } }
- #5 {##2}
- #6
- }
- {#7}
- {
- \exp_after:wN \@@_pop_linked:wnNNnTF #1 {#2}
- #3 #4 {#5} {#6} {#7}
- }
- }
-% \end{macrocode}
-% The next auxiliary \cs{@@_pop_linked:wnNNnTF}, together with the |NNNn|
-% auxiliary, checks if the key is present in the \meta{linked prop}, then the
-% corresponding value (if present) is passed as a braced argument to the
-% \meta{code} and the \meta{true code} or \meta{false code} is run as
-% appropriate. Before that, there are also three assignments: the token lists
-% for the previous key and next key are made to point to each other, cf.\
-% \cs{@@_pop_linked:w}, and the token list for the given key is made
-% undefined.
-% \begin{macrocode}
-\cs_new_protected:Npn \@@_pop_linked:wnNNnTF
- \@@_flatten:w #1 \s_@@ #2#3#4#5#6#7
- {
- \if_cs_exist:w @@ ~ #2 ~ \tl_to_str:n {#4} \cs_end:
- \exp_after:wN \@@_pop_linked:NNNn
- \cs:w @@ ~ #2 ~ \tl_to_str:n {#4} \cs_end:
- #5 #6 {#7}
- \else:
- \exp_after:wN \use_iii:nnn
- \fi:
- \use_i:nn
- }
-\cs_new_protected:Npn \@@_pop_linked:NNNn #1#2#3#4
- {
- \if_meaning:w \scan_stop: #1
- \exp_after:wN \exp_after:wN \exp_after:wN \use_iii:nnn
- \else:
- \exp_after:wN \@@_pop_linked:w #1 #1 #2 #3 {#4}
- \fi:
- }
-\cs_new_protected:Npn \@@_pop_linked:w
- \use_none:n #1#2 \s_@@ #3#4#5#6#7#8
- {
- #6 #5 \tex_undefined:D
- #7 #1
- {
- \exp_after:wN \@@_pop_linked_prev:w #1
- \exp_not:N #4
- }
- #7 #4
- {
- \exp_not:n { \use_none:n #1 }
- \exp_not:f { \exp_after:wN \@@_pop_linked_next:w #4 }
- }
- #8 {#3}
- }
-\cs_new:Npn \@@_pop_linked_prev:w #1 \s_@@ #2#3
- { \exp_not:n { #1 \s_@@ {#2} } }
-\cs_new:Npn \@@_pop_linked_next:w \use_none:n #1 { \exp_stop_f: }
-% \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}[tested = m3prop002]
-% {
-% \prop_remove:Nn, \prop_remove:NV, \prop_remove:Ne,
-% \prop_remove:cn, \prop_remove:cV, \prop_remove:ce
-% }
-% \begin{macro}[tested = m3prop002]
-% {
-% \prop_gremove:Nn, \prop_gremove:NV, \prop_gremove:Ne,
-% \prop_gremove:cn, \prop_gremove:cV, \prop_gremove:ce
-% }
-% Deleting from a property relies on \cs{@@_pop:NnNNnTF}. The three
-% assignment functions are suitably local or global. The last three arguments
-% are \cs{use_none:n} and two empty brace groups: if the key is found we get
-% \cs{use_none:n} \Arg{key} \meta{empty}, which expands to nothing, and
-% otherwise we just get \meta{empty}. The auxiliary takes care of actually
-% removing the entry from the prop.
-% \begin{macrocode}
-\cs_new_protected:Npn \prop_remove:Nn #1#2
- {
- \@@_pop:NnNNnTF #1 {#2}
- \cs_set_eq:NN \cs_set_nopar:Npe
- \use_none:n { } { }
- }
-\cs_new_protected:Npn \prop_gremove:Nn #1#2
- {
- \@@_pop:NnNNnTF #1 {#2}
- \cs_gset_eq:NN \cs_gset_nopar:Npe
- \use_none:n { } { }
- }
-\cs_generate_variant:Nn \prop_remove:Nn { NV , Ne , c , cV , ce }
-\cs_generate_variant:Nn \prop_gremove:Nn { NV , Ne , c , cV , ce }
-% \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[tested = m3prop002]
-% {
-% \prop_pop:NnN, \prop_pop:NVN, \prop_pop:NoN,
-% \prop_pop:cnN, \prop_pop:cVN, \prop_pop:coN,
-% \prop_gpop:NnN, \prop_gpop:NVN, \prop_gpop:NoN,
-% \prop_gpop:cnN, \prop_gpop:cVN, \prop_gpop:coN,
-% }
-% \begin{macro}[TF, tested = m3prop004]
-% {
-% \prop_pop:NnN, \prop_pop:NVN, \prop_pop:NoN,
-% \prop_pop:cnN, \prop_pop:cVN, \prop_pop:coN,
-% \prop_gpop:NnN, \prop_gpop:NVN, \prop_gpop:NoN,
-% \prop_gpop:cnN, \prop_gpop:cVN, \prop_gpop:coN,
-% }
-% Popping a value is almost the same, but the value found is kept.
-% For the non-branching version, we additionally set the target token list to
-% \cs{q_no_value}, while for the branching version we must produce
-% \cs{prg_return_true:} or \cs{prg_return_false:}.
