xintsession (1jun21)

git-svn-id: svn://tug.org/texlive/trunk@59426 c570f23f-e606-0410-a88d-b1316a301751

2 files changed, 240 insertions, 161 deletions

diff --git a/Master/texmf-dist/doc/plain/xintsession/README.md b/Master/texmf-dist/doc/plain/xintsession/README.md
index a53772f9d8b..4b9e918a823 100644
--- a/Master/texmf-dist/doc/plain/xintsession/README.md
+++ b/Master/texmf-dist/doc/plain/xintsession/README.md
@@ -1,6 +1,6 @@
 # xintsession README #
 
-Release: 0.2b (2021-05-23)
+Release: 0.3 (2021-05-31)
 
 ## Usage ##
 
@@ -11,7 +11,7 @@ It will load [xintexpr](http://www.ctan.org/pkg/xint) and
 [polexpr](http://www.ctan.org/pkg/polexpr)
 (its version `0.8` or later is needed).
 
-You need 2 steps to start a session:
+To start a session:
 
 1. execute `etex xintsession`, or if available, `rlwrap etex xintsession`
    to benefit from arrow keys navigation and other improvements such
@@ -19,7 +19,8 @@ You need 2 steps to start a session:
    Alternatively, execute `rlwrap etex` and enter `xintsession` at the `**`
    prompt.
    One can also use the `-jobname` option of `etex` at this step.
-2. a welcome message is printed, hit the `RET` key at the `*` prompt.
+2. an `>>>` invite appears, start entering input, terminate it via `;`.
+   You can say `&help` for help.
 
 The above explanations have been tested on a Unixen (Mac OS), and probably
 `rlwrap` is not available on all platforms, but it is not a requirement.
@@ -30,40 +31,51 @@ so I only have to type `xs` at the command line.
 You are now ready to make computations!
 Here is a sample session (spaces do not matter):
 
-    (Please type a command or say `\end')
-    *  1+1/2+1/3+1/4+1/5;
-    (@_1)    137/60
-    *  @_^3 ;
-    (@_2)    2571353/216000
-    *  add(1/i, i=1..50);
-    (@_3)    13943237577224054960759/3099044504245996706400
-    *&fp
+    >>> 1+1/2+1/3+1/4+1/5;
+    @_1     137/60
+    >>> @_^3;
+    @_2     2571353/216000
+    >>> add(1/i, i=1..50);
+    @_3     13943237577224054960759/3099044504245996706400
+    >>> &fp
     fp mode (16 digits)
-    *  @_;
-    (@_4)    4.499205338329425
-    *  add(1/i, i=1..1000);
-    (@_5)    7.485470860550346
-    *&bye
+    >>> @_;
+    @_4     4.499205338329425
+    >>> add(1/i, i=1..1000);
+    @_5     7.485470860550346
+    >>> 1
+    ... +
+    ... \message{xintsession is great!}
+    (executing \message {xintsession is great!} in background)
+    xintsession is great!
+    ... 2
+    ... ;
+    @_6     3.0
+    >>> &bye
     Did I say something wrong?
-    Session transcript written on xintsession-210413_20h24.tex
+    Session transcript written on xintsession-210531_09h08.tex
+     )
     No pages of output.
     Transcript written on xintsession.log.
 
-As this example shows, the computational engine can work in various
-modes: exact, fp, int, and pol.  Say `&fp=number` at the prompt
-to activate floating point mode with `number` as Digits (scientific
-functions implemented up to 62 digits at xint 1.4e).
+As this example illustrates, the computational engine can work in
+various modes: exact, fp, int, and pol.  Say `&fp=number` at the
+`>>>` prompt
+to activate floating point mode with "Digits" set to `number`.
 
-If ill-formed input drops you into TeX error interaction mode, try
-hitting `S` it may work to bring you back to normal session.
+If ill-formed input drops you deep into TeX error interaction mode,
+try hitting `S`  as it may work to bring you back to normal session.
 
-For important explanations, enter `&help` at the prompt.
+For additional explanations, enter `&help` at the `>>>` prompt.
 
