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Diffstat (limited to 'README.org')
| -rw-r--r-- | README.org | 35 |
1 files changed, 22 insertions, 13 deletions
@@ -1,10 +1,9 @@ - * Fennel Cljlib -Library for [[https://fennel-lang.org/][Fennel]] language that adds a lot of functions from [[https://clojure.org/][Clojure]] standard library. -This is not a one to one port of Clojure =core=, because many Clojure functions require certain guarantees, like immutability of the underlying data structures. +Experimental library for [[https://fennel-lang.org/][Fennel]] language, that adds many functions from [[https://clojure.org/][Clojure]]'s standard library. +This is not a one to one port of Clojure =core=, because many Clojure functions require certain guarantees, like immutability of the underlying data structures, or laziness. Therefore some names were changed, but they should be still recognizable. -Goals of this project are: +Even though it is project is experimental, the goals of this project are: - Have a self contained library, with no dependencies, that provides a set of useful functions from Clojure =core=, - Be close to the platform, e.g. implement functions in a way that is efficient to use in Lua VM, @@ -155,20 +154,17 @@ It also calls =seq= on it's argument. #+end_src *** =conj= and =cons= +Append and prepend item to the table. Unlike Clojure, =conj=, and =cons= modify table passed to these functions. This is done both to avoid copying of whole thing, and because Fennel doesn't have immutability guarantees. -Both functions return the resulting table, so it is possible to nest these, or build a classic =map=: + +=cons= accepts value as its first argument and table as second, and puts value to the front of the table: #+begin_src fennel - (fn map [f col] - (if-some [val (first col)] - (cons (f val) (map f (rest col))) - [])) + (cons 1 [2 3]) + ;; [1 2 3] #+end_src -=cons= accepts value as its first argument and table as second and puts value to the front of the table. -=col= is not modified by the =map= function described above, but the =[]= table in the =else= branch of =is-some= is. - =conj= accepts table as it's first argument and any amount of values afterwards. It puts values in order given into the table: @@ -177,6 +173,19 @@ It puts values in order given into the table: ; [1 2 3] #+end_src +Both functions return the resulting table, so it is possible to nest calls to both of these. +As an example, here's a classic map function: + +#+begin_src fennel + (fn map [f col] + (if-some [val (first col)] + (cons (f val) (map f (rest col))) + [])) +#+end_src + +=col= is not modified by the =map= function described above, but the =[]= table in the =else= branch of =is-some= is eventually modified by the stack of calls to =cons=. +However this library provides more efficient versions of map, that support arbitrary amount of tables. + *** =mapv= and =mapkv= Mapping functions. In Clojure we have a =seq= abstraction, that allows us to use single =mapv= on both vectors, and hash tables. @@ -228,4 +237,4 @@ Then it maps function over the associative map, by passing initial value as a fi ;; 20 #+end_src -# LocalWords: Luajit VM +# LocalWords: Luajit VM arity runtime multi Cljlib fn |