%D \module
%D   [       file=mp-func.mpii,
%D        version=2001.12.29,
%D          title=\CONTEXT\ \METAPOST\ graphics,
%D       subtitle=function hacks,
%D         author=Hans Hagen,
%D           date=\currentdate,
%D      copyright={PRAGMA / Hans Hagen \& Ton Otten}]
%C
%C This module is part of the \CONTEXT\ macro||package and is
%C therefore copyrighted by \PRAGMA. See licen-en.pdf for
%C details.

%D Under construction.

if known context_func : endinput ; fi ;

boolean context_func ; context_func := true ;

string pathconnectors[] ;

pathconnectors[0] := ","   ;
pathconnectors[1] := "--"  ;
pathconnectors[2] := ".."  ;
pathconnectors[3] := "..." ;

vardef function (expr f) (expr u, t, b, e, s) = save x ; numeric x ;
  for xx := b step s until e :
    hide (x := xx ;) if xx>b : scantokens(pathconnectors[f]) fi
    (scantokens(u),scantokens(t))
  endfor
enddef ;

def punkedfunction = function (1) enddef ;
def curvedfunction = function (2) enddef ;
def tightfunction  = function (3) enddef ;

vardef constructedpath (expr f) (text t) =
  save ok ; boolean ok ; ok := false ;
  for i=t :
    if ok : scantokens(pathconnectors[f]) else : ok := true ; fi i
  endfor
enddef ;

def punkedpath = constructedpath (1) enddef ;
def curvedpath = constructedpath (2) enddef ;
def tightpath  = constructedpath (3) enddef ;

vardef constructedpairs (expr f) (text p) =
  save i ; i := -1 ;
  forever : exitif unknown p[incr(i)] ;
    if i>0 : scantokens(pathconnectors[f]) fi p[i]
  endfor
enddef ;

def punkedpairs = constructedpairs (1) enddef ;
def curvedpairs = constructedpairs (2) enddef ;
def tightpairs  = constructedpairs (3) enddef ;