 ## Change log ##
 
+- 0.3 (2021-05-31)
+  - implement `>>>` primary and `...` secondary invite prompts
+  - breaking: rename `\xintresume` into `\xintsession`
 - 0.2b (2021-05-23)
   - use `\errorcontextlines=0` regime (if not paused)
-  - load `xintexpr` with `\newlinechar` set to `10` to track
+  - load `xintexpr` with `\newlinechar` set to `10` to activate
     nicer error messages coming with `xintexpr 1.4g`
   - add help panel navigation via `n`, `p`, `q` and `1`, ..., `5`
   - fix catcode of @ was set to letter
diff --git a/Master/texmf-dist/tex/plain/xintsession/xintsession.tex b/Master/texmf-dist/tex/plain/xintsession/xintsession.tex
index b37d69dc262..d7f6cffb069 100644
--- a/Master/texmf-dist/tex/plain/xintsession/xintsession.tex
+++ b/Master/texmf-dist/tex/plain/xintsession/xintsession.tex
@@ -1,4 +1,4 @@
-% Release 0.2b (2021-05-23) of xintsession.tex
+% Release 0.3 (2021-05-31) of xintsession.tex
 % author: Jean-Francois Burnol
 % License: LPPL 1.3c (author-maintained)
 % Usage: execute "etex (or pdftex) xintsession"
@@ -20,13 +20,13 @@
 % \newlinechar).  It was renamed at 1.4e and this is one reason
 % why we aborted input with earlier xintexpr...
 \edef\xsrestorecatcodes{\XINTrestorecatcodes\xsrestorenewlinechar}%
-\endlinechar 13 %
+\endlinechar 13 % default anyhow
 \newlinechar 10
 \catcode`_ 11
 \catcode`& 11
 \catcode`@ 11
 \catcode`^ 11 
-\catcode`" 7
+\catcode`$ 7 %$
 \catcode0 12
 \newwrite\xs_out
 \edef\xs_name{\jobname-\expandafter\xint_gobble_ii\the\year
@@ -37,62 +37,69 @@
                       \expandafter\xint_gobble_i\the\numexpr100+\time-60*((\time+30)/60-1).tex}%
 \immediate\openout\xs_out=\xs_name\relax
 \begingroup\catcode37 12
-\long\gdef\xs_message#1{\message{#1}\immediate\write\xs_out{%#1}}\endgroup
+\long\gdef\xs_message#1{\message{#1$$J}\immediate\write\xs_out{%#1}}\endgroup%$$
 {\catcode13\active\def
-{""J}\catcode32\active\edef {\string }%
+{$$J}\catcode32\active\let \space%$$
 \catcode`?=0\catcode`\\=12\relax%
 ?xdef?xs_logo{%
-                _____       _____
-         ____  ____(_)________  /_________  _________________
-         __  |/_/_  /__  __ \  __/  _ \_  |/_/__  __ \_  ___/
-         __>  < _  / _  / / / /_ /  __/_>  < __  /_/ /  /
-         /_/|_| /_/  /_/ /_/\__/ \___//_/|_| _  .___//_/
+               _____       _____
+        ____  ____(_)________  /_________  _________________
+        __  |/_/_  /__  __ \  __/  _ \_  |/_/__  __ \_  ___/
+        __>  < _  / _  / / / /_ /  __/_>  < __  /_/ /  /
+        /_/|_| /_/  /_/ /_/\__/ \___//_/|_| _  .___//_/
                                               /_/
-  _____       _____                         __________
-  ___(_)________  /__________________ ________  /___(_)__   ______
-  __  /__  __ \  __/  _ \_  ___/  __ `/  ___/  __/_  /__ | / /  _ \
-  _  / _  / / / /_ /  __/  /   / /_/ // /__ / /_ _  / __ |/ //  __/
-  /_/  /_/ /_/\__/ \___//_/    \__,_/ \___/ \__/ /_/  _____/ \___/%
+_____       _____                         __________            ______
+___(_)________  /__________________ ________  /___(_)__   ______   / /
+__  /__  __ \  __/  _ \_  ___/  __ `/  ___/  __/_  /__ | / /  _ \ /_/
+_  / _  / / / /_ /  __/  /   / /_/ // /__ / /_ _  / __ |/ //  __/__
+/_/  /_/ /_/\__/ \___//_/    \__,_/ \___/ \__/ /_/  _____/ \___//_/%
 }%
-?immediate?write128{%
-
-  xintsession 0.2b
-  Copyright (c) Jean-Francois Burnol, 2021.
-
-  \jobname is ?jobname
-  Transcript will go to log and to ?xs_name
-
-  ===> HIT THE <RET> KEY NOW! <===%
+?xdef?xs_copyright{%
+  xintsession 0.3 (2021-05-31)
+  Copyright (c) Jean-Francois Burnol, 2021.%
 }}%
 \def\xs_no{0}%
 \XINT_expr_defvar_one{@___}{{0}}%
 \XINT_expr_defvar_one{@__}{{0}}%
 \XINT_expr_defvar_one{@_}{{0}}%
-\def\xs_fetch{\let\xs_in\empty\xs_fetch_a}%
-\begingroup
-\catcode13\active%
-\long\gdef\xs_fetch_a#1
+\def\xs_prime_invite{>>> }%
+\def\xs_second_invite{... }%
+\def\xs_fetch
+{%
+  \let\xs_in\empty
+  \let\xs_invite\xs_prime_invite
+  \xs_fetch_aa
+}%
+\def\xs_fetch_aa
+{%
+  \message{\xs_invite}\read-1to\xs_buf
+  \expandafter\xs_fetch_a\xs_buf\xs_fetch_a
+}%
+\long\def\xs_fetch_a#1\xs_fetch_a
 {%
   \odef\xs_firstitem{\romannumeral0\xintfirstitem{#1.}}%
-  \ifcat\relax\expandafter\noexpand\xs_firstitem%
-    \expandafter\xs_cs%
-  \else%
-   \if &\expandafter\noexpand\xs_firstitem%
-    \expandafter\expandafter\expandafter\xs_magic%
-   \fi%
-  \fi%
+  \ifcat\relax\expandafter\noexpand\xs_firstitem
+    \expandafter\xs_cs
+  \else
+   \if &\expandafter\noexpand\xs_firstitem
+    \expandafter\expandafter\expandafter\xs_magic
+   \fi
+  \fi
   \if;\expandafter\noexpand\romannumeral0\xintlastitem{#1}%
     \xs_fetch_b#1^%
-  \else%
-    \message{(Use ; to end multi-line input)}%
-    \odef\xs_in{\xs_in#1}\expandafter\xs_fetch_a%
+  \else
+    \odef\xs_in{\xs_in#1}%
