Move max function test cases to snippet dir. Implement key and default argument on max function.

parser/src/lexer.rs

@@ -197,6 +197,9 @@ where
                 // Skip backslash and newline
                 self.shift();
                 self.shift();
+            // Idea: insert trailing newline here:
+            // } else if self.chr0 != Some('\n') && self.chr1.is_none() {
+            //     self.chr1 = Some('\n');
             } else {
                 break;
             }

tests/snippets/builtins.py

@@ -17,3 +17,7 @@ assert list(zip(['a', 'b', 'c'], range(3), [9, 8, 7, 99])) == [('a', 0, 9), ('b'
 
 assert list(filter(lambda x: ((x % 2) == 0), [0, 1, 2])) == [0, 2]
 
+assert 3 == eval('1+2')
+
+code = compile('5+3', 'x.py', 'eval')
+assert eval(code) == 8

vm/src/builtins.rs

@@ -132,6 +132,8 @@ fn builtin_compile(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
         ]
     );
     let source = objstr::get_value(source);
+    // TODO: fix this newline bug:
+    let source = format!("{}\n", source);
 
     let mode = {
         let mode = objstr::get_value(mode);
@@ -206,19 +208,36 @@ fn builtin_eval(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     arg_check!(
         vm,
         args,
-        required = [
-            (source, None), // TODO: Use more specific type
+        required = [(source, None)],
+        optional = [
             (_globals, Some(vm.ctx.dict_type())),
             (locals, Some(vm.ctx.dict_type()))
         ]
     );
-    // TODO: handle optional global and locals
 
-    let code_obj = source; // if source.borrow().kind
+    // Determine code object:
+    let code_obj = if objtype::isinstance(source, &vm.ctx.code_type()) {
+        source.clone()
+    } else if objtype::isinstance(source, &vm.ctx.str_type()) {
+        let mode = compile::Mode::Eval;
+        let source = objstr::get_value(source);
+        // TODO: fix this newline bug:
+        let source = format!("{}\n", source);
+        compile::compile(vm, &source, mode, None)?
+    } else {
+        return Err(vm.new_type_error("code argument must be str or code object".to_string()));
+    };
 
+    let locals = if let Some(locals) = locals {
+        locals.clone()
+    } else {
+        vm.new_dict()
+    };
+
+    // TODO: handle optional globals
     // Construct new scope:
     let scope_inner = Scope {
-        locals: locals.clone(),
+        locals: locals,
         parent: None,
     };
     let scope = PyObject {
@@ -235,26 +254,38 @@ fn builtin_exec(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     arg_check!(
         vm,
         args,
-        required = [
-            (source, None),
+        required = [(source, None)],
+        optional = [
             (_globals, Some(vm.ctx.dict_type())),
             (locals, Some(vm.ctx.dict_type()))
         ]
     );
-    // TODO: handle optional global and locals
 
     // Determine code object:
     let code_obj = if objtype::isinstance(source, &vm.ctx.str_type()) {
         let mode = compile::Mode::Exec;
         let source = objstr::get_value(source);
+        // TODO: fix this newline bug:
+        let source = format!("{}\n", source);
         compile::compile(vm, &source, mode, None)?
-    } else {
+    } else if objtype::isinstance(source, &vm.ctx.code_type()) {
         source.clone()
+    } else {
+        return Err(vm.new_type_error("source argument must be str or code object".to_string()));
     };
 
+    // handle optional global and locals
+    let locals = if let Some(locals) = locals {
+        locals.clone()
+    } else {
+        vm.new_dict()
+    };
+
+    // TODO: use globals
+
     // Construct new scope:
     let scope_inner = Scope {
-        locals: locals.clone(),
+        locals: locals,
         parent: None,
     };
     let scope = PyObject {
@@ -416,15 +447,56 @@ fn builtin_map(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
 }
 
 fn builtin_max(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
-    arg_check!(vm, args, required = [(x, None), (y, None)]);
+    // arg_check!(vm, args, required = [(x, None), (y, None)]);
 
