This document is a description of unexpected behavior in Clojure's language implementation, not a prescription as to how it ought to behave differently.
I enjoy using Clojure and find most of the language design decisions to be excellent. Please do not use this gist for unconstructive purposes.
| ;;;;;;;;;;;;;; | |
| ;; Numerics ;; | |
| ;;;;;;;;;;;;;; | |
| ;; + ;; | |
| ;; Expected: | |
| (+ Long/MAX_VALUE 1) | |
| ;=> ArithmeticException integer overflow clojure.lang.Numbers.throwIntOverflow (Numbers.java:1526) | |
| ;; Unexpected: | |
| (+ Integer/MAX_VALUE 1) | |
| ;=> 2147483648 | |
| ;; - ;; | |
| ;; Expected: | |
| (- Long/MIN_VALUE 1) | |
| ;=> ArithmeticException integer overflow clojure.lang.Numbers.throwIntOverflow (Numbers.java:1526) | |
| ;; Unexpected: | |
| (- Integer/MIN_VALUE 1) | |
| ;=> -2147483649 | |
| ;; N.B.: Clojure provides +' *' and -' which auto-promote numeric types. | |
| ;;;;;;;;;;;;; | |
| ;; Seq API ;; | |
| ;;;;;;;;;;;;; | |
| ;; Expected: | |
| (take 2 []) | |
| ;=> () | |
| (drop 1 []) | |
| ;=> () | |
| (drop-last 1 []) | |
| ;=> () | |
| ;; Unexpected: | |
| (take-last 2 []) | |
| nil | |
| ;; N.B.: nil is seqable so nothing should break about this inconsistency. | |
| ;; Expected? | |
| (get "foo" :bar) | |
| ;=> nil | |
| ;; Unexpected, given the above: | |
| (contains? "foo" :bar) | |
| ;=> IllegalArgumentException contains? not supported on type: java.lang.String clojure.lang.RT.contains (RT.java:846) | |
| ;;;;;;;;;;;;;;;;; | |
| ;; Complecting ;; | |
| ;;;;;;;;;;;;;;;;; | |
| ;; EJ: Consider metadata, and fact that only IMeta/IObj types can have it. |