Python's generator/yield feature in Clojure and ClojureScript to generate lazy sequences.
How is it different from clj-generators and clj-yield? It is much simpler with lower overhead, because it does not depend on core.async or threading in the background. It does simple term rewriting to change imperative style code to functional sequence compositions.
Use the (gen-seq) macro to create a lazy sequence. Invocations of (yield) in the macro sets the next return value of the sequence.
For example, (gen-seq (yield 1) (yield 2)) will return (1 2). A more complex example:
(gen-seq
(dotimes [i 3]
(yield i))
(yield "Hello")
(doseq [c "Greetings"]
(yield c))
(loop [i 3]
(when (pos? i)
(yield i)
(recur (dec i))))
(yield "End."))Returns:
(0 1 2 "Hello" \G \r \e \e \t \i \n \g \s \3 \2 \1 "End.")See the test cases for more examples.
Use (yield-all xs) instead of (doseq [x xs] (yield x)) to set multiple elements in the sequence.
Copyright © 2020 Janos Erdos
This program and the accompanying materials are made available under the terms of the Eclipse Public License 2.0 which is available at http://www.eclipse.org/legal/epl-2.0.
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