Add Str <-> Int, Nat convertors

compiler/erg_compiler/codegen.rs

@@ -143,6 +143,7 @@ pub struct PyCodeGenerator {
     record_type_loaded: bool,
     module_type_loaded: bool,
     control_loaded: bool,
+    convertors_loaded: bool,
     abc_loaded: bool,
     unit_size: usize,
     units: PyCodeGenStack,
@@ -160,6 +161,7 @@ impl PyCodeGenerator {
             record_type_loaded: false,
             module_type_loaded: false,
             control_loaded: false,
+            convertors_loaded: false,
             abc_loaded: false,
             unit_size: 0,
             units: PyCodeGenStack::empty(),
@@ -436,6 +438,7 @@ impl PyCodeGenerator {
 
     fn emit_load_const<C: Into<ValueObj>>(&mut self, cons: C) {
         let value: ValueObj = cons.into();
+        let is_str = value.is_str();
         let is_int = value.is_int();
         let is_nat = value.is_nat();
         let is_bool = value.is_bool();
@@ -449,8 +452,12 @@ impl PyCodeGenerator {
             } else if is_int {
                 self.emit_push_null();
                 self.emit_load_name_instr(Identifier::public("Int"));
+            } else if is_str {
+                self.emit_push_null();
+                self.emit_load_name_instr(Identifier::public("Str"));
             }
         }
+        let wrapped = is_str || is_int; // is_int => is_nat and is_bool
         let idx = self
             .mut_cur_block_codeobj()
             .consts
@@ -463,8 +470,7 @@ impl PyCodeGenerator {
         self.write_instr(LOAD_CONST);
         self.write_arg(idx);
         self.stack_inc();
-        if !self.cfg.no_std && is_int {
+        if !self.cfg.no_std && wrapped {
-            // is_int => is_nat and is_bool
             self.emit_call_instr(1, Name);
             self.stack_dec();
         }
@@ -632,9 +638,15 @@ impl PyCodeGenerator {
     fn emit_load_name_instr(&mut self, ident: Identifier) {
         log!(info "entered {}({ident})", fn_name!());
         let escaped = escape_name(ident);
-        if let "if__" | "for__" | "while__" | "with__" | "discard__" = &escaped[..] {
+        match &escaped[..] {
+            "if__" | "for__" | "while__" | "with__" | "discard__" => {
                 self.load_control();
             }
+            "int__" | "nat__" => {
+                self.load_convertors();
+            }
+            _ => {}
+        }
         let name = self
             .local_search(&escaped, Name)
             .unwrap_or_else(|| self.register_name(escaped));
@@ -2797,6 +2809,12 @@ impl PyCodeGenerator {
         self.control_loaded = true;
     }
 
+    fn load_convertors(&mut self) {
+        let mod_name = Identifier::public("_erg_convertors");
+        self.emit_import_all_instr(mod_name);
+        self.convertors_loaded = true;
+    }
+
     fn load_prelude_py(&mut self) {
         self.emit_global_import_items(
             Identifier::public("sys"),

