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Ambiguous binary operator in a PLSQL grammar [message #1728777]

Thu, 07 April 2016 04:59

Eclipse User

Ambiguous binary operator in a PLSQL grammar

I'm developing a grammar for Oracle PLSQL and I found a conflict between the multiplication operator (*, asterisk) and the wildcard '*' in SELECT * FROM.

QueryBlockFoo
: selectSentence='SELECT' '*' 'FROM' ';'
;

Multiplication returns Expression
: UnitaryOperator (({Operation.left=current} op='*') right=UnitaryOperator)*
;

When I test the grammar, the SELECT * FROM sentence works in a correct way, while the arithmetic operation ( var_a := 5*4; ) produces the error "mismatched input '*' expecting ';'

How can I resolve that?

Thanks in advance,
Cristo Rodriguez

Re: Ambiguous binary operator in a PLSQL grammar [message #1728832 is a reply to message #1728777]

Thu, 07 April 2016 13:16

Eclipse User

can you share a complete grammar that reproduces the problem?

maybe SELECT * FROM; could be a VarableRef(Select) * VariableRef(FROM); in your grammar

Re: Ambiguous binary operator in a PLSQL grammar [message #1729465 is a reply to message #1728832]

Thu, 14 April 2016 06:27

Eclipse User

Thank you Christian,

I made a mistake because I defined '*' as a "terminal" rule.
When I remove the clause terminal, the grammar work well.

Regards,
Cristo

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