[antlr-interest] unexpected char error

[Kevin J. Cummings]

Hi Folks,
	I wrote a PL/I compiler front end in PCCTS 1.33 10 years ago.  Now, I'm
returning to the fold, and I'll be using antlr-2.7.7.  So, I'm writing
some small test programs, and I have a couple of questions:

options { language = cpp; }

1) Why does this work (code snippets only):

EQ : '=' ;
UINT : ( '0'..'9' )+ ;

stmt : "a" EQ UINT ;

while this gives me errors when I run it:

UINT : ( '0'..'9' )+ ;

stmt : "a" "=" UINT ;

see the errors below:

> ./mytest a = 5
>  > goal; LA(1)== > lexer mIDENT; c==99
>  < lexer mIDENT; c==32
> a
>   > stmt; LA(1)==a
>  > lexer mWHITESPACE; c==32
>  < lexer mWHITESPACE; c==61
> Parse exception: <arguments>:1:8: unexpected char: '='

2) The tree generated by:

stmt : "a" "=" UINT

is #(a)

while

stmnt : "a"^ "=" UINT

generates #(a, =, UINT)

I don't remember having to specify my root node on every rule in PCCTS
1.33, why is it necessary in antlr 2.7.7

Or am I missing something?

THANKS!

-- 
Kevin J. Cummings
kjchome at rcn.com
cummings at kjchome.homeip.net
cummings at kjc386.framingham.ma.us
Registered Linux User #1232 (http://counter.li.org)