precedence tests and a parse_tree method for Precedence objects

jedi/evaluate/precedence.py

@@ -55,6 +55,18 @@ class Precedence(object):
         self.operator = operator
         self.right = right
 
+    def parse_tree(self, strip_literals=False):
+        def process(which):
+            try:
+                which = which.parse_tree
+            except AttributeError:
+                pass
+            if strip_literals and isinstance(which, pr.Literal):
+                which = which.value
+            return which
+
+        return (process(self.left), self.operator, process(self.right))
+
     def __repr__(self):
         return '(%s %s %s)' % (self.left, self.operator, self.right)
 
@@ -98,17 +110,18 @@ def _check_operator(iterator, priority=PythonGrammar.LOWEST_PRIORITY):
                 break  # respect priorities.
 
             try:
-                match = check.index(el)
+                match_index = check.index(el)
             except ValueError:
                 continue
 
+            match = check[match_index]
             if isinstance(match, PythonGrammar.MultiPart):
                 next_tok = next(iterator)
                 if next_tok != match.second:
                     iterator.push_back(next_tok)
                 continue
 
-            operator = check
+            operator = match
             break
 
         if operator is None:

test/test_evaluate/test_precedence.py

@@ -1,26 +1,26 @@
-import pytest
-
+from jedi.parser import Parser
 from jedi.evaluate import precedence
-cp = lambda *args: precedence.create_precedence(iter(args))
 
 
-@pytest.skip('sorry precedence stuff is still not implemented yet')
+def parse_tree(statement_string):
+    p = Parser(statement_string, no_docstr=True)
+    stmt = p.module.statements[0]
+    iterable = iter(stmt.expression_list())
+    pr = precedence.create_precedence(iterable)
+    if isinstance(pr, precedence.Precedence):
+        return pr.parse_tree(strip_literals=True)
+    else:
+        return pr
+
+
 def test_simple():
-    p = cp(1, '+', 2)
-    assert p.left == 1
-    assert p.operator == '+'
-    assert p.right == 2
-
-    p = cp('+', 2)
-    assert p.left is None
-    assert p.operator == '+'
-    assert p.right == 2
+    assert parse_tree('1+2') == (1, '+', 2)
+    assert parse_tree('+2') == (None, '+', 2)
 
 
-@pytest.skip('sorry precedence stuff is still not implemented yet')
 def test_invalid():
     """Should just return a simple operation."""
-    assert cp(1, '+') == 1
-    assert cp('+') is None
+    assert parse_tree('1 +') == 1
+    assert parse_tree('+') is None
 
-    assert cp('*', 1) == 1
+    assert parse_tree('* 1') == 1