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8a19f60386
- Reorder README to have implementation list after "learning tool" bullet. - This also moves tests/ and libs/ into impls. It would be preferrable to have these directories at the top level. However, this causes difficulties with the wasm implementations which need pre-open directories and have trouble with paths starting with "../../". So in lieu of that, symlink those directories to the top-level. - Move the run_argv_test.sh script into the tests directory for general hygiene.
26 lines
933 B
Plaintext
26 lines
933 B
Plaintext
;; Memoize any function.
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;; Implement `memoize` using an atom (`mem`) which holds the memoized results
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;; (hash-map from the arguments to the result). When the function is called,
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;; the hash-map is checked to see if the result for the given argument was already
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;; calculated and stored. If this is the case, it is returned immediately;
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;; otherwise, it is calculated and stored in `mem`.
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;; For recursive functions, take care to store the wrapper under the
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;; same name than the original computation with an assignment like
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;; `(def! f (memoize f))`, so that intermediate results are memorized.
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;; Adapted from http://clojure.org/atoms
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(def! memoize
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(fn* [f]
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(let* [mem (atom {})]
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(fn* [& args]
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(let* [key (str args)]
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(if (contains? @mem key)
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(get @mem key)
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(let* [ret (apply f args)]
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(do
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(swap! mem assoc key ret)
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ret))))))))
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