My knowledge of MetaPost falls short. I hope someone will be able to help me with the following problem: This is a macro along the line of the mode_def definition (see the MetaFont book, Appendix B). def count_ suffix $ = $ := incr counter_; countnames_[$] := str$; enddef; called from some other macro, abbreviated: def defineCount(expr xyz) suffix name = begingroup % among other statements count_ name; endgroup; The problem is that I would like to modify the contents of 'name' before it is used in 'count'. I tried several solutions as for example: save name; string newname; newname := str name & "extension"; count_ newname; but then newname is not accepted. The error message is:
unknown string newname ! Equation cannot be performed (unknown string=numeric). and occurs count_->(SUFFIX0):=incr.counter_; countnames_[(SUFFIX0)]:=str (SUFFI...
Directly changing name (because assignment to a suffix is possible): name := str name & "extension"; gives a similar error. Nor did encapsulating of 'defineCount' with an outer calling macro where the extension as added work for me. Hans van der Meer