add match splatted list opcode

src/compiler.rs

@@ -42,6 +42,7 @@ pub enum Op {
     PushTuple,
     LoadTuple,
     MatchList,
+    MatchSplattedList,
     LoadList,
     PushList,
     AppendList,
@@ -162,6 +163,7 @@ impl std::fmt::Display for Op {
             PushTuple => "push_tuple",
             LoadTuple => "load_tuple",
             MatchList => "match_list",
+            MatchSplattedList => "match_splatted_list",
             LoadList => "load_list",
             PushList => "push_list",
             AppendList => "append_list",
@@ -260,9 +262,9 @@ impl Chunk {
                 println!("{i:04}: {:16} {next:03}: {value}", op.to_string());
                 *i += 1;
             }
-            PushBinding | MatchTuple | MatchList | MatchDict | LoadDictValue | PushTuple
-            | PushBox | MatchDepth | PopN | StoreAt | Call | SetUpvalue | GetUpvalue | Partial
-            | MatchString | PushStringMatches => {
+            PushBinding | MatchTuple | MatchList | MatchSplattedList | 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;
@@ -778,7 +780,12 @@ impl<'a> Compiler<'a> {
                 self.match_depth = match_depth + members.len();
             }
             ListPattern(members) => {
-                self.emit_op(Op::MatchList);
+                if let Some((Splattern(patt), _)) = members.last() {
+                    self.emit_op(Op::MatchSplattedList)
+                } else {
+                    self.emit_op(Op::MatchList);
+                }
+                // TODO: lists must be able to be longer than 256 elements; fix this
                 self.emit_byte(members.len());
                 let before_load_tup_idx = self.stub_jump(Op::JumpIfNoMatch);
 

src/main.rs

@@ -75,14 +75,7 @@ pub fn run(src: &'static str) {
 pub fn main() {
     env::set_var("RUST_BACKTRACE", "1");
     let src = "
-let foo = loop (1, 2, 3) with {
-    (0, 0, 1) -> :done
-    (1, 2, 3) -> recur (4, 5, 6)
-    (4, 5, 6) -> recur (:foo, :bar, :baz)
-    (:foo, :bar, :baz) -> recur (0, 0, 0)
-}
-
-(foo, 42)
-   ";
+let [] = []
+";
     run(src);
 }

src/vm.rs

@@ -466,6 +466,9 @@ impl Vm {
                     };
                     self.ip += 2;
                 }
+                MatchSplattedList => {
+                    todo!()
+                }
                 LoadList => {
                     let idx = self.stack.len() - self.match_depth as usize - 1;
                     let tuple = self.stack[idx].clone();