-% \begin{macrocode}
-\cs_new_protected:Npn \prop_pop:NnN #1#2#3
- {
- \@@_pop:NnNNnTF #1 {#2}
- \cs_set_eq:NN \cs_set_nopar:Npe
- { \tl_set:Nn #3 } { } { \tl_set:Nn #3 { \q_no_value } }
- }
-\cs_new_protected:Npn \prop_gpop:NnN #1#2#3
- {
- \@@_pop:NnNNnTF #1 {#2}
- \cs_gset_eq:NN \cs_gset_nopar:Npe
- { \tl_set:Nn #3 } { } { \tl_set:Nn #3 { \q_no_value } }
- }
-\cs_generate_variant:Nn \prop_pop:NnN { NV , No }
-\cs_generate_variant:Nn \prop_pop:NnN { c , cV , co }
-\cs_generate_variant:Nn \prop_gpop:NnN { NV , No }
-\cs_generate_variant:Nn \prop_gpop:NnN { c , cV , co }
-\prg_new_protected_conditional:Npnn \prop_pop:NnN #1#2#3 { T , F , TF }
- {
- \@@_pop:NnNNnTF #1 {#2}
- \cs_set_eq:NN \cs_set_nopar:Npe
- { \tl_set:Nn #3 } \prg_return_true: \prg_return_false:
- }
-\prg_new_protected_conditional:Npnn \prop_gpop:NnN #1#2#3 { T , F , TF }
- {
- \@@_pop:NnNNnTF #1 {#2}
- \cs_gset_eq:NN \cs_gset_nopar:Npe
- { \tl_set:Nn #3 } \prg_return_true: \prg_return_false:
- }
-\prg_generate_conditional_variant:Nnn \prop_pop:NnN
- { NV , No , c , cV , co } { T , F , TF }
-\prg_generate_conditional_variant:Nnn \prop_gpop:NnN
- { NV , No , c , cV , co } { T , F , TF }
-% \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \subsection{Adding data to property lists}
-%
-% \begin{macro}[tested = m3prop002]
-% {
-% \prop_put:Nnn, \prop_put:NnV, \prop_put:Nnv, \prop_put:Nne,
-% \prop_put:NVn, \prop_put:NVV, \prop_put:NVv, \prop_put:NVe,
-% \prop_put:Nvn, \prop_put:NvV, \prop_put:Nvv, \prop_put:Nve,
-% \prop_put:Nen, \prop_put:NeV, \prop_put:Nev, \prop_put:Nee,
-% \prop_put:Nno, \prop_put:Non, \prop_put:Noo,
-% \prop_put:Nnx, \prop_put:NVx, \prop_put:NxV, \prop_put:Nxx,
-% \prop_put:cnn, \prop_put:cnV, \prop_put:cnv, \prop_put:cne,
-% \prop_put:cVn, \prop_put:cVV, \prop_put:cVv, \prop_put:cVe,
-% \prop_put:cvn, \prop_put:cvV, \prop_put:cvv, \prop_put:cve,
-% \prop_put:cen, \prop_put:ceV, \prop_put:cev, \prop_put:cee,
-% \prop_put:cno, \prop_put:con, \prop_put:coo,
-% \prop_put:cnx, \prop_put:cVx, \prop_put:cxV, \prop_put:cxx
-% }
-% \begin{macro}[tested = m3prop002]
-% {
-% \prop_gput:Nnn, \prop_gput:NnV, \prop_gput:Nnv, \prop_gput:Nne,
-% \prop_gput:NVn, \prop_gput:NVV, \prop_gput:NVv, \prop_gput:NVe,
-% \prop_gput:Nvn, \prop_gput:NvV, \prop_gput:Nvv, \prop_gput:Nve,
-% \prop_gput:Nen, \prop_gput:NeV, \prop_gput:Nev, \prop_gput:Nee,
-% \prop_gput:Nno, \prop_gput:Non, \prop_gput:Noo,
-% \prop_gput:Nnx, \prop_gput:NVx, \prop_gput:NxV, \prop_gput:Nxx,
-% \prop_gput:cnn, \prop_gput:cnV, \prop_gput:cnv, \prop_gput:cne,
-% \prop_gput:cVn, \prop_gput:cVV, \prop_gput:cVv, \prop_gput:cVe,
-% \prop_gput:cvn, \prop_gput:cvV, \prop_gput:cvv, \prop_gput:cve,
-% \prop_gput:cen, \prop_gput:ceV, \prop_gput:cev, \prop_gput:cee,
-% \prop_gput:cno, \prop_gput:con, \prop_gput:coo,
-% \prop_gput:cnx, \prop_gput:cVx, \prop_gput:cxV, \prop_gput:cxx
-% }
-% \begin{macro}[tested = m3prop002]
-% {
-% \prop_put_if_new:Nnn, \prop_put_if_new:NVn, \prop_put_if_new:NnV,
-% \prop_put_if_new:cnn, \prop_put_if_new:cVn, \prop_put_if_new:cnV,
-% \prop_gput_if_new:Nnn, \prop_gput_if_new:NVn, \prop_gput_if_new:NnV,
-% \prop_gput_if_new:cnn, \prop_gput_if_new:cVn, \prop_gput_if_new:cnV
-% }
-% \begin{macro}[tested = m3prop002]
-% {
-% \@@_put:NNNnn, \@@_put_linked:wnNN,
-% \@@_put_linked:NNNN, \@@_put_linked_old:w,
-% \@@_put_linked_new:w
-% }
-% All of the \cs[no-index]{prop_(g)put(_if_new):Nnn} functions are
-% based on the same auxiliary, which receives \meta{code} and an
-% \enquote{assignment}, followed by \meta{prop} \Arg{key} \Arg{new
-% value}. The
-% assignment \cs[index=cs_set_nopar:Npe]{cs_(g)set_nopar:Npe} is the
-% primitive assignment without any checking: in the case of linked
-% props it is applied to individual
-% pieces of the linked prop, which are typically not yet defined.
