Mdthbs

I am wondering if there is a simple way to expand some input text such as "3-7" as "3,4,5,6,7"?

For context, I am using foreach and want to be able to write

foreach x in {3-7, 9, 14, 52}

and have x run through 3, 4, 5, 6, 7, 9, 14, and 52.

Alternatively, if there's an easy way to have

foreach x in {1,3,...7}

result in x being defined as "1, 3, 4, 5, 6, and 7" instead of the standard "1, 3, 5, and 7", that would be great.

EDIT: I don't think I was clear in my explanation, but I personally understand how to do these foreach commands in TeX, but wanted a simple input structure for a non-TeX user to use, i.e. typing makeProblems{1, 3-7, 9, 14, 52} and having the associated problems as output.

With a little bit of code you can make yourself a parser. I defined makeProblems{<integer list>}{<code>} for you, in which <integer list> is a comma separated list of numbers where <x>-<y> is parsed as the list of integers between <x> and <y>, inclusive. The function parses the list of numbers and then iterates over the generated list, and makes the current number available for <code> as #1. For example:

makeProblems{1,3-7, 9, 14, 52}{Do something with #1.par}

prints:

The code is long because, as the function takes user input, the function takes extra care to make sure that the <integer list> doesn't contain wrong input.

documentclass{article}

usepackage{xparse}

ExplSyntaxOn

tl_new:N l_ryanj_list_tl

NewDocumentCommand makeProblems { m +m }

  {

    tl_clear:N l_ryanj_list_tl

    exp_args:Nx clist_map_function:nN {#1} __ryanj_parse_item:n

    tl_map_inline:Nn l_ryanj_list_tl {#2}

  }

cs_new_protected:Npn __ryanj_add_item:n #1

  { tl_put_right:Nn l_ryanj_list_tl { {#1} } }

cs_new_protected:Npn __ryanj_parse_item:n #1

  {

    __ryanj_if_number:nTF {#1}

      { __ryanj_add_item:n {#1} }

      {

        str_if_in:nnTF {#1} {-}

          { exp_args:Nf __ryanj_parse_range:n { tl_to_str:n {#1} } }

          { msg_error:nnn { ryanj } { invalid-number } {#1} }

      }

  }

cs_new_protected:Npn __ryanj_parse_range:n #1

  { __ryanj_parse_range:nw {#1} #1 q_mark }

cs_new_protected:Npn __ryanj_parse_range:nw #1#2-#3 q_mark

  {

    __ryanj_validate_number:nn {#1} {#2}

    __ryanj_validate_number:nn {#1} {#3}

    int_step_function:nnnN {#2} { 1 } {#3} __ryanj_add_item:n

    use_none:n q_stop

  }

cs_new_protected:Npn __ryanj_validate_number:nn #1 #2

  {

    __ryanj_if_number:nF {#2}

      {

        msg_error:nnnn { ryanj } { invalid-number-in-range } {#2} {#1}

        use_none_delimit_by_q_stop:w

      }

  }

msg_new:nnn { ryanj } { invalid-range } { Invalid~range~`#1'. }

msg_new:nnn { ryanj } { invalid-number } { Invalid~number~`#1'. }

msg_new:nnn { ryanj } { invalid-number-in-range } { Invalid~number~`#1'~in~range~`#2'. }

prg_new_conditional:Npnn __ryanj_if_number:n #1 { T, F, TF }

  {

    tl_if_empty:oTF

      { tex_romannumeral:D - 0#1 exp_stop_f: }

      {

        tl_if_empty:nTF {#1}

          { prg_return_false: }

          { prg_return_true: }

      }

      { prg_return_false: }

  }

% For older expl3:

prg_set_protected_conditional:Npnn str_if_in:nn #1#2 { T , F , TF }

  {

    use:x

      { tl_if_in:nnTF { tl_to_str:n {#1} } { tl_to_str:n {#2} } }

      { prg_return_true: } { prg_return_false: }

  }

ExplSyntaxOff

begin{document}

makeProblems{1,3-7, 9, 14, 52}{Do something with #1.par}

end{document}

documentclass{article}

usepackage{listofitems,pgffor}

newcommandmakeProblems[2]{%

  setsepchar{,/-}%

  readlist*numlist{#1}%

  defz##1{#2par}%

  foreachitemzzinnumlist[]{%

    ifnumlistlennumlist[zzcnt]=1relaxz{zz}else

      itemtomacronumlist[zzcnt,1]tmpA

      itemtomacronumlist[zzcnt,2]tmpB

      foreachzzz in {tmpA,...,tmpB}{%

        z{zzz}}%

    fi

  }%

}

begin{document}

makeProblems{1,3-7, 9, 14-16, 52}{Do something with #1.}

end{document}

I map the given comma separated list; each item is examined and if it contains a hyphen, a loop is done; in any case, an integer is added to a sequence.

Finally the sequence is expanded with separators between the items; optionally this token list is saved to a macro.

documentclass{article}

usepackage{xparse}



ExplSyntaxOn



NewDocumentCommand{expandlist}{om}

 {

  ryanj_expandlist:n { #2 }

  IfNoValueTF { #1 }

   {

    ryanj_expandlist_print:

   }

   {

    ryanj_expandlist_store:N #1

   }

 }



tl_new:N l_ryan_expandlist_tl

seq_new:N l__ryan_expandlist_seq



cs_new_protected:Nn ryanj_expandlist:n

 {

  seq_clear:N l__ryan_expandlist_seq

  clist_map_function:nN { #1 } __ryan_expandlist_item:n

  tl_set:Nx l_ryan_expandlist_tl

   {

    seq_use:Nnnn l__ryan_expandlist_seq {~and~} { ,~ } { ,~and~ }

   }

 }



cs_new_protected:Nn __ryan_expandlist_item:n

 {

  __ryan_expandlist_item:w #1 - - q_stop

 }



cs_new_protected:Npn __ryan_expandlist_item:w #1 - #2 - #3 q_stop

 {

  tl_if_blank:nTF { #2 }

   {

    seq_put_right:Nn l__ryan_expandlist_seq { #1 }

   }

   {

    int_step_inline:nnn { #1 } { #2 } { seq_put_right:Nn l__ryan_expandlist_seq { ##1 } }

   }

 }



cs_new:Nn ryanj_expandlist_print:

 {

  tl_use:N l_ryan_expandlist_tl

 }



cs_new_protected:Nn ryanj_expandlist_store:N

 {

  tl_if_exist:NF #1

   {

    tl_set_eq:NN #1 l_ryan_expandlist_tl

   }

 }



ExplSyntaxOff



begin{document}



expandlist{3-7, 9, 14, 52}



expandlist{1}



expandlist{1,4}



expandlist{1-2}



expandlist[foo]{3-7, 9, 14, 52}



texttt{meaningfoo}



end{document}