compiler/erg_compiler/context/initialize/mod.rs

@@ -941,6 +941,12 @@ impl Context {
             Immutable,
             Public,
         );
+        str_.register_builtin_impl(
+            "to_int",
+            fn_met(Str, vec![], None, vec![], or(Int, NoneType)),
+            Immutable,
+            Public,
+        );
         let str_getitem_t = fn1_kw_met(Str, kw("idx", Nat), Str);
         str_.register_builtin_impl("__getitem__", str_getitem_t, Immutable, Public);
         let mut str_eq = Self::builtin_methods(Some(mono("Eq")), 2);
@@ -1731,6 +1737,7 @@ impl Context {
             or(T, U),
         )
         .quantify();
+        let t_int = nd_func(vec![kw("obj", Obj)], None, or(Int, NoneType));
         let t_import = nd_func(
             vec![anon(tp_enum(Str, set! {Path.clone()}))],
             None,
@@ -1769,6 +1776,7 @@ impl Context {
             ],
             NoneType,
         );
+        let t_nat = nd_func(vec![kw("obj", Obj)], None, or(Nat, NoneType));
         // e.g. not(b: Bool!): Bool!
         let B = mono_q("B", subtypeof(Bool));
         let t_not = nd_func(vec![kw("b", B.clone())], None, B).quantify();
@@ -1808,6 +1816,7 @@ impl Context {
         self.register_builtin_py_impl("discard", t_discard, Immutable, Private, Some("discard__"));
         self.register_builtin_py_impl("exit", t_exit, Immutable, Private, Some("exit"));
         self.register_builtin_py_impl("if", t_if, Immutable, Private, Some("if__"));
+        self.register_builtin_py_impl("int", t_int, Immutable, Private, Some("int__"));
         self.register_builtin_py_impl("import", t_import, Immutable, Private, Some("__import__"));
         self.register_builtin_py_impl(
             "isinstance",
@@ -1825,6 +1834,7 @@ impl Context {
         );
         self.register_builtin_py_impl("len", t_len, Immutable, Private, Some("len"));
         self.register_builtin_py_impl("log", t_log, Immutable, Private, Some("print"));
+        self.register_builtin_py_impl("nat", t_nat, Immutable, Private, Some("nat__"));
         self.register_builtin_py_impl("not", t_not, Immutable, Private, None); // `not` is not a function in Python
         self.register_builtin_py_impl("oct", t_oct, Immutable, Private, Some("oct"));
         self.register_builtin_py_impl("ord", t_ord, Immutable, Private, Some("ord"));

compiler/erg_compiler/lib/std/_erg_convertors.py

@@ -0,0 +1,14 @@
+from _erg_int import Int
+from _erg_nat import Nat
+
+def int__(i):
+    try:
+        return Int(i)
+    except:
+        return None
+
+def nat__(i):
+    try:
+        return Nat(i)
+    except:
+        return None

compiler/erg_compiler/lib/std/_erg_str.py

@@ -1,4 +1,5 @@
 from _erg_result import Error
+from _erg_int import Int
 
 class Str(str):
     def __instancecheck__(cls, obj):
@@ -15,6 +16,8 @@ class Str(str):
             return None
     def mutate(self):
         return StrMut(self)
+    def to_int(self):
+        return Int(self) if self.isdigit() else None
 
 class StrMut(): # Inherits Str
     value: Str

compiler/erg_compiler/transpile.rs

@@ -227,6 +227,7 @@ pub struct ScriptGenerator {
     range_ops_loaded: bool,
     builtin_types_loaded: bool,
     builtin_control_loaded: bool,
+    convertors_loaded: bool,
     prelude: String,
 }
 
@@ -241,6 +242,7 @@ impl ScriptGenerator {
             range_ops_loaded: false,
             builtin_types_loaded: false,
             builtin_control_loaded: false,
+            convertors_loaded: false,
             prelude: String::new(),
         }
     }
@@ -317,6 +319,10 @@ impl ScriptGenerator {
         self.prelude += include_str!("lib/std/_erg_control.py");
     }
 
+    fn load_convertors(&mut self) {
+        self.prelude += &Self::replace_import(include_str!("lib/std/_erg_convertors.py"));
+    }
+
     fn escape_str(s: &str) -> String {
         s.replace('\n', "\\n")
             .replace('\r', "\\r")
@@ -525,6 +531,10 @@ impl ScriptGenerator {
                         self.load_builtin_controls();
                         self.builtin_control_loaded = true;
                     }
+                    "int" | "nat" if !self.convertors_loaded => {
+                        self.load_convertors();
+                        self.convertors_loaded = true;
+                    }
                     _ => {}
                 }
                 Self::transpile_ident(ident)

compiler/erg_compiler/ty/value.rs

@@ -677,6 +677,10 @@ impl ValueObj {
         }
     }
 
+    pub const fn is_str(&self) -> bool {
+        matches!(self, Self::Str(_))
+    }
+
     pub const fn is_type(&self) -> bool {
         matches!(self, Self::Type(_))
     }