[Python-ideas] AST Transformation Hooks for Domain Specific Languages

[Carl M. Johnson]

> I did not realize you're proposing to skip parsing of the body of dsl
> function and just tuck all the code into Str literal.

If I can ask a noobish question, in that case, what's the advantage of
the new syntax over the currently existing ability to have a decorator
parse a docstring? Eg., an SQL DSL could be done today as


import dsl.sql

@dsl.sql
def lookup_address(name : dsl.sql.char, dob : dsl.sql.date):
   """select address
   from people
   where name = {name} and dob = {dob}"""
   pass

If you can't bear to lose the docstring, you could instead write something like,


import dsl.sql

@dsl.sql
def lookup_address(name : dsl.sql.char, dob : dsl.sql.date):
   "Looks up the address of a name and DOB."
   return """select address
   from people
   where name = {name} and dob = {dob}"""



What's the advantage of the "def from" over this? Bear in mind that
this way of doing has the advantage of working with today's Python
syntax highlighters. ;-)