Fixed up the path expressions

pavelvelikhov · pavelvelikhov · commit 648aa45af92e · 2016-05-27T20:08:27.000+03:00
diff --git a/examples/pe.pql b/examples/pe.pql
@@ -0,0 +1,14 @@
+
+x = [[1,2], [3,4], [5,6]]
+y = {"a": [1,2,3], "b": [2,3,4]}
+
+print("x./", list(x./))
+print("x./ ./", list(x ./ ./))
+print("x.//", list(x.//))
+
+print("y./", list(y./))
+print("y./ ./", list(y ./ ./))
+print("y.//", list(y.//))
+
+print("x{ 1 in item}", list(x{1 in item}))
+print('y{ key == "b"}', dict(y{key=="b"}))
diff --git a/src/pythonql/Executor.py b/src/pythonql/Executor.py
@@ -25,17 +25,49 @@ def PQChildPath (coll):
 
 # Implement a descendents path on some collection or map
 def PQDescPath(coll):
-  stack = [coll]
+  stack = []
+  if isList(coll):
+    stack = [i for i in coll]
+  elif isMap(coll):
+    stack = list(coll.values())
   while stack:
     i = stack.pop()
+    yield i
     if isList(i):
-      [stack.push(j) for j in i[1:]]
+      [stack.append(j) for j in i[1:]]
+      if isList(i[0]):
+        stack.extend([ci for ci in i[0]])
+      elif isMap(i[0]):
+        stack.extend(i[0].values())
       yield i[0]
-    if isMap(i):
+    elif isMap(i):
       keys = list(i.keys())
-      [stack.push(i[j]) for j in keys[1:]]
+      [stack.append(i[j]) for j in keys[1:]]
       yield i[keys[0]]
 
+#Implements a predicate step on a collection
+def PQPred(coll, pred):
+  if isList(coll):
+    return PQPred_list(coll,pred)
+  elif isMap(coll):
+    return PQPred_map(coll,pred)
+
+def PQPred_list(coll,pred):
+  lcs = locals()
+  for i in coll:
+    lcs.update({'item':i})
+    if eval(pred,globals(),lcs):
+      yield i
+
+def PQPred_map(coll,pred):
+  lcs = locals()
+  result = {}
+  for (k,v) in coll.items():
+    lcs.update({'key':k, 'value':v})
+    if eval(pred,globals(),lcs):
+      result[k] = v
+  return result
+
 # create a table with an empty tuple
 def emptyTuple(schema):
   return PQTuple([None] * len(schema), schema)
diff --git a/src/pythonql/parser/Preprocessor.py b/src/pythonql/parser/Preprocessor.py
@@ -120,12 +120,12 @@ def get_path_expression_terminals(tree,parser):
     
     for c in children[1:]:
         if isChildStep(c,parser):
-            result = mk_tok([ "child_path", "(", result, ")" ])
+            result = mk_tok([ "PQChildPath", "(", result, ")" ])
         elif isDescStep(c,parser):
-            result = mk_tok([ "desc_path", "(", result, ")"])
+            result = mk_tok([ "PQDescPath", "(", result, ")"])
         elif isPredStep(c,parser):
             condition = mk_tok([ '"""', get_all_terminals(c,parser)[1:-1], '"""'])
-            result = mk_tok([ "pred_path", "(", result, ",", condition, ")"])
+            result = mk_tok([ "PQPred", "(", result, ",", condition, ")"])
     
     return result
 
