Implement helper methods for AST/HIR construction

compiler/erg_compiler/codegen.rs

@@ -29,8 +29,8 @@ use crate::compile::{AccessKind, Name, StoreLoadKind};
 use crate::context::eval::type_from_token_kind;
 use crate::error::CompileError;
 use crate::hir::{
-    Accessor, Args, Array, AttrDef, Attribute, BinOp, Block, Call, ClassDef, Def, DefBody, Expr,
-    Identifier, Lambda, Literal, Params, PosArg, Record, Signature, SubrSignature, Tuple, UnaryOp,
+    Accessor, Args, Array, AttrDef, BinOp, Block, Call, ClassDef, Def, DefBody, Expr, Identifier,
+    Lambda, Literal, Params, PosArg, Record, Signature, SubrSignature, Tuple, UnaryOp,
     VarSignature, HIR,
 };
 use crate::ty::free::fresh_varname;
@@ -1717,22 +1717,19 @@ impl CodeGenerator {
                 for field in rec.keys() {
                     let obj =
                         Expr::Accessor(Accessor::private_with_line(Str::from(&param_name), line));
-                    let expr = Expr::Accessor(Accessor::Attr(Attribute::new(
-                        obj,
-                        Identifier::bare(
-                            Some(Token::dummy()),
-                            VarName::from_str(field.symbol.clone()),
-                        ),
-                    )));
+                    let expr = obj.attr_expr(Identifier::bare(
+                        Some(Token::dummy()),
+                        VarName::from_str(field.symbol.clone()),
+                    ));
                     let obj = Expr::Accessor(Accessor::private_with_line(Str::ever("self"), line));
                     let dot = if field.vis.is_private() {
                         None
                     } else {
                         Some(Token::dummy())
                     };
-                    let attr = Accessor::Attr(Attribute::new(
-                        obj,
-                        Identifier::bare(dot, VarName::from_str(field.symbol.clone())),
+                    let attr = obj.attr(Identifier::bare(
+                        dot,
+                        VarName::from_str(field.symbol.clone()),
                     ));
                     let attr_def = AttrDef::new(attr, Block::new(vec![expr]));
                     attrs.push(Expr::AttrDef(attr_def));
@@ -1769,12 +1766,8 @@ impl CodeGenerator {
         let mut new_ident =
             Identifier::bare(None, VarName::from_str_and_line(Str::ever("__new__"), line));
         new_ident.vi.py_name = Some(Str::ever("__call__"));
-        let class_new = Expr::Accessor(Accessor::attr(class, new_ident));
-        let call = Expr::Call(Call::new(
-            class_new,
-            None,
-            Args::new(vec![arg], None, vec![], None),
-        ));
+        let class_new = class.attr_expr(new_ident);
+        let call = class_new.call_expr(Args::new(vec![arg], None, vec![], None));
         let block = Block::new(vec![call]);
         let body = DefBody::new(Token::dummy(), block, DefId(0));
         self.emit_subr_def(Some(class_ident.inspect()), sig, body);

compiler/erg_compiler/desugar_hir.rs

@@ -39,7 +39,7 @@ impl HIRDesugarer {
                         .into_iter()
                         .map(|expr| match expr {
                             Expr::Def(def) => {
-                                let acc = Accessor::attr(class.clone(), def.sig.into_ident());
+                                let acc = class.clone().attr(def.sig.into_ident());
                                 let attr_def = AttrDef::new(acc, def.body.block);
                                 Expr::AttrDef(attr_def)
                             }

compiler/erg_compiler/hir.rs

@@ -1836,6 +1836,33 @@ impl Expr {
     pub fn is_type_asc(&self) -> bool {
         matches!(self, Expr::TypeAsc(_))
     }
+
+    pub fn call(self, args: Args) -> Call {
+        match self {
+            Self::Accessor(Accessor::Attr(attr)) => Call::new(*attr.obj, Some(attr.ident), args),
+            other => Call::new(other, None, args),
+        }
+    }
+
+    pub fn call_expr(self, args: Args) -> Self {
+        Self::Call(self.call(args))
+    }
+
+    pub fn attr(self, ident: Identifier) -> Accessor {
+        Accessor::attr(self, ident)
+    }
+
+    pub fn attr_expr(self, ident: Identifier) -> Self {
+        Self::Accessor(self.attr(ident))
+    }
+
+    pub fn type_asc(self, t_spec: TypeSpec) -> TypeAscription {
+        TypeAscription::new(self, t_spec)
+    }
+
+    pub fn type_asc_expr(self, t_spec: TypeSpec) -> Self {
+        Self::TypeAsc(self.type_asc(t_spec))
+    }
 }
 
