Add Del

compiler/erg_compiler/codegen.rs

@@ -1203,6 +1203,17 @@ impl CodeGenerator {
         }
     }
 
+    fn emit_del_instr(&mut self, mut args: Args) {
+        let ident = enum_unwrap!(args.remove_left_or_key("obj").unwrap(), Expr::Accessor:(Accessor::Ident:(_)));
+        log!(info "entered {} ({ident})", fn_name!());
+        let escaped = escape_name(ident);
+        let name = self
+            .local_search(&escaped, Name)
+            .unwrap_or_else(|| self.register_name(escaped));
+        self.write_instr(DELETE_NAME);
+        self.write_arg(name.idx as u8);
+    }
+
     fn emit_discard_instr(&mut self, mut args: Args) {
         log!(info "entered {}", fn_name!());
         while let Some(arg) = args.try_remove(0) {
@@ -1446,6 +1457,7 @@ impl CodeGenerator {
         log!(info "entered {}", fn_name!());
         match &local.inspect()[..] {
             "assert" => self.emit_assert_instr(args),
+            "Del" => self.emit_del_instr(args),
             "discard" => self.emit_discard_instr(args),
             "for" | "for!" => self.emit_for_instr(args),
             "if" | "if!" => self.emit_if_instr(args),

compiler/erg_compiler/context/initialize/mod.rs

@@ -1586,7 +1586,7 @@ impl Context {
             mono_q("T"),
         );
         let t_cond = quant(t_cond, set! {static_instance("T", Type)});
-        let t_discard = nd_func(vec![param_t("old", Obj)], None, NoneType);
+        let t_discard = nd_func(vec![param_t("obj", Obj)], None, NoneType);
         // FIXME: quantify
         let t_if = func(
             vec![
@@ -1694,6 +1694,9 @@ impl Context {
             None,
         ));
         self.register_builtin_const("Inheritable", ValueObj::Subr(inheritable));
+        // TODO: register Del function object
+        let t_del = nd_func(vec![param_t("obj", Obj)], None, NoneType);
+        self.register_builtin_impl("Del", t_del, Immutable, Private);
     }
 
     fn init_builtin_procs(&mut self) {

compiler/erg_compiler/context/mod.rs

@@ -274,15 +274,17 @@ pub enum RegistrationMode {
     Normal,
 }
 
+/// Some Erg functions require additional operation by the compiler.
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub enum ImportKind {
-    ErgImport,
+pub enum OperationKind {
+    Import,
     PyImport,
+    Del,
 }
 
-impl ImportKind {
+impl OperationKind {
     pub const fn is_erg_import(&self) -> bool {
-        matches!(self, Self::ErgImport)
+        matches!(self, Self::Import)
     }
     pub const fn is_py_import(&self) -> bool {
         matches!(self, Self::PyImport)

compiler/erg_compiler/context/register.rs

@@ -15,7 +15,7 @@ use erg_parser::ast;
 
 use erg_type::constructors::{func, func1, proc, ref_, ref_mut, v_enum};
 use erg_type::value::{GenTypeObj, TypeKind, TypeObj, ValueObj};
-use erg_type::{ParamTy, SubrType, TyBound, Type};
+use erg_type::{ParamTy, SubrType, Type};
 
 use crate::build_hir::HIRBuilder;
 use crate::context::{
@@ -25,6 +25,7 @@ use crate::error::readable_name;
 use crate::error::{
     CompileResult, SingleTyCheckResult, TyCheckError, TyCheckErrors, TyCheckResult,
 };
+use crate::hir;
 use crate::hir::Literal;
 use crate::mod_cache::SharedModuleCache;
 use crate::varinfo::{Mutability, ParamIdx, VarInfo, VarKind};
@@ -33,7 +34,7 @@ use RegistrationMode::*;
 use Visibility::*;
 
 use super::instantiate::TyVarContext;
-use super::ImportKind;
+use super::OperationKind;
 
 impl Context {
     /// If it is a constant that is defined, there must be no variable of the same name defined across all scopes
@@ -856,7 +857,7 @@ impl Context {
 
     pub(crate) fn import_mod(
         &mut self,
-        kind: ImportKind,
+        kind: OperationKind,
         mod_name: &Literal,
     ) -> CompileResult<PathBuf> {
         if kind.is_erg_import() {
@@ -1031,11 +1032,32 @@ impl Context {
         Ok(path)
     }
 
-    pub(crate) fn _push_subtype_bound(&mut self, sub: Type, sup: Type) {
-        self.bounds.push(TyBound::subtype_of(sub, sup));
-    }
-
-    pub(crate) fn _push_instance_bound(&mut self, name: Str, t: Type) {
-        self.bounds.push(TyBound::instance(name, t));
+    pub fn del(&mut self, ident: &hir::Identifier) -> CompileResult<()> {
+        if self.rec_get_const_obj(ident.inspect()).is_some()
+            || self
+                .get_builtins()
+                .unwrap()
+                .get_local_kv(ident.inspect())
+                .is_some()
+        {
+            Err(TyCheckErrors::from(TyCheckError::del_error(
+                self.cfg.input.clone(),
+                line!() as usize,
+                ident,
+                self.caused_by(),
+            )))
+        } else if self.locals.get(ident.inspect()).is_some() {
+            self.locals.remove(ident.inspect());
+            Ok(())
+        } else {
+            Err(TyCheckErrors::from(TyCheckError::no_var_error(
+                self.cfg.input.clone(),
+                line!() as usize,
+                ident.loc(),
+                self.caused_by(),
+                ident.inspect(),
+                self.get_similar_name(ident.inspect()),
+            )))
+        }
     }
 }

compiler/erg_compiler/error.rs

@@ -16,7 +16,7 @@ use erg_parser::error::{ParserRunnerError, ParserRunnerErrors};
 
 use erg_type::{Predicate, Type};
 
