Re: WIP: default values for function parameters

Peter Eisentraut <peter_e@gmx.net> writes:
> On Monday 24 November 2008 23:21:15 Pavel Stehule wrote:
>> Default parameters are implemented similar to variadic functions - so
>> no changes on PL part - all changes are on caller part.

> Then I don't understand why you need this special data type instead of using 
> an array of text with nulls for parameters without default.

I'm not even sure you need to store any nulls.  We're going to require
defaults to be provided for the last N parameters consecutively, right?
So that's just what the array contents are.  Or maybe it's not an array
at all but a single text item containing the representation of a List
--- compare the storage of index expressions.  There shouldn't be any
need to read the contents of the value during function resolution;
an appropriate representation will have the number of non-defaultable
parameters stored as a separate integer column.
        regards, tom lane