fix: simple knot tests

src/AstGen.zig

@@ -1410,11 +1410,11 @@ fn knotDecl(gi: *GenIr, parent_scope: *Scope, decl_node: *const Ast.Node) InnerE
         .data = .{ .payload = undefined },
     });
 
+    var node_index: usize = 0;
     var child_block = gi.makeSubBlock();
     defer child_block.unstack();
 
     const knot_inst = try gi.makePayloadNode(.decl_knot);
-
     var child_scope = parent_scope.makeChild();
     defer child_scope.deinit();
 
@@ -1432,18 +1432,18 @@ fn knotDecl(gi: *GenIr, parent_scope: *Scope, decl_node: *const Ast.Node) InnerE
             });
         }
     }
-
+    if (nested_decls_list.len > 0) {
-    var start_index: usize = 0;
+        const first_child = nested_decls_list[0];
-    const first_child = nested_decls_list[0];
+        if (first_child.tag == .block_stmt) {
-    if (first_child.tag == .block_stmt) {
+            try blockStmt(&child_block, &child_scope, first_child);
-        try blockStmt(&child_block, &child_scope, first_child);
+            node_index += 1;
-        start_index += 1;
+        }
     }
 
     var nested_block = child_block.makeSubBlock();
     defer nested_block.unstack();
 
-    for (nested_decls_list[start_index..]) |nested_decl_node| {
+    for (nested_decls_list[node_index..]) |nested_decl_node| {
         switch (nested_decl_node.tag) {
             .stitch_decl => try stitchDecl(&nested_block, &child_scope, nested_decl_node),
             .function_decl => try functionDecl(&nested_block, &child_scope, nested_decl_node),
@@ -1469,18 +1469,20 @@ fn file(gi: *GenIr, scope: *Scope, file_node: *const Ast.Node) InnerError!void {
         },
     });
 
+    var node_index: usize = 0;
     var file_scope = gi.makeSubBlock();
     defer file_scope.unstack();
 
     // TODO: Make sure this is non-nullable.
     const nested_decls_list = file_node.data.list.items orelse return;
-    if (nested_decls_list.len == 0) return;
+    if (nested_decls_list.len > 0) {
-
+        const first_child = nested_decls_list[0];
-    const first_child = nested_decls_list[0];
+        if (first_child.tag == .block_stmt) {
-    if (first_child.tag == .block_stmt) {
+            try defaultBlock(&file_scope, scope, first_child);
-        try defaultBlock(&file_scope, scope, first_child);
+            node_index += 1;
+        }
     }
-    for (nested_decls_list[1..]) |child_node| {
+    for (nested_decls_list[node_index..]) |child_node| {
         switch (child_node.tag) {
             .knot_decl => try knotDecl(gi, scope, child_node),
             .stitch_decl => try stitchDecl(gi, scope, child_node),

src/Parse.zig

@@ -247,7 +247,7 @@ fn popScratch(p: *Parse, context: *const StmtContext) *Ast.Node {
 
 fn nodeListFromScratch(p: *Parse, start_offset: usize, end_offset: usize) Error![]*Ast.Node {
     const span = end_offset - start_offset;
-    assert(span > 0);
+    assert(span >= 0);
 
     const list = try p.arena.alloc(*Ast.Node, span);
     defer p.scratch.shrinkRetainingCapacity(start_offset);