+    \let\xs_invite\xs_second_invite
+    \expandafter\xs_fetch_aa
   \fi%
 }%
-\endgroup
 \long\def\xs_cs\if;\expandafter\noexpand\romannumeral0\xintlastitem#1#2\fi
 {%
    \xs_message{(executing \detokenize{#1} in background)}%
-   #1\xs_fetch_a
+% potential problems if a group is closed by #1.
+% should I issue \xs_resetenv here ?
+   #1%
+   \message{$$J}\xs_fetch_aa%$$
 }%
 \def\xs_firstfour#1#2#3#4#5\xint_bye{\edef\xs_magic_in{#1#2#3#4}\def\xs_magic_inb{#5}}%
 \long\def\xs_magic\if;\expandafter\noexpand\romannumeral0\xintlastitem#1#2\fi
@@ -102,8 +109,9 @@
       \csname xs_magic@\xs_magic_in\expandafter\endcsname
   \else
    \xs_message{(\detokenize\expandafter{\xint_gobble_i#1} is not a magic keyword:
-            ignored)}%
-  \fi\xs_fetch_a
+            ignored)$$J}%$$
+  \fi
+  \xs_fetch_aa
 }%
 \long\def\xs_fetch_b#1;^%
 {%
@@ -111,20 +119,20 @@
 }%
 \def\xs_fetch_c
 {%
-   \if\relax\romannumeral`""@\detokenize\expandafter{\xs_in}\relax\expandafter\xs_pause\fi
+   \if\relax\romannumeral`$$@\detokenize\expandafter{\xs_in}\relax\expandafter\xs_pause\fi%$$
    \expandafter\xs_parse_a\xs_in:=^%
 }%
-\def\xs_pause\expandafter\xs_parse_a\xs_in:=^{\xs_pause_a\xs_fetch_a}%
-\def\xs_pause_a\xs_fetch_a
+\def\xs_pause\expandafter\xs_parse_a\xs_in:=^{\xs_pause_a\xs_fetch_aa}%
+\def\xs_pause_a\xs_fetch_aa
 {%
-   \xs_message{Need a break? OK, use \string\xintresume\space if you change your mind.}%
-   \xs_resetcats
+   \xs_message{Need a break? OK, use \string\xintsession\space if you change your mind.}%
+   \xs_resetenv
 }%
-\def\xs_bye\xs_fetch_a
+\def\xs_bye\xs_fetch_aa
 {%
    \xs_message{Did I say something wrong?}%
    \xs_message{Session transcript written on \xs_name}%
-%   \xs_resetcats
+%   \xs_resetenv
    \immediate\closeout\xs_out
 % expeditive exit because I need to think about generating new output
 % filename with a check that it is not same (a minute may be too coarse?).
@@ -146,9 +154,13 @@
    \XINT_expr_defvar_one{@___}{\csname XINT_expr_varvalue_@__\endcsname}%
    \XINT_expr_defvar_one{@__}{\csname XINT_expr_varvalue_@_\endcsname}%
    \XINT_expr_defvar_one{@_}{\csname XINT_expr_varvalue_@_\xs_no\endcsname}%
-   \xs_message{(@_\xs_no)\space\space\space\space\xs_xinteval{@_\xs_no}}%
+   \xs_message{%
+     @_\expandafter\xs_keepsix\xs_no\space\space\space\space\space\relax
+     \xs_xinteval{@_\xs_no}%
+   }%
    \xs_fetch
 }%
+\def\xs_keepsix#1#2#3#4#5#6#7\relax{#1#2#3#4#5#6}%
 \def\xs_parse_b #1:=^%
 {%
    \def\xs_right{#1}\expandafter\xs_parse_c\xs_left(;%
@@ -216,7 +228,8 @@
 }%
 \def\xs_magic@&int
 {%
-   \xs_message{int mode (integer only: / rounds, // is floored division, /: is modulo)}%
+   \xs_message{int mode (integer only: / rounds, // is floored division, /: is
+   modulo)}%
    \def\xs_mode{int}%
    \def\xs_xintdefvar{\xintdefiivar}%
    \def\xs_xintdeffunc{\xintdefiifunc}%
@@ -231,53 +244,69 @@
    \def\xs_xinteval{\xinteval}%
 }%
 \def\xs_magic@&mod{\xs_message{current mode: \xs_mode}}%
-\def\xs_setcats
+\def\xs_setenv
 {%
-    \newlinechar10\endlinechar13\errorcontextlines0\relax
-    \catcode13\active
+    \newlinechar10\endlinechar-1\errorcontextlines0\relax
 }%
-\def\xs_storecats{\edef\xs_resetcats
+\def\xs_storeenv{\edef\xs_resetenv
 {%
     \newlinechar\the\newlinechar
     \endlinechar\the\endlinechar
     \errorcontextlines\the\errorcontextlines
-    \catcode13=\the\catcode13\relax
 }}%
+\def\xintsession
+   {\let\xintsession\xintsessionresume
+    \xs_setenv\xint_welcome\message{Starting in}\xs_magic@&exa\xs_fetch}%
+\def\xintsessionresume
+   {\xs_storeenv\xs_setenv\xs_welcome_back\xs_fetch}%
 \begingroup
+% some things here are weird but this was initially to make the 0.3 transition
+% to usage of \read-1 in place of active ^^M with minimal collateral changes
+% the active ^^M here is now reduced to avoid to have to type explicit ^^J in the
+% definition of the help messages
 \catcode13\active\catcode32\active%
-\gdef\xintstart{\edef {\string }\xs_setcats\def
-{""J}\message{\xs_logo
-
-  Welcome to xintexpr interactive mode!
-  - input is `;'-terminated and can extend over multiple lines,
-  - definitions must be done using the `:=' syntax, not `='.
-  - any line starting with a control sequence is executed in the
-    background, the interrupted numerical input resumes at prompt.
+\let \space% this is Plain default anyhow
+\def
+{$$J}%$$
+\xdef\xint_welcome{\noexpand\message{\xs_copyright
+  Welcome to
+\xs_logo
+
+  - input is `;'-terminated and can extend over multiple lines
+    ("\xs_prime_invite" is main input invite, "\xs_second_invite" is continuation prompt)
+  - definitions are done with `:=' not with `='.
+%  - any line starting with a control sequence is executed in the
+%    background, the interrupted numerical input resumes at prompt.
 
