Macro wide_log 

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

The wide_log! proc-macro. See the crate-level documentation for syntax and usage details.

Takes a JSON object literal as its only parameter. The JSON structure defines all keys, their nesting/paths, default values, and which keys are counters or durations. The macro generates:

• The EventKey enum (#[repr(u8)], one variant per unique JSON key)
• The Key trait impl (as_str, MAX_KEYS, as_index, DURATION_PATH, TIMESTAMP_PATH, ID_PATH)
• __wl_resolve_path — compile-time path resolution function
• Thread-local storage (CURRENT_EVENT: ContextCell<WideEvent<EventKey>>)
• default_emit — serializes via sonic_rs and writes the JSON line to non-blocking stdout via stdout_emit::submit
• WideLogGuardBuilder — builder for constructing guards with timezone, ID generator, and emit function
• WideLogGuard — guard type (constructed via builder().build())
• current() — returns the innermost active event
• scope() / scope_default() (behind tokio feature)
• WideLogLayer tower middleware (behind tokio feature)
• All logging macros: wl_set!, wl_inc!, wl_dec!, wl_add!, wl_null!, info!, warn!, error!, debug!, trace!

Value Markers

Marker	Meaning
duration!	Duration leaf; set to elapsed ms on drop
counter!	Incrementable counter; init to 0 (absent)
null	No default value; set via wl_set!
"literal"	String default; set on guard creation
123	Numeric default; set on guard creation
true/false	Boolean default; set on guard creation

Duration Auto-Add Rules

If no "duration" key is declared, the macro adds "duration": { "total_ms": duration! } automatically. See the README for the full duration resolution table.

Event Auto-Add Rules

If no "event" key is declared, the macro adds "event": { "timestamp": null, "id": null } automatically. The timestamp is set to an RFC 3339 string on drop. The id is set to a ULID string (or UUIDv4 with the uuid feature) on build().