src/Sema.zig

@@ -90,7 +90,7 @@ pub fn lookupInNamespace(
     var scope: ?*Module.Namespace = namespace;
     while (scope) |s| : (scope = s.parent) {
         if (s.decls.get(ident)) |decl| switch (decl.tag) {
-            .knot => return .{ .knot = .{
+            .knot, .stitch => return .{ .knot = .{
                 .namespace = decl.namespace.?,
                 .const_index = ident,
             } },
@@ -814,6 +814,27 @@ pub fn analyzeTopLevelDecl(
                 try analyzeNestedDecl(sema, child_namespace, st);
             }
         },
+        .decl_stitch => {
+            const child_namespace = try sema.module.createNamespace(namespace);
+            const gop = try namespace.decls.getOrPut(sema.arena, decl_name);
+            if (gop.found_existing) {
+                return sema.fail(src_loc, "duplicate identifier", .{});
+            } else {
+                gop.value_ptr.* = .{
+                    .tag = .stitch,
+                    .decl_inst = extra.value,
+                    .args_count = 0,
+                    .namespace = child_namespace,
+                };
+            }
+
+            try sema.module.queueWorkItem(.{
+                .tag = .stitch,
+                .decl_name = decl_name,
+                .inst_index = extra.value,
+                .namespace = child_namespace,
+            });
+        },
         else => unreachable,
     }
 }

src/compile.zig

@@ -205,6 +205,7 @@ pub const Module = struct {
 
             pub const Tag = enum {
                 knot,
+                stitch,
                 variable,
             };
         };

src/parser_tests.zig

@@ -93,6 +93,41 @@ test "parser: temporary assignment" {
     );
 }
 
+test "parser: simple knot" {
+    try testEqual(
+        \\=== knot ===
+        \\Hello, world!
+    ,
+        \\File "<STDIN>"
+        \\`--KnotDecl <line:1, line:2>
+        \\   |--KnotProto <col:1, col:13>
+        \\   |  `--Identifier `knot` <col:5, col:9>
+        \\   `--BlockStmt <line:2, line:2>
+        \\      `--ContentStmt <line:2, col:1:14>
+        \\         `--Content <col:1, col:14>
+        \\            `--StringLiteral `Hello, world!` <col:1, col:14>
+        \\
+        ,
+    );
+}
+
+test "parser: empty knot declarations" {
+    try testEqual(
+        \\== a
+        \\== b
+    ,
+        \\File "<STDIN>"
+        \\|--KnotDecl <line:1, line:1>
+        \\|  `--KnotProto <col:1, col:5>
+        \\|     `--Identifier `a` <col:4, col:5>
+        \\`--KnotDecl <line:2, line:2>
+        \\   `--KnotProto <col:1, col:5>
+        \\      `--Identifier `b` <col:4, col:5>
+        \\
+        ,
+    );
+}
+
 fn testEqual(source_bytes: [:0]const u8, expected_ast: []const u8) !void {
     const gpa = std.testing.allocator;
     var arena_allocator = std.heap.ArenaAllocator.init(gpa);

testing/regression/syntax/empty-knots.ink

@@ -1,12 +0,0 @@
-// RUN: %ink-compiler --stdin --compile-only --dump-ast < %s | FileCheck %s
-
-// CHECK: File "<STDIN>"
-// CHECK-NEXT: |--KnotDecl <line:11, line:11>
-// CHECK-NEXT: |  `--KnotProto <col:1, col:5>
-// CHECK-NEXT: |     `--Identifier `a` <col:4, col:5>
-// CHECK-NEXT: `--KnotDecl <line:12, line:12>
-// CHECK-NEXT:    `--KnotProto <col:1, col:5>
-// CHECK-NEXT:       `--Identifier `b` <col:4, col:5>
-
-== a
-== b

testing/regression/syntax/simple-knot.ink

@@ -1,13 +0,0 @@
-// RUN: %ink-compiler --stdin --compile-only --dump-ast < %s | FileCheck %s
-
-// CHECK: File "<STDIN>"
-// CHECK-NEXT: `--KnotDecl <line:12, line:13>
-// CHECK-NEXT:    |--KnotProto <col:1, col:13>
-// CHECK-NEXT:    |  `--Identifier `knot` <col:5, col:9>
-// CHECK-NEXT:    `--BlockStmt <line:13, line:13>
-// CHECK-NEXT:       `--ContentStmt <line:13, col:1:14>
-// CHECK-NEXT:          `--Content <col:1, col:14>
-// CHECK-NEXT:             `--StringLiteral `Hello, world!` <col:1, col:14>
-
-=== knot ===
-Hello, world!