-% Debugging the scope of the variable is done at a higher level by
-% letting \pkg{l3debug} change \cs{prop_put:Nnn} and friends. This
-% allows other \pkg{l3prop} commands to directly call the underlying
-% auxiliary to skip this checking step and avoid getting multiple
-% error messages for the same error.
-% The \meta{code} (empty for |put| and \cs{use_none:nnn} for
-% |put_if_new|) is placed before the assignment in cases where the key
-% is already present, in order to suppress the assignment in the
-% |put_if_new| case.
-% \begin{macrocode}
-\cs_new_protected:Npn \prop_put:Nnn
- { \@@_put:nNNnn { } \cs_set_nopar:Npe }
-\cs_new_protected:Npn \prop_gput:Nnn
- { \@@_put:nNNnn { } \cs_gset_nopar:Npe }
-\cs_new_protected:Npn \prop_put_if_new:Nnn
- { \@@_put:nNNnn \use_none:nnn \cs_set_nopar:Npe }
-\cs_new_protected:Npn \prop_gput_if_new:Nnn
- { \@@_put:nNNnn \use_none:nnn \cs_gset_nopar:Npe }
-\cs_generate_variant:Nn \prop_put:Nnn
- {
- NnV , Nnv , Nne , NV , NVV , NVv , NVe ,
- Nv , NvV , Nvv , Nve , Ne , NeV , Nev , Nee
- }
-\cs_generate_variant:Nn \prop_put:Nnn
- { Nno , No , Noo , Nnx , NVx , NxV , Nxx }
-\cs_generate_variant:Nn \prop_put:Nnn
- {
- c , cnV , cnv , cne , cV , cVV , cVv , cVe ,
- cv , cvV , cvv , cve , ce , ceV , cev , cee
- }
-\cs_generate_variant:Nn \prop_put:Nnn
- { cno , co , coo , cnx , cVx , cxV , cxx }
-\cs_generate_variant:Nn \prop_gput:Nnn
- {
- NnV , Nnv , Nne , NV , NVV , NVv , NVe ,
- Nv , NvV , Nvv , Nve , Ne , NeV , Nev , Nee
- }
-\cs_generate_variant:Nn \prop_gput:Nnn
- { Nno , No , Noo , Nnx , NVx , NxV , Nxx }
-\cs_generate_variant:Nn \prop_gput:Nnn
- {
- c , cnV , cnv , cne , cV , cVV , cVv , cVe ,
- cv , cvV , cvv , cve , ce , ceV , cev , cee
- }
-\cs_generate_variant:Nn \prop_gput:Nnn
- { cno , co , coo , cnx , cVx , cxV , cxx }
-\cs_generate_variant:Nn \prop_put_if_new:Nnn
- { NnV , NV , cnV , cV }
-\cs_generate_variant:Nn \prop_gput_if_new:Nnn
- { NnV , NV , cnV , cV }
-% \end{macrocode}
-% Since the true branch of \cs{@@_split:NnTFn} is used as the
-% replacement text of an internal macro, and since the \meta{key} and
-% new \meta{value} may contain arbitrary tokens, it is not safe to
-% include them in the argument of \cs{@@_split:NnTFn}. We thus start
-% by storing in \cs{l_@@_internal_tl} tokens which (after
-% \texttt{x}-expansion) encode the key--value pair. This variable can
-% safely be used in \cs{@@_split:NnTFn}. For a flat prop, if the
-% \meta{key} was absent, append the new key--value to the list;
-% otherwise concatenate the extracts |##2| and |##4| with the new
-% key--value pair \cs{l_@@_internal_tl}. The updated entry is placed
-% at the same spot as the original \meta{key} in the property list,
-% preserving the order of entries. For a linked prop, call
-% \cs{@@_put_linked:wnNN}, which constructs the control sequence in
-% which we will place the new value. If it matches \cs{scan_stop:}
-% then the key was not yet there and we add it using
-% \cs{@@_put_linked_new:w}, otherwise it was already there and we use
-% \cs{@@_put_linked_old:w}.
