Grammars and jumps

[Bruno Ribeiro]

Hello everybody!

I have two questions about bison grammars and jump implemention:

1) I have the following grammar (part of it):

program:    programbody
                 ;

programbody:    MODULE newline statementlist ENDMODULE
                        ;

statementlist:    statement
                      | statementlist newline statement
                      ;

statement:    vardecl
                  | single_command
                  | ifthen statementlist endif
                  | ifthen statementlist else statementlist endif

Well, everything is working properly when I use just one single_command 
per line. But I want to have things like:

A = B + C +
D + E

In other words, a newline ("\n") inside a single_command. But if I do 
this way, I have a parser error. So I try:

statementlist:    statement
                      | statementlist statement
                      ;

and I have a shift/reduce and reduce/reduce conflict in my grammar.

Conclusion: my only alternative is use just commands like A= B + C + D + 
E (everything in one line).

Does anybody knows how to implement newlines between commands?

2) I'm trying to implement a function like:

A = B + FAT(3) + C

But when I jump yyacc to the position of FAT(3), I have to know the 
return position (+ C). There's a way for retrieve the current position 
of yyin (before jump)?

Thanks very much for eveybody!

Bruno.

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There are 10 types of people,
Those that understand binary,
and those that do not.
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