diff options
Diffstat (limited to 'cljlib.fnl')
| -rw-r--r-- | cljlib.fnl | 39 |
1 files changed, 29 insertions, 10 deletions
@@ -265,25 +265,44 @@ val and f is not called. Calls `seq` on `col`." _ (let [[a b & rest] col] (reduce f (f a b) rest))))) ([f val col] - (let [col (or (seq col) (empty []))] - (let [[x & xs] col] - (if (nil? x) - val - (reduce f (f val x) xs)))))) + (if-some [reduced (when-some [m (getmetatable val)] + (and m.cljlib/reduced + (= m.cljlib/reduced.status :ready) + m.cljlib/reduced.val))] + reduced + (let [col (or (seq col) (empty []))] + (let [[x & xs] col] + (if (nil? x) + val + (reduce f (f val x) xs))))))) + +(fn* core.reduced + "Wraps `x` in such a way so [`reduce`](#reduce) will terminate early + with this value." + [x] + (setmetatable + {} {:cljlib/reduced {:status :ready + :val x}})) (fn* core.reduce-kv "Reduces an associative table using function `f` and initial value `val`. `f` should be a function of 3 arguments. Returns the result of -applying `f` to `val`, the first key and the first value in `coll`, +applying `f` to `val`, the first key and the first value in `tbl`, then applying `f` to that result and the 2nd key and value, etc. If -`coll` contains no entries, returns `val` and `f` is not called. Note +`tbl` contains no entries, returns `val` and `f` is not called. Note that reduce-kv is supported on sequential tables and strings, where the keys will be the ordinals." - [f val col] + [f val tbl] (var res val) - (each [_ [k v] (pairs (or (seq col) (empty [])))] - (set res (f res k v))) + (each [_ [k v] (pairs (or (seq tbl) (empty [])))] + (set res (f res k v)) + (when-some [reduced (when-some [m (getmetatable res)] + (and m.cljlib/reduced + (= m.cljlib/reduced.status :ready) + m.cljlib/reduced.val))] + (set res reduced) + (lua :break))) res) (fn* core.mapv |