Merge pull request #16 from z0u/master

Inequality operators and other fixes

py_expression_eval/__init__.py

@@ -532,7 +532,7 @@ def parse(self, expr):
             if self.isOperator():
                 if self.isSign() and expected & self.SIGN:
                     if self.isNegativeSign():
-                        self.tokenprio = 2
+                        self.tokenprio = 5
                         self.tokenindex = '-'
                         noperators += 1
                         self.addfunc(tokenstack, operstack, TOP1)
@@ -752,66 +752,32 @@ def isConst(self):
         return False
 
     def isOperator(self):
-        code = self.expression[self.pos]
-        if code == '+':
-            self.tokenprio = 0
-            self.tokenindex = '+'
-        elif code == '-':
-            self.tokenprio = 0
-            self.tokenindex = '-'
-        elif code == '|':
-            if self.expression[self.pos] == '|':
-                self.pos += 1
-                self.tokenprio = 0
-                self.tokenindex = '||'
-            else:
-                return False
-        elif code == '=':
-            if self.expression[self.pos + 1] == "=":
-                self.pos += 1
-                self.tokenprio = 1
-                self.tokenindex = "=="
-
-            else:
-                return False
-        elif code == "!":
-            if self.expression[self.pos + 1] == "=":
-                self.pos += 1
-                self.tokenprio = 1
-                self.tokenindex = "!="
-            else:
-                return False
-        elif code == 'a':
-            if self.expression[self.pos + 1] == 'n' and self.expression[self.pos + 2] == 'd':
-                self.pos += 2
-                self.tokenprio = 0
-                self.tokenindex = "and"
-            else:
-                return False
-        elif code == 'o':
-            if self.expression[self.pos + 1] == 'r':
-                self.pos += 1
-                self.tokenprio = 0
-                self.tokenindex = "or"
-            else:
-                return False
-
-        elif code == '*':
-            self.tokenprio = 1
-            self.tokenindex = '*'
-        elif code == '/':
-            self.tokenprio = 2
-            self.tokenindex = '/'
-        elif code == '%':
-            self.tokenprio = 2
-            self.tokenindex = '%'
-        elif code == '^':
-            self.tokenprio = 3
-            self.tokenindex = '^'
-        else:
-            return False
-        self.pos += 1
-        return True
+        ops = (
+            ('+', 2, '+'),
+            ('-', 2, '-'),
+            ('*', 3, '*'),
+            (u'\u2219', 3, '*'), # bullet operator
+            (u'\u2022', 3, '*'), # black small circle
+            ('/', 4, '/'),
+            ('%', 4, '%'),
+            ('^', 6, '^'),
+            ('||', 1, '||'),
+            ('==', 1, '=='),
+            ('!=', 1, '!='),
+            ('<=', 1, '<='),
+            ('>=', 1, '>='),
+            ('<', 1, '<'),
+            ('>', 1, '>'),
+            ('and', 0, 'and'),
+            ('or', 0, 'or'),
+        )
+        for token, priority, index in ops:
+            if self.expression.startswith(token, self.pos):
+                self.tokenprio = priority
+                self.tokenindex = index
+                self.pos += len(token)
+                return True
+        return False
 
     def isSign(self):
         code = self.expression[self.pos - 1]
@@ -867,7 +833,7 @@ def isOp1(self):
             str += c
         if len(str) > 0 and str in self.ops1:
             self.tokenindex = str
-            self.tokenprio = 5
+            self.tokenprio = 7
             self.pos += len(str)
             return True
         return False
@@ -882,7 +848,7 @@ def isOp2(self):
             str += c
         if len(str) > 0 and (str in self.ops2):
             self.tokenindex = str
-            self.tokenprio = 5
+            self.tokenprio = 7
             self.pos += len(str)
             return True
         return False

py_expression_eval/tests.py

@@ -28,8 +28,18 @@ def test_parser(self):
         self.assertEqual(parser.parse('lulu(x,y)').variables(), ['lulu','x','y'])
 
         #evaluate
+        self.assertEqual(parser.parse('1').evaluate({}), 1)
+        self.assertEqual(parser.parse('a').evaluate({'a': 2}), 2)
         self.assertEqual(parser.parse('2 * 3').evaluate({}), 6)
+        self.assertEqual(parser.parse(u'2 \u2219 3').evaluate({}), 6)
+        self.assertEqual(parser.parse(u'2 \u2022 3').evaluate({}), 6)
         self.assertEqual(parser.parse('2 ^ x').evaluate({'x': 3}), 8)
+        self.assertEqual(parser.parse('x < 3').evaluate({'x': 3}), False)
+        self.assertEqual(parser.parse('x < 3').evaluate({'x': 2}), True)
+        self.assertEqual(parser.parse('x <= 3').evaluate({'x': 3}), True)
+        self.assertEqual(parser.parse('x <= 3').evaluate({'x': 4}), False)
+        self.assertEqual(parser.parse('x > 3').evaluate({'x': 4}), True)
+        self.assertEqual(parser.parse('x >= 3').evaluate({'x': 3}), True)
         self.assertEqual(parser.parse('2 * x + 1').evaluate({'x': 3}), 7)
         self.assertEqual(parser.parse('2 + 3 * x').evaluate({'x': 4}), 14)
         self.assertEqual(parser.parse('(2 + 3) * x').evaluate({'x': 4}), 20)
@@ -81,6 +91,9 @@ def test_parser(self):
         self.assertEqual(expr.variables(), ['x', 'y'])
         self.assertEqual(expr.simplify({'y': 4}).variables(), ['x'])
 
+        # list operations
+        self.assertEqual(parser.parse('a, 3').evaluate({'a': [1, 2]}), [1, 2, 3])
+
     def test_consts(self):
         # self.assertEqual(self.parser.parse("PI ").variables(), [""])
         self.assertEqual(self.parser.parse("PI").variables(), [])