-% \begin{macrocode}
-\cs_new_protected:Npn \@@_put:nNNnn #1#2#3#4#5
- {
- \tl_set:Nn \l_@@_internal_tl
- {
- \exp_not:N \@@_pair:wn \tl_to_str:n {#4}
- \s_@@ { \exp_not:n {#5} }
- }
- \@@_split:NnTFn #3 {#4}
- {
- #1 #2 #3
- {
- \s_@@ \@@_chk:w \exp_not:n {##1}
- \l_@@_internal_tl \exp_not:n {##3}
- }
- }
- { #2 #3 { \exp_not:o {#3} \l_@@_internal_tl } }
- { \exp_after:wN \@@_put_linked:wnnN #3 {#4} {#1} #2 }
- }
-\cs_new_protected:Npn \@@_put_linked:wnnN
- \@@_flatten:w #1 \s_@@ #2#3#4
- {
- \exp_after:wN \@@_put_linked:NNnN
- \cs:w @@ ~ #2 ~ \tl_to_str:n {#4} \cs_end:
- #1
- }
-\cs_new_protected:Npn \@@_put_linked:NNnN #1#2#3#4
- {
- \if_meaning:w \scan_stop: #1
- \exp_after:wN \@@_put_linked_new:w #2 #1 #2 #4
- \else:
- \exp_after:wN \@@_put_linked_old:w #1 { #3 #4 #1 }
- \fi:
- }
-% \end{macrocode}
-% To add a new entry, \cs{@@_put_linked_new:w} receives the expansion
-% of the end-pointer, namely \cs{use_none:n} \meta{last key pointer},
-% followed by the new key pointer~|#2|, the end pointer~|#3|, and an
-% assignment function~|#4|. Set up the doubly-linked list in the
-% order |#1|, |#2|, |#3|, placing the key--value pair
-% \cs{l_@@_internal_tl} in~|#2|. To replace an old entry,
-% \cs{@@_put_linked_old:w} receives the expansion of that entry, and
-% it reassigns it (|#5|) using the assignment~|#6|, by simply
-% replacing the payload |#2| \cs{s_@@} |#3| by \cs{l_@@_internal_tl}.
-% \begin{macrocode}
-\cs_new_protected:Npn \@@_put_linked_new:w
- \use_none:n #1#2#3#4
- {
- #4 #1
- {
- \exp_after:wN \@@_pop_linked_prev:w #1
- \exp_not:N #2
- }
- #4 #2
- {
- \exp_not:n { \use_none:n #1 }
- \l_@@_internal_tl
- \exp_not:N #3
- }
- #4 #3 { \exp_not:n { \use_none:n #2 } }
- }
-\cs_new_protected:Npn \@@_put_linked_old:w
- \use_none:n #1#2 \s_@@ #3#4#5
- {
- #5
- {
- \exp_not:n { \use_none:n #1 }
- \l_@@_internal_tl
- \exp_not:N #4
- }
- }
-% \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \subsection{Property list conditionals}
-%
-% \begin{macro}[pTF, tested = m3prop004]{\prop_if_exist:N, \prop_if_exist:c}
-% Copies of the \texttt{cs} functions defined in \pkg{l3basics}.
-% \begin{macrocode}
-\prg_new_eq_conditional:NNn \prop_if_exist:N \cs_if_exist:N
- { TF , T , F , p }
-\prg_new_eq_conditional:NNn \prop_if_exist:c \cs_if_exist:c
- { TF , T , F , p }
-% \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}[pTF, tested = m3prop003]{\prop_if_empty:N, \prop_if_empty:c}
-% \begin{macro}{\@@_if_empty_return:w}
-% A flat property list is empty if it matches \cs{c_empty_prop}. A linked
-% property list is empty if its second token (the end pointer) and last token
-% (the first key pointer) are equal. There cannot be false positives because
-% the end pointer takes the form \cs{use_none:n} \meta{pointer} while the
-% other pointers have more elaborate structure. The subtle code branch here
-% is when a non-empty flat property list is given: then \cs{@@_if_empty:w}
-% reads the whole property list as~|#1| and |#2|, |#3|, |#4| are |2|, |3|,
-% |4|, respectively.
-% \begin{macrocode}
-\prg_new_conditional:Npnn \prop_if_empty:N #1 { p , T , F , TF }
- {
- \if_meaning:w #1 \c_empty_prop
- \prg_return_true:
- \else:
- \exp_after:wN \@@_if_empty_return:w #1
- \@@_flatten:w 2 \s_@@ 34 \s_@@_stop
- \fi:
- }
-\cs_new:Npn \@@_if_empty_return:w
- #1 \@@_flatten:w #2 \s_@@ #3#4#5 \s_@@_stop
- {
- \if_meaning:w #2 #4
- \prg_return_true:
- \else:
- \prg_return_false:
- \fi:
- }
-\prg_generate_conditional_variant:Nnn \prop_if_empty:N
- { c } { p , T , F , TF }
-% \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[pTF, tested = m3prop003]
-% {
-% \prop_if_in:Nn, \prop_if_in:NV, \prop_if_in:Ne, \prop_if_in:No,
-% \prop_if_in:cn, \prop_if_in:cV, \prop_if_in:ce, \prop_if_in:co
-% }
-% \begin{macro}[EXP]{\@@_if_in_flat:nnn}
-% For a linked prop, use \cs{@@_get_linked:w} to look up whether the control
-% sequence constructed from the prefix and the sought-after key exists; this
-% auxiliary calls \cs{use_none:n} \Arg{value} \cs{prg_return_true:} if the key
-% is found, and otherwise \cs{prg_return_false:}. For a flat prop, testing
-% expandably if a key is there requires to go through the key--value pairs one
-% by one. This is rather slow, and a faster test would be
-% \begin{verbatim}
-% \prg_new_protected_conditional:Npnn \prop_if_in:Nn #1 #2
-% {
-% \@@_split:NnTFn #1 {#2}
-% { \prg_return_true: }
-% { \prg_return_false: }
-% { ... }
-% }
-% \end{verbatim}
-% but \cs{@@_split:NnTFn} is non-expandable.
