From 579615d76e62e41f400371619ab88c26a38a602c Mon Sep 17 00:00:00 2001
From: Shunsuke Shibayama <sbym1346@gmail.com>
Date: Fri, 14 Jul 2023 23:45:13 +0900
Subject: [PATCH] feat: add `Slice`

---
 crates/erg_compiler/context/initialize/classes.rs |  7 +++++++
 crates/erg_compiler/context/initialize/funcs.rs   | 13 +++++++++++++
 crates/erg_compiler/context/initialize/mod.rs     |  2 ++
 3 files changed, 22 insertions(+)

diff --git a/crates/erg_compiler/context/initialize/classes.rs b/crates/erg_compiler/context/initialize/classes.rs
index 4097e6af4..3f14bade4 100644
--- a/crates/erg_compiler/context/initialize/classes.rs
+++ b/crates/erg_compiler/context/initialize/classes.rs
@@ -1330,6 +1330,12 @@ impl Context {
             array_t(T.clone(), TyParam::erased(Nat)),
         );
         array_.register_py_builtin(FUNC_DEDUP, t.quantify(), Some(FUNC_DEDUP), 28);
+        /* Slice */
+        let mut slice = Self::builtin_mono_class(SLICE, 3);
+        slice.register_superclass(Obj, &obj);
+        slice.register_builtin_erg_impl(KW_START, Int, Immutable, Visibility::BUILTIN_PUBLIC);
+        slice.register_builtin_erg_impl(KW_STOP, Int, Immutable, Visibility::BUILTIN_PUBLIC);
+        slice.register_builtin_erg_impl(KW_STEP, Int, Immutable, Visibility::BUILTIN_PUBLIC);
         /* GenericSet */
         let mut generic_set = Self::builtin_mono_class(GENERIC_SET, 1);
         generic_set.register_superclass(Obj, &obj);
@@ -2370,6 +2376,7 @@ impl Context {
             Some(ARRAY),
         );
         self.register_builtin_type(arr_t, array_, vis.clone(), Const, Some(ARRAY));
+        self.register_builtin_type(mono(SLICE), slice, vis.clone(), Const, Some(FUNC_SLICE));
         self.register_builtin_type(
             mono(GENERIC_SET),
             generic_set,
diff --git a/crates/erg_compiler/context/initialize/funcs.rs b/crates/erg_compiler/context/initialize/funcs.rs
index 529cc643d..3e0cc45b6 100644
--- a/crates/erg_compiler/context/initialize/funcs.rs
+++ b/crates/erg_compiler/context/initialize/funcs.rs
@@ -220,6 +220,12 @@ impl Context {
         )
         .quantify();
         let t_round = nd_func(vec![kw(KW_NUMBER, Float)], None, Int);
+        let t_slice = func(
+            vec![kw(KW_START, Int)],
+            None,
+            vec![kw(KW_STOP, Int), kw(KW_STEP, Int)],
+            mono(SLICE),
+        );
         let t_sorted = nd_func(
             vec![kw(KW_ITERABLE, poly(ITERABLE, vec![ty_tp(T.clone())]))],
             None,
@@ -393,6 +399,13 @@ impl Context {
             vis.clone(),
             Some(FUNC_ROUND),
         );
+        self.register_builtin_py_impl(
+            FUNC_SLICE,
+            t_slice,
+            Immutable,
+            vis.clone(),
+            Some(FUNC_SLICE),
+        );
         self.register_builtin_py_impl(
             FUNC_SORTED,
             t_sorted,
diff --git a/crates/erg_compiler/context/initialize/mod.rs b/crates/erg_compiler/context/initialize/mod.rs
index f3ec9aba9..1533c7aa8 100644
--- a/crates/erg_compiler/context/initialize/mod.rs
+++ b/crates/erg_compiler/context/initialize/mod.rs
@@ -284,6 +284,7 @@ const NAMED_FUNC: &str = "NamedFunc";
 const FUNC: &str = "Func";
 const QUANTIFIED: &str = "Quantified";
 const QUANTIFIED_FUNC: &str = "QuantifiedFunc";
+const SLICE: &str = "Slice";
 const FUNC_OBJECT: &str = "object";
 const FUNC_INT: &str = "int";
 const FUNC_INT__: &str = "int__";
@@ -335,6 +336,7 @@ const FUNC_POW: &str = "pow";
 const FUNC_QUIT: &str = "quit";
 const FUNC_REPR: &str = "repr";
 const FUNC_ROUND: &str = "round";
+const FUNC_SLICE: &str = "slice";
 const FUNC_SORTED: &str = "sorted";
 const FUNC_SUM: &str = "sum";
 const FUNC_IF: &str = "if";