[antlr-interest] RES: RES: COBOL grammar

[Parsiad Azimzadeh]

I think I can make some educated guesses as to the syntax you're
trying to describe from your example:

> There is another sample I can show:
>     IF some_expression
>        A
>        B
>     ELSE
>        C.

The END character is used in an IF statement to terminate it. It is
not an optional element in each statement, it is a required element
for particular statements. See the (unambiguous) grammar below:

grammar COBOL;

options
{
	language = Java;
}

program
	:	'procedure' 'division' END
		section *
	;

section
	:	ID 'section' END
		paragraph *
	;

paragraph
	:	ID END
		command *
		END
	;

// TODO: replace with actual commands
command
	:	'A'
	|	'B'

	// Conditional, as shown in your example
	|	IF expression
		command *
		ELSE
		command *
		END
	;

// TODO: replace with actual expressions
expression
	:	'E0'
	|	'E1'
	;

fragment LETTER: 'a'..'z' | 'A'..'Z';
END: '.';
IF: 'IF';
ELSE: 'ELSE';
ID: LETTER ( LETTER | '0'..'9' | '-' )*;