RE: [HACKERS] Postgres' lexer - Mailing list pgsql-hackers

From Ansley, Michael
Subject RE: [HACKERS] Postgres' lexer
Date
Msg-id 1BF7C7482189D211B03F00805F8527F748C038@S-NATH-EXCH2
Whole thread Raw
List pgsql-hackers
>> 
>> > Point taken.  So, if the spaces are used, then a>-2 is not 
>> the same as a>-
>> > 2.  The latter should then generate an error, right?
>> 
>> It wasn't real clear where you intended to insert whitespace in this
>> example... but in any case, it might or might not generate an error
>> depending on what operators have been defined.  Both "a >- 2" (three
>> tokens) and "a > - 2" (four tokens) might be legal expressions.
>> If they are not, it's not the lexer's job to figure that out.
Yes, and -2 is two tokens, whether it's - 2 or -2.  Taking the unary minus
and the number, and creating a single expression meaning two less than zero
is not the lexer's job.  Or is it?  Or am I missing the plot?

MikeA


pgsql-hackers by date:

Previous
From: Yu Cao
Date:
Subject: Re: [HACKERS] PostgreSQL 6.5.1: libpq++ libraries on IRIX 6.5
Next
From: Leon
Date:
Subject: Re: [HACKERS] DROP TABLE inside transaction block