add fixed-length lists

src/ast/list.rs

@@ -23,6 +23,7 @@ pub struct List {
 pub enum ListDefault {
     Values(Vec<ConstExpr>),
     File { path: SmolStr, span: Span },
+    FixedLength(ConstExpr, ConstExpr),
 }
 
 impl List {
@@ -63,4 +64,20 @@ impl List {
             is_used: false,
         }
     }
+
+    pub fn new_fixed_length(
+        name: SmolStr,
+        span: Span,
+        type_: Type,
+        default: ConstExpr,
+        length: ConstExpr,
+    ) -> Self {
+        Self {
+            name,
+            span,
+            type_,
+            default: Some(ListDefault::FixedLength(default, length)),
+            is_used: false,
+        }
+    }
 }

src/codegen/sb3.rs

@@ -938,6 +938,16 @@ where T: Write + Seek
                     vec![]
                 }
             },
+            Some(ListDefault::FixedLength(value, length)) => {
+                let value = s.evaluate_const_expr(d, value);
+                let len = s.evaluate_const_expr(d, length).to_number();
+                if len > 200_000_f64 {
+                    d.report(DiagnosticKind::ListTooBig, &length.span());
+                    vec![]
+                } else {
+                    vec![value; len as usize]
+                }
+            }
             None => vec![],
         };
         match &list.type_ {

src/diagnostic/diagnostic_kind.rs

@@ -127,6 +127,7 @@ pub enum DiagnosticKind {
     UnusedFunc(SmolStr),
     UnusedArg(SmolStr),
     UnusedStructField(SmolStr),
+    ListTooBig,
 }
 
 impl DiagnosticKind {
@@ -298,6 +299,7 @@ impl DiagnosticKind {
                 format!("duplicate variant {variant_name} in enum {enum_name}")
             }
             DiagnosticKind::EmptyStruct(name) => format!("struct {name} is empty"),
+            DiagnosticKind::ListTooBig => format!("list too big, length should be atmost 200,000"),
         }
     }
 
@@ -485,6 +487,7 @@ impl From<&DiagnosticKind> for Level {
             | DiagnosticKind::InvalidCostumeFormat { .. }
             | DiagnosticKind::InvalidSoundFormat { .. }
             | DiagnosticKind::LocalNotSupported
+            | DiagnosticKind::ListTooBig
             | DiagnosticKind::UnknownDirective(_) => Level::Error,
 
             | DiagnosticKind::FollowedByUnreachableCode

src/parser/grammar.lalrpop

@@ -89,6 +89,9 @@ Declr: () = {
     LIST <type_:Type> <l:@L> <name:NAME> <r:@R> <pl:@L> <path:STR> <pr:@R> ";" => {
         sprite.add_list(List::new_file(name, l..r, type_, path, pl..pr), diagnostics);
     },
+    LIST <type_:Type> <l:@L> <name:NAME> <r:@R> "=" "[" <default:ConstExpr> ";" <length:ConstExpr> "]" ";" => {
+        sprite.add_list(List::new_fixed_length(name, l..r, type_, default, length), diagnostics);
+    }
 }
 
 EnumVariant: EnumVariant = {