Module format 

Printf-style formatting node.

Takes a format string and N inputs, produces a formatted String. Uses {} placeholders (Rust-style, not C printf-style), with optional format specifiers.

Supported specifiers:

• {} — default display
• {:05} — zero-padded to width 5 (u64)
• {:.2} — 2 decimal places (f64)
• {:x} — lowercase hex (u64)
• {:X} — uppercase hex (u64)
• {:b} — binary (u64)
• {:o} — octal (u64)

printf takes a Const<&str> format string, a #[poly_const] cached ParsedFormat, and &[Value] variadic wires. The cached ParsedFormat is computed once at construction (in the parse_format setup-fn) so per-eval work is just iterating the pre-parsed segments.

Structs

FormatSpec

One placeholder’s formatting: which argument, and how to render it.

ParsedFormat

Pre-parsed format string cached on the Printf node. The #[polydat_node] macro invokes parse_format once at construction; eval reads the segments directly with no per-call parsing.

Printf

Printf-style N→1 formatting node. Variadic: accepts 0..N wire inputs.

Enums

FmtArg

One argument to a format, as the formatter needs it: a scalar by value, a string by reference, anything else as the Value whose display form is used. The P1 node builds these from its Value inputs and the compiled helper from slot bits and handles, so both tiers run the same formatting code (SRD 115 §6, axiom H7) and a string argument is formatted without being copied first.

Segment

A parsed format segment: either literal text or a placeholder.