ODLv21.g4

/*****************************************************************************
 * ODLv2 as Defined Here: http://pds.nasa.gov/documents/sr/Chapter12.pdf
 *****************************************************************************/

grammar ODLv21;


WS
    : [ \t] -> skip
    ;

INTEGER
    : (SIGN) UNSIGNED_INTEGER
    ;

UNSIGNED_INTEGER
    : (DIGIT)+
    ;

SIGN
    : [+-]
    ;

REAL
    : (SIGN) UNSCALED_REAL
    | (SIGN) SCALED_REAL
    ;

UNSCALED_REAL
    : UNSIGNED_INTEGER.(UNSIGNED_INTEGER)
    | .UNSIGNED_INTEGER
    ;

SCALED_REAL
    : UNSCALED_REAL EXPONENT
    ;

EXPONENT
    : 'E' INTEGER
    | 'e' INTEGER
    ;

STRING_CHARACTER
    : LETTER
    | DIGIT
    | [ .]
    ;

STRING
    : '"' STRING_CHARACTER+ '"'
    | STRING_CHARACTER+
    ;

IDENTIFIER
    : LETTER(LETTER|DIGIT|'_'LETTER|'_'DIGIT)*
    ;

NEWLINE
    : '\r\n'
    ;

LETTER
    : [a-zA-Z]
    ;

DIGIT
    : [0-9]
    ;

label
    : (statement)*('END'|'end')
    ;

statement
    : assignment_stmt (comment_stmt)* NEWLINE
    | comment_stmt NEWLINE
    | NEWLINE
    ;

assignment_stmt
    : IDENTIFIER '=' value
    ;


comment_stmt
    : '/*' STRING '*/'
    ;

value
    : STRING
    | INTEGER
    ;

sample1.lbl

PDS_VERSION_ID = PDS3
INTEGER1       = 1
FLOAT          = 2.3
COMMENT1       = THING TEST
COMMENT2       = Alive.
END

trace

enter   label, LT(1)=PDS_VERSION_ID
enter   statement, LT(1)=PDS_VERSION_ID
enter   assignment_stmt, LT(1)=PDS_VERSION_ID
consume [@0,0:13='PDS_VERSION_ID',<16>,1:0] rule assignment_stmt
consume [@1,15:15='=',<2>,1:15] rule assignment_stmt
enter   value, LT(1)= PDS3
consume [@2,16:20=' PDS3',<15>,1:16] rule value
exit    value, LT(1)=

exit    assignment_stmt, LT(1)=

consume [@3,21:22='\r\n',<17>,1:21] rule statement
exit    statement, LT(1)=INTEGER1       
line 2:0 extraneous input 'INTEGER1       ' expecting {'END', 'end', '/*', IDENTIFIER, '
'}
enter   statement, LT(1)=

consume [@7,41:42='\r\n',<17>,2:18] rule statement
exit    statement, LT(1)=FLOAT          
line 3:0 extraneous input 'FLOAT          ' expecting {'END', 'end', '/*', IDENTIFIER, '
'}
enter   statement, LT(1)=

consume [@11,63:64='\r\n',<17>,3:20] rule statement
exit    statement, LT(1)=COMMENT1       
line 4:0 extraneous input 'COMMENT1       ' expecting {'END', 'end', '/*', IDENTIFIER, '
'}
enter   statement, LT(1)=

consume [@15,92:93='\r\n',<17>,4:27] rule statement
exit    statement, LT(1)=COMMENT2       
line 5:0 extraneous input 'COMMENT2       ' expecting {'END', 'end', '/*', IDENTIFIER, '
'}
enter   statement, LT(1)=

consume [@19,117:118='\r\n',<17>,5:23] rule statement
exit    statement, LT(1)=END
consume [@20,119:121='END',<3>,6:0] rule label
exit    label, LT(1)=