Etc pattern

crates/codegen/src/lib.rs

@@ -236,6 +236,8 @@ impl GetRust for TypeExprKind {
 impl GenRust for Pattern {
     fn gen_rust(&self, ctx: &mut Context, cg: &mut RustCodegen) {
         match self {
+            Self::Etc => cg.add(".."),
+            Self::Literal(lit) => lit.gen_rust(ctx, cg),
             Self::Path(mutable, path) => {
                 if *mutable {
                     cg.add("mut ");
@@ -243,19 +245,26 @@ impl GenRust for Pattern {
 
                 cg.add(&path.get_rust())
             }
-            Self::Literal(lit) => lit.gen_rust(ctx, cg),
-
             Self::Struct(path, inner) => {
                 cg.add(&path.get_rust());
                 cg.add(" {");
-                for (name, pat) in inner {
-                    cg.add(&name.get_rust());
-                    if let Some(pat) = pat {
-                        cg.add(": ");
-                        pat.gen_rust(ctx, cg);
+
+                for (idx, i) in inner.iter().enumerate() {
+                    if idx > 0 {
+                        cg.add(", ");
+                    }
+
+                    if let Some((name, pat)) = i {
+                        cg.add(&name.get_rust());
+                        if let Some(pat) = pat {
+                            cg.add(": ");
+                            pat.gen_rust(ctx, cg);
+                        }
+                    } else {
+                        cg.add("..");
                     }
-                    cg.add(",");
                 }
+
                 cg.add("}");
             }
 

crates/parser/src/ast/expr.rs

@@ -33,10 +33,11 @@ pub enum Literal {
 #[derive(Debug, Clone, Serialize)]
 pub enum Pattern {
     NamedTuple(Path, Vec<Box<Pattern>>),
-    Struct(Path, Vec<(Identifier, Option<Box<Pattern>>)>),
+    Struct(Path, Vec<Option<(Identifier, Option<Box<Pattern>>)>>),
     Tuple(Vec<Box<Pattern>>),
     Literal(Literal),
     Path(bool, Path),
+    Etc,
 }
 
 #[derive(Debug, Clone, Serialize)]

crates/parser/src/grammar.pest

@@ -134,12 +134,14 @@ literal = {
 // PATTERNS
 // ======================================================
 
+etc_pattern = { ".." }
+
 multi_pat_template = _{
-    (pattern ~ ("," ~ pattern)*)?
+    ((pattern | etc_pattern) ~ ("," ~ (pattern | etc_pattern))*)?
 }
 
 tuple_pattern = {
-    "[" ~ pattern ~ "," ~ multi_pat_template ~ "]"
+    "[" ~ (pattern | etc_pattern) ~ "," ~ multi_pat_template ~ "]"
 }
 
 named_tuple_pattern = {
@@ -151,7 +153,7 @@ struct_destruct = {
 }
 
 struct_pattern = {
-    static_path ~ "{" ~ (struct_destruct ~ ("," ~ struct_destruct)*)? ~ "}"
+    static_path ~ "{" ~ ((struct_destruct | etc_pattern) ~ ("," ~ (struct_destruct | etc_pattern))*)? ~ "}"
 }
 
 path_pattern = {

crates/parser/src/parser/common/mod.rs

@@ -72,14 +72,19 @@ impl<'a> TryFrom<pest::iterators::Pair<'a, Rule>> for Pattern {
             Rule::struct_pattern => ast_expr!(Pattern::Struct(
                 Path::try_from(inner.next().unwrap()),
                 collect_recovered_map(inner, |v| {
-                    let mut inner = v.into_inner();
-                    ast_expr!((
+                    if v.as_rule() == Rule::etc_pattern {
+                        return Ok(None);
+                    }
+
+                    let mut inner = dbg!(v).into_inner();
+                    Some(ast_expr!((
                         Identifier::try_from(inner.next().unwrap()),
                         inner
                             .next()
                             .map(|v| Self::try_from(v).map(Box::new).get_map(Box::new))
                             .transpose()
-                    ))
+                    )))
+                    .transpose()
                 }),
             )),
 
@@ -90,6 +95,8 @@ impl<'a> TryFrom<pest::iterators::Pair<'a, Rule>> for Pattern {
                 inner.next().unwrap().try_into()
             )),
 
+            Rule::etc_pattern => Ok(Pattern::Etc),
+
             _ => AstError::bug_unimplemented(pair),
         }
     }