-    let order = vm.call_method(x, "__gt__", vec![y.clone()])?;
-
-    if objbool::get_value(&order) {
-        Ok(x.clone())
+    let candidates = if args.args.len() > 1 {
+        args.args.clone()
+    } else if args.args.len() == 1 {
+        vm.extract_elements(&args.args[0])?
     } else {
-        Ok(y.clone())
+        // zero arguments means type error:
+        return Err(vm.new_type_error("Expected 1 or more arguments".to_string()));
+    };
+
+    if candidates.len() == 0 {
+        let default = args.get_optional_kwarg("default");
+        if default.is_none() {
+            return Err(vm.new_value_error("max() arg is an empty sequence".to_string()));
+        } else {
+            return Ok(default.unwrap());
+        }
     }
+
+    let key_func = args.get_optional_kwarg("key");
+
+    // Start with first assumption:
+    let mut candidates_iter = candidates.into_iter();
+    let mut x = candidates_iter.next().unwrap();
+    // TODO: this key function looks pretty duplicate. Maybe we can create
+    // a local function?
+    let mut x_key = if let Some(f) = &key_func {
+        let args = PyFuncArgs::new(vec![x.clone()], vec![]);
+        vm.invoke(f.clone(), args)?
+    } else {
+        x.clone()
+    };
+
+    for y in candidates_iter {
+        let y_key = if let Some(f) = &key_func {
+            let args = PyFuncArgs::new(vec![y.clone()], vec![]);
+            vm.invoke(f.clone(), args)?
+        } else {
+            y.clone()
+        };
+        let order = vm.call_method(&x_key, "__gt__", vec![y_key.clone()])?;
+
+        if !objbool::get_value(&order) {
+            x = y.clone();
+            x_key = y_key;
+        }
+    }
+
+    Ok(x)
 }
 
 // builtin_memoryview

vm/src/obj/objcode.rs

@@ -11,6 +11,7 @@ use super::objtype;
 
 pub fn init(context: &PyContext) {
     let ref code_type = context.code_type;
+    code_type.set_attr("__new__", context.new_rustfunc(code_new));
     code_type.set_attr("__repr__", context.new_rustfunc(code_repr));
 }
 
@@ -24,6 +25,11 @@ pub fn copy_code(code_obj: &PyObjectRef) -> bytecode::CodeObject {
     }
 }
 
+fn code_new(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
+    arg_check!(vm, args, required = [(_cls, None)]);
+    Err(vm.new_type_error(format!("Cannot directly create code object")))
+}
+
 fn code_repr(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     arg_check!(vm, args, required = [(o, Some(vm.ctx.code_type()))]);
 

vm/src/obj/objdict.rs

@@ -109,6 +109,27 @@ fn dict_delitem(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     }
 }
 
+/// When iterating over a dictionary, we iterate over the keys of it.
+fn dict_iter(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
+    arg_check!(vm, args, required = [(dict, Some(vm.ctx.dict_type()))]);
+
+    let keys = get_elements(dict)
+        .keys()
+        .map(|k| vm.ctx.new_str(k.to_string()))
+        .collect();
+    let key_list = vm.ctx.new_list(keys);
+
+    let iter_obj = PyObject::new(
+        PyObjectKind::Iterator {
+            position: 0,
+            iterated_obj: key_list,
+        },
+        vm.ctx.iter_type(),
+    );
+
+    Ok(iter_obj)
+}
+
 fn dict_setitem(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     arg_check!(
         vm,
@@ -165,6 +186,7 @@ pub fn init(context: &PyContext) {
     dict_type.set_attr("__contains__", context.new_rustfunc(dict_contains));
     dict_type.set_attr("__delitem__", context.new_rustfunc(dict_delitem));
     dict_type.set_attr("__getitem__", context.new_rustfunc(dict_getitem));
+    dict_type.set_attr("__iter__", context.new_rustfunc(dict_iter));
     dict_type.set_attr("__new__", context.new_rustfunc(dict_new));
     dict_type.set_attr("__repr__", context.new_rustfunc(dict_repr));
     dict_type.set_attr("__setitem__", context.new_rustfunc(dict_setitem));

vm/src/obj/objframe.rs

@@ -10,9 +10,15 @@ use super::objtype;
 
 pub fn init(context: &PyContext) {
     let ref frame_type = context.frame_type;
+    frame_type.set_attr("__new__", context.new_rustfunc(frame_new));
     frame_type.set_attr("__repr__", context.new_rustfunc(frame_repr));
 }
 
