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diff --git a/doc/core.md b/doc/core.md new file mode 100644 index 0000000..fa3d678 --- /dev/null +++ b/doc/core.md @@ -0,0 +1,2078 @@ +# Core (v1.0.0) +Fennel-cljlib - functions from Clojure's core.clj implemented on top +of Fennel. + +This library contains a set of functions providing functions that +behave similarly to Clojure's equivalents. Library itself has nothing +Fennel specific so it should work on Lua, e.g: + +``` lua +Lua 5.3.5 Copyright (C) 1994-2018 Lua.org, PUC-Rio +> clj = require"cljlib" +> table.concat(clj.mapv(function (x) return x * x end, {1, 2, 3}), " ") +-- 1 4 9 +``` + +This example is mapping an anonymous `function` over a table, +producing new table and concatenating it with `" "`. + +However this library also provides Fennel-specific set of +[macros](./macros.md), that provides additional facilities like +`defn` or `defmulti` which extend the language allowing writing code +that looks and works mostly like Clojure. + +Each function in this library is created with `defn`, which is a +special macros for creating multi-arity functions. So when you see +function signature like `(foo [x])`, this means that this is function +`foo`, that accepts exactly one argument `x`. In contrary, functions +created with `fn` will produce `(foo x)` signature (`x` is not inside +brackets). + +Functions, which signatures look like `(foo ([x]) ([x y]) ([x y & +zs]))`, it is a multi-arity function, which accepts either one, two, +or three-or-more arguments. Each `([...])` represents different body +of a function which is chosen by checking amount of arguments passed +to the function. See [Clojure's doc section on multi-arity +functions](https://clojure.org/guides/learn/functions#_multi_arity_functions). + +## Compatibility +This library is mainly developed with Lua 5.4, and tested against +Lua 5.2, 5.3, 5.4, and LuaJIT 2.1.0-beta3. Note, that in lua 5.2 and +LuaJIT equality semantics are a bit different from Lua 5.3 and Lua 5.4. +Main difference is that when comparing two tables, they must have +exactly the same `__eq` metamethods, so comparing hash sets with hash +sets will work, but comparing sets with other tables works only in +Lua5.3+. Another difference is that Lua 5.2 and LuaJIT don't have +inbuilt UTF-8 library, therefore [`seq`](#seq) function will not work for +non-ASCII strings. + +**Table of contents** + +- [`apply`](#apply) +- [`add`](#add) +- [`sub`](#sub) +- [`mul`](#mul) +- [`div`](#div) +- [`le`](#le) +- [`lt`](#lt) +- [`ge`](#ge) +- [`gt`](#gt) +- [`inc`](#inc) +- [`dec`](#dec) +- [`eq`](#eq) +- [`map?`](#map) +- [`vector?`](#vector) +- [`multifn?`](#multifn) +- [`set?`](#set) +- [`nil?`](#nil) +- [`zero?`](#zero) +- [`pos?`](#pos) +- [`neg?`](#neg) +- [`even?`](#even) +- [`odd?`](#odd) +- [`string?`](#string) +- [`boolean?`](#boolean) +- [`true?`](#true) +- [`false?`](#false) +- [`int?`](#int) +- [`pos-int?`](#pos-int) +- [`neg-int?`](#neg-int) +- [`double?`](#double) +- [`empty?`](#empty) +- [`not-empty`](#not-empty) +- [`vector`](#vector-1) +- [`seq`](#seq) +- [`first`](#first) +- [`rest`](#rest) +- [`last`](#last) +- [`butlast`](#butlast) +- [`conj`](#conj) +- [`disj`](#disj) +- [`cons`](#cons) +- [`concat`](#concat) +- [`reduce`](#reduce) +- [`reduced`](#reduced) +- [`reduce-kv`](#reduce-kv) +- [`mapv`](#mapv) +- [`filter`](#filter) +- [`every?`](#every) +- [`some`](#some) +- [`not-any?`](#not-any) +- [`range`](#range) +- [`reverse`](#reverse) +- [`take`](#take) +- [`nthrest`](#nthrest) +- [`partition`](#partition) +- [`identity`](#identity) +- [`comp`](#comp) +- [`complement`](#complement) +- [`constantly`](#constantly) +- [`memoize`](#memoize) +- [`assoc`](#assoc) +- [`hash-map`](#hash-map) +- [`get`](#get) +- [`get-in`](#get-in) +- [`keys`](#keys) +- [`vals`](#vals) +- [`find`](#find) +- [`dissoc`](#dissoc) +- [`remove-method`](#remove-method) +- [`remove-all-methods`](#remove-all-methods) +- [`methods`](#methods) +- [`get-method`](#get-method) +- [`hash-set`](#hash-set) +- [`assoc!`](#assoc-1) +- [`assoc-in`](#assoc-in) +- [`cat`](#cat) +- [`class`](#class) +- [`completing`](#completing) +- [`conj!`](#conj-1) +- [`contains?`](#contains) +- [`count`](#count) +- [`cycle`](#cycle) +- [`dedupe`](#dedupe) +- [`deref`](#deref) +- [`disj!`](#disj-1) +- [`dissoc!`](#dissoc-1) +- [`distinct`](#distinct) +- [`doall`](#doall) +- [`dorun`](#dorun) +- [`drop`](#drop) +- [`drop-last`](#drop-last) +- [`drop-while`](#drop-while) +- [`empty`](#empty-1) +- [`ensure-reduced`](#ensure-reduced) +- [`filterv`](#filterv) +- [`frequencies`](#frequencies) +- [`group-by`](#group-by) +- [`halt-when`](#halt-when) +- [`interleave`](#interleave) +- [`interpose`](#interpose) +- [`into`](#into) +- [`iterate`](#iterate) +- [`keep`](#keep) +- [`keep-indexed`](#keep-indexed) +- [`lazy-seq`](#lazy-seq) +- [`line-seq`](#line-seq) +- [`list`](#list) +- [`list*`](#list-1) +- [`map`](#map-1) +- [`map-indexed`](#map-indexed) +- [`mapcat`](#mapcat) +- [`merge`](#merge) +- [`next`](#next) +- [`nth`](#nth) +- [`nthnext`](#nthnext) +- [`partition-all`](#partition-all) +- [`partition-by`](#partition-by) +- [`persistent!`](#persistent) +- [`pop!`](#pop) +- [`random-sample`](#random-sample) +- [`realized?`](#realized) +- [`reduced?