JEP-16 Evaluates arithmetic expressions

jmespath/visitor.py

@@ -107,6 +107,18 @@ class TreeInterpreter(Visitor):
         'gte': operator.ge
     }
     _EQUALITY_OPS = ['eq', 'ne']
+    _ARITHMETIC_UNARY_FUNC = {
+        'minus': operator.neg,
+        'plus': lambda x: x
+    }
+    _ARITHMETIC_FUNC = {
+        'div': operator.floordiv,
+        'divide': operator.truediv,
+        'minus': operator.sub,
+        'modulo': operator.mod,
+        'multiply': operator.mul,
+        'plus': operator.add,
+    }
     MAP_TYPE = dict
 
     def __init__(self, options=None):
@@ -157,6 +169,19 @@ def visit_comparator(self, node, value):
                 return None
             return comparator_func(left, right)
 
+    def visit_arithmetic_unary(self, node, value):
+        operation = self._ARITHMETIC_UNARY_FUNC[node['value']]
+        return operation(
+            self.visit(node['children'][0], value)
+        )
+
+    def visit_arithmetic(self, node, value):
+        operation = self._ARITHMETIC_FUNC[node['value']]
+        return operation(
+            self.visit(node['children'][0], value),
+            self.visit(node['children'][1], value)
+        )
+
     def visit_current(self, node, value):
         return value
 

tests/compliance/arithmetic.json

@@ -0,0 +1,62 @@
+[
+  {
+    "given": {
+      "a": {
+        "b": 1
+      },
+      "c": {
+        "d": 2
+      }
+    },
+    "cases": [
+      {
+        "expression": "`1` + `2`",
+        "result": 3.0
+      },
+      {
+        "expression": "`1` - `2`",
+        "result": -1.0
+      },
+      {
+        "expression": "`2` * `4`",
+        "result": 8.0
+      },
+      {
+        "expression": "`2` × `4`",
+        "result": 8.0
+      },
+      {
+        "expression": "`2` / `3`",
+        "result": 0.6666666666666666
+      },
+      {
+        "expression": "`2` ÷ `3`",
+        "result": 0.6666666666666666
+      },
+      {
+        "expression": "`10` % `3`",
+        "result": 1.0
+      },
+      {
+        "expression": "`10` // `3`",
+        "result": 3.0
+      },
+      {
+        "expression": "-`1` - + `2`",
+        "result": -3.0
+      },
+      {
+        "expression": "{ ab: a.b, cd: c.d } | ab + cd",
+        "result": 3.0
+      },
+      {
+        "expression": "{ ab: a.b, cd: c.d } | ab + cd × cd",
+        "result": 5.0
+      },
+      {
+        "expression": "{ ab: a.b, cd: c.d } | (ab + cd) × cd",
+        "result": 6.0
+      }
+    ]
+  }
+]