A postgres parser related question

Hi everyone, I just want to know something about postgresql parser, because I want to add a new feature for pgAdmin
graphicalquery builder (GQB) that allow an user to create a query graphical model from a sql statment, and I just want
toreuse postgres parser code (reuse this) to do the task of create an abstract tree like structure for the sql
statment.<br/><br /> I just remember that read at some place that I don't remember that the syntax and semantic checks
aredone in two different stages, and as I can understand, then is possible to just reuse only the parser stage in an
"easyway", but before even trying to do this task, I want some advices from people that know a lot more than me from
postgresinternals.<br /><br />Thanks in advance.<br />Regards, <br />Luis Ochoa.<br /><br />