nested \ifnum commands

Question

I'm trying to make macro to work in biblatex edition field. Logic is following:

• if edition =1 there is suffix -li (1-li)
• if edition>1 and if edition<21 there is prefix me- (me-15,me-20 ..etc)
• if edition = 40,60,80,100,200,...1000 there is also prefix me-
• in other cases suffix -e (31-e, 21-e, 129-e, 1010-e)

here is a code which works:

 \protected\def\mkbibmascord#1{%
 \ifnum #1=1 #1-li \else %
 \ifnum #1<21 %
\ifnum #1>1 me-#1 \fi \else %
\ifnum #1 = 40  me-#1 \else%
\ifnum #1 = 60  me-#1 \else%
\ifnum #1 = 80  me-#1 \else%
\ifnum #1 = 100 me-#1 \else %
\ifnum #1 = 200  me-#1 \else %
#1-e
\fi\fi\fi\fi\fi\fi\fi%
}%
\protected\def\mkbibordinal{\mkbibmascord}%
\protected\def\mkbibfemord{\mkbibmascord}%
\protected\def\mkbibneutord{\mkbibmascord}%

but how can i write general code/improve above code? (not only for 200), becouse let say for calendar there will be alot if/fi-s

Answer 1

Here's an implementation in expl3:

\documentclass{article}

\usepackage{xparse}

\ExplSyntaxOn
\cs_new:Nn \georgian_ordinal:n
 {
  \int_compare:nTF { 1 < #1 < 21 }
   { me\mbox{-}#1 }
   { \georgian_ordinal_aux:n { #1 } }
 }

\cs_new:Nn \georgian_ordinal_aux:n
 {
  \int_case:nnF { #1 }
   {
    {    1 }{ #1\mbox{-}li }
    {   40 }{ me\mbox{-}#1 }
    {   60 }{ me\mbox{-}#1 }
    {   80 }{ me\mbox{-}#1 }
    {  100 }{ me\mbox{-}#1 }
    {  200 }{ me\mbox{-}#1 }
    {  300 }{ me\mbox{-}#1 }
    {  400 }{ me\mbox{-}#1 }
    {  500 }{ me\mbox{-}#1 }
    {  600 }{ me\mbox{-}#1 }
    {  700 }{ me\mbox{-}#1 }
    {  800 }{ me\mbox{-}#1 }
    {  900 }{ me\mbox{-}#1 }
    { 1000 }{ me\mbox{-}#1 }
  }
  { #1\mbox{-}e }
 }

\cs_set_eq:NN \mkbibmascord  \georgian_ordinal:n
\cs_set_eq:NN \mkbibordinal  \georgian_ordinal:n
\cs_set_eq:NN \mkbibfemord   \georgian_ordinal:n
\cs_set_eq:NN \mkbibneutcord \georgian_ordinal:n

\ExplSyntaxOff

\begin{document}

% a loop for testing
\ExplSyntaxOn
\int_step_inline:nnnn { 1 } { 1 } { 1010 } { \mkbibmascord { #1 } ~ }
\ExplSyntaxOff

\end{document}

I only show the test between 1 and 210:

Maybe something more efficient can be done if the rules for numbers above 1000 are explained.

Answer 2

The solution using \ifnums and using \variants{num}{list}{true-text}{false-text} macro which expands to the "true-text" if num is equal to the number in the list else it expands to the "false-text".

\def\variants#1#2{\variantsA{#1}#2,,\end}
\def\variantsA#1#2,{\ifx,#2,\expandafter\variantsE \else
   \ifnum#1=#2 \variantsC \else
      \expandafter\expandafter\expandafter\variantsA
   \fi\fi{#1}}
\def\variantsC#1\end#2#3{\fi\fi#2}
\def\variantsE#1\end#2#3{#3}

\protected\def\mkbibmascord#1{%
   \ifnum#1<1 #1-e\else
   \ifnum#1=1 #1-li\else
   \ifnum#1<21 me-#1\else
   \variants{#1}{40,60,80,100,200,300,400,500,600,700,800,900,1000}{me-#1}{#1-e}%
   \fi\fi\fi
}

Answer 3

The question has two relatively independent aspects:

 1. how to organize gracefully a long list of `\ifnum..` clauses, 
 2. how to automatize over a list.

I won't delve much about the second part here, illustrated in the code below by the handling of 300, 400, .., 1000 via \xintApplyUnbraced from package xinttools. This is expandable. And the Test itself uses an \xintFor loop (non-expandable). For example wipet's answer has one-line macros sufficient here. By laziness I used the loops from xinttools.

My answer is mainly the observation that very simple macros:

\long\def\DoThis #1#2\OrThat #3{\fi #1}
\long\def\OrThat #1{#1}

can be used to handle point 1. No more \fi\fi\fi\fi...\fi. And expandability is maintained.

\long\def\DoThis #1#2\OrThat #3{\fi #1}
\long\def\OrThat #1{#1}

% for the (optional) list manipulations in the code and in the Test
\input xinttools.sty

% Notice that this \georgianordinal is an expandable macro
\def\georgianordinal #1{%
   \ifnum #1=1  \DoThis{1-li}\fi
   \ifnum #1<21 \DoThis{me-#1}\fi
   \ifnum #1=40 \DoThis{me-#1}\fi
   \ifnum #1=60 \DoThis{me-#1}\fi
   \ifnum #1=80 \DoThis{me-#1}\fi
   \ifnum #1=100 \DoThis{me-#1}\fi
   \ifnum #1=200 \DoThis{me-#1}\fi
   \xintApplyUnbraced
        {\georgianordinalaux {#1}}
        {{300}{400}{500}{600}{700}{800}{900}{1000}}%
   \OrThat {#1-e}%
}

% notice the space before \ifnum, which is there to stop 
% an expansion done via \romannumeral-`0 by \xintApplyUnbraced
\def\georgianordinalaux #1#2{ \ifnum #1=#2 \DoThis{me-#1}\fi}

% Test:

\xintFor #1 in {\xintintegers} \do {%
     \georgianordinal {\the#1},
     \ifnum#1>1050 \expandafter\xintBreakFor\fi
}

\bye