`](#reduced-1) +- [`reductions`](#reductions) +- [`remove`](#remove) +- [`repeat`](#repeat) +- [`repeatedly`](#repeatedly) +- [`replace`](#replace) +- [`rseq`](#rseq) +- [`seq?`](#seq-1) +- [`sequence`](#sequence) +- [`some?`](#some-1) +- [`sort`](#sort) +- [`split-at`](#split-at) +- [`split-with`](#split-with) +- [`take-last`](#take-last) +- [`take-nth`](#take-nth) +- [`take-while`](#take-while) +- [`transduce`](#transduce) +- [`transient`](#transient) +- [`tree-seq`](#tree-seq) +- [`unreduced`](#unreduced) +- [`update`](#update) +- [`update-in`](#update-in) +- [`vec`](#vec) +- [`zipmap`](#zipmap) + +## `apply` +Function signature: + +``` +(apply ([f args]) ([f a args]) ([f a b args]) ([f a b c args]) ([f a b c d & args])) +``` + +Apply `f` to the argument list formed by prepending intervening +arguments to `args`, and `f` must support variadic amount of +arguments. + +### Examples +Applying `add` to different amount of arguments: + +``` fennel +(assert-eq (apply add [1 2 3 4]) 10) +(assert-eq (apply add 1 [2 3 4]) 10) +(assert-eq (apply add 1 2 3 4 5 6 [7 8 9]) 45) +``` + +## `add` +Function signature: + +``` +(add ({}) ([a]) ([a b]) ([a b c]) ([a b c d]) ([a b c d & rest])) +``` + +Sum arbitrary amount of numbers. + +## `sub` +Function signature: + +``` +(sub ({}) ([a]) ([a b]) ([a b c]) ([a b c d]) ([a b c d & rest])) +``` + +Subtract arbitrary amount of numbers. + +## `mul` +Function signature: + +``` +(mul ({}) ([a]) ([a b]) ([a b c]) ([a b c d]) ([a b c d & rest])) +``` + +Multiply arbitrary amount of numbers. + +## `div` +Function signature: + +``` +(div ([a]) ([a b]) ([a b c]) ([a b c d]) ([a b c d & rest])) +``` + +Divide arbitrary amount of numbers. + +## `le` +Function signature: + +``` +(le ([a]) ([a b]) ([a b & [c d & more]])) +``` + +Returns true if nums are in monotonically non-decreasing order + +## `lt` +Function signature: + +``` +(lt ([a]) ([a b]) ([a b & [c d & more]])) +``` + +Returns true if nums are in monotonically decreasing order + +## `ge` +Function signature: + +``` +(ge ([a]) ([a b]) ([a b & [c d & more]])) +``` + +Returns true if nums are in monotonically non-increasing order + +## `gt` +Function signature: + +``` +(gt ([a]) ([a b]) ([a b & [c d & more]])) +``` + +Returns true if nums are in monotonically increasing order + +## `inc` +Function signature: + +``` +(inc [x]) +``` + +Increase number `x` by one + +## `dec` +Function signature: + +``` +(dec [x]) +``` + +Decrease number `x` by one + +## `eq` +Function signature: + +``` +(eq ({}) ([_]) ([a b]) ([a b & cs])) +``` + +Comparison function. + +Accepts arbitrary amount of values, and does the deep comparison. If +values implement `__eq` metamethod, tries to use it, by checking if +first value is equal to second value, and the second value is equal to +the first value. If values are not equal and are tables does the deep +comparison. Tables as keys are supported. + +## `map?` +Function signature: + +``` +(map? [x]) +``` + +Check whether `x` is an associative table. + +Non-empty tables are tested by calling `next`. If the length of the +table is greater than zero, the last integer key is passed to the +`next`, and if `next` returns a key, the table is considered +associative. If the length is zero, `next` is called with what `paris` +returns for the table, and if the key is returned, table is considered +associative. + +Empty tables can't be analyzed with this method, and `map?` will +always return `false`. If you need this test pass for empty table, +see `hash-map` for creating tables that have additional metadata +attached for this test to work. + +### Examples +Non empty map: + +``` fennel +(assert-is (map? {:a 1 :b 2})) +``` + +Empty tables don't pass the test: + +``` fennel +(assert-not (map? {})) +``` + +Empty tables created with `hash-map` will pass the test: + +``` fennel +(assert-is (map? (hash-map))) +``` + +## `vector?` +Function signature: + +``` +(vector? [x]) +``` + +Check whether `tbl` is an sequential table. + +Non empty sequential tables are tested for two things: +- `next` returns the key-value pair, +- key, that is returned by the `next` is equal to `1`. + +Empty tables can't be analyzed with this method, and `vector?` will +always return `false`. If you need this test pass for empty table, +see `vector` for creating tables that have additional +metadata attached for this test to work. + +### Examples +Non empty vector: + +``` fennel +(assert-is (vector? [1 2 3 4])) +``` + +Empty tables don't pass the test: + +``` fennel +(assert-not (vector? [])) +``` + +Empty tables created with `vector` will pass the test: + +``` fennel +(assert-is (vector? (vector))) +``` + +## `multifn?` +Function signature: + +``` +(multifn? [mf]) +``` + +Test if `mf` is an instance of `multifn`. + +`multifn` is a special kind of table, created with `defmulti` macros +from `macros.fnl`. + +## `set?` +Function signature: + +``` +(set? [x]) +``` + +Check if object is a set. + +## `nil?` +Function signature: + +``` +(nil? ({}) ([x])) +``` + +Test if `x` is nil. + +## `zero?` +Function signature: + +``` +(zero? [x]) +``` + +Test if `x` is equal to zero. + +## `pos?` +Function signature: + +``` +(pos? [x]) +``` + +Test if `x` is greater than zero. + +## `neg?` +Function signature: + +``` +(neg? [x]) +``` + +Test if `x` is less than zero. + +## `even?` +Function signature: + +``` +(even? [x]) +``` + +Test if `x` is even. + +## `odd?