first succeeding precedence tests

jedi/evaluate/precedence.py

@@ -0,0 +1,71 @@
+"""
+Handles operator precedence.
+"""
+
+from jedi.parser import representation as pr
+
+
+class PythonGrammar(object):
+    """
+    Some kind of mirror of http://docs.python.org/3/reference/grammar.html.
+    """
+
+    class AtStart(tuple):
+        pass
+
+    class MultiPart(str):
+        def __new__(cls, first, second):
+            self = str.__new__(cls, first)
+            self.second = second
+
+    factor = AtStart(('+', '-', '~'))
+    power = '**',
+    term = '*', '/', '%', '//'
+    arith_expr = '+', '-'
+
+    shift_expr = '<<', '>>'
+    and_expr = '&',
+    xor_expr = '^',
+    expr = '|',
+
+    comparison = ('<', '>', '==', '>=', '<=', '!=', 'in',
+                  MultiPart('not', 'in'), 'is', MultiPart('is', 'not'))
+
+    not_test = AtStart(('not',))
+    and_test = 'and',
+    or_test = 'or',
+
+    #test = or_test ['if' or_test 'else' test] | lambdef
+
+    #sliceop = ':' [test]
+    #subscript = test | [test] ':' [test] [sliceop]
+    order = (factor, power, term, arith_expr, shift_expr, and_expr, xor_expr,
+             expr, comparison, not_test, and_test, or_test)
+
+
+class Precedence(object):
+    def __init__(self, left, operator, right=None):
+        self.left = left
+        self.operator = operator
+        self.right = right
+
+
+def create_precedence(expression_list, previous=None):
+    element = next(expression_list, None)
+    if element is None:
+        return previous
+
+    if isinstance(element, pr.Call):
+        element = str(element.name)
+    elif not isinstance(element, str):
+        if previous is None:
+            previous = element
+        return create_precedence(expression_list, previous=previous)
+
+    for term in PythonGrammar.order:
+        if element in term:
+            right = create_precedence(expression_list)
+            if right is None:
+                return previous
+            else:
+                return Precedence(previous, element, right)