Re: Updated CREATE FUNCTION syntax

Peter Eisentraut <peter_e(at)gmx(dot)net> writes:
> Joel Burton writes:
>> Is there any standardized way of handling the single-quotes within function
>> definition? Rather than doubling them up (which can make for very messy code
>> when your scripting language uses single quotes!), allowing another symbol
>> to be used, with that symbol be declared in the CREATE FUNCTION line?
>> Interbase uses a system like this: you can set the delimiter to anything you
>> want and use that instead of '.

> I think we need something like that. How exactly does Interbase "set" the
> delimiter? Keep in mind that our lexer and parser are static.

Seems like the only way to do that in the backend would be to find a way
of slipping the function text past the lexer/parser entirely. While I
can imagine ways of doing that, I think it'd be a *whole* lot cleaner
to fix things on the client side.

How do you feel about a psql hack that provides a "function definition"
mode? More generally it could be a mode to enter random text and have
it be converted to an SQL literal string. Perhaps

psql=> create function foo (int) returns int as
psql-> \beginliteral
psql-LIT> begin
psql-LIT> x := $1;
psql-LIT> ...
psql-LIT> end;
psql-LIT> \endliteral
psql-> language plpgsql;

Essentially, \beginliteral and \endliteral each convert to a quote
mark, and everywhere in between quotes and backslashes get doubled.
We might want to specify that the leading and trailing newlines get
dropped, too, though for function-definition applications that would
not matter.

regards, tom lane