+fn frame_new(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
+    arg_check!(vm, args, required = [(_cls, None)]);
+    Err(vm.new_type_error(format!("Cannot directly create frame object")))
+}
+
 fn frame_repr(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     arg_check!(vm, args, required = [(_frame, Some(vm.ctx.frame_type()))]);
     let repr = format!("<frame object at .. >");

vm/src/obj/objiter.rs

@@ -3,8 +3,7 @@
  */
 
 use super::super::pyobject::{
-    AttributeProtocol, PyContext, PyFuncArgs, PyObject, PyObjectKind, PyObjectRef, PyResult,
-    TypeProtocol,
+    AttributeProtocol, PyContext, PyFuncArgs, PyObjectKind, PyObjectRef, PyResult, TypeProtocol,
 };
 use super::super::vm::VirtualMachine;
 use super::objbool;
@@ -17,30 +16,10 @@ use super::objtype; // Required for arg_check! to use isinstance
  * function 'iter' is called.
  */
 pub fn get_iter(vm: &mut VirtualMachine, iter_target: &PyObjectRef) -> PyResult {
-    // Check what we are going to iterate over:
-    let iterated_obj = if objtype::isinstance(iter_target, &vm.ctx.iter_type()) {
-        // If object is already an iterator, return that one.
-        return Ok(iter_target.clone());
-    } else if objtype::isinstance(iter_target, &vm.ctx.list_type()) {
-        iter_target.clone()
-    // } else if hasattr(iter_target, "__iter__") {
-    } else {
-        return vm.call_method(iter_target, "__iter__", vec![]);
-        // let type_str = objstr::get_value(&vm.to_str(iter_target.typ()).unwrap());
-        // let type_error = vm.new_type_error(format!("Cannot iterate over {}", type_str));
-        // return Err(type_error);
-    };
-
-    let iter_obj = PyObject::new(
-        PyObjectKind::Iterator {
-            position: 0,
-            iterated_obj: iterated_obj,
-        },
-        vm.ctx.iter_type(),
-    );
-
-    // We are all good here:
-    Ok(iter_obj)
+    vm.call_method(iter_target, "__iter__", vec![])
+    // let type_str = objstr::get_value(&vm.to_str(iter_target.typ()).unwrap());
+    // let type_error = vm.new_type_error(format!("Cannot iterate over {}", type_str));
+    // return Err(type_error);
 }
 
 /*

vm/src/obj/objlist.rs

@@ -183,6 +183,21 @@ fn list_getitem(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     get_item(vm, list, &get_elements(list), needle.clone())
 }
 
+fn list_iter(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
+    arg_check!(vm, args, required = [(list, Some(vm.ctx.list_type()))]);
+
+    let iter_obj = PyObject::new(
+        PyObjectKind::Iterator {
+            position: 0,
+            iterated_obj: list.clone(),
+        },
+        vm.ctx.iter_type(),
+    );
+
+    // We are all good here:
+    Ok(iter_obj)
+}
+
 fn list_setitem(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     arg_check!(
         vm,
@@ -199,6 +214,7 @@ pub fn init(context: &PyContext) {
     list_type.set_attr("__contains__", context.new_rustfunc(list_contains));
     list_type.set_attr("__eq__", context.new_rustfunc(list_eq));
     list_type.set_attr("__getitem__", context.new_rustfunc(list_getitem));
+    list_type.set_attr("__iter__", context.new_rustfunc(list_iter));
     list_type.set_attr("__setitem__", context.new_rustfunc(list_setitem));
     list_type.set_attr("__len__", context.new_rustfunc(list_len));
     list_type.set_attr("__new__", context.new_rustfunc(list_new));

