这是对 Egregs 在这个问题中的回答的后续可扩展数学, 代码作为 MWE 包含在这里。
如果我能以某种方式删除所有先前定义的变量,或者仅在一个组内分配它们,那将是一个很大的帮助。另一种可能性是简单地允许重新分配具有相同名称的变量。到目前为止,尝试这样做时会出现错误。
编辑:我在底部的 MWE 添加了几行,它尝试设置组内的变量(但仍使它们成为全局变量),尝试重新定义一个变量,这在尝试打印时会出现错误。
错误提示:
./root.tex:122: 缺少插入的 \endcsname。\cs_set_nopar:Npx l.122 }
\documentclass{article}
\usepackage{xparse,l3regex,siunitx,xcolor}
\ExplSyntaxOn
\seq_new:N \g_runart_variables_seq
\prop_new:N \l__runart_variables_temp_prop
\tl_new:N \l__runart_variables_matte_tl
\tl_new:N \l__runart_variables_item_tl
\NewDocumentCommand{\definevariable}{mm}
{ % #1 is the name, #2 is the key-value set
\seq_gput_right:Nn \g_runart_variables_seq { #1 }
\prop_clear:N \l__runart_variables_temp_prop
\keys_set:nn { runart/variables } { #2 }
\prop_gclear_new:c { g_runart_var_#1_prop }
\prop_gset_eq:cN { g_runart_var_#1_prop } \l__runart_variables_temp_prop
}
% syntactic sugar
\cs_new_protected:Nn \__runart_gput:nn
{
\prop_gput:Nnn \l__runart_variables_temp_prop { #1 } { #2 }
}
% keys
\keys_define:nn { runart/variables }
{
value .code:n = \__runart_gput:nn { value } { #1 },
value .value_required:n = true,
unit .code:n = \__runart_gput:nn { unit } { #1 },
unit .value_required:n = true,
name .code:n = \__runart_gput:nn { name } { #1 },
name .value_required:n = true,
sisetup .code:n = \__runart_gput:nn { sisetup } { #1 },
}
\NewDocumentCommand{\matte}{m}
{ % #1 is the expression to output
\tl_set:Nn \l__runart_variables_matte_tl { #1 }
\seq_map_inline:Nn \g_runart_variables_seq
{
\regex_replace_all:nnN
{ ##1 }
{ \c{runart_variable_use_matte:n} \cB\{ ##1 \cE\} }
\l__runart_variables_matte_tl
}
\tl_use:N \l__runart_variables_matte_tl
}
\NewDocumentCommand{\formal}{m}
{
\tl_set:Nn \l__runart_variables_matte_tl { #1 }
\seq_map_inline:Nn \g_runart_variables_seq
{
\regex_replace_all:nnN
{ ##1 }
{ \c{runart_variable_use_formal:n} \cB\{ ##1 \cE\} }
\l__runart_variables_matte_tl
}
\tl_use:N \l__runart_variables_matte_tl
}
\cs_new_protected:Nn \runart_variable_use_matte:n
{
\use:x % it's necessary to expand the optional argument
{
\SI
[\prop_item:cn { g_runart_var_#1_prop } {sisetup}]
{\prop_item:cn { g_runart_var_#1_prop } {value}}
{\prop_item:cn { g_runart_var_#1_prop } {unit}}
}
}
\cs_new_protected:Nn \runart_variable_use_formal:n
{
\prop_item:cn { g_runart_var_#1_prop } { name }
}
\ExplSyntaxOff
\begin{document}
{
\definevariable{a_car}
{
name=a_{\mathrm{car}},
value=20,
unit=\metre\per\second,
}
\definevariable{v_car}
{
name=v_{\mathrm{car}},
value=40,
unit=\metre,
}
\definevariable{t_car}
{
name=t_{\mathrm{car}},
value=2,
unit=\second,
sisetup={color=red},
}
\[
\matte{
a_car=\frac{v_car}{t_car}
}
\]
}
Trying to redefine a variable:
\definevariable{t_car}
{
name=t_{\mathrm{car}},
value=2,
unit=\second,
sisetup={color=red},
}
\[
\matte{
t_car
}
\]
\end{document}
答案1
重新定义变量应该是可能的;这是一个完善的版本,带有错误检查的提示。
\documentclass{article}
\usepackage{xparse,l3regex,siunitx,xcolor}
\ExplSyntaxOn
\seq_new:N \g_runart_variables_seq
\prop_new:N \l__runart_variables_temp_prop