   Magic words: `&pause' (or `;'), `&help', `&bye',
                `&exact', `&fp', `&int', `&pol'.
-  Say e.g. `&fp=24' to activate floating point mode with Digits=24.
-  Starting in}\xs_magic@&exa\let
-=\xs_fetch}%
-\gdef\xintresume{\edef {\string }\xs_storecats\xs_setcats%
-\message{Welcome back to xintexpr interactive mode!}%
-\let
-=\xs_fetch}%
+
+  \string\jobname is \jobname
+  Transcript will go to log and to \xs_name
+}}%
+\xdef\xs_welcome_back{\noexpand\message{%
+  You are back to the xintexpr interactive session!
+  (current mode: \noexpand\xs_mode, with Digits=\noexpand\xinttheDigits)
+
+  ">>> " means central computing is waiting for input
+  "... " means that multi-line input continues.  Use `;' to terminate it.
+
+  Say `&bye' at any time to terminate the session and the TeX run.
+}}%
 \catcode`?0\catcode`\\12\relax%
-?gdef?xs_help?xs_fetch_a{?begingroup?def
-{""J}?edef {?string }?xs_help_i}%
-?gdef?xs_help_i{?message{%
-  - Terminate inputs using the `;' character. Input can extend over
-    multiple lines (<RET> terminated).
+?xdef?xs_help_message_i{%
+  - Terminate inputs with the `;' character.  Inputs can extend over
+    multiple lines (each terminated by <return>).
 