-% Instead, we use \cs{prop_map_tokens:Nn} to compare the search key to
-% each key in turn using \cs{str_if_eq:ee}, which is expandable.
-% \begin{macrocode}
-\prg_new_conditional:Npnn \prop_if_in:Nn #1#2 { p , T , F , TF }
- {
- \@@_if_flat:NTF #1
- {
- \exp_after:wN \prop_map_tokens:Nn \exp_after:wN #1
- {
- \exp_after:wN \@@_if_in_flat:nnn
- \exp_after:wN { \tl_to_str:n {#2} }
- }
- \prg_return_false:
- }
- {
- \exp_after:wN \@@_get_linked:w #1 {#2}
- \use_none:n \prg_return_true: \prg_return_false:
- }
- }
-\cs_new:Npn \@@_if_in_flat:nnn #1#2#3
- {
- \str_if_eq:eeT {#1} {#2}
- { \prop_map_break:n { \use_i:nn \prg_return_true: } }
- }
-\prg_generate_conditional_variant:Nnn \prop_if_in:Nn
- { NV , Ne , No , c , cV , ce , co } { p , T , F , TF }
-% \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \subsection{Mapping over property lists}
-%
-% \begin{macro}[tested = m3prop003]
-% {
-% \prop_map_function:NN, \prop_map_function:Nc,
-% \prop_map_function:cN, \prop_map_function:cc
-% }
-% \begin{macro}{\@@_map_function:Nw}
-% We first |f|-expand to flatten~|#1| in case it was a linked list.
-% The \cs{use_i:nnn} removes the leading \cs{s_@@} \cs{@@_chk:w} of
-% the flattened prop.
-% The even-numbered arguments of \cs{@@_map_function:Nw} are keys,
-% hence have string catcodes, except at the end where they are
-% \cs{fi:} \cs{prop_map_break:}. The \cs{fi:} ends the \cs{if_false:}
-% |#|\meta{even} \cs{fi:} construction and we jump out of the loop.
-% No need for any quark test.
-% \begin{macrocode}
-\cs_new:Npn \prop_map_function:NN #1#2
- {
- \exp_last_unbraced:Nnf
- \use_i:nnn { \@@_map_function:Nw #2 } #1
- \@@_pair:wn \fi: \prop_map_break: \s_@@ { }
- \@@_pair:wn \fi: \prop_map_break: \s_@@ { }
- \@@_pair:wn \fi: \prop_map_break: \s_@@ { }
- \@@_pair:wn \fi: \prop_map_break: \s_@@ { }
- \prg_break_point:Nn \prop_map_break: { }
- }
-\cs_new:Npn \@@_map_function:Nw #1
- \@@_pair:wn #2 \s_@@ #3
- \@@_pair:wn #4 \s_@@ #5
- \@@_pair:wn #6 \s_@@ #7
- \@@_pair:wn #8 \s_@@ #9
- {
- \if_false: #2 \fi: #1 {#2} {#3}
- \if_false: #4 \fi: #1 {#4} {#5}
- \if_false: #6 \fi: #1 {#6} {#7}
- \if_false: #8 \fi: #1 {#8} {#9}
- \@@_map_function:Nw #1
- }
-\cs_generate_variant:Nn \prop_map_function:NN { Nc , c , cc }
-% \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[tested = m3prop003]{\prop_map_inline:Nn, \prop_map_inline:cn}
-% Mapping in line requires a nesting level counter. Store the current
-% definition of \cs{@@_pair:wn}, and define it anew. At the end of
-% the loop, revert to the earlier definition. Note that besides pairs
-% of the form \cs{@@_pair:wn} \meta{key} \cs{s_@@} \Arg{value}, there
-% are a leading and a trailing tokens, but both are equal to
-% \cs{scan_stop:}, hence have no effect in such inline mapping.
-% Such \cs{scan_stop:} could have affected ligatures if they appeared
-% during the mapping.
-% \begin{macrocode}
-\cs_new_protected:Npn \prop_map_inline:Nn #1#2
- {
- \cs_gset_eq:cN
- { @@_map_ \int_use:N \g__kernel_prg_map_int :wn } \@@_pair:wn
- \int_gincr:N \g__kernel_prg_map_int
- \cs_gset_protected:Npn \@@_pair:wn ##1 \s_@@ ##2 {#2}
- \exp_last_unbraced:Nf \use_none:nn #1
- \prg_break_point:Nn \prop_map_break:
- {
- \int_gdecr:N \g__kernel_prg_map_int
- \cs_gset_eq:Nc \@@_pair:wn
- { @@_map_ \int_use:N \g__kernel_prg_map_int :wn }
- }
- }
-\cs_generate_variant:Nn \prop_map_inline:Nn { c }
-% \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}[rEXP]{\prop_map_tokens:Nn, \prop_map_tokens:cn}
-% \begin{macro}{\@@_map_tokens:nw}
-% The mapping is very similar to \cs{prop_map_function:NN}.
