Improve testing procedure

 - only run queries with correct code once
 - use msort/2 to implement quicksort/3, used for some tests
 - correctly split programs in the presence of =.. operator

2 files changed, 23 insertions, 4 deletions

diff --git a/prolog/engine.py b/prolog/engine.py
index 9e7340f..7f91a30 100755
--- a/prolog/engine.py
+++ b/prolog/engine.py
@@ -3,6 +3,7 @@
 import re
 
 from prolog.core import *
+from prolog.util import *
 
 class Atom(object):
     __slots__ = 'ref'
@@ -41,7 +42,7 @@ class Term(object):
 
     def __str__(self):
         ptr = c_char_p()
-        if PL_get_chars(self.ref, byref(ptr), CVT_ALL|CVT_WRITE|BUF_RING):
+        if PL_get_chars(self.ref, byref(ptr), CVT_WRITE|BUF_RING):
             return str(ptr.value, encoding=encoding)
 
 class Termv(object):
@@ -111,11 +112,16 @@ class PrologEngine(object):
         return out == 1
 
     def load(self, program, module=None):
+        tokens = tokenize(program)
         refs = []
         try:
-            for rule in re.split('\.(?:\s+|\Z)', program):
-                if rule == '':
+            start = 0
+            for idx in range(len(tokens)):
+                if tokens[idx] != ('PERIOD', '.') or idx - start <= 1:
                     continue
+                rule = stringify(tokens[start:idx])
+                start = idx + 1
+
                 if module != None:
                     rule = module + ':(' + rule + ')'
                 args = Termv([Term(rule), Term('Ref')])
@@ -150,10 +156,12 @@ class PrologEngine(object):
         # parse term
         if not PL_call_predicate(None, self.err_flags, self.p['read_term_from_atom'],
                                  Termv([Term(Atom(q)), goal, options]).ref):
+            sys.stderr.write('WARNING: Could not read term from {}\n'.format(q))
             return None
         # check if goal is safe with currently loaded rules
         if not PL_call_predicate(None, self.err_flags, self.p['safe_goal'],
                                  Termv([goal]).ref):
+            sys.stderr.write('WARNING: Unsafe goal: {}\n'.format(q))
             return None
 
         solutions = []
@@ -162,7 +170,16 @@ class PrologEngine(object):
                             Termv([Term(0.01), goal]).ref)
         while len(solutions) < 10:
             if PL_next_solution(qid):
-                solutions += [str(var_list)]
+                # get variable values in this solution as strings
+                variables = {}
+                head, tail = Term(), Term()
+                while PL_get_list(var_list.ref, head.ref, tail.ref):
+                    name, value = Term(), Term()
+                    PL_get_arg(1, head.ref, name.ref)
+                    PL_get_arg(2, head.ref, value.ref)
+                    variables[str(name)] = str(value)
+                    var_list = tail
+                solutions += [variables]
             else:
                 ex = PL_exception(qid)
                 if ex != None:
@@ -176,6 +193,7 @@ class PrologEngine(object):
                         else:
                             sys.stderr.write('Unknown error\n')
                 break
+
         PL_close_query(qid)
         PL_discard_foreign_frame(fid)
 
diff --git a/prolog/sandbox.pl b/prolog/sandbox.pl
index 2ba5af0..a4f7426 100644
--- a/prolog/sandbox.pl
+++ b/prolog/sandbox.pl
@@ -208,6 +208,7 @@ safe_primitive(var(_)).
 safe_primitive(nonvar(_)).
 safe_primitive(integer(_)).
 safe_primitive(float(_)).
+safe_primitive(number(_)).
 safe_primitive(atom(_)).
 safe_primitive(compound(_)).
 safe_primitive(ground(_)).