Variables in concrete syntax patterns cannot use [ and ] in the sort name

[BertLisser]

Created 2010-03-02 by [email protected] assigned to [email protected]

In attempting to use a concrete syntax pattern for matching a Rascal map, I've encountered a problem with declaring a variable to represent a mapping. Pasted below is part of an email sent to Jurgen on 19/2/2010:

I'll look through the code to see if I can figure this out, but will just work on other things for now. I'm trying to match mappings in the type checker, but I'm getting a parser error:

rascal>( <{Mapping[[Expression]] ","}* mps> ) := expMap;
^ parse error here
rascal>( < {Mapping[[Expression]] ","}* mps > ) := expMap;
^ parse error here
rascal>( < {Mapping ","}* mps > ) := expMap;
internal exception: java.lang.NullPointerException
rascal>( < {Mapping[Expression] ","}* mps > ) := expMap;
^ parse error here

I think this is because of the use of [ and ] in the pattern, but this is what is used in the SDF definition:

sorts Mapping
context-free syntax
from:Expression ":" to:Expression -> Mapping[[Expression]] {cons("Default")}
"(" mappings:{Mapping[[Expression]] ","}* ")" -> Expression {cons("Map")}