+1 to Mon Key's suggestions. Those are very FAQ-like questions. -Matt On Dec 19, 12:45 am, Mon Key <s...@derbycityprints.com> wrote: > Some thoughts on really stupid things that have tripped me up: > > - How do I exit Clojure - srsly > C-c > > - Whatsa JVM - does this mean Clojure is really just Java with parens? > > - Whatsa Classpath? > this answer presents the *ALL* important opportunity to mention that > *nix uses `:' to separate paths whereas windz uses `;' > > - How do I access Clojure documentation - e.g. where is `man Clojure' > > - Is a Clojure docstring the same as Javadoc? > > - Is Clojure stable? > > - Where's the Clojure manual? > > - What happened to setf? > > - Why are Clojure's docstring placements different than other lisps > > - Where do I make donations? > > - Why are Clojure's defun params passed in a [] vector? > > - Does Clojure do TCO? > > - Whatsa TCO? > > - How do I compile Clojure? OR Where's the Clojure Compiler? > > - How does Clojure's nil differ from other Lisps? > > - Clojure has a `cons' function and a `conj' function - whats the > difference? > > - At what point do calls out to external Java interfaces limit/alter > Clojures' internal handling of sequences > ---- How do I avoid interopearating with Java - e.g. when is Clojure > all I need for task X > ---- When should I make use of external Java libraries > > - Whatsa Clojure Sequence - how does it corellate to language X > - Whatsa Collection - how does it corellate to language X > - Whatsa Map - how does it corellate to language X > > On Dec 19, 12:41 am, "Adrian Cuthbertson" > > <adrian.cuthbert...@gmail.com> wrote: > > > Suggestions for entries welcome here. > > > > > Rich > > > Here's another that was a "gotcha" for me for an hour or two... > > > Why after using map/reduce/for to change a java object does the object > > remain unchanged? > > > (defn initv1 [myseq] (let [v (java.util.Vector.)] (for [x myseq] > > (.addElement v x)) v)) > > (initv1 [1 2 3]) > > ; => (java.util.Vector. []) > > > ; or... > > > (defn initv2 [myseq] (let [v (java.util.Vector.)] (map (fn [x] (.addElement > > v x)) myseq) v)) > > (initv2 [1 2 3]) > > ; => (java.util.Vector. []) > > > As map/reduce/for are lazy, the "let" construct does not actually "take" any > > elements from the map/reduce/for. In this case, use doseq... > > > (defn initv3 [myseq] (let [v (java.util.Vector.)] (doseq [x myseq] > > (.addElement v x)) v)) > > (initv3 [1 2 3]) > > ; => (java.util.Vector. [1 2 3]) > > > (Actually this happened in a more complex function, but the essence was that > > a new java object was instantiated in a let and I'd used a map to call a > > method on that object with all the items from a sequence. I could not > > understand why the object remained unchanged afterwards until I simplified > > it down to the above example). > > > Regards, Adrian --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~----------~----~----~----~------~----~------~--~---
