Function getmathfunc 

pub fn getmathfunc(
    table: &mut modulestab,
    name: &str,
    autol: i32,
) -> Option<String>

Port of getmathfunc(const char *name, int autol) from Src/module.c:1283.

C body: linear-search mathfuncs for name; if found and autol is true and the entry is autoloadable, demand-load via ensurefeature("f:", name). Returns the resolved entry or NULL.

Rust port returns Some(module_name) on hit, None on miss.

Faithful port of c:1283-1306:

MathFunc
getmathfunc(const char *name, int autol)
{
    MathFunc p, q = NULL;
    for (p = mathfuncs; p; q = p, p = p->next)
        if (!strcmp(name, p->name)) {
            if (autol && p->module && !(p->flags & MFF_USERFUNC)) {
                char *n = dupstring(p->module);
                int flags = p->flags;
                removemathfunc(q, p);
                (void)ensurefeature(n, "f:",
                                    (flags & MFF_AUTOALL) ? NULL : name);
                p = getmathfunc(name, 0);
                if (!p) {
                    zerr("autoloading module %s failed to define math function: %s", n, name);
                }
            }
            return p;
        }
    return NULL;
}

C walks mathfuncs (file-static linked list) — Rust walks MATHFUNCS (same shape, Vec). The MFF_USERFUNC filter (functions -M user-defined math) keeps user fns from being autoloaded out from under the caller. The autoload arm:

1. snapshot module name + flags
2. removemathfunc(name) — drop the autoload stub
3. ensurefeature(module, “f:”, AUTOALL?NULL:name) — load real
4. re-query mathfuncs (autol=0) — return the loaded entry
5. zerr if still missing (load failed to populate the table) WARNING: param names don’t match C — Rust=(table, name, autol) vs C=(name, autol)