 /// Toplevel grammar unit

compiler/erg_compiler/link.rs

@@ -185,7 +185,7 @@ impl<'a> Linker<'a> {
             let module_type =
                 Expr::Accessor(Accessor::private_with_line(Str::ever("#ModuleType"), line));
             let args = Args::new(vec![PosArg::new(mod_name.clone())], None, vec![], None);
-            let block = Block::new(vec![Expr::Call(Call::new(module_type, None, args))]);
+            let block = Block::new(vec![module_type.call_expr(args)]);
             let tmp =
                 Identifier::private_with_line(Str::from(fresh_varname()), expr.ln_begin().unwrap());
             let mod_def = Expr::Def(Def::new(
@@ -194,9 +194,9 @@ impl<'a> Linker<'a> {
             ));
             let module = Expr::Accessor(Accessor::Ident(tmp));
             let __dict__ = Identifier::public("__dict__");
-            let m_dict = Expr::Accessor(Accessor::attr(module.clone(), __dict__));
+            let m_dict = module.clone().attr_expr(__dict__);
             let locals = Expr::Accessor(Accessor::public_with_line(Str::ever("locals"), line));
-            let locals_call = Expr::Call(Call::new(locals, None, Args::empty()));
+            let locals_call = locals.call_expr(Args::empty());
             let args = Args::new(vec![PosArg::new(locals_call)], None, vec![], None);
             let mod_update = Expr::Call(Call::new(
                 m_dict.clone(),
@@ -210,7 +210,7 @@ impl<'a> Linker<'a> {
                 vec![],
                 None,
             );
-            let exec_code = Expr::Call(Call::new(exec, None, args));
+            let exec_code = exec.call_expr(args);
             let compound = Block::new(vec![mod_def, mod_update, exec_code, module]);
             *expr = Expr::Compound(compound);
         }
@@ -256,15 +256,13 @@ impl<'a> Linker<'a> {
         args.insert_pos(0, PosArg::new(mod_name));
         let line = expr.ln_begin().unwrap_or(0);
         for attr in comps {
-            *expr = Expr::Accessor(Accessor::attr(
-                // instead of mem::take(),
-                mem::replace(expr, Expr::Code(Block::empty())),
+            *expr = mem::replace(expr, Expr::Code(Block::empty())).attr_expr(
                 Identifier::public_with_line(
                     Token::dummy(),
                     Str::rc(attr.as_os_str().to_str().unwrap()),
                     line,
                 ),
-            ));
+            );
         }
     }
 }

compiler/erg_compiler/lower.rs

@@ -1418,7 +1418,7 @@ impl ASTLowerer {
             expr.loc(),
             Some(&Str::from(expr.to_string())),
         )?;
-        Ok(hir::TypeAscription::new(expr, tasc.t_spec))
+        Ok(expr.type_asc(tasc.t_spec))
     }
 