-% The odd construction
-% |\use:n {#1}| allows |#1| to contain any token without interfering
-% with \cs{prop_map_break:}. The loop stops when the \meta{key}
-% between \cs{@@_pair:wn} and \cs{s_@@} is \cs{fi:}
-% \cs{prop_map_break:} instead of being a string.
-% \begin{macrocode}
-\cs_new:Npn \prop_map_tokens:Nn #1#2
- {
- \exp_last_unbraced:Nnf
- \use_i:nnn { \@@_map_tokens:nw {#2} } #1
- \@@_pair:wn \fi: \prop_map_break: \s_@@ { }
- \@@_pair:wn \fi: \prop_map_break: \s_@@ { }
- \@@_pair:wn \fi: \prop_map_break: \s_@@ { }
- \@@_pair:wn \fi: \prop_map_break: \s_@@ { }
- \prg_break_point:Nn \prop_map_break: { }
- }
-\cs_new:Npn \@@_map_tokens:nw #1
- \@@_pair:wn #2 \s_@@ #3
- \@@_pair:wn #4 \s_@@ #5
- \@@_pair:wn #6 \s_@@ #7
- \@@_pair:wn #8 \s_@@ #9
- {
- \if_false: #2 \fi: \use:n {#1} {#2} {#3}
- \if_false: #4 \fi: \use:n {#1} {#4} {#5}
- \if_false: #6 \fi: \use:n {#1} {#6} {#7}
- \if_false: #8 \fi: \use:n {#1} {#8} {#9}
- \@@_map_tokens:nw {#1}
- }
-\cs_generate_variant:Nn \prop_map_tokens:Nn { c }
-% \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-%
-% \begin{macro}[tested = m3prop003]{\prop_map_break:}
-% \begin{macro}[tested = m3prop003]{\prop_map_break:n}
-% The break statements are based on the general \cs{prg_map_break:Nn}.
-% \begin{macrocode}
-\cs_new:Npn \prop_map_break:
- { \prg_map_break:Nn \prop_map_break: { } }
-\cs_new:Npn \prop_map_break:n
- { \prg_map_break:Nn \prop_map_break: }
-% \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \subsection{Uses of mapping over property lists}
-%
-% \begin{macro}[EXP]{\prop_count:N, \prop_count:c}
-% \begin{macro}[EXP]{\@@_count:nn}
-% Counting the key--value pairs in a property list is done using the
-% same approach as for other count functions: turn each entry into a
-% \texttt{+1} then use integer evaluation to actually do the
-% mathematics.
-% \begin{macrocode}
-\cs_new:Npn \prop_count:N #1
- {
- \int_eval:n
- {
- 0
- \prop_map_function:NN #1 \@@_count:nn
- }
- }
-\cs_new:Npn \@@_count:nn #1#2 { + 1 }
-\cs_generate_variant:Nn \prop_count:N { c }
-% \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[EXP]{\prop_to_keyval:N}
-% \begin{macro}[EXP]
-% {\@@_to_keyval_exp_after:wN, \@@_to_keyval:nn, \@@_to_keyval:nnw}
-% Each property name and value pair will be returned in the form
-% \verb*| |\marg{name}\verb*|= |\marg{value}. As one of the main use cases for
-% this macro is to pass the \meta{property list} on to a key--value parser, we
-% have to make sure that the behaviour is as good as possible. Using a space
-% before the opening brace we get the correct brace stripping behaviour for
-% most of the key--value parsers available in \LaTeX{}.
-% Iterate over the
-% \meta{property list} and remove the leading comma afterwards. Only the value
-% has to be protected in \cs{__kernel_exp_not:w} as the property name is
-% always a string. After the loop the leading comma is removed by
-% \cs{use_none:n} and afterwards \cs{__kernel_exp_not:w} eventually finds the
-% opening brace of its argument.
-% \begin{macrocode}
-\cs_new:Npn \prop_to_keyval:N #1
- {
- \__kernel_exp_not:w
- \prop_if_empty:NTF #1
- { {} }
- {
- \exp_after:wN \exp_after:wN \exp_after:wN
- {
- \tex_expanded:D
- {
- \exp_not:N \use_none:n
- \prop_map_function:NN #1 \@@_to_keyval:nn
- }
- }
- }
- }
-\cs_new:Npn \@@_to_keyval:nn #1#2
- { , ~ {#1} =~ { \__kernel_exp_not:w {#2} } }
-% \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \subsection{Viewing property lists}
-%
-% \begin{macro}[tested = m3show001]
-% {\prop_show:N, \prop_show:c, \prop_log:N, \prop_log:c}
-% \begin{macro}{\@@_show:NN, \@@_show_finally:NNn, \@@_show_prepare:w, \@@_show_loop:NNw, \@@_show_bad_name:NNN, \@@_show_end:NNN, \@@_show_loop_key:wNNN}
-% \begin{macro}[rEXP]{\@@_show_flat:w, \@@_show_linked:w}
-% Experience shows one source of problems is very hard to debug: when
-% a data structure such as a |seq| or~|prop| gets corrupted. In the
-% past, \cs{prop_show:N} would in some cases happily show items of
-% such a |prop|, even though other more demanding \pkg{l3prop}
-% functions would choke. It is thus best to make \cs{prop_show:N}
-% check very thoroughly the structure and flag issues, even though
-% that is very painful for linked props. Throughout the code below,
-% we strive to remain as safe as possible, but in the explanations we
-% only state what the arguments are when the prop is correctly formed,
-% rather than saying at every step that various arguments can be
-% arbitrary junk, made safe by using \cs{tl_to_str:n} generously.
