076 optional effect branch decl

✓ Passing This code compiles and runs correctly.

Code

// Test 210_076: optional effect branch (`! ?warning`) at event decl.
// Symmetric with `| ?name` — consumers may omit handlers without
// exhaustiveness error; unhandled calls become no-ops.

~pub event tokenize { source: []const u8 }
! token []const u8
! ?warning []const u8
| done usize
input.kz

Expected AST

{
  "module_annotations": [],
  "items": [
    {
      "type": "import_decl",
      "path": "$std/compiler",
      "location": {
        "file": "tests/regression/200_COMPILER_FEATURES/210_PARSER/210_076_optional_effect_branch_decl/input.kz",
        "line": 2,
        "col": 0
      }
    },
    {
      "type": "host_line",
      "module": "input",
      "location": {
        "file": "tests/regression/200_COMPILER_FEATURES/210_PARSER/210_076_optional_effect_branch_decl/input.kz",
        "line": 2,
        "col": 0
      }
    },
    {
      "type": "host_line",
      "module": "input",
      "location": {
        "file": "tests/regression/200_COMPILER_FEATURES/210_PARSER/210_076_optional_effect_branch_decl/input.kz",
        "line": 3,
        "col": 0
      }
    },
    {
      "type": "host_line",
      "module": "input",
      "location": {
        "file": "tests/regression/200_COMPILER_FEATURES/210_PARSER/210_076_optional_effect_branch_decl/input.kz",
        "line": 4,
        "col": 0
      }
    },
    {
      "type": "event_decl",
      "name": "tokenize",
      "path": [
        "tokenize"
      ],
      "module": "input",
      "input": {
        "fields": [
          {
            "name": "source",
            "type": "[]const u8",
            "is_source": false,
            "is_file": false,
            "is_embed_file": false,
            "is_expression": false,
            "is_invocation_meta": false,
            "phantom": null
          }
        ]
      },
      "branches": [
        {
          "name": "token",
          "kind": "effect",
          "resume": null,
          "is_optional": false,
          "payload": {
            "fields": [
              {
                "name": "__type_ref",
                "type": "[]const u8",
                "is_source": false,
                "is_file": false,
                "is_embed_file": false,
                "is_expression": false,
                "is_invocation_meta": false,
                "phantom": null
              }
            ]
          }
        },
        {
          "name": "warning",
          "kind": "effect",
          "resume": null,
          "is_optional": true,
          "payload": {
            "fields": [
              {
                "name": "__type_ref",
                "type": "[]const u8",
                "is_source": false,
                "is_file": false,
                "is_embed_file": false,
                "is_expression": false,
                "is_invocation_meta": false,
                "phantom": null
              }
            ]
          }
        },
        {
          "name": "done",
          "kind": "terminal",
          "resume": null,
          "is_optional": false,
          "payload": {
            "fields": [
              {
                "name": "__type_ref",
                "type": "usize",
                "is_source": false,
                "is_file": false,
                "is_embed_file": false,
                "is_expression": false,
                "is_invocation_meta": false,
                "phantom": null
              }
            ]
          }
        }
      ],
      "location": {
        "file": "tests/regression/200_COMPILER_FEATURES/210_PARSER/210_076_optional_effect_branch_decl/input.kz",
        "line": 10,
        "col": 0
      }
    }
  ]
}

Test Configuration

PARSER_TEST
← 075 effect branch consumer dispatch 077 effect catchall dispatch →