vm/src/obj/objstr.rs

@@ -14,6 +14,7 @@ pub fn init(context: &PyContext) {
     str_type.set_attr("__eq__", context.new_rustfunc(str_eq));
     str_type.set_attr("__contains__", context.new_rustfunc(str_contains));
     str_type.set_attr("__getitem__", context.new_rustfunc(str_getitem));
+    str_type.set_attr("__gt__", context.new_rustfunc(str_gt));
     str_type.set_attr("__len__", context.new_rustfunc(str_len));
     str_type.set_attr("__mul__", context.new_rustfunc(str_mul));
     str_type.set_attr("__new__", context.new_rustfunc(str_new));
@@ -53,6 +54,21 @@ fn str_eq(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     Ok(vm.ctx.new_bool(result))
 }
 
+fn str_gt(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
+    arg_check!(
+        vm,
+        args,
+        required = [
+            (zelf, Some(vm.ctx.str_type())),
+            (other, Some(vm.ctx.str_type()))
+        ]
+    );
+    let zelf = get_value(zelf);
+    let other = get_value(other);
+    let result = zelf > other;
+    Ok(vm.ctx.new_bool(result))
+}
+
 fn str_str(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     arg_check!(vm, args, required = [(s, Some(vm.ctx.str_type()))]);
     Ok(s.clone())

vm/src/obj/objtuple.rs

@@ -48,6 +48,20 @@ fn tuple_hash(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     Ok(vm.ctx.new_int(x.to_bigint().unwrap()))
 }
 
+fn tuple_iter(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
+    arg_check!(vm, args, required = [(tuple, Some(vm.ctx.tuple_type()))]);
+
+    let iter_obj = PyObject::new(
+        PyObjectKind::Iterator {
+            position: 0,
+            iterated_obj: tuple.clone(),
+        },
+        vm.ctx.iter_type(),
+    );
+
+    Ok(iter_obj)
+}
+
 fn tuple_len(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     arg_check!(vm, args, required = [(zelf, Some(vm.ctx.tuple_type()))]);
     let elements = get_elements(zelf);
@@ -132,6 +146,7 @@ pub fn init(context: &PyContext) {
     tuple_type.set_attr("__contains__", context.new_rustfunc(tuple_contains));
     tuple_type.set_attr("__getitem__", context.new_rustfunc(tuple_getitem));
     tuple_type.set_attr("__hash__", context.new_rustfunc(tuple_hash));
+    tuple_type.set_attr("__iter__", context.new_rustfunc(tuple_iter));
     tuple_type.set_attr("__len__", context.new_rustfunc(tuple_len));
     tuple_type.set_attr("__new__", context.new_rustfunc(tuple_new));
     tuple_type.set_attr("__repr__", context.new_rustfunc(tuple_repr));

vm/src/pyobject.rs

@@ -728,6 +728,15 @@ impl PyFuncArgs {
         }
         default.clone()
     }
+
+    pub fn get_optional_kwarg(&self, key: &str) -> Option<PyObjectRef> {
+        for (arg_name, arg_value) in self.kwargs.iter() {
+            if arg_name == key {
+                return Some(arg_value.clone());
+            }
+        }
+        None
+    }
 }
 
 type RustPyFunc = fn(vm: &mut VirtualMachine, PyFuncArgs) -> PyResult;

vm/src/vm.rs

@@ -35,6 +35,7 @@ pub struct VirtualMachine {
     pub sys_module: PyObjectRef,
     pub stdlib_inits: HashMap<String, stdlib::StdlibInitFunc>,
     pub ctx: PyContext,
+    pub current_frame: Option<PyObjectRef>,
 }
 
 impl VirtualMachine {
@@ -51,6 +52,7 @@ impl VirtualMachine {
             sys_module: sysmod,
             stdlib_inits,
             ctx: ctx,
+            current_frame: None,
         }
     }