Macro prosaic_template 

prosaic_template!() { /* proc-macro */ }

Compile-time-validated template string.

Parses the template, checks every slot reference against the declared slots list, and checks every pipe name against the engine’s known-pipe set. On success, expands to the original template string literal (&'static str). On mismatch, emits a compile error pointing at the template: argument.

When context: <Type> is provided, the macro also emits const assertions at compile time, verifying that each slot’s required type (inferred from its pipe chain) is compatible with the corresponding field in <Type>’s HasProsaicSchema implementation. A missing slot or type mismatch is a hard compile error with a clear message identifying the slot and context type.

Syntax

use prosaic_derive::prosaic_template;

let tpl: &'static str = prosaic_template! {
    template: "The {entity_type} {name|refer} was renamed to {new_name}",
    slots: [entity_type, name, new_name],
};
assert!(tpl.contains("{name|refer}"));

The slots: list uses bare identifiers matching the slot keys in the template. Declaring extra slots that are not used in the template is allowed. Slots used by conditional guards ({?key}) must also be declared.

Limitations (v1)

• Pipe arguments (truncate:3, verb:past, etc.) are not validated — only the pipe name.
• Slots inside partial inclusions ({>name}) are not validated — partials are opaque at compile time and resolved by the engine at registration time.
• Compile-fail tests require an external trybuild harness (deferred to v2).