Can't parse an existing expression with the antlr4 grammar(see it in the question) - expression

Question

I have the following grammar
grammar ExpressionsParserGrammar;
expression
:
left = expression identity_operation =
(
IDENTITY
| NOT_IDENTITY
) right = expression # identity_operation
| left = expression equality_operation =
(
EQUALS
| NOT_EQUALS
| MORE_THAN
| LESS
| MORE_OR_EQUALS
| LESS_OR_EQUALS
) right = expression # equality_operation
| condition = expression '?' left = expression COLON right = expression #
question_expr
| left = expression mul_or_div =
(
MUL
| DIV
) right = expression # mul_div_expr
| left = expression plus_minus =
(
PLUS
| MINUS
) right = expression # add_expr
| NOT expr = expression # not_expr
| left = expression AND right = expression # and_expr
| left = expression OR right = expression # or_expr
| LPAREN expr = expression RPAREN # brackets_expr
| POWER_FUNC LPAREN expr1 = expression COMMA expr2 = expression RPAREN #
power_expr
| LAST_VAL_FUNC LPAREN last_str_func = STRING_VALUE
(
(
COMMA config = STRING_VALUE
)?
) RPAREN # last_val_func
| LAST_STR_FUNC LPAREN last_str_func = STRING_VALUE RPAREN # last_str_func
| SUBMISSION_VAL_FUNC LPAREN sumission_val_str = STRING_VALUE RPAREN #
submission_val_func
| SUBMISSION_STR_FUNC LPAREN submission_str = STRING_VALUE RPAREN #
submission_str_func
| DATE_FORMAT_FUNC LPAREN date_format_expr = expression COMMA formatParam =
STRING_VALUE RPAREN # date_format_func
| NEW DATE LPAREN
(
(
expr = expression
(
COMMA expr = expression
)*
)
)* RPAREN # date
| DIFFERENCE_IN_HOURS LPAREN left = expression COMMA right = expression #
dif_in_hours
| DIFFERENCE_IN_DAYS LPAREN left = expression COMMA right = expression #
dif_in_days
| DIFFERENCE_IN_MINUTES LPAREN left = expression COMMA right = expression #
dif_in_minutes
| DATE_ADD LPAREN date = expression COMMA d=duration RPAREN # dateAddFunc
| DATE_SUBTRACT LPAREN date = expression COMMA d=duration RPAREN # dateSubtractFunc
| NOW LPAREN RPAREN # now
| numLiteral = NUMBER_LITERAL # process_number
| strValueLiteral = STRING_VALUE # process_str
| boolLiteral =
(
TRUE
| FALSE
) # process_bool
;
duration:L_CURLY_BRACE (YEARS COLON years =
expression) ( COMMA MONTHS COLON months = expression)? (COMMA WEEKS COLON weeks =
expression )? (COMMA DAYS COLON days = expression )? ( COMMA HOURS COLON hours = expression )?
( COMMA MINUTES COLON minutes = expression )? (COMMA SECONDS COLON seconds = expression)? R_CURLY_BRACE;
SECONDS: 'seconds';
MINUTES: 'minutes' ;
HOURS
:'hours'
;
DAYS
:
'days'
;
WEEKS
:
'weeks'
;
MONTHS
:
'months'
;
YEARS
:
'years'
;
OR
:
'||'
;
AND
:
'&&'
;
NOT
:
'!'
;
DIFFERENCE_IN_MINUTES
:
'differenceInMinutes'
;
DIFFERENCE_IN_DAYS
:
'differenceInDays'
;
DIFFERENCE_IN_HOURS
:
'differenceInHours'
;
DATE_ADD
:
'dateAdd'
;
DATE_SUBTRACT
:
'dateSubtract'
;
// ----------------- lexer -----------------
// using the NA pattern marks this Token class as 'irrelevant' for the Lexer.
// AdditionOperator defines a Tokens hierarchy but only the leafs in this hierarchy define
// actual Tokens that can appear in the text
COLON
:
':'
;
NOW
:
'now'
;
NEW
:
'new'
;
DATE
:
'Date'
;
PLUS
:
'+'
;
MINUS
:
'-'
;
MUL
:
'*'
;
DIV
:
'/'
;
LPAREN
:
'('
;
RPAREN
:
')'
;
NUMBER_LITERAL
:
'0'
|
(
[1-9]
(
[0-9]*
)
)
;
IDENTITY
:
'==='
;
NOT_IDENTITY
:
'!=='
;
EQUALS
:
'=='
;
NOT_EQUALS
:
'!='
;
MORE_THAN
:
'>'
;
LESS
:
'<'
;
MORE_OR_EQUALS
:
'>='
;
LESS_OR_EQUALS
:
'<='
;
LAST_VAL_FUNC
:
'lastVal'
;
LAST_STR_FUNC
:
'lastStr'
;
SUBMISSION_VAL_FUNC
:
'submissionVal'
;
SUBMISSION_STR_FUNC
:
'submissionStr'
;
POWER_FUNC
:
'power'
;
DATE_FORMAT_FUNC
:
'dateFormat'
;
COMMA
:
','
;
L_CURLY_BRACE
:
'{'
;
R_CURLY_BRACE
:
'}'
;
TRUE
:
'true'
;
FALSE
:
'false'
;
STRING_VALUE
:
'"'
(
'\\"'
| .
)*? '"'
;
WS
:
[ \r\t\n]+ -> skip
;
And on the expression
differenceInDays(new Date(1999, 10,1), true ? new Date(1999, 10,2) :
"A")>3
I have following error
ExpressionsParserGrammar::expression:1:72: extraneous input ')'
expecting {, '?', '||', '&&', '+', '-', '*', '/', '===', '!==',
'==', '!=', '>', '<', '>=', '<='}
There is a Eclipse view of the syntax tree of my expression
Where I'm wrong and how to fix my grammar to make the mentioned expression fit to the grammar?

Answer 1

The error message "extraneous input ')' expecting {, '?', '||', '&&', '+', '-', '*', '/', '===', '!==', '==', '!=', '>', '<', '>=', '<='}" is telling you that a ) is encountered, but is unexpected. The parser is trying to continue matching an expression, which might continue if one of the tokens {, '?', '||', '&&', '+', '-', '*', '/', '===', '!==', '==', '!=', '>', '<', '>=', '<='} was found instead of ).
The root cause is that in your #dif_in_days alternative, there is no RPAREN token defined:
Instead of:
| DIFFERENCE_IN_DAYS LPAREN left = expression COMMA right = expression #dif_in_days
do this:
| DIFFERENCE_IN_DAYS LPAREN left = expression COMMA right = expression RPAREN #dif_in_days
Note that the same goes for the alternatives #dif_in_hours and #dif_in_minutes: those too are missing an RPAREN token.