[cvs-nhc98] Corrected several bugs in hat-stack.

[User olaf]

olaf: Tue May 15 16:40:07 CEST 2001

Update of /usr/src/master/nhc/docs
In directory hinken:/tmp/cvs-serv27763/docs

Modified Files:
	hatuser.tex 
Log Message:
Corrected several bugs in hat-stack.

Set string buffers for expressions in readTraceAt and infixPrint to 10000 instead of 255 (no final solution).
If an expression has no source reference hatStack prints a message that says so instead of seg faulting.
Hidden itself is never a stack entry. If a parent is a hidden, we follow the hidden parent. Hidden is only shown in subexpressions.
Infix printing is only used when the operator has at least 2 arguments.

Improvements:
Expressions are cut off at a depth of 6 to avoid very large expressions.
if, case and guard redexes are shown correctly, with the parent as next stack entry.