From 2b95094eca78c1d5070d2c24d622b2a38704ebf6 Mon Sep 17 00:00:00 2001
From: Scott Richmond <kredati@users.noreply.github.com>
Date: Thu, 19 Jun 2025 12:06:47 -0400
Subject: [PATCH] first stab at splatted lists

---
 src/compiler.rs | 16 ++++++++++++----
 src/vm.rs       | 21 ++++++++++++++++++---
 2 files changed, 30 insertions(+), 7 deletions(-)

diff --git a/src/compiler.rs b/src/compiler.rs
index 656de41..59ac133 100644
--- a/src/compiler.rs
+++ b/src/compiler.rs
@@ -44,6 +44,7 @@ pub enum Op {
     MatchList,
     MatchSplattedList,
     LoadList,
+    LoadSplattedList,
     PushList,
     AppendList,
     ConcatList,
@@ -165,6 +166,7 @@ impl std::fmt::Display for Op {
             MatchList => "match_list",
             MatchSplattedList => "match_splatted_list",
             LoadList => "load_list",
+            LoadSplattedList => "load_splatted_list",
             PushList => "push_list",
             AppendList => "append_list",
             ConcatList => "concat_list",
@@ -262,9 +264,9 @@ impl Chunk {
                 println!("{i:04}: {:16} {next:03}: {value}", op.to_string());
                 *i += 1;
             }
-            PushBinding | MatchTuple | MatchList | MatchSplattedList | MatchDict
-            | LoadDictValue | PushTuple | PushBox | MatchDepth | PopN | StoreAt | Call
-            | SetUpvalue | GetUpvalue | Partial | MatchString | PushStringMatches => {
+            PushBinding | MatchTuple | MatchList | MatchSplattedList | LoadSplattedList
+            | MatchDict | LoadDictValue | PushTuple | PushBox | MatchDepth | PopN | StoreAt
+            | Call | SetUpvalue | GetUpvalue | Partial | MatchString | PushStringMatches => {
                 let next = self.bytecode[*i + 1];
                 println!("{i:04}: {:16} {next:03}", op.to_string());
                 *i += 1;
@@ -780,7 +782,9 @@ impl<'a> Compiler<'a> {
                 self.match_depth = match_depth + members.len();
             }
             ListPattern(members) => {
+                let mut is_splatted = false;
                 if let Some((Splattern(patt), _)) = members.last() {
+                    is_splatted = true;
                     self.emit_op(Op::MatchSplattedList)
                 } else {
                     self.emit_op(Op::MatchList);
@@ -793,7 +797,11 @@ impl<'a> Compiler<'a> {
                 let match_depth = self.match_depth;
                 self.match_depth = members.len();
 
-                self.emit_op(Op::LoadList);
+                if is_splatted {
+                    self.emit_op(Op::LoadSplattedList);
+                } else {
+                    self.emit_op(Op::LoadList);
+                }
                 self.stack_depth += members.len();
 
                 for member in members {
diff --git a/src/vm.rs b/src/vm.rs
index ad8c391..2552ac6 100644
--- a/src/vm.rs
+++ b/src/vm.rs
@@ -471,17 +471,32 @@ impl Vm {
                 }
                 LoadList => {
                     let idx = self.stack.len() - self.match_depth as usize - 1;
-                    let tuple = self.stack[idx].clone();
-                    match tuple {
+                    let list = self.stack[idx].clone();
+                    match list {
                         Value::List(members) => {
                             for member in members.iter() {
                                 self.push(member.clone());
                             }
                         }
-                        _ => return self.panic("internal error: expected tuple"),
+                        _ => return self.panic("internal error: expected list"),
                     };
                     self.ip += 1;
                 }
+                LoadSplattedList => {
+                    let loaded_len = self.chunk().bytecode[self.ip + 1] as usize;
+                    let idx = self.stack.len() - self.match_depth as usize - 1;
+                    let list = self.stack[idx].clone();
+                    let Value::List(members) = list else {
+                        return self.panic("internal error: expected list");
+                    };
+                    for i in 0..loaded_len - 1 {
+                        self.push(members[i].clone());
+                    }
+                    let splatted = Value::List(Box::new(members.skip(loaded_len - 1)));
+                    self.push(splatted);
+                    self.ip += 2;
+                    todo!()
+                }
                 // PushDict => {
                 //     let dict_len = self.chunk().bytecode[self.ip + 1] as usize * 2;
                 //     let dict_members = self.stack.split_off(self.stack.len() - dict_len);