-%
-% The general \cs{__kernel_chk_tl_type:NnnT} checks that its first
-% argument is a token list, and if it is, then it \texttt{e}-expands
-% its second argument and compares with the contents of its first
-% argument. Thus, within this \texttt{e}-expansion it is safe to use
-% \cs{@@_if_flat:NTF} to check if the prop is flat or linked. In the
-% flat case we simply reconstruct the expected structure using
-% \cs{@@_show_flat:w}, which loops through the prop and correctly
-% turns all keys to strings for instance. In the linked case, we use
-% \cs{@@_show_linked:w}, which ensures the form \cs{@@_flatten:w}
-% \cs[no-index]{@@~\meta{prefix}} \cs{s_@@} \Arg{prefix} \meta{rest},
-% where \meta{prefix} is made into a string and \meta{rest} cannot be
-% a brace group or multiple tokens since \cs{@@_show_linked:w} would
-% in such cases give a different result from the original token list.
-% \begin{macrocode}
-\cs_new_protected:Npn \prop_show:N { \@@_show:NN \msg_show:nneeee }
-\cs_generate_variant:Nn \prop_show:N { c }
-\cs_new_protected:Npn \prop_log:N { \@@_show:NN \msg_log:nneeee }
-\cs_generate_variant:Nn \prop_log:N { c }
-\cs_new_protected:Npn \@@_show:NN #1#2
- {
- \__kernel_chk_tl_type:NnnT #2 { prop }
- {
- \@@_if_flat:NTF #2
- {
- \s_@@ \@@_chk:w
- \exp_after:wN \@@_show_flat:w #2
- \s_@@ { }
- \@@_pair:wn \q_@@_recursion_tail \s_@@ { }
- \q_@@_recursion_stop
- }
- { \exp_after:wN \@@_show_linked:w #2 \s_@@ ! ? \s_@@_stop }
- }
- {
- \@@_if_flat:NTF #2
- { \@@_show_finally:NNn #1 #2 { flat } }
- {
- \tl_set:Nn \l_@@_internal_tl { #1 #2 }
- \exp_after:wN \@@_show_prepare:w #2 #2
- }
- }
- }
-\cs_new:Npn \@@_show_flat:w #1 \@@_pair:wn #2 \s_@@ #3
- {
- \@@_if_recursion_tail_stop:n {#2}
- \exp_not:N \@@_pair:wn \tl_to_str:n {#2} \s_@@ \exp_not:n { {#3} }
- \@@_show_flat:w
- }
-\cs_new:Npn \@@_show_linked:w #1 \s_@@ #2#3#4 \s_@@_stop
- {
- \exp_not:N \@@_flatten:w
- \exp_not:c { @@ ~ \tl_to_str:n {#2} }
- \s_@@ { \tl_to_str:n {#2} }
- \exp_not:n {#3}
- }
-% \end{macrocode}
-% For flat props we are done by using \cs{msg_show:nneeee} or
-% \cs{msg_log:nneeee}. The auxiliary \cs{@@_show_finally:NNn} is
-% eventually also used in the linked case after some more tests. To
-% avoid having to bring along the message function and the property
-% list, we store them into \cs{l_@@_internal_tl}.
-% \begin{macrocode}
-\cs_new_protected:Npn \@@_show_finally:NNn #1#2#3
- {
- #1 { prop } { show }
- { \token_to_str:N #2 }
- { \prop_map_function:NN #2 \msg_show_item:nn }
- {#3} { }
- }
-% \end{macrocode}
-% For linked props, we now know they have a reasonable form so that we
-% are calling \cs{@@_show_prepare:w} \cs{@@_flatten:w}
-% \cs[no-index]{@@~\meta{prefix}} \cs{s_@@} \Arg{prefix} \meta{token}
-% \meta{property list}, and the task is to loop through the linked
-% list and check integrity. We first set things up: the auxiliary
-% \cs{@@_tmp:w} will be in charge of checking that various tokens
-% start with \cs[no-index]{@@~\meta{prefix}} (in the sense of string
-% representations), and calling one of \cs{@@_show_loop_key:wNNN},
-% \cs{@@_show_end:NNN}, \cs{@@_show_bad_name:NNN}.
