leftindex (25aug20)

git-svn-id: svn://tug.org/texlive/trunk@56182 c570f23f-e606-0410-a88d-b1316a301751

1 files changed, 157 insertions, 0 deletions

diff --git a/Master/texmf-dist/tex/latex/leftindex/leftindex.sty b/Master/texmf-dist/tex/latex/leftindex/leftindex.sty
new file mode 100644
index 00000000000..fdd7a6a822b
--- /dev/null
+++ b/Master/texmf-dist/tex/latex/leftindex/leftindex.sty
@@ -0,0 +1,157 @@
+\RequirePackage{xparse,mathtools}
+\ProvidesExplPackage{leftindex}{2020/08/25}{0.1beta}{}
+
+%----------------------------------------------------------------
+%	leftindex -- left indices with better spacing
+%	Version: 0.1beta
+%	Maintained by Sebastian Ørsted
+%	E-mail: sorsted@gmail.com
+%	Released under the LaTeX Project Public License v1.3c or later
+%	See http://www.latex-project.org/lppl.txt
+%----------------------------------------------------------------
+
+\DeclareDocumentCommand\manualleftindex { mmmm }
+{
+	% #1 = height phantom
+	% #2 = slanting phantom
+	% #3 = left superscript
+	% #4 = left subscript
+	\mathpalette \__leftindex_auxiliary_mathpalette_command:nn { {#1}{#2}{#3}{#4} }
+}
+
+\ExplSyntaxOff
+
+\DeclareDocumentCommand\leftindex { o o E{^_}{{}{}} m }
+{
+	% #1 = slanting phantom
+	% #2 = height phantom
+	% #3 = left superscript
+	% #4 = left subscript
+	% #5 = symbol
+	\IfValueTF {#1}
+	{
+		\IfValueTF{#2}
+		{
+			\manualleftindex { #2 } { #1 } { #3 } { #4 }
+		}
+		{
+			\manualleftindex { #5 } { #1 } { #3 } { #4 }
+		}
+	}
+	{
+		\manualleftindex { #5 } { #5 } { #3 } { #4 }
+	}
+	#5
+}
+
+\ExplSyntaxOn
+
+\cs_new_protected:Npn\leftindex_kern_horizontal:n#1
+{
+	\kern #1 \relax
+}
+
+\cs_new_protected:Npn\leftindex_set_mathsurround_to_zero:
+{
+	 % This is equivalent to "\m@th"
+	\dim_set:Nn \mathsurround { 0pt }
+}
+
+\cs_new_protected:Npn\__leftindex_auxiliary_mathpalette_command:nn#1#2
+{
+	\__leftindex_auxiliary:nnnnn { #1 } #2
+}
+
+\dim_new:N\l__leftindex_phantom_height_dim
+
+\box_new:N \l__leftindex_slanting_phantom_with_subscript_box
+\dim_new:N \l__leftindex_slanting_phantom_with_subscript_dim
+
+\box_new:N \l__leftindex_slanting_phantom_with_subscript_without_indentation_box
+\dim_new:N \l__leftindex_slanting_phantom_with_subscript_without_indentation_dim
+
+\dim_new:N \l__leftindex_indentation_of_slanting_phantom_subscript
+
+\box_new:N \l__leftindex_superscript_temp_box
+\dim_new:N \l__leftindex_width_of_superscript_dim
+
+\box_new:N \l__leftindex_subscript_temp_box
+\dim_new:N \l__leftindex_width_of_subscript_dim
+
+\cs_new_protected:Npn\__leftindex_auxiliary:nnnnn#1#2#3#4#5
+{
+	\group_begin:
+		\hbox_set:Nn \l__leftindex_slanting_phantom_with_subscript_box
+			{ $ #1 #3 \sb{xxxxxx} $ }
+		\dim_set:Nn \l__leftindex_slanting_phantom_with_subscript_dim
+			{ \box_wd:N \l__leftindex_slanting_phantom_with_subscript_box }
+		\hbox_set:Nn \l__leftindex_slanting_phantom_with_subscript_without_indentation_box
+			{ $ #1 \hbox:n {$ #1 #3 $} \sb{xxxxxx} $ }
+		\dim_set:Nn \l__leftindex_slanting_phantom_with_subscript_without_indentation_dim
+			{ \box_wd:N \l__leftindex_slanting_phantom_with_subscript_without_indentation_box }
+		\dim_set:Nn \l__leftindex_indentation_of_slanting_phantom_subscript
+		{
+			\l__leftindex_slanting_phantom_with_subscript_without_indentation_dim
+			-
+			\l__leftindex_slanting_phantom_with_subscript_dim
+		}
+		\tl_if_blank:nTF { #4 }
+		{
+			\dim_zero:N \l__leftindex_width_of_superscript_dim
+		}
+		{
+			\hbox_set:Nn \l__leftindex_superscript_temp_box
+			{
+				$
+				\leftindex_set_mathsurround_to_zero:
+				#1 \sp { #4 }
+				$
+			}
+			\dim_set:Nn \l__leftindex_width_of_superscript_dim
+			{
+				\box_wd:N \l__leftindex_superscript_temp_box
+				-
+				\l__leftindex_indentation_of_slanting_phantom_subscript
+			}
+		}
+		\tl_if_blank:nTF { #5 }
+		{
+			\dim_zero:N \l__leftindex_width_of_subscript_dim
+		}
+		{
+			\hbox_set:Nn \l__leftindex_subscript_temp_box
+			{
+				$
+				\leftindex_set_mathsurround_to_zero:
+				#1 \sb { #5 }
+				$
+			}
+			\dim_set:Nn \l__leftindex_width_of_subscript_dim
+			{
+				\box_wd:N \l__leftindex_subscript_temp_box
+			}
+		}
+		\leftindex_kern_horizontal:n
+		{
+			\dim_max:nn
+				{ \l__leftindex_width_of_superscript_dim }
+				{ \l__leftindex_width_of_subscript_dim }
+		}
+		\mathop{}
+		\mathopen{ \vphantom { #2 } }
+		\tl_if_blank:nF { #4 }
+		{
+			\sp {
+				\mathmakebox[0pt][l]{
+					\mathmakebox[ \l__leftindex_indentation_of_slanting_phantom_subscript ][r]{ #4 }
+				}
+			}
+		}
+		\tl_if_blank:nF { #5 }
+		{
+			\sb {
+				\mathmakebox[0pt][r]{ #5 }
+			}
+		}
+	\group_end:
+}
\ No newline at end of file