   - An empty input (`;' terminated) or the magic word `&pause' puts
-    the session on hold and switches to normal TeX interaction. Use
-    \xintresume to resume the session.
+    the session on hold and switches to normal TeX interaction, with
+    its `*' prompt.  Use \xintsession to resume the session.
 
   - Lines starting with any control sequence are handed over to
-    TeX, and numerical input resumes on next line.
+    TeX (no end of line space token is included), and the current
+    numerical input resumes on next line.
 
-  - The numerical engine can work in various modes:
+  - The computing kernel can work in various modes:
     exact (uses \xintexpr), fp (uses \xintfloatexpr), int (uses
     (\xintiiexpr), and pol (makes definitions using \poldef).
     To activate a mode enter `&<mode name>' at the prompt
@@ -285,18 +314,14 @@
   - Issue `&mode' if you forgot in what mode you are currently in.
 
 (1/5) say `n' (or directly <return>) for next, `q' to quit, or one of
-      `2', `3', `4', or `5' to jump directly to corresponding panel.%
-}?def?xs_help_next##1
-{?if?xintFirstItem{##1n}n?xint_dothis?xs_help_ii?fi%
-?ifnum10<1?expandafter?string?romannumeral0?xintfirstitem{##1}?relax%
-?xint_dothis{?csname?xint_gobble_i xs_help_?romannumeral?xintFirstItem{##1}?endcsname}?fi%
-?xint_orthat?xs_help_quit}?xs_help_next}%
-?gdef?xs_help_ii{?message{%
+      `2', `3', `4', or `5' to jump directly to corresponding panel.
+}%
+?xdef?xs_help_message_ii{%
   - Say `&exact' resp. `&fp' to go back and forth between exact
     and floating point mode
 
   - Say `&fp=<number>' for example `&fp=32' at the prompt to activate
-    fp mode at a given Digits setting. This can be done in the midst
+    fp mode at a given Digits setting.  This can be done in the midst
     of the input of a multi-line computation!
 
   - Math functions are supported up to Digits=62 (since xint 1.4e);
@@ -316,24 +341,19 @@
 %    `<=', `>=', `!=', `==' or `seq()' syntax but this currently was
 %    considered to add too much overhead for the benefit.
 %    
-(2/5) say `n' (next), `p' (previous), `q' (quit), or one of `1' to `5'.%
-}?def?xs_help_next##1
-{?if?xintFirstItem{##1n}n?xint_dothis?xs_help_iii?fi%
-?if?xintFirstItem{##1}p?xint_dothis?xs_help_i?fi%
-?ifnum10<1?expandafter?string?romannumeral0?xintfirstitem{##1}?relax%
-?xint_dothis{?csname?xint_gobble_i xs_help_?romannumeral?xintFirstItem{##1}?endcsname}?fi%
-?xint_orthat?xs_help_quit}?xs_help_next}%
-?gdef?xs_help_iii{?message{%
+(2/5) say `n' (next), `p' (previous), `q' (quit), or one of `1' to `5'.
+}%
+?xdef?xs_help_message_iii{%
   - Functions defined in one mode are not available for usage in
     other modes without further steps; check xintexpr doc.
 
   - Polynomials in pol mode are defined using polname(x):=expression;
-    (or with another letter). They can serve as functions in the exact
-    mode. To use a polynomial also as an fp mode function, issue
+    (or with another letter).  They can serve as functions in the exact
+    mode.  To use a polynomial also as an fp mode function, issue
     \PolGenFloatVariant{<polname>} at the prompt.
 
