[stringtemplate-interest] error messages

[Terence Parr]

hiya. working on identifying exact error location in group files.

group t;
foo() ::= "hi <.> mom"

Previously we'd get an error at the '.' inside the <.> but where in  
the file was it?  Now, i know everything:

line 2:10: can't parse chunk: '1:4..4:.' in hi <.> mom

i'll make that more readable but it says ST expr is one char (line 1  
in template and from char index 4 to 4 relative to the template),  
which starts at line 2, char position 10 in that line.

Ter