` +Function signature: + +``` +(odd? [x]) +``` + +Test if `x` is odd. + +## `string?` +Function signature: + +``` +(string? [x]) +``` + +Test if `x` is a string. + +## `boolean?` +Function signature: + +``` +(boolean? [x]) +``` + +Test if `x` is a Boolean + +## `true?` +Function signature: + +``` +(true? [x]) +``` + +Test if `x` is `true` + +## `false?` +Function signature: + +``` +(false? [x]) +``` + +Test if `x` is `false` + +## `int?` +Function signature: + +``` +(int? [x]) +``` + +Test if `x` is a number without floating point data. + +Number is rounded with `math.floor` and compared with original number. + +## `pos-int?` +Function signature: + +``` +(pos-int? [x]) +``` + +Test if `x` is a positive integer. + +## `neg-int?` +Function signature: + +``` +(neg-int? [x]) +``` + +Test if `x` is a negative integer. + +## `double?` +Function signature: + +``` +(double? [x]) +``` + +Test if `x` is a number with floating point data. + +## `empty?` +Function signature: + +``` +(empty? [x]) +``` + +Check if collection is empty. + +## `not-empty` +Function signature: + +``` +(not-empty [x]) +``` + +If `x` is empty, returns `nil`, otherwise `x`. + +## `vector` +Function signature: + +``` +(vector [& args]) +``` + +Constructs sequential table out of it's arguments. + +Sets additional metadata for function `vector?` to work. + +### Examples + +``` fennel +(def :private v (vector 1 2 3 4)) +(assert-eq v [1 2 3 4]) +``` + +## `seq` +Function signature: + +``` +(seq [coll]) +``` + +Construct a sequnce from the given collection `coll`. If `coll` is an +associative table, returns sequence of vectors with key and +value. If `col` is sequential table, returns its shallow copy. If +`col` is string, return sequential table of its codepoints. + +### Examples +Sequential tables are transformed to sequences: + +``` fennel +(seq [1 2 3 4]) ;; @seq(1 2 3 4) +``` + +Associative tables are transformed to format like this `[[key1 value1] +... [keyN valueN]]` and order is non deterministic: + +``` fennel +(seq {:a 1 :b 2 :c 3}) ;; @seq([:b 2] [:a 1] [:c 3]) +``` + +## `first` +Function signature: + +``` +(first [coll]) +``` + +Return first element of a `coll`. Calls `seq` on its argument. + +## `rest` +Function signature: + +``` +(rest [coll]) +``` + +Returns a sequence of all elements of a `coll` but the first one. +Calls `seq` on its argument. + +## `last` +Function signature: + +``` +(last [coll]) +``` + +Returns the last element of a `coll`. Calls `seq` on its argument. + +## `butlast` +Function signature: + +``` +(butlast [coll]) +``` + +Returns everything but the last element of the `coll` as a new + sequence. Calls `seq` on its argument. + +## `conj` +Function signature: + +``` +(conj ({}) ([s]) ([s x]) ([s x & xs])) +``` + +Insert `x` as a last element of a table `tbl`. + +If `tbl` is a sequential table or empty table, inserts `x` and +optional `xs` as final element in the table. + +If `tbl` is an associative table, that satisfies `map?` test, +insert `[key value]` pair into the table. + +Mutates `tbl`. + +### Examples +Adding to sequential tables: + +``` fennel +(conj [] 1 2 3 4) +;; => [1 2 3 4] +(conj [1 2 3] 4 5) +;; => [1 2 3 4 5] +``` + +Adding to associative tables: + +``` fennel +(conj {:a 1} [:b 2] [:c 3]) +;; => {:a 1 :b 2 :c 3} +``` + +Note, that passing literal empty associative table `{}` will not work: + +``` fennel +(conj {} [:a 1] [:b 2]) +;; => [[:a 1] [:b 2]] +(conj (hash-map) [:a 1] [:b 2]) +;; => {:a 1 :b 2} +``` + +See `hash-map` for creating empty associative tables. + +## `disj` +Function signature: + +``` +(disj ([Set]) ([Set key]) ([Set key & keys])) +``` + +Returns a new set type, that does not contain the +specified `key` or `keys`. + +## `cons` +Function signature: + +``` +(cons [head tail]) +``` + +Construct a cons cell. +Prepends new `head` to a `tail`, which must be either a table, +sequence, or nil. + +### Examples + +``` fennel +(assert-eq [0 1] (cons 0 [1])) +(assert-eq (list 0 1 2 3) (cons 0 (cons 1 (list 2 3)))) +``` + +## `concat` +Function signature: + +``` +(concat [& colls]) +``` + +Return a lazy sequence of concatenated `colls`. + +## `reduce` +Function signature: + +``` +(reduce ([f coll]) ([f val coll])) +``` + +`f` should be a function of 2 arguments. If `val` is not supplied, +returns the result of applying `f` to the first 2 items in `coll`, +then applying `f` to that result and the 3rd item, etc. If `coll` +contains no items, f must accept no arguments as well, and reduce +returns the result of calling `f` with no arguments. If `coll` has +only 1 item, it is returned and `f` is not called. If `val` is +supplied, returns the result of applying `f` to `val` and the first +item in `coll`, then applying `f` to that result and the 2nd item, +etc. If `coll` contains no items, returns `val` and `f` is not +called. Early termination is supported via `reduced`. + +### Examples + +``` fennel +(defn- add + ([] 0) + ([a] a) + ([a b] (+ a b)) + ([a b & cs] (apply add (+ a b) cs))) +;; no initial value +(assert-eq 10 (reduce add [1 2 3 4])) +;; initial value +(assert-eq 10 (reduce add 1 [2 3 4])) +;; empty collection - function is called with 0 args +(assert-eq 0 (reduce add [])) +(assert-eq 10.3 (reduce math.floor 10.3 [])) +;; collection with a single element doesn't call a function unless the +;; initial value is