Shiny threading macros with tracing. Why the name? Because.
Artifacts are published on Clojars.
Wouldn't it be nice to use the threading macros (->, ->>) but be
able to see what the intermediate values are? I know, I know, that
would be great, wouldn't it?
[Psst, before going any further, type this into your REPL:
(require '[tinsel.core :refer [=> =>>]]).]
So what if this code:
(let [a 61
[result trace]
(=> (inc a)
inc
dec
(fn [x] (+ x 1))
#(- % 1)
(+ 1)
(* 2)
(/ 3))]
(clojure.pprint/pprint {:result result
:trace trace}))Produced this output?
-| {:result 42,
-| :trace
-| [[(inc a) 62]
-| [inc 63]
-| [dec 62]
-| [(fn [x] (+ x 1)) 63]
-| [(fn* [p1__31059#] (- p1__31059# 1)) 62]
-| [(+ 1) 63]
-| [(* 2) 126]
-| [(/ 3) 42]]}
By the way, tinsel supports raw function names, sugared anonymous
functions e.g. #(- % 1), "regular" anonymous functions using the
fn special form, integers, and keywords. As an example of the last, (let [m {:a 42}] (=> m :a)) evaluates to:
[42
[[m {:a 42}]
[:a 42]]]As for integers, they work similarly to keywords, selecting the item
at the given index. I implemented this feature after deciding against
doing so because retrieving a particular item in a vector is not
possible to do elegantly as an item in a ->> (or =>>) form,
because get takes the collection as its first argument. So, (=>> [:a :b :c] 2) evaluates to [:c [[[:a :b :c] [:a :b :c]] [2 :c]]]
i.e. :c plus the trace.
Copyright © 2013 Edwin Watkeys
Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.