1.5 Literals

Rules:

• Interpolation {expr} in a string evaluates expr and calls Show.show. A literal curly brace is {{ and }}. Format: {x:.2}, {x:08x}, {t:dd.MM.yyyy} (§17.5). The specifier {expression:spec}: spec = [[fill]align][sign][#][0][width][.precision][type]; alignment <, ^, > (numbers — >, text — <); sign + or -; # — the radix prefix (0x, 0o, 0b); 0 — zero padding (numbers only); .N — the number of fraction digits for floating-point values and the length (in characters) for text. Type: integers — x X o b; floating-point — e E; str, char — ? (quoted with escaping); Duration — a unit ns us ms s m h d: the value in these units followed by the suffix ({d:ms} → 1500ms, {d:.2s} → 1.50s); Time, LocalDateTime, Date — a pattern (§17.5); a type with a method fmt(spec: str) -> str — a custom format. A specifier that does not fit the type of the value is the compile error bad-format-spec; for types unknown at checking time (a generic parameter) only the syntax is checked (D-8064; D-7810).
• Escape sequences: \n \r \t \\ \" \' \0 \xHH \u{H…}.
• Duration units: ns us ms s m h d. A compound duration has the units in strictly descending order, without spaces (1h30m15s). Calendar intervals (months, years) are not literals but Period (§17.2).
• Dates and date-times are recognised by the lexer greedily by the pattern DDDD-DD-DD[TDD:DD[:DD[.D+]]][Z]. Subtraction of numbers is written with spaces: 2026 - 11.
• A prefixed literal p"…" calls the comptime function literal fn p(s: str) -> T from the scope (§15.3). An error in the handler is a compile error. Built-in prefixes: r b re tz cron sha256 ip url html.
• An integer literal that does not fit the inferred type is a compile error.

Related diagnostics

bad-format-spec, invalid-char-literal, invalid-date, invalid-duration, invalid-escape, invalid-number, literal-overflow, unterminated-string

Source: docs/spec/oxl-standard.en.md