\tl_new:N \l__runart_variables_matte_tl
\tl_new:N \l__runart_variables_item_tl
\NewDocumentCommand{\definevariable}{mm}
{ % #1 is the name, #2 is the key-value set
\seq_if_in:NnF \g_runart_variables_seq { #1 }
{
\seq_gput_right:Nn \g_runart_variables_seq { #1 }
}
\prop_clear:N \l__runart_variables_temp_prop
\keys_set:nn { runart/variables } { #2 }
\prop_gclear_new:c { g_runart_var_#1_prop }
\prop_gset_eq:cN { g_runart_var_#1_prop } \l__runart_variables_temp_prop
}
% syntactic sugar
\cs_new_protected:Nn \__runart_put:nn
{
\prop_put:Nnn \l__runart_variables_temp_prop { #1 } { #2 }
}
% keys
\keys_define:nn { runart/variables }
{
value .code:n = \__runart_put:nn { value } { #1 },
value .value_required:n = true,
unit .code:n = \__runart_put:nn { unit } { #1 },
unit .value_required:n = true,
name .code:n = \__runart_put:nn { name } { #1 },
name .value_required:n = true,
sisetup .code:n = \__runart_put:nn { sisetup } { #1 },
}
\NewDocumentCommand{\matte}{m}
{ % #1 is the expression to output
\__runart_matte_or_formal:nn { runart_variable_use_matte:n } { #1 }
}
\NewDocumentCommand{\formal}{m}
{
\__runart_matte_or_formal:nn { runart_variable_use_formal:n } { #1 }
}
\cs_new_protected:Nn \__runart_matte_or_formal:nn
{
\tl_set:Nn \l__runart_variables_matte_tl { #2 }
\seq_map_inline:Nn \g_runart_variables_seq
{
\regex_replace_all:nnN
{ ##1 }
{ \c{#1} \cB\{ ##1 \cE\} }
\l__runart_variables_matte_tl
}
\tl_use:N \l__runart_variables_matte_tl
}
\cs_new:Nn \__runart_use_prop:nn
{
\prop_if_in:cnTF { g_runart_var_#1_prop } { #2 }
{
\prop_item:cn { g_runart_var_#1_prop } { #2 }
}
{
\str_case:nn { #2 }
{
{value}{999999}
{unit}{\metre}
{name}{undefined}
}
}
}
\cs_generate_variant:Nn \tl_if_empty:nTF { f }
\cs_new_protected:Nn \runart_variable_use_matte:n
{
\use:x % it's necessary to expand the optional argument
{
\SI
[\__runart_use_prop:nn { #1 } {sisetup}]
{\__runart_use_prop:nn { #1 } {value}}
{\__runart_use_prop:nn { #1 } {unit}}
}
}
\cs_new_protected:Nn \runart_variable_use_formal:n
{
\__runart_use_prop:nn { #1 } { name }
}
\ExplSyntaxOff
\begin{document}
\definevariable{a_car}
{
name=a_{\mathrm{car}},
value=20,
unit=\metre\per\second,
}
\definevariable{v_car}
{
name=v_{\mathrm{car}},
value=40,
unit=\metre,
}
\definevariable{t_car}
{
name=t_{\mathrm{car}},
value=2,
unit=\second,
sisetup={color=red},
}
\[
\matte{
a_car=\frac{v_car}{t_car}
}
\]
\[
\formal{
a_car=\frac{v_car}{t_car}
}
\]
\[
\matte{
a_car=\frac{v_car}{t_car}
}
\]
Trying to redefine a variable:
\definevariable{t_car}
{
name=t_{\mathrm{car}},
value=2,
unit=\second,
sisetup={color=blue},
}
\[
\matte{
t_car
}
\]
Trying to redefine a variable, but forgetting the value:
\definevariable{t_car}
{
name=t_{\mathrm{car}},
unit=\second,
sisetup={color=blue},
}
\[
\matte{
t_car
}
\]
\end{document}
如果忘记了某个值,则可以使用后备值(并且可能添加更合理的错误消息)。
使用局部分配似乎不是最好的方法;例如,您可以在环境(或其变体)\definevariable
中使用,但不能在中使用,因为对齐的每个单元都形成一个组。equation
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