     // Call.obj == Accessor cannot be type inferred by itself (it can only be inferred with arguments)
@@ -1527,8 +1527,7 @@ impl ASTLowerer {
             ast::Expr::Accessor(ast::Accessor::Attr(attr)) => {
                 let obj = self.fake_lower_obj(*attr.obj)?;
                 let ident = hir::Identifier::bare(attr.ident.dot, attr.ident.name);
-                let acc = hir::Accessor::attr(obj, ident);
-                Ok(hir::Expr::Accessor(acc))
+                Ok(obj.attr_expr(ident))
             }
             other => Err(LowerErrors::from(LowerError::declare_error(
                 self.cfg.input.clone(),
@@ -1596,10 +1595,7 @@ impl ASTLowerer {
                 let py_name = Str::rc(ident.inspect().trim_end_matches('!'));
                 let vi = VarInfo::new(t, muty, vis, VarKind::Declared, None, None, Some(py_name));
                 let ident = hir::Identifier::new(ident.dot, ident.name, None, vi);
-                Ok(hir::TypeAscription::new(
-                    hir::Expr::Accessor(hir::Accessor::Ident(ident)),
-                    tasc.t_spec,
-                ))
+                Ok(hir::Expr::Accessor(hir::Accessor::Ident(ident)).type_asc(tasc.t_spec))
             }
             ast::Expr::Accessor(ast::Accessor::Attr(attr)) => {
                 let py_name = Str::rc(attr.ident.inspect().trim_end_matches('!'));
@@ -1625,11 +1621,8 @@ impl ASTLowerer {
                 let py_name = Str::rc(attr.ident.inspect().trim_end_matches('!'));
                 let vi = VarInfo::new(t, muty, vis, VarKind::Declared, None, None, Some(py_name));
                 let ident = hir::Identifier::new(attr.ident.dot, attr.ident.name, None, vi);
-                let attr = hir::Accessor::attr(obj, ident);
-                Ok(hir::TypeAscription::new(
-                    hir::Expr::Accessor(attr),
-                    tasc.t_spec,
-                ))
+                let attr = obj.attr_expr(ident);
+                Ok(attr.type_asc(tasc.t_spec))
             }
             other => Err(LowerErrors::from(LowerError::declare_error(
                 self.cfg.input.clone(),

compiler/erg_parser/ast.rs

@@ -3222,6 +3222,49 @@ impl Expr {
     pub fn static_local(name: &'static str) -> Self {
         Self::Accessor(Accessor::local(Token::static_symbol(name)))
     }
+
+    pub fn attr(self, ident: Identifier) -> Accessor {
+        Accessor::attr(self, ident)
+    }
+
+    pub fn attr_expr(self, ident: Identifier) -> Self {
+        Self::Accessor(self.attr(ident))
+    }
+
+    pub fn subscr(self, index: Expr, r_sqbr: Token) -> Accessor {
+        Accessor::subscr(self, index, r_sqbr)
+    }
+
+    pub fn subscr_expr(self, index: Expr, r_sqbr: Token) -> Self {
+        Self::Accessor(self.subscr(index, r_sqbr))
+    }
+
+    pub fn tuple_attr(self, index: Literal) -> Accessor {
+        Accessor::tuple_attr(self, index)
+    }
+
+    pub fn tuple_attr_expr(self, index: Literal) -> Self {
+        Self::Accessor(self.tuple_attr(index))
+    }
+
+    pub fn call(self, args: Args) -> Call {
+        match self {
+            Self::Accessor(Accessor::Attr(attr)) => Call::new(*attr.obj, Some(attr.ident), args),
+            other => Call::new(other, None, args),
+        }
+    }
+
+    pub fn call_expr(self, args: Args) -> Self {
+        Self::Call(self.call(args))
+    }
+
+    pub fn type_asc(self, op: Token, t_spec: TypeSpec) -> TypeAscription {
+        TypeAscription::new(self, op, t_spec)
+    }
+
+    pub fn type_asc_expr(self, op: Token, t_spec: TypeSpec) -> Self {
+        Self::TypeAsc(self.type_asc(op, t_spec))
+    }
 }
 
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]

compiler/erg_parser/desugar.rs

@@ -15,8 +15,8 @@ use crate::ast::{
     DefBody, DefId, Dict, Expr, Identifier, KeyValue, KwArg, Lambda, LambdaSignature, Literal,
     Methods, Module, NonDefaultParamSignature, NormalArray, NormalDict, NormalRecord, NormalSet,
     NormalTuple, ParamPattern, Params, PosArg, Record, RecordAttrs, Set as astSet, SetWithLength,
-    ShortenedRecord, Signature, SubrSignature, Tuple, TypeAscription, TypeBoundSpecs, TypeSpec,
-    UnaryOp, VarName, VarPattern, VarRecordAttr, VarSignature,
+    ShortenedRecord, Signature, SubrSignature, Tuple, TypeBoundSpecs, TypeSpec, UnaryOp, VarName,
+    VarPattern, VarRecordAttr, VarSignature,
 };
 use crate::token::{Token, TokenKind};
 
