support while (#7)

synr/ast.py

@@ -642,6 +642,24 @@ class For(Stmt):
     body: Block
 
 
+@attr.s(auto_attribs=True, frozen=True)
+class While(Stmt):
+    """An while statement.
+
+    Examples
+    --------
+    .. code-block:: python
+
+        while x <= 2:
+            pass
+
+    Here :code:`condition` is :code:`x <= 2`, and :code:`body` will be :code:`pass`.
+    """
+
+    condition: Expr
+    body: Block
+
+
 @attr.s(auto_attribs=True, frozen=True)
 class With(Stmt):
     """A with statement.

synr/compiler.py

@@ -288,6 +288,11 @@ def compile_stmt(self, stmt: py_ast.stmt) -> Stmt:
             body = self.compile_block(stmt.body)
             return For(self.span_from_ast(stmt), lhs_vars, rhs, body)
 
+        elif isinstance(stmt, py_ast.While):
+            condition = self.compile_expr(stmt.test)
+            body = self.compile_block(stmt.body)
+            return While(stmt_span, condition, body)
+
         elif isinstance(stmt, py_ast.With):
             if len(stmt.items) != 1:
                 self.error(

tests/test_synr.py

@@ -92,6 +92,26 @@ def test_for():
     assert fr.body.stmts[0].value.id.name == "x"
 
 
+def func_while():
+    while x < 10:
+        return x
+
+
+def test_while():
+    module = to_ast(func_while)
+    fn = assert_one_fn(module, "func_while", no_params=0)
+
+    while_stmt = fn.body.stmts[0]
+    assert isinstance(while_stmt, synr.ast.While)
+    assert isinstance(while_stmt.body.stmts[0], synr.ast.Return)
+    assert while_stmt.body.stmts[0].value.id.name == "x"
+    cond = while_stmt.condition
+    assert isinstance(cond, synr.ast.Call)
+    assert cond.func_name.name == synr.ast.BuiltinOp.LT
+    assert cond.params[0].id.name == "x"
+    assert cond.params[1].value == 10
+
+
 def func_with():
     with x as y:
         return x
@@ -615,6 +635,7 @@ def foo():
     test_id_function()
     test_class()
     test_for()
+    test_while()
     test_with()
     test_block()
     test_assign()