Beginning ANTLR4 definition for the Clarion language

24

Thanks for figuring out how put the spec all in one tab to make the test easier!

When I paste in this Class as would be in an INC file:

ConstantClass   CLASS,TYPE,MODULE('ABUTIL.CLW'),LINK('ABUTIL.CLW',_ABCLinkMode_),DLL(_ABCDllMode_)
CharPnt           LONG,PRIVATE
Next              PROCEDURE(FILE F)
                END

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The 2nd error 2:65 missing ')' at ',' wants Parens () after “Class” and not just a comma e.g. CLASS,TYPE.
The fix is to make the (fieldRef) optional with ()?
Before : ID CLASSKW LPAREN fieldRef? RPAREN classAttrList? lineEnd
Fixed : ID CLASSKW (LPAREN fieldRef? RPAREN)? classAttrList? lineEnd

After fixing the above it did not like the ,_ABCLinkMode_ in
LINK('ABUTIL.CLW',_ABCLinkMode_)
In classAttr there’s the LINK line
| LINKKW LPAREN expr? RPAREN
that does not allow a comma and second attribute ('file',_abc_).

It worked to add an optional “, ID” as
| LINKKW LPAREN expr? (COMMA ID)? RPAREN

Edit:
Link can have a number Link(,1) so change ID to expr?
| LINKKW LPAREN expr? (COMMA expr?)? RPAREN

After fixing LINK(,_id_) above then the error 4:18 no viable alternative at input 'Next PROCEDURE'
on the line Next PROCEDURE(FILE F)
I think Mark pointed out there is nothing to allow the format starting in column 1 of Name Procedure(parms).

The 1st error 1:0 missing 'PROGRAM' at 'ConstantClass'
makes me think the spec always wants “PROGRAM” first, but you can have a Class .INC / .CLW file that does not. Or a Member MODULE, or Equates, or code snippet.

To fix maybe add ? after programHeader to make it 1 or 0 times
Yes! No more error after adding ? so : programHeader?

program
    : programHeader?   //<--- Add ? on End -----------
      lineEnd*               // allow blank lines after PROGRAM
      mapSection?
      (lineEnd | declarationSection)*  // allow interleaved blank lines and declarations
      codeSection
      lineEnd*               // allow trailing blank lines
      EOF
    ;

programHeader
    : PROGRAM
    ;

Re mapSection? there can be multiple MAP’s so change ? to * = mapSection*
Those can be mixed with Data declartions so maybe (group)* MAP and Data:

program
    : programHeader?   //<--- Add ? on End so PROGRAM is optional -------
      lineEnd*         // allow blank lines after PROGRAM
      (                // Group (MAP + DATA)* to allow multiple MAPs mixed with Data
        mapSection*    //change ? to * to allow multiple MAPs
        (lineEnd | declarationSection)*  // allow interleaved blank lines and declarations
      )*               // Group (MAP + DATA)* 
      codeSection

FYI in the very first post at the bottom I added a few syntax rules about ANTLR.

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