PDDL in Python – Python DSL for writing a PDDL
A minimal implementation of a DSL which allows people to write PDDL in python. Based on parsing python’s AST.
Author: Masataro Asai
License: MIT.
Example in examples/blocksworld.py:
#+begin_src python
class Blocksworld(Domain):
def move_b_to_b(bm, bf, bt):
if clear[bm] and clear[bt] and on[bm, bf]:
clear[bt] = False
on[bm, bf] = False
on[bm, bt] = True
clear[bf] = True
def move_b_to_t(bm, bf):
if clear[bm] and on[bm, bf]:
on[bm, bf] = False
on_table[bm] = True
clear[bf] = True
def move_t_to_b(bm, bt):
if clear[bm] and clear[bt] and on_table[bm]:
clear[bt] = False
on_table[bm] = False
on[bm, bt] = True
print(Blocksworld())
#+end_src
will print
#+begin_src lisp
(domain blocksworld
(:requirement :strips)
(:types)
(:predicates
(clear ?x0)
(on ?x0 ?x1)
(on-table ?x0))
(:action move-b-to-b :parameters (?bm ?bf ?bt)
:preconditions
(and
(clear ?bm)
(clear ?bt)
(on ?bm ?bf))
:effects
(and
(not (clear ?bt))
(not (on ?bm ?bf))
(on ?bm ?bt)
(clear ?bf)))
(:action move-b-to-t :parameters (?bm ?bf)
:preconditions
(and
(clear ?bm)
(on ?bm ?bf))
:effects
(and
(not (on ?bm ?bf))
(on-table ?bm)
(clear ?bf)))
(:action move-t-to-b :parameters (?bm ?bt)
:preconditions
(and
(clear ?bm)
(clear ?bt)
(on-table ?bm))
:effects
(and
(not (clear ?bt))
(not (on-table ?bm))
(on ?bm ?bt))))
#+end_src
Example in examples/briefcaseworld.py:
#+begin_src python
class location:
pass
class portable:
pass
class Briefcaseworld(Domain):
def move(m : location, l : location):
if is_at[m]:
is_at[l] = True
is_at[m] = False
for x in all(portable): # current python syntax does not allow annotating loop variable
if _in[x]:
at[x,l] = True
at[x,m] = False
def take_out(x : portable):
if _in[x]:
_in[x] = False
def put_in(x : portable, l : location):
if not _in[x] and at[x,l] and is_at[l]:
_in[x] = True
print(Briefcaseworld())
#+end_src
will print
#+begin_src lisp
(domain briefcaseworld
(:requirement :strips)
(:types
portable - object)
(:predicates
(is-at ?x0)
(in ?x0)
(at ?x0 ?x1))
(:action move :parameters (?m - location ?l - location)
:preconditions
(is-at ?m)
:effects
(and
(is-at ?l)
(not (is-at ?m))
(forall (?x - portable)
(when (in ?x)
(and
(at ?x ?l)
(not (at ?x ?m)))))))
(:action put-in :parameters (?x - portable ?l - location)
:preconditions
(and
(not (in ?x))
(at ?x ?l)
(is-at ?l))
:effects
(in ?x))
(:action take-out :parameters (?x - portable)
:preconditions
(in ?x)
:effects
(not (in ?x))))
#+end_src