supplied +(assert-eq 10.3 (reduce math.floor [10.3])) +(assert-eq 7 (reduce add 3 [4])) +``` + +## `reduced` +Function signature: + +``` +(reduced [value]) +``` + +Terminates the `reduce` early with a given `value`. + +### Examples + +``` fennel +(assert-eq :NaN + (reduce (fn [acc x] + (if (not= :number (type x)) + (reduced :NaN) + (+ acc x))) + [1 2 :3 4 5])) +``` + +## `reduce-kv` +Function signature: + +``` +(reduce-kv [f val s]) +``` + +Reduces an associative table using function `f` and initial value `val`. + +`f` should be a function of 3 arguments. Returns the result of +applying `f` to `val`, the first key and the first value in `tbl`, +then applying `f` to that result and the 2nd key and value, etc. If +`tbl` contains no entries, returns `val` and `f` is not called. Note +that reduce-kv is supported on sequential tables and strings, where +the keys will be the ordinals. + +Early termination is possible with the use of `reduced` +function. + +### Examples +Reduce associative table by adding values from all keys: + +``` fennel +(local t {:a1 1 + :b1 2 + :a2 2 + :b2 3}) + +(reduce-kv #(+ $1 $3) 0 t) +;; => 8 +``` + +Reduce table by adding values from keys that start with letter `a`: + +``` fennel +(local t {:a1 1 + :b1 2 + :a2 2 + :b2 3}) + +(reduce-kv (fn [res k v] (if (= (string.sub k 1 1) :a) (+ res v) res)) + 0 t) +;; => 3 +``` + +## `mapv` +Function signature: + +``` +(mapv ([f coll]) ([f coll & colls])) +``` + +Returns a vector consisting of the result of applying `f` to the +set of first items of each `coll`, followed by applying `f` to the set +of second items in each coll, until any one of the `colls` is exhausted. +Any remaining items in other colls are ignored. Function `f` should +accept number-of-colls arguments. + +## `filter` +Function signature: + +``` +(filter ([pred]) ([pred coll])) +``` + +Returns a lazy sequence of the items in `coll` for which +`pred` returns logical true. Returns a transducer when no collection +is provided. + +## `every?` +Function signature: + +``` +(every? [pred coll]) +``` + +Test if every item in `coll` satisfies the `pred`. + +## `some` +Function signature: + +``` +(some [pred coll]) +``` + +Test if any item in `coll` satisfies the `pred`. + +## `not-any?` +Function signature: + +``` +(not-any? [pred coll]) +``` + +Test if no item in `coll` satisfy the `pred`. + +## `range` +Function signature: + +``` +(range ({}) ([upper]) ([lower upper]) ([lower upper step])) +``` + +Returns lazy sequence of of numbers from `lower` to `upper` with optional `step`. + +## `reverse` +Function signature: + +``` +(reverse [coll]) +``` + +Returns a lazy sequnce with same items as in `coll` but in reverse order. + +## `take` +Function signature: + +``` +(take ([n]) ([n coll])) +``` + +Returns a lazy sequence of the first `n` items in `coll`, or all items if +there are fewer than `n`. + +## `nthrest` +Function signature: + +``` +(nthrest [coll n]) +``` + +Returns the nth rest of `coll`, `coll` when `n` is 0. + +### Examples + +``` fennel +(assert-eq (nthrest [1 2 3 4] 3) [4]) +(assert-eq (nthrest [1 2 3 4] 2) [3 4]) +(assert-eq (nthrest [1 2 3 4] 1) [2 3 4]) +(assert-eq (nthrest [1 2 3 4] 0) [1 2 3 4]) +``` + +## `partition` +Function signature: + +``` +(partition ([n coll]) ([n step coll]) ([n step pad coll])) +``` + +Given a collection `coll`, returns a lazy sequence of lists of `n` +items each, at offsets `step` apart. If `step` is not supplied, +defaults to `n`, i.e. the partitions do not overlap. If a `pad` +collection is supplied, use its elements as necessary to complete last +partition upto `n` items. In case there are not enough padding +elements, return a partition with less than `n` items. + +## `identity` +Function signature: + +``` +(identity [x]) +``` + +Returns its argument. + +## `comp` +Function signature: + +``` +(comp ({}) ([f]) ([f g]) ([f g & fs])) +``` + +Compose functions. + +## `complement` +Function signature: + +``` +(complement [f]) +``` + +Takes a function `f` and returns the function that takes the same +amount of arguments as `f`, has the same effect, and returns the +oppisite truth value. + +## `constantly` +Function signature: + +``` +(constantly [x]) +``` + +Returns a function that takes any number of arguments and returns `x`. + +## `memoize` +Function signature: + +``` +(memoize [f]) +``` + +Returns a memoized version of a referentially transparent function. +The memoized version of the function keeps a cache of the mapping from +arguments to results and, when calls with the same arguments are +repeated often, has higher performance at the expense of higher memory +use. + +## `assoc` +Function signature: + +``` +(assoc ([tbl]) ([tbl k v]) ([tbl k v & kvs])) +``` + +Associate `val` under a `key`. +Accepts extra keys and values. + +### Examples + +``` fennel +(assert-eq {:a 1 :b 2} (assoc {:a 1} :b 2)) +(assert-eq {:a 1 :b 2} (assoc {:a 1 :b 1} :b 2)) +(assert-eq {:a 1 :b 2 :c 3} (assoc {:a 1 :b 1} :b 2 :c 3)) +``` + +## `hash-map` +Function signature: + +``` +(hash-map [& kvs]) +``` + +Create associative table from `kvs` represented as sequence of keys +and values + +## `get` +Function signature: + +``` +(get ([tbl key]) ([tbl key not-found])) +``` + +Get value from the table by accessing it with a `key`. +Accepts additional `not-found` as a marker to return if value