   - Whenever a variable is defined, or a computation is performed,
-    the result is assigned a label @_<integer>. These labels are
+    the result is assigned a label @_<integer>.  These labels are
     variables which can then be used in subsequent computations.
 
   - The special variables @_, @__, and @___ hold the last, next
@@ -343,19 +363,14 @@
     the automatic variable @_<integer> holds the whole thing, which
     may be a nutple or an ople, in addition to individual variables.
 
-(3/5) say `n' (next), `p' (previous), `q' (quit), or one of `1' to `5'.%
-}?def?xs_help_next##1
-{?if?xintFirstItem{##1n}n?xint_dothis?xs_help_iv?fi%
-?if?xintFirstItem{##1}p?xint_dothis?xs_help_ii?fi%
-?ifnum10<1?expandafter?string?romannumeral0?xintfirstitem{##1}?relax%
-?xint_dothis{?csname?xint_gobble_i xs_help_?romannumeral?xintFirstItem{##1}?endcsname}?fi%
-?xint_orthat?xs_help_quit}?xs_help_next}%
-?gdef?xs_help_iv{?message{%
+(3/5) say `n' (next), `p' (previous), `q' (quit), or one of `1' to `5'.
+}%
+?xdef?xs_help_message_iv{%
   - Variables defined in any mode can be used in any mode except:
     * polynomials can be used as variables only in the pol and the
       exact modes,
     * integer-only mode requires... integer-only variables, also
-      internally. Use num() or \xintiexpr...\relax as wrappers in int
+      internally.  Use num() or \xintiexpr...\relax as wrappers in int
       mode around exact or fp variables (even integer-valued ones).
 
   Known issues:
@@ -365,23 +380,18 @@
     the float() function with its second argument.
 
   - An \xintexpr...\relax wrapper can not start a line, as it would
-    trigger control sequence execution. Use parentheses or 0+\...
+    trigger control sequence execution.  Use parentheses or 0+\...
 
   - Exact mode does not reduce to lowest terms, use reduce().
 
-(4/5) say `n' (next), `p' (previous), `q' (quit), or one of `1' to `5'.%
-}?def?xs_help_next##1
-{?if?xintFirstItem{##1n}n?xint_dothis?xs_help_v?fi%
-?if?xintFirstItem{##1}p?xint_dothis?xs_help_iii?fi%
-?ifnum10<1?expandafter?string?romannumeral0?xintfirstitem{##1}?relax%
-?xint_dothis{?csname?xint_gobble_i xs_help_?romannumeral?xintFirstItem{##1}?endcsname}?fi%
-?xint_orthat?xs_help_quit}?xs_help_next}%
-?gdef?xs_help_v{?message{%
+(4/5) say `n' (next), `p' (previous), `q' (quit), or one of `1' to `5'.
+}%
+?xdef?xs_help_message_v{%
   (cont.)
   - A session transcript file is created which can be executed by
     eTeX to redo all calculations; however @_, @__, and @___ will
     not be defined in this context so need to be manually replaced
-    by the suitable @_<integer>. The format of the transcript
+    by the suitable @_<integer>.  The format of the transcript
     is to be considered unstable at this stage.
 
   Future:
@@ -396,25 +406,82 @@
   the prompt and a recovery will be attempted.   If deep in core
   TeX errors, try escaping using `S'.  It does work sometimes.
 
