Add support for multi operator expressions (pyccel#2083)

Add support for multi operator expressions by extending the syntactic
stage. Fixes pyccel#2081

Author: EmilyBourne

pyccel/parser/syntactic.py

@@ -692,37 +692,38 @@ def _visit_BoolOp(self, stmt):
                       severity='error')
 
     def _visit_Compare(self, stmt):
-        if len(stmt.ops)>1:
-            return errors.report(PYCCEL_RESTRICTION_MULTIPLE_COMPARISONS,
-                      symbol = stmt,
-                      severity='error')
-
         first = self._visit(stmt.left)
-        second = self._visit(stmt.comparators[0])
-        op = stmt.ops[0]
-
-        if isinstance(op, ast.Eq):
-            return PyccelEq(first, second)
-        if isinstance(op, ast.NotEq):
-            return PyccelNe(first, second)
-        if isinstance(op, ast.Lt):
-            return PyccelLt(first, second)
-        if isinstance(op, ast.Gt):
-            return PyccelGt(first, second)
-        if isinstance(op, ast.LtE):
-            return PyccelLe(first, second)
-        if isinstance(op, ast.GtE):
-            return PyccelGe(first, second)
-        if isinstance(op, ast.Is):
-            return PyccelIs(first, second)
-        if isinstance(op, ast.IsNot):
-            return PyccelIsNot(first, second)
-        if isinstance(op, ast.In):
-            return PyccelIn(first, second)
+        comparison = None
+        for comparators, op in zip(stmt.comparators, stmt.ops):
+            second = self._visit(comparators)
+
+            if isinstance(op, ast.Eq):
+                expr = PyccelEq(first, second)
+            elif isinstance(op, ast.NotEq):
+                expr = PyccelNe(first, second)
+            elif isinstance(op, ast.Lt):
+                expr = PyccelLt(first, second)
+            elif isinstance(op, ast.Gt):
+                expr = PyccelGt(first, second)
+            elif isinstance(op, ast.LtE):
+                expr = PyccelLe(first, second)
+            elif isinstance(op, ast.GtE):
+                expr = PyccelGe(first, second)
+            elif isinstance(op, ast.Is):
+                expr = PyccelIs(first, second)
+            elif isinstance(op, ast.IsNot):
+                expr = PyccelIsNot(first, second)
+            elif isinstance(op, ast.In):
+                expr = PyccelIn(first, second)
+            else:
+                return errors.report(PYCCEL_RESTRICTION_UNSUPPORTED_SYNTAX,
+                              symbol = stmt,
+                              severity='error')
 
-        return errors.report(PYCCEL_RESTRICTION_UNSUPPORTED_SYNTAX,
-                      symbol = stmt,
-                      severity='error')
+            first = second
+            comparison = PyccelAnd(comparison, expr) if comparison else expr
+
+        return comparison
 
     def _visit_Return(self, stmt):
         results = self._visit(stmt.value)

tests/epyccel/test_compare_expressions.py

@@ -11,6 +11,9 @@ def mod_neq_pow(a : int, m : int, n : int):
 def idiv_gt_add(a : int, m : int, n : int):
     return a//m > n+1
 
+def in_range(a : float, b : float, c : float):
+    return a <= b < c
+
 #==============================================================================
 def test_mod_eq_pow(language):
     test = epyccel_test(mod_eq_pow, lang=language)
@@ -44,3 +47,14 @@ def test_idiv_gt_add(language):
     test.compare_epyccel(10, 3, 2)
     test.compare_epyccel(8, 2, 3)
     test.compare_epyccel(16, 3, 5)
+
+def test_in_range(language):
+    test = epyccel_test(in_range, lang=language)
+    # True
+    test.compare_epyccel(0.0, 1.0, 2.0)
+    test.compare_epyccel(-2.0, -1.0, 2.0)
+    test.compare_epyccel(-2.0, -1.3, -1.0)
+    # False
+    test.compare_epyccel(0.0, 10.0, 2.0)
+    test.compare_epyccel(-2.0, -10.0, 2.0)
+    test.compare_epyccel(-2.0, -0.3, -1.0)