wasn't +found in the table. + +## `get-in` +Function signature: + +``` +(get-in ([tbl keys]) ([tbl keys not-found])) +``` + +Get value from nested set of tables by providing key sequence. +Accepts additional `not-found` as a marker to return if value wasn't +found in the table. + +## `keys` +Function signature: + +``` +(keys [coll]) +``` + +Returns a sequence of the map's keys, in the same order as `seq`. + +## `vals` +Function signature: + +``` +(vals [coll]) +``` + +Returns a sequence of the table's values, in the same order as `seq`. + +## `find` +Function signature: + +``` +(find [coll key]) +``` + +Returns the map entry for `key`, or `nil` if key not present in `coll`. + +## `dissoc` +Function signature: + +``` +(dissoc ([tbl]) ([tbl key]) ([tbl key & keys])) +``` + +Remove `key` from table `tbl`. Optionally takes more `keys`. + +## `remove-method` +Function signature: + +``` +(remove-method [multimethod dispatch-value]) +``` + +Remove method from `multimethod` for given `dispatch-value`. + +## `remove-all-methods` +Function signature: + +``` +(remove-all-methods [multimethod]) +``` + +Removes all of the methods of `multimethod` + +## `methods` +Function signature: + +``` +(methods [multimethod]) +``` + +Given a `multimethod`, returns a map of dispatch values -> dispatch fns + +## `get-method` +Function signature: + +``` +(get-method [multimethod dispatch-value]) +``` + +Given a `multimethod` and a `dispatch-value`, returns the dispatch +`fn` that would apply to that value, or `nil` if none apply and no +default. + +## `hash-set` +Function signature: + +``` +(hash-set [& xs]) +``` + +Create hash set. + +Set is a collection of unique elements, which sore purpose is only to +tell you if something is in the set or not. + +## `assoc!` +Function signature: + +``` +(assoc! [map k & ks]) +``` + +Remove `k`from transient map, and return `map`. + +## `assoc-in` +Function signature: + +``` +(assoc-in [tbl key-seq val]) +``` + +Associate `val` into set of immutable nested tables `t`, via given `key-seq`. +Returns a new immutable table. Returns a new immutable table. + +### Examples + +Replace value under nested keys: + +``` fennel +(assert-eq + {:a {:b {:c 1}}} + (assoc-in {:a {:b {:c 0}}} [:a :b :c] 1)) +``` + +Create new entries as you go: + +``` fennel +(assert-eq + {:a {:b {:c 1}} :e 2} + (assoc-in {:e 2} [:a :b :c] 1)) +``` + +## `cat` +Function signature: + +``` +(cat [rf]) +``` + +A transducer which concatenates the contents of each input, which must be a + collection, into the reduction. + +## `class` +Function signature: + +``` +(class [x]) +``` + +Return cljlib type of the `x`, or lua type. + +## `completing` +Function signature: + +``` +(completing ([f]) ([f cf])) +``` + +Takes a reducing function `f` of 2 args and returns a function +suitable for transduce by adding an arity-1 signature that calls +`cf` (default - `identity`) on the result argument. + +## `conj!` +Function signature: + +``` +(conj! ({}) ([coll]) ([coll x])) +``` + +Adds `x` to the transient collection, and return `coll`. + +## `contains?` +Function signature: + +``` +(contains? [coll elt]) +``` + +Test if `elt` is in the `coll`. May be a linear search depending on the type of the collection. + +## `count` +Function signature: + +``` +(count [s]) +``` + +Count amount of elements in the sequence. + +## `cycle` +Function signature: + +``` +(cycle [coll]) +``` + +Create a lazy infinite sequence of repetitions of the items in the +`coll`. + +## `dedupe` +Function signature: + +``` +(dedupe ({}) ([coll])) +``` + +Returns a lazy sequence removing consecutive duplicates in coll. +Returns a transducer when no collection is provided. + +## `deref` +Function signature: + +``` +(deref [x]) +``` + +Dereference an object. + +## `disj!` +Function signature: + +``` +(disj! ([Set]) ([Set key & ks])) +``` + +disj[oin]. Returns a transient set of the same type, that does not +contain `key`. + +## `dissoc!` +Function signature: + +``` +(dissoc! [map k & ks]) +``` + +Remove `k`from transient map, and return `map`. + +## `distinct` +Function signature: + +``` +(distinct ({}) ([coll])) +``` + +Returns a lazy sequence of the elements of the `coll` without +duplicates. Comparison is done by equality. Returns a transducer when +no collection is provided. + +## `doall` +Function signature: + +``` +(doall [seq]) +``` + +Realize whole lazy sequence `seq`. + +Walks whole sequence, realizing each cell. Use at your own risk on +infinite sequences. + +## `dorun` +Function signature: + +``` +(dorun [seq]) +``` + +Realize whole sequence `seq` for side effects. + +Walks whole sequence, realizing each cell. Use at your own risk on +infinite sequences. + +## `drop` +Function signature: + +``` +(drop ([n]) ([n coll])) +``` + +Drop `n` elements from collection `coll`, returning a lazy sequence +of remaining elements. Returns a transducer when no collection is +provided. + +## `drop-last` +Function signature: + +``` +(drop-last ({}) ([coll]) ([n coll])) +``` + +Return a lazy sequence from `coll` without last `n` elements. + +## `drop-while` +Function signature: + +``` +(drop-while ([pred]) ([pred coll])) +``` + +Drop the elements from the collection `coll` until `pred` returns logical +false for any of the elemnts. Returns a lazy sequence. Returns a +transducer when no collection is provided. + +## `empty` +Function