@@ -201,7 +201,7 @@ impl Desugarer {
             }
             Expr::TypeAsc(tasc) => {
                 let expr = desugar(*tasc.expr);
-                Expr::TypeAsc(TypeAscription::new(expr, tasc.op, tasc.t_spec))
+                expr.type_asc_expr(tasc.op, tasc.t_spec)
             }
             Expr::Methods(method_defs) => {
                 let mut new_defs = vec![];
@@ -323,7 +323,7 @@ impl Desugarer {
             vec![],
             None,
         );
-        let call = Call::new(match_symbol, None, args);
+        let call = match_symbol.call(args);
         (call, return_t_spec)
     }
 
@@ -439,9 +439,7 @@ impl Desugarer {
     ) {
         let obj = Expr::local(buf_name, sig.ln_begin().unwrap(), sig.col_begin().unwrap());
         let acc = match buf_index {
-            BufIndex::Tuple(n) => {
-                Accessor::tuple_attr(obj, Literal::nat(n, sig.ln_begin().unwrap()))
-            }
+            BufIndex::Tuple(n) => obj.tuple_attr(Literal::nat(n, sig.ln_begin().unwrap())),
             BufIndex::Array(n) => {
                 let r_brace = Token::new(
                     TokenKind::RBrace,
@@ -449,13 +447,9 @@ impl Desugarer {
                     sig.ln_begin().unwrap(),
                     sig.col_begin().unwrap(),
                 );
-                Accessor::subscr(
-                    obj,
-                    Expr::Lit(Literal::nat(n, sig.ln_begin().unwrap())),
-                    r_brace,
-                )
+                obj.subscr(Expr::Lit(Literal::nat(n, sig.ln_begin().unwrap())), r_brace)
             }
-            BufIndex::Record(attr) => Accessor::attr(obj, attr.clone()),
+            BufIndex::Record(attr) => obj.attr(attr.clone()),
         };
         let id = DefId(get_hash(&(&acc, buf_name)));
         let block = Block::new(vec![Expr::Accessor(acc)]);

