diff options
| -rw-r--r-- | src/clj/clojure/core.clj | 43 |
1 files changed, 24 insertions, 19 deletions
diff --git a/src/clj/clojure/core.clj b/src/clj/clojure/core.clj index 0b58b4ff..be452aa4 100644 --- a/src/clj/clojure/core.clj +++ b/src/clj/clojure/core.clj @@ -1817,18 +1817,34 @@ "Reads one object from the string s" [s] (clojure.lang.RT/readString s)) +(defn subvec + "Returns a persistent vector of the items in vector from + start (inclusive) to end (exclusive). If end is not supplied, + defaults to (count vector). This operation is O(1) and very fast, as + the resulting vector shares structure with the original and no + trimming is done." + ([v start] + (subvec v start (count v))) + ([v start end] + (. clojure.lang.RT (subvec v start end)))) + (defmacro with-open - "bindings => name init + "bindings => [name init ...] - Evaluates body in a try expression with name bound to the value of - init, and a finally clause that calls (.close name)." + Evaluates body in a try expression with names bound to the values + of the inits, and a finally clause that calls (.close name) on each + name in reverse order." [bindings & body] (if (vector? bindings) - `(let ~bindings - (try - ~@body - (finally - (.close ~(first bindings))))) + (cond + (= (count bindings) 0) `(do ~@body) + (symbol? (bindings 0)) `(let ~(subvec bindings 0 2) + (try + (with-open ~(subvec bindings 2) ~@body) + (finally + (. ~(bindings 0) close)))) + :else (throw (IllegalArgumentException. + "with-open only allows Symbols in bindings"))) (throw (IllegalArgumentException. "with-open now requires a vector for its binding")))) @@ -2023,17 +2039,6 @@ [s key] (. clojure.lang.PersistentStructMap (getAccessor s key))) -(defn subvec - "Returns a persistent vector of the items in vector from - start (inclusive) to end (exclusive). If end is not supplied, - defaults to (count vector). This operation is O(1) and very fast, as - the resulting vector shares structure with the original and no - trimming is done." - ([v start] - (subvec v start (count v))) - ([v start end] - (. clojure.lang.RT (subvec v start end)))) - (defn load-reader "Sequentially read and evaluate the set of forms contained in the stream/file" |