signature: + +``` +(empty [x]) +``` + +Get an empty variant of a given collection. + +## `ensure-reduced` +Function signature: + +``` +(ensure-reduced [x]) +``` + +If x is already reduced?, returns it, else returns (reduced x) + +## `filterv` +Function signature: + +``` +(filterv [pred coll]) +``` + +Returns a vector of the items in `coll` for which +`pred` returns logical true. + +## `frequencies` +Function signature: + +``` +(frequencies [t]) +``` + +Return a table of unique entries from table `t` associated to amount +of their appearances. + +### Examples + +Count each entry of a random letter: + +``` fennel +(let [fruits [:banana :banana :apple :strawberry :apple :banana]] + (assert-eq (frequencies fruits) + {:banana 3 + :apple 2 + :strawberry 1})) +``` + +## `group-by` +Function signature: + +``` +(group-by [f t]) +``` + +Group table items in an associative table under the keys that are +results of calling `f` on each element of sequential table `t`. +Elements that the function call resulted in `nil` returned in a +separate table. + +### Examples + +Group rows by their date: + +``` fennel +(local rows + [{:date "2007-03-03" :product "pineapple"} + {:date "2007-03-04" :product "pizza"} + {:date "2007-03-04" :product "pineapple pizza"} + {:date "2007-03-05" :product "bananas"}]) + +(assert-eq (group-by #(. $ :date) rows) + {"2007-03-03" + [{:date "2007-03-03" :product "pineapple"}] + "2007-03-04" + [{:date "2007-03-04" :product "pizza"} + {:date "2007-03-04" :product "pineapple pizza"}] + "2007-03-05" + [{:date "2007-03-05" :product "bananas"}]}) +``` + +## `halt-when` +Function signature: + +``` +(halt-when ([pred]) ([pred retf])) +``` + +Returns a transducer that ends transduction when `pred` returns `true` +for an input. When `retf` is supplied it must be a `fn` of 2 arguments +- it will be passed the (completed) result so far and the input that +triggered the predicate, and its return value (if it does not throw an +exception) will be the return value of the transducer. If `retf` is +not supplied, the input that triggered the predicate will be +returned. If the predicate never returns `true` the transduction is +unaffected. + +## `interleave` +Function signature: + +``` +(interleave ({}) ([s]) ([s1 s2]) ([s1 s2 & ss])) +``` + +Returns a lazy sequence of the first item in each sequence, then the +second one, until any sequence exhausts. + +## `interpose` +Function signature: + +``` +(interpose ([sep]) ([separator coll])) +``` + +Returns a lazy sequence of the elements of `coll` separated by +`separator`. Returns a transducer when no collection is provided. + +## `into` +Function signature: + +``` +(into ({}) ([to]) ([to from]) ([to xform from])) +``` + +Returns a new coll consisting of to-coll with all of the items of + from-coll conjoined. A transducer may be supplied. + +### Examples + +Thransofmr a hash-map into a sequence of key-value pairs: + +```fennel +(assert-eq [[:a 1]] (into (vector) {:a 1})) +``` + + Construct a hash-map from a sequence of key-value pairs: + +```fennel +(assert-eq {:a 1 :b 2 :c 3} + (into (hash-map) [[:a 1] [:b 2] [:c 3]])) +``` + +## `iterate` +Function signature: + +``` +(iterate [f x]) +``` + +Returns an infinete lazy sequence of x, (f x), (f (f x)) etc. + +## `keep` +Function signature: + +``` +(keep ([f]) ([f coll])) +``` + +Returns a lazy sequence of the non-nil results of calling `f` on the +items of the `coll`. Returns a transducer when no collection is +provided. + +## `keep-indexed` +Function signature: + +``` +(keep-indexed ([f]) ([f coll])) +``` + +Returns a lazy sequence of the non-nil results of (f index item) in +the `coll`. Note, this means false return values will be included. +`f` must be free of side-effects. Returns a transducer when no +collection is provided. + +## `lazy-seq` +Function signature: + +``` +(lazy-seq [f]) +``` + +Create lazy sequence from the result of calling a function `f`. +Delays execution of `f` until sequence is consumed. `f` must return a +sequence or a vector. + +## `line-seq` +Function signature: + +``` +(line-seq [file]) +``` + +Accepts a `file` handle, and creates a lazy sequence of lines using +`lines` metamethod. + +### Examples + +Lazy sequence of file lines may seem similar to an iterator over a +file, but the main difference is that sequence can be shared onve +realized, and iterator can't. Lazy sequence can be consumed in +iterator style with the `doseq` macro. + +Bear in mind, that since the sequence is lazy it should be realized or +truncated before the file is closed: + +```fennel +(let [lines (with-open [f (io.open "init.fnl" :r)] + (line-seq f))] + ;; this errors because only first line was realized, but the file + ;; was closed before the rest of lines were cached + (assert-not (pcall next lines))) +``` + +Sequence is realized with `doall` before file was closed and can be shared: + +``` fennel +(let [lines (with-open [f (io.open "init.fnl" :r)] + (doall (line-seq f)))] + (assert-is (pcall next lines))) +``` + +Infinite files can't be fully realized, but can be partially realized +with `take`: + +``` fennel +(let [lines (with-open [f (io.open "/dev/urandom" :r)] + (doall (take 3 (line-seq f))))] + (assert-is (pcall next lines))) +``` + +## `list` +Function signature: + +``` +(list ...) +``` + +Create eager sequence of provided