func main(): i32 { let value = load_value() catch failure { fallback_for(failure.message()) } if value == 42 { return 0 } return 1 } func load_value(): i32! { return error.new("example.unavailable", "the primary value is unavailable") } func fallback_for(message: &str): i32 { return 42 }

use std/fmt.Format use std/io struct Point { x: i32 y: i32 } instance Point { impl Format method &self.try_format_into(output: &+String): void! { output.try_push_str("(")? self.x.try_format_into(output)? output.try_push_str(", ")? self.y.try_format_into(output)? output.try_push_str(")")? return } } func main(): i32! { let point = Point { x: 3, y: 4 } let message = "point = ${point}\n" io.print(&message)? return 0 }

use std/io use std/vec.Vec struct Point { x: i32 y: i32 } instance Point { operator (&self == other: &Self): bool { return self.x == other.x && self.y == other.y } } func main(): i32! { let first = Point { x: 3, y: 4 } let same = Point { x: 3, y: 4 } let other = Point { x: 5, y: 6 } if first != same || first == other { return 1 } let points = Vec [move first, move other] if points[0] != same { return 1 } var values = Vec [1, 2, 3] values[1] = 4 if values[0] + values[1] + values[2] != 8 { return 1 } io.print("equality found the point\n")? return 0 }

struct Buffer { values: [i32; 3] } instance Buffer { operator (&self[index: usize]): &i32 { return &self.values[index] } operator (&+self[index: usize]): &+i32 { return &+self.values[index] } } func at<C>(container: &C, index: usize): i32 where (&C[usize]): &i32 { return container[index] } func main(): i32 { var buffer = Buffer { values: [3, 4, 5] } buffer[1] = 9 if at(&buffer, 1) != 9 { return 1 } return 0 }

v0.34.0 Phase 4 Unicode-scalar Tooling Review

Result: complete with no open finding (2026-09-04). Compiler structural output, semantic tooling, runnable examples, and an installed-standard-library invocation now exercise the same Unicode-scalar product established by Phases 1 through 3.

Closed Product

Tokens and AST JSON preserve character_literal as a category distinct from byte and string literals and retain the exact authored spelling. The formatter treats the literal as one lossless token, normalizes only surrounding layout, and proves concrete-syntax equivalence after rewriting. Malformed scalar spellings remain E0117 source diagnostics in structural and language-server requests.

Semantic presentation renders character constants through the existing checked constant value and canonical source renderer. Hover on a checked scalar literal obtains its type through an explicit analysis capability over a BodyNode identity; the query layer neither inspects checker storage nor decodes quote text. Inferred bindings display char, the built-in type navigates to the selected standard declaration, and ordinary member completion exposes char instance methods.

Semantic highlighting merges exact source-index bindings with accepted syntax-owned character tokens in one sorted compiler result. The language-server adapter maps the protocol-independent CharacterLiteral category to the standard LSP string token kind and performs no literal parsing. The readonly modifier remains reserved for binding/place mutability and is not attached to the literal token.

Practical Integration

examples/unicode-text.nct distinguishes byte length from scalar count, traverses borrowed UTF-8, copies scalars into owned text, and constructs a scalar from a code point. The complete native single-file example gate accepts it. The CLI installed-toolchain gate copies the physical standard package into an isolated Nocter home, compiles and executes mixed-width scalar iteration through that installation, and therefore detects omitted standard sources or stale profile locations.

Authority Review

source tooling consumes lexer/parser tokens and never decodes a character literal;
analysis receives scalar-literal type facts through its semantic-evidence adapter rather than exposing CheckedBody internals to hover;
LSP owns only UTF-16 coordinate and protocol-token projection;
completion and navigation use the ordinary declaration and instance indexes;
no editor, example, or installed-home test introduces a second Unicode validity or UTF-8 table.

Phase 5 remains responsible for the complete qualification matrix, performance evidence, release candidate packaging, and final duplicate-authority review.