-use crate::hir::Expr;
+use crate::hir::{Expr, Identifier};
 
 /// dname is for "double under name"
 pub fn binop_to_dname(op: &str) -> &str {
@@ -1305,6 +1305,26 @@ impl LowerError {
         )
     }
 
+    pub fn del_error(input: Input, errno: usize, ident: &Identifier, caused_by: AtomicStr) -> Self {
+        let name = readable_name(ident.inspect());
+        Self::new(
+            ErrorCore::new(
+                errno,
+                NameError,
+                ident.loc(),
+                switch_lang!(
+                    "japanese" => format!("{YELLOW}{name}{RESET}は削除できません"),
+                    "simplified_chinese" => format!("{YELLOW}{name}{RESET}不能删除"),
+                    "traditional_chinese" => format!("{YELLOW}{name}{RESET}不能刪除"),
+                    "english" => format!("{YELLOW}{name}{RESET} cannot be deleted"),
+                ),
+                None,
+            ),
+            input,
+            caused_by,
+        )
+    }
+
     pub fn visibility_error(
         input: Input,
         errno: usize,

compiler/erg_compiler/hir.rs

@@ -20,7 +20,7 @@ use erg_type::value::{TypeKind, ValueObj};
 use erg_type::{impl_t, impl_t_for_enum, HasType, Type};
 
 use crate::context::eval::type_from_token_kind;
-use crate::context::ImportKind;
+use crate::context::OperationKind;
 use crate::error::readable_name;
 
 #[derive(Debug, Clone)]
@@ -1011,10 +1011,11 @@ impl Call {
         }
     }
 
-    pub fn import_kind(&self) -> Option<ImportKind> {
+    pub fn additional_operation(&self) -> Option<OperationKind> {
         self.obj.show_acc().and_then(|s| match &s[..] {
-            "import" => Some(ImportKind::ErgImport),
-            "pyimport" | "py" => Some(ImportKind::PyImport),
+            "import" => Some(OperationKind::Import),
+            "pyimport" | "py" => Some(OperationKind::PyImport),
+            "Del" => Some(OperationKind::Del),
             _ => None,
         })
     }

compiler/erg_compiler/link.rs

@@ -14,7 +14,7 @@ use erg_type::typaram::TyParam;
 use erg_type::value::ValueObj;
 use erg_type::{HasType, Type};
 
-use crate::context::ImportKind;
+use crate::context::OperationKind;
 use crate::hir::*;
 use crate::mod_cache::SharedModuleCache;
 
@@ -85,14 +85,14 @@ impl<'a> Linker<'a> {
             Expr::UnaryOp(unaryop) => {
                 self.replace_import(&mut unaryop.expr);
             }
-            Expr::Call(call) => match call.import_kind() {
-                Some(ImportKind::ErgImport) => {
+            Expr::Call(call) => match call.additional_operation() {
+                Some(OperationKind::Import) => {
                     self.replace_erg_import(expr);
                 }
-                Some(ImportKind::PyImport) => {
+                Some(OperationKind::PyImport) => {
                     self.replace_py_import(expr);
                 }
-                None => {
+                _ => {
                     for arg in call.args.pos_args.iter_mut() {
                         self.replace_import(&mut arg.expr);
                     }

compiler/erg_compiler/lower.rs

@@ -24,7 +24,7 @@ use erg_type::value::{GenTypeObj, TypeKind, TypeObj, ValueObj};
 use erg_type::{HasType, ParamTy, Type};
 
 use crate::context::instantiate::TyVarContext;
-use crate::context::{ClassDefType, Context, ContextKind, RegistrationMode};
+use crate::context::{ClassDefType, Context, ContextKind, OperationKind, RegistrationMode};
 use crate::error::{
     CompileError, CompileErrors, LowerError, LowerErrors, LowerResult, LowerWarnings,
     SingleLowerResult,
@@ -457,12 +457,31 @@ impl ASTLowerer {
             None
         };
         let call = hir::Call::new(obj, method_name, hir_args, sig_t);
-        if let Some(kind) = call.import_kind() {
-            let mod_name = enum_unwrap!(call.args.get_left_or_key("Path").unwrap(), hir::Expr::Lit);
+        match call.additional_operation() {
+            Some(kind @ (OperationKind::Import | OperationKind::PyImport)) => {
+                let mod_name =
+                    enum_unwrap!(call.args.get_left_or_key("Path").unwrap(), hir::Expr::Lit);
                 if let Err(errs) = self.ctx.import_mod(kind, mod_name) {
                     self.errs.extend(errs.into_iter());
                 };
             }
+            Some(OperationKind::Del) => match call.args.get_left_or_key("obj").unwrap() {
+                hir::Expr::Accessor(hir::Accessor::Ident(ident)) => {
+                    self.ctx.del(ident)?;
+                }
+                other => {
+                    return Err(LowerErrors::from(LowerError::syntax_error(
+                        self.input().clone(),
+                        line!() as usize,
+                        other.loc(),
+                        self.ctx.caused_by(),
+                        "",
+                        None,
+                    )))
+                }
+            },
+            _ => {}
+        }
         Ok(call)
     }
 

doc/JA/syntax/12_dict.md

@@ -5,7 +5,7 @@
 Dictはキーと値のペアを持つコレクションです。
 
 ```python
-ids = {"Alice": 145, "Bob": 214, "Charlie": 301}
+ids = {"Alice" >: 145, "Bob": 214, "Charlie": 301}
 assert ids["Alice"] == 145
 ```