-% \begin{macrocode}
-\cs_new_protected:Npn \@@_show_prepare:w
- \@@_flatten:w #1 \s_@@ #2#3#4
- {
- \use:e
- {
- \cs_set_nopar:Npn \exp_not:N \@@_tmp:w
- ##1 \token_to_str:N #1 ##2 \s_@@_mark ##3 \s_@@_stop
- {
- \exp_not:N \tl_if_empty:nTF {##1}
- {
- \exp_not:N \tl_if_head_is_space:nTF {##2}
- { \exp_not:N \exp_args:Nf \@@_show_loop_key:wNNN }
- { \exp_not:N \tl_if_empty:nTF }
- {##2}
- }
- { \exp_not:N \use_ii:nn }
- \@@_show_end:NNN
- \@@_show_bad_name:NNN
- }
- }
- \exp_last_unbraced:NNNo \@@_show_loop:NNw #1 #4 #4
- }
-% \end{macrocode}
-% The loop will consist of calls to \cs{@@_show_loop:NNw}
-% \cs[no-index]{@@~\meta{prefix}} \meta{token} \meta{expansion}, where
-% \meta{token} is one of the items in the list, specifically the key
-% container for \meta{key$_{i-1}$} (starting at $i=1$ with the
-% property list variable itself), and \meta{expansion} stands for the
-% expansion of that token, which has already been checked, and takes
-% the form \meta{junk} \cs{s_@@} \Arg{value}
-% \cs[no-index]{@@~\meta{prefix}~\meta{key_i}}. Thus, the loop
-% auxiliary receives the prefix command as |#1|, and the $(i-1)$-th
-% and $i$-th key containers as |#2| and~|#5|. Then \cs{@@_tmp:w}
-% checks that the name of the $i$-th key container is valid.
-% \begin{macrocode}
-\cs_new_protected:Npn \@@_show_loop:NNw #1#2 #3 \s_@@ #4#5
- {
- \exp_last_two_unbraced:Noo \@@_tmp:w
- { \token_to_str:N #5 \s_@@_mark }
- { \token_to_str:N #1 \s_@@_mark \s_@@_stop }
- #1 #2 #5
- }
-% \end{macrocode}
-% If the $i$-th key container has the wrong name we get
-% \cs{@@_show_bad_name:NNN} \cs[no-index]{@@~\meta{prefix}}
-% \meta{previous container} \meta{current container with bad name}.
-% \begin{macrocode}
-\cs_new_protected:Npn \@@_show_bad_name:NNN #1#2#3
- {
- \msg_error:nneeee { prop } { bad-link }
- { \tl_tail:N \l_@@_internal_tl }
- { \token_to_str:N #2 }
- { \token_to_str:N #3 }
- { \token_to_str:N #1 }
- }
-% \end{macrocode}
-% If the $i$-th key container has the name
-% \cs[no-index]{@@~\meta{prefix}} (without space), it is the trailing
-% one. We check that it is the right kind of macro to be a token
-% list, and that it has the right contents \cs{use_none:n}
-% \meta{previous container}. If so, we are done checking everything,
-% and we display the property list using the message function and
-% property list name stored in \cs{l_@@_internal_tl}. Note that we
-% also use this \cs{l_@@_internal_tl} in the type argument of
-% \cs{__kernel_chk_tl_type:NnnT}, to build up the name
-% \enquote{\meta{property list} prop entry} used in error messages.
-% \begin{macrocode}
-\cs_new_protected:Npn \@@_show_end:NNN #1#2#3
- {
- \__kernel_chk_tl_type:NnnT #3
- { \tl_tail:N \l_@@_internal_tl prop~entry }
- { \exp_not:n { \use_none:n #2 } }
- {
- \exp_after:wN \@@_show_finally:NNn
- \l_@@_internal_tl { linked }
- }
- }
-% \end{macrocode}
-% If the $i$-th container has a name \cs[no-index]{@@~\meta{prefix}
-% \meta{key}} (with a space before the key), then we have a call to
-% \cs{@@_show_loop_key:wNNN} \Arg{key} \meta{junk_1} \meta{junk_2}
-% \cs[no-index]{@@~\meta{prefix}} \meta{previous container}
-% \meta{current container}. (with an \texttt{f}-expansion to eliminate
-% the space). The first argument is the \meta{key} without a leading
-% space, thanks to a judicious \texttt{f}-expansion earlier on. We
-% check that the \meta{current container} is a token list with the
-% expected structure \cs{use_none:n} \meta{previous container}
-% \cs{@@_pair:wn} \meta{string} \cs{s_@@} \Arg{anything} \meta{single
-% token}. The auxiliary \cs{@@_show_flat:w} is reused to produce the
-% \cs{@@_pair:wn} part, and the last token is produced by
-% \cs{tl_item:Nn} (we don't waste a specialized auxiliary to speed
-% that up). If the check succeed, move on to the next item.
-% \begin{macrocode}
-\cs_new_protected:Npn \@@_show_loop_key:wNNN #1#2#3#4#5#6
- {
- \__kernel_chk_tl_type:NnnT #6
- { \tl_tail:N \l_@@_internal_tl prop~entry }
- {
- \exp_not:n { \use_none:n #5 }
- \exp_after:wN \@@_show_flat:w #6 \s_@@ { }
- \@@_pair:wn \q_@@_recursion_tail \s_@@ { }
- \q_@@_recursion_stop
- \tl_item:Nn #6 { -1 }
- }
- { \exp_last_unbraced:NNNo \@@_show_loop:NNw #4 #6 #6 }
- }
-% \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macrocode}
-%</package>
-% \end{macrocode}
-%
-% \end{implementation}
-%
-% \PrintIndex