values. + +### Examples + +``` fennel +(local l (list 1 2 3 4 5)) +(assert-eq [1 2 3 4 5] l) +``` + +## `list*` +Function signature: + +``` +(list* [& args]) +``` + +Creates a new sequence containing the items prepended to the rest, +the last of which will be treated as a sequence. + +### Examples + +``` fennel +(local l (list* 1 2 3 [4 5])) +(assert-eq [1 2 3 4 5] l) +``` + +## `map` +Function signature: + +``` +(map ([f]) ([f coll]) ([f coll & colls])) +``` + +Returns a lazy sequence consisting of the result of applying `f` to +the set of first items of each `coll`, followed by applying `f` to the +set of second items in each `coll`, until any one of the `colls` is +exhausted. Any remaining items in other `colls` are ignored. Function +`f` should accept number-of-colls arguments. Returns a transducer when +no collection is provided. + +### Examples + +```fennel +(map #(+ $ 1) [1 2 3]) ;; => @seq(2 3 4) +(map #(+ $1 $2) [1 2 3] [4 5 6]) ;; => @seq(5 7 9) +(def :private res (map #(+ $ 1) [:a :b :c])) ;; will raise an error only when realized +``` + +## `map-indexed` +Function signature: + +``` +(map-indexed ([f]) ([f coll])) +``` + +Returns a lazy sequence consisting of the result of applying `f` to 1 +and the first item of `coll`, followed by applying `f` to 2 and the +second item in `coll`, etc, until `coll` is exhausted. Returns a +transducer when no collection is provided. + +## `mapcat` +Function signature: + +``` +(mapcat ([f]) ([f & colls])) +``` + +Apply `concat` to the result of calling `map` with `f` and +collections `colls`. Returns a transducer when no collection is +provided. + +## `merge` +Function signature: + +``` +(merge [& maps]) +``` + +Merge `maps` rght to left into a single hash-map. + +## `next` +Function signature: + +``` +(next [s]) +``` + +Return the tail of a sequence. + +If the sequence is empty, returns nil. + +## `nth` +Function signature: + +``` +(nth ([coll i]) ([coll i not-found])) +``` + +Returns the value at the `index`. `get` returns `nil` if `index` out +of bounds, `nth` raises an error unless `not-found` is supplied. +`nth` also works for strings and sequences. + +## `nthnext` +Function signature: + +``` +(nthnext [coll n]) +``` + +Returns the nth next of `coll`, (seq coll) when `n` is 0. + +## `partition-all` +Function signature: + +``` +(partition-all ([n]) ([n coll]) ([n step coll])) +``` + +Given a collection `coll`, returns a lazy sequence of lists like +`partition`, but may include partitions with fewer than n items at the +end. Accepts addiitonal `step` argument, similarly to `partition`. +Returns a transducer, if collection is not supplied. + +## `partition-by` +Function signature: + +``` +(partition-by ([f]) ([f coll])) +``` + +Applies `f` to each value in `coll`, splitting it each time `f` +returns a new value. Returns a lazy seq of partitions. Returns a +transducer, if collection is not supplied. + +## `persistent!` +Function signature: + +``` +(persistent! [coll]) +``` + +Returns a new, persistent version of the transient collection. The +transient collection cannot be used after this call, any such use will +raise an error. + +## `pop!` +Function signature: + +``` +(pop! [coll]) +``` + +Removes the last item from a transient vector. If the collection is +empty, raises an error Returns coll + +## `random-sample` +Function signature: + +``` +(random-sample ([prob]) ([prob coll])) +``` + +Returns items from coll with random probability of prob (0.0 - +1.0). Returns a transducer when no collection is provided. + +## `realized?` +Function signature: + +``` +(realized? [s]) +``` + +Check if sequence's first element is realized. + +## `reduced?` +Function signature: + +``` +(reduced? [x]) +``` + +Returns true if `x` is the result of a call to reduced + +## `reductions` +Function signature: + +``` +(reductions ([f coll]) ([f init coll])) +``` + +Returns a lazy seq of the intermediate values of the reduction (as +per reduce) of `coll` by `f`, starting with `init`. + +## `remove` +Function signature: + +``` +(remove ([pred]) ([pred coll])) +``` + +Returns a lazy sequence of the items in the `coll` without elements +for wich `pred` returns logical true. Returns a transducer when no +collection is provided. + +## `repeat` +Function signature: + +``` +(repeat [x]) +``` + +Takes a value `x` and returns an infinite lazy sequence of this value. + +### Examples + +``` fennel +(assert-eq 10 (accumulate [res 0 + _ x (pairs (take 10 (repeat 1)))] + (+ res x))) +``` + +## `repeatedly` +Function signature: + +``` +(repeatedly [f & args]) +``` + +Takes a function `f` and returns an infinite lazy sequence of +function applications. Rest arguments are passed to the function. + +## `replace` +Function signature: + +``` +(replace ([smap]) ([smap coll])) +``` + +Given a map of replacement pairs and a vector/collection `coll`, +returns a vector/seq with any elements `=` a key in `smap` replaced +with the corresponding `val` in `smap`. Returns a transducer when no +collection is provided. + +## `rseq` +Function signature: + +``` +(rseq [rev]) +``` + +Returns, in possibly-constant time, a seq of the items in `rev` in reverse order. +Input must be traversable with `ipairs`. Doesn't work in constant +time if `rev` implements a linear-time `__len` metamethod, or invoking +Lua `#` operator on `rev` takes linar time. If `t` is empty returns +`nil`. + +### Examples + +``` fennel +(def :private v [1 2 3]) +(def :private r (rseq v)) + +(assert-eq (reverse v) r) +``` + +## `seq?