-(5/5) say `p' (previous), `q' (quit), or one of `1' to `5'.%
-}?def?xs_help_next##1
-{?if?xintFirstItem{##1n}p?xint_dothis?xs_help_iv?fi%
-?ifnum10<1?expandafter?string?romannumeral0?xintfirstitem{##1}?relax%
-?xint_dothis{?csname?xint_gobble_i xs_help_?romannumeral?xintFirstItem{##1}?endcsname}?fi%
-?xint_orthat?xs_help_quit}?xs_help_next}%
-?gdef?xs_help_quit{?message{%
-  You are back to the xintexpr interactive session!
-  (current mode: ?xs_mode)
-
-  Waiting for input...
-
-(say `&bye' at any time to terminate the session and the TeX run.)%
-}?endgroup?xs_fetch}%
+(5/5) say `p' (previous), `q' (quit), or one of `1' to `5'.
+}%
 ?endgroup
+\def\xs_help\xs_fetch_aa{\xs_help_i}%
+\def\xs_help_i
+{%
+  \message{\xs_help_message_i}%
+  \def\xs_help_next##1\xs_help_next
+  {%
+   \if\xintFirstItem{##1n}n\xint_dothis\xs_help_ii\fi%
+   \ifnum10<1\expandafter\string\romannumeral0\xintfirstitem{##1}\relax%
+      \xint_dothis{\csname xs_help_\romannumeral\xintFirstItem{##1}\endcsname}\fi%
+   \xint_orthat\xs_help_quit
+  }%
+  \message{n, q, or 1 to 5: }%
+  \read-1to\xs_tmp\expandafter\xs_help_next\xs_tmp\xs_help_next
+}%
+\def\xs_help_ii
+{%
+  \message{\xs_help_message_ii}%
+  \def\xs_help_next##1\xs_help_next
+  {%
+   \if\xintFirstItem{##1n}n\xint_dothis\xs_help_iii\fi%
+   \if\xintFirstItem{##1}p\xint_dothis\xs_help_i\fi%
+   \ifnum10<1\expandafter\string\romannumeral0\xintfirstitem{##1}\relax%
+      \xint_dothis{\csname xs_help_\romannumeral\xintFirstItem{##1}\endcsname}\fi%
+   \xint_orthat\xs_help_quit
+  }%
+  \message{n, p, q, or 1 to 5: }%
+  \read-1to\xs_tmp\expandafter\xs_help_next\xs_tmp\xs_help_next
+}%
+\def\xs_help_iii
+{%
+  \message{\xs_help_message_iii}%
+  \def\xs_help_next##1\xs_help_next
+  {%
+   \if\xintFirstItem{##1n}n\xint_dothis\xs_help_iv\fi%
+   \if\xintFirstItem{##1}p\xint_dothis\xs_help_ii\fi%
+   \ifnum10<1\expandafter\string\romannumeral0\xintfirstitem{##1}\relax%
+      \xint_dothis{\csname xs_help_\romannumeral\xintFirstItem{##1}\endcsname}\fi%
+   \xint_orthat\xs_help_quit
+  }%
+  \message{n, p, q, or 1 to 5: }%
+  \read-1to\xs_tmp\expandafter\xs_help_next\xs_tmp\xs_help_next
+}%
+\def\xs_help_iv
+{%
+  \message{\xs_help_message_iv}%
+  \def\xs_help_next##1\xs_help_next
+  {%
+   \if\xintFirstItem{##1n}n\xint_dothis\xs_help_v\fi%
+   \if\xintFirstItem{##1}p\xint_dothis\xs_help_iii\fi%
+   \ifnum10<1\expandafter\string\romannumeral0\xintfirstitem{##1}\relax%
+      \xint_dothis{\csname xs_help_\romannumeral\xintFirstItem{##1}\endcsname}\fi%
+   \xint_orthat\xs_help_quit
+  }%
+  \message{n, p, q, or 1 to 5: }%
+  \read-1to\xs_tmp\expandafter\xs_help_next\xs_tmp\xs_help_next
+}%
+\def\xs_help_v
+{%
+  \message{\xs_help_message_v}%
+  \def\xs_help_next##1\xs_help_next
+  {%
+   \if\xintFirstItem{##1n}p\xint_dothis\xs_help_iv\fi%
+   \ifnum10<1\expandafter\string\romannumeral0\xintfirstitem{##1}\relax%
+      \xint_dothis{\csname xs_help_\romannumeral\xintFirstItem{##1}\endcsname}\fi%
+   \xint_orthat\xs_help_quit
+  }%
+  \message{p, q, or 1 to 5: }%
+  \read-1to\xs_tmp\expandafter\xs_help_next\xs_tmp\xs_help_next
+}%
+\def\xs_help_quit{\xs_welcome_back\xs_fetch}%
 \let\xs_magic@&hel\xs_help\let\xs_help_vi\xs_help_quit\let\xs_help_vii\xs_help_quit
 \let\xs_help_viii\xs_help_quit\let\xs_help_ix\xs_help_quit
+%
 \xsrestorecatcodes%
-\csname xs\string _storecats\endcsname\endlinechar13\relax%
-\catcode13\active\def
-{\xintstart
-}\endinput%
+\csname xs\string _storeenv\endcsname\endlinechar13\relax%
+\endinput\xintsession%