compiler/erg_parser/parse.rs

@@ -885,7 +885,7 @@ impl Parser {
                 Some(arg) if arg.is(Symbol) || arg.category_is(TC::Literal) => {
                     let args = self.try_reduce_args(false).map_err(|_| self.stack_dec())?;
                     let obj = enum_unwrap!(stack.pop(), Some:(ExprOrOp::Expr:(_)));
-                    stack.push(ExprOrOp::Expr(Expr::Call(Call::new(obj, None, args))));
+                    stack.push(ExprOrOp::Expr(obj.call_expr(args)));
                 }
                 Some(op) if op.category_is(TC::DefOp) => {
                     let op = self.lpop();
@@ -934,7 +934,7 @@ impl Parser {
                         .try_reduce_expr(false, false, false, false)
                         .map_err(|_| self.stack_dec())?;
                     let t_spec = Self::expr_to_type_spec(t_spec).map_err(|e| self.errs.push(e))?;
-                    let expr = Expr::TypeAsc(TypeAscription::new(lhs, op, t_spec));
+                    let expr = lhs.type_asc_expr(op, t_spec);
                     stack.push(ExprOrOp::Expr(expr));
                 }
                 Some(op) if op.category_is(TC::BinOp) => {
@@ -985,8 +985,7 @@ impl Parser {
                                 stack.push(ExprOrOp::Expr(Expr::Call(call)));
                             } else {
                                 let ident = Identifier::new(None, VarName::new(symbol));
-                                let acc = Accessor::attr(obj, ident);
-                                stack.push(ExprOrOp::Expr(Expr::Accessor(acc)));
+                                stack.push(ExprOrOp::Expr(obj.attr_expr(ident)));
                             }
                         }
                         line_break if line_break.is(Newline) => {
@@ -1049,13 +1048,12 @@ impl Parser {
                                 let mut call = Expr::Call(Call::new(obj, Some(ident), args));
                                 while let Some(res) = self.opt_reduce_args(false) {
                                     let args = res.map_err(|_| self.stack_dec())?;
-                                    call = Expr::Call(Call::new(call, None, args));
+                                    call = call.call_expr(args);
                                 }
                                 stack.push(ExprOrOp::Expr(call));
                             } else {
                                 let ident = Identifier::new(Some(vis), VarName::new(symbol));
-                                let acc = Accessor::attr(obj, ident);
-                                stack.push(ExprOrOp::Expr(Expr::Accessor(acc)));
+                                stack.push(ExprOrOp::Expr(obj.attr_expr(ident)));
                             }
                         }
                         line_break if line_break.is(Newline) => {
@@ -1201,7 +1199,7 @@ impl Parser {
                         .try_reduce_expr(false, in_type_args, in_brace, false)
                         .map_err(|_| self.stack_dec())?;
                     let t_spec = Self::expr_to_type_spec(t_spec).map_err(|e| self.errs.push(e))?;
-                    let expr = Expr::TypeAsc(TypeAscription::new(lhs, op, t_spec));
+                    let expr = lhs.type_asc_expr(op, t_spec);
                     stack.push(ExprOrOp::Expr(expr));
                 }
                 Some(op) if op.category_is(TC::BinOp) => {
@@ -1252,8 +1250,7 @@ impl Parser {
                                 stack.push(ExprOrOp::Expr(Expr::Call(call)));
                             } else {
                                 let ident = Identifier::new(Some(vis), VarName::new(symbol));
-                                let acc = Accessor::attr(obj, ident);
-                                stack.push(ExprOrOp::Expr(Expr::Accessor(acc)));
+                                stack.push(ExprOrOp::Expr(obj.attr_expr(ident)));
                             }
                         }
                         other => {
@@ -1353,10 +1350,10 @@ impl Parser {
                     Signature::Var(var) => {
                         let mut last = def.body.block.pop().unwrap();
                         for deco in decos.into_iter() {
-                            last = Expr::Call(Call::new(
-                                deco.into_expr(),
+                            last = deco.into_expr().call_expr(Args::new(
+                                vec![PosArg::new(last)],
+                                vec![],
                                 None,
-                                Args::new(vec![PosArg::new(last)], vec![], None),
                             ));
                         }
                         def.body.block.push(last);
@@ -1501,11 +1498,11 @@ impl Parser {
                     match token.kind {
                         Symbol => {
                             let ident = Identifier::new(Some(vis), VarName::new(token));
-                            obj = Expr::Accessor(Accessor::attr(obj, ident));
+                            obj = obj.attr_expr(ident);
                         }
                         NatLit => {
                             let index = Literal::from(token);
-                            obj = Expr::Accessor(Accessor::tuple_attr(obj, index));
+                            obj = obj.tuple_attr_expr(index);
                         }
                         Newline => {
                             self.restore(token);
@@ -1527,8 +1524,7 @@ impl Parser {
                     token.content = Str::rc(&token.content[1..]);
                     token.kind = NatLit;
                     token.col_begin += 1;
-                    let index = Literal::from(token);
-                    obj = Expr::Accessor(Accessor::tuple_attr(obj, index));
+                    obj = obj.tuple_attr_expr(Literal::from(token));
                 }
                 Some(t) if t.is(DblColon) && obj.col_end() == t.col_begin() => {
                     let vis = self.lpop();
@@ -1536,7 +1532,7 @@ impl Parser {
                     match token.kind {
                         Symbol => {
                             let ident = Identifier::new(None, VarName::new(token));
-                            obj = Expr::Accessor(Accessor::attr(obj, ident));
+                            obj = obj.attr_expr(ident);
                         }
                         LBrace => {
                             self.restore(token);