` +Function signature: + +``` +(seq? [x]) +``` + +Check if object is a sequence. + +## `sequence` +Function signature: + +``` +(sequence ([coll]) ([xform coll]) ([xform coll & colls])) +``` + +Coerces coll to a (possibly empty) sequence, if it is not already +one. Will not force a lazy seq. `(sequence nil)` yields an empty list, +When a transducer is supplied, returns a lazy sequence of applications +of the transform to the items in `coll`, i.e. to the set of first +items of each `coll`, followed by the set of second items in each +`coll`, until any one of the `colls` is exhausted. Any remaining +items in other `colls` are ignored. The transform should accept +number-of-colls arguments + +## `some?` +Function signature: + +``` +(some? [x]) +``` + +Returns true if x is not nil, false otherwise. + +## `sort` +Function signature: + +``` +(sort ([coll]) ([comparator coll])) +``` + +Returns a sorted sequence of the items in `coll`. If no `comparator` +is supplied, uses `<`. + +## `split-at` +Function signature: + +``` +(split-at [n coll]) +``` + +Return a table with sequence `coll` being split at `n` + +## `split-with` +Function signature: + +``` +(split-with [pred coll]) +``` + +Return a table with sequence `coll` being split with `pred` + +## `take-last` +Function signature: + +``` +(take-last [n coll]) +``` + +Return a sequence of last `n` elements of the `coll`. + +## `take-nth` +Function signature: + +``` +(take-nth ([n]) ([n coll])) +``` + +Return a lazy sequence of every `n` item in `coll`. Returns a +transducer when no collection is provided. + +## `take-while` +Function signature: + +``` +(take-while ([pred]) ([pred coll])) +``` + +Take the elements from the collection `coll` until `pred` returns logical +false for any of the elemnts. Returns a lazy sequence. Returns a +transducer when no collection is provided. + +## `transduce` +Function signature: + +``` +(transduce ([xform f coll]) ([xform f init coll])) +``` + +`reduce` with a transformation of `f` (`xform`). If `init` is not +supplied, `f` will be called to produce it. f should be a reducing +step function that accepts both 1 and 2 arguments, if it accepts only +2 you can add the arity-1 with `completing`. Returns the result of +applying (the transformed) `xform` to `init` and the first item in +`coll`, then applying `xform` to that result and the 2nd item, etc. If +`coll` contains no items, returns `init` and `f` is not called. Note +that certain transforms may inject or skip items. + +## `transient` +Function signature: + +``` +(transient [coll]) +``` + +Returns a new, transient version of the collection. + +## `tree-seq` +Function signature: + +``` +(tree-seq [branch? children root]) +``` + +Returns a lazy sequence of the nodes in a tree, via a depth-first walk. + +`branch?` must be a function of one arg that returns true if passed a +node that can have children (but may not). `children` must be a +function of one arg that returns a sequence of the children. Will +only be called on nodes for which `branch?` returns true. `root` is +the root node of the tree. + +### Examples + +For the given tree `["A" ["B" ["D"] ["E"]] ["C" ["F"]]]`: + + A + / \ + B C + / \ \ + D E F + +Calling `tree-seq` with `next` as the `branch?` and `rest` as the +`children` returns a flat representation of a tree: + +``` fennel +(assert-eq (map first (tree-seq next rest ["A" ["B" ["D"] ["E"]] ["C" ["F"]]])) + ["A" "B" "D" "E" "C" "F"]) +``` + +## `unreduced` +Function signature: + +``` +(unreduced [x]) +``` + +**Undocumented** + +## `update` +Function signature: + +``` +(update [tbl key f]) +``` + +Update table value stored under `key` by calling a function `f` on +that value. `f` must take one argument, which will be a value stored +under the key in the table. + +### Examples + +Same as `assoc` but accepts function to produce new value based on key value. + +``` fennel +(assert-eq + {:data "THIS SHOULD BE UPPERCASE"} + (update {:data "this should be uppercase"} :data string.upper)) +``` + +## `update-in` +Function signature: + +``` +(update-in [tbl key-seq f]) +``` + +Update table value stored under set of immutable nested tables, via +given `key-seq` by calling a function `f` on the value stored under the +last key. `f` must take one argument, which will be a value stored +under the key in the table. Returns a new immutable table. + +### Examples + +Same as `assoc-in` but accepts function to produce new value based on key value. + +``` fennel +(fn capitalize-words [s] + (pick-values 1 + (s:gsub "(%a)([%w_`]*)" #(.. ($1:upper) ($2:lower))))) + +(assert-eq + {:user {:name "John Doe"}} + (update-in {:user {:name "john doe"}} [:user :name] capitalize-words)) +``` + +## `vec` +Function signature: + +``` +(vec [coll]) +``` + +Coerce collection `coll` to a vector. + +## `zipmap` +Function signature: + +``` +(zipmap [keys vals]) +``` + +Return an associative table with the `keys` mapped to the +corresponding `vals`. + + +--- + +Copyright (C) 2020-2021 Andrey Listopadov + +License: [MIT](https://gitlab.com/andreyorst/fennel-cljlib/-/raw/master/LICENSE) + + +<!-- Generated with Fenneldoc v0.1.9 + https://gitlab.com/andreyorst/fenneldoc --> |