Function with_parse_cache

src/parser/mod.rs:713–732

Activate the thread-local parse cache for `content`. While the returned [`ParseCacheGuard`] is alive, every call to [`with_parsed_program`] whose `content` argument is byte-equal to the cached content will reuse the already-parsed `Program` instead of re-parsing. Typical usage: ```ignore let _guard = with_parse_cache(content); // … many calls to resolve_variable_types / resolve_variable_type /

(content: &str)

/// // Guard is dropped here, clearing the cache.
/// ```
pub(crate) fn with_parse_cache(content: &str) -> ParseCacheGuard {
    // If there's already an active cache (nested call), just return a
    // no-op guard — the outermost guard owns the lifetime.
    let already_active = PARSE_CACHE.with(|cell| cell.borrow().is_some());
    if already_active {
        return ParseCacheGuard { owns_cache: false };
    }

    // Store only the content string.  The actual parse is deferred
    // until the first `with_parsed_program` call that hits the cache.
    PARSE_CACHE.with(|cell| {
        *cell.borrow_mut() = Some(ParseCacheEntry {
            content: content.to_string(),
            arena: None,
            program_ptr: None,
        });
    });

    ParseCacheGuard { owns_cache: true }
}

/// Parse `content` with the mago-syntax parser and pass the resulting
/// `Program` (plus the content string) to `f`.