Dtyjlui

I want to include some braces in my string variable:

documentclass{article}

usepackage{expl3}



begin{document}

    ExplSyntaxOn

    str_new:N l_example_var

    int_new:N l_example_int



    str_set:Nn l_example_var {{}

    str_put_right:NV l_example_var {l_example_int}

    str_put_right:Nn l_example_var {}~some~text}



    str_show:N l_example_var

    ExplSyntaxOff

end{document}

Unfortunately this results in the braces being preceded by pesky backslashes:

> l_example_var={0} some text.

<recently read> }



l.13 ^^Istr_show:N l_example_var

How would I be able to get rid of the backslashes in front of the braces? E.g. l_example_var={0} some text.

I'm not sure what's the benefit of a string such as {42} and probably you need a token list instead. However,

str_set:Nx l_example_str { c_left_brace_str int_use:N l_example_int c_right_brace_str }

will do. For a token list it's similar

tl_set:Nx l_example_tl { { int_use:N l_example_int } }

Apparently, the { and } 'strings' shall appear literally in the string, so one way to add them is to use c_left_brace_str and c_right_brace_str and the V modifier for the str_set:Nn macro

There are other literal string constants such as c_hash_str or c_dollar_str, which are constant token lists with catcode 12 actually. See page 75 in the current interface3 manual (as of 2018/12/27).

documentclass{article}

usepackage{expl3}



begin{document}

    ExplSyntaxOn

    str_new:N l_example_var

    int_new:N l_example_int



    str_set:NV l_example_var c_left_brace_str

    str_put_right:NV l_example_var l_example_int

    str_put_right:NV l_example_var c_right_brace_str

    str_put_right:Nn l_example_var {~some~text}





    str_show:N l_example_var

    ExplSyntaxOff

end{document}

The output is

This is pdfTeX, Version 3.14159265-2.6-1.40.19 (TeX Live 2018)

(preloaded format=pdflatex) write18 enabled. entering extended mode

(./stringwith.tex LaTeX2e <2018-12-01>

(/usr/local/texlive/2018/texmf-dist/tex/latex/base/article.cls

Document Class: article 2018/09/03 v1.4i Standard LaTeX document class

(/usr/local/texlive/2018/texmf-dist/tex/latex/base/size10.clo))

(/usr/local/texlive/2018/texmf-dist/tex/latex/l3kernel/expl3.sty

(/usr/local/texlive/2018/texmf-dist/tex/latex/l3kernel/expl3-code.tex)

(/usr/local/texlive/2018/texmf-dist/tex/latex/l3kernel/l3pdfmode.def))

(./stringwith.aux)

l_example_var={0} some text. }

l.16 str_show:N l_example_var

? x No pages of output. Transcript written on stringwith.log.