(namespace core)


(docs "This is the macro that is called when brackets (`[]`) are
used. Emits a javascript array literal. Splats (`...`) can be used to
in-line other arrays."
      tags [arrays collections]
      examples [ (list 1 2 3 4 5)
                 [ 'a 'b 'c 'd 'e ]
                 [ a b ...c d ...e ] ])
      
(macro list (...args)
       (var arg-segments [])
       (if (empty? args) "[]"
           (do
            (def simple-list (args)
                 ["[ " (interleave ", " (map args (#(arg) arg.transpiled))) " ]"])

            (args.for-each (#(arg)
                  (if (node? arg 'dots) (arg-segments.push {transpiled (transpile arg)})
                   (list? (last arg-segments)) (.push (last arg-segments) { transpiled (transpile arg)})
                   (arg-segments.push [{transpiled (transpile arg)}]))))

            (assign arg-segments (map arg-segments
                                      (#(segment)
                                        (if (list? segment)
                                            (simple-list segment)
                                            segment.transpiled))))

            (if (= 1 (length arg-segments))
                (first arg-segments)
                [(first arg-segments) ".concat(" (interleave ", " (rest arg-segments))")"]))))

(docs "fetches length attribute from `arr`"
      tags [ arrays collections ]
      example (length [ 1 2 3 ]))
(macro length (arr)
       '(get @arr 'length))


(docs "`get`s the first element of `arr`"
      tags [ arrays collections ]
      example (first `[ a b c d e ]))
(macro first (arr) `(get @arr 0))

(docs "`get`s the second element of `arr`"
      tags [ arrays collections ]
      example (second `[ a b c d e ]))
(macro second (arr) `(get @arr 1))

(docs "`get`s the third element of `arr`"
      tags [ arrays collections ]
      example (third `[ a b c d e ]))
(macro third (arr) `(get @arr 2))


(docs "fetches all but the first item of `arr`"
      tags [arrays collections]
      example (rest [ 1 2 3 ]))
(macro rest (arr) '(.slice @arr 1))

(docs "fetches just the last element of `arr` by slicing."
      tags [arrays collections]
      example (last [ 1 2 3 ]))
(macro last (arr) '(first (.slice @arr -1)))



(docs "builds an array with `first` as the zeroth index and the
elements provided by array `rest` as the subsequent elements, as
siblings with `first`."
      tags [arrays collections deprecated]
      example (cons 1 [ 2 3 4 ]))

(macro cons (first rest)
       `(pipe
         (list @first)
         (.concat @rest)))


(docs "adds `additional` elements onto the right-side (tail) of `list`. deprecated"
      tags [ arrays collections deprecated ]
      example (append [ 1 2 3 ] 4 5 6))
(macro append (list ...additional)
       `(.concat @list (list ...@additional)))

(docs "iterates over `array`, evaluating `body` once for each value in
`array`.  If `item` is a literal name, that will be the variable into
which the `array` element is yielded (current value).  If `item` is an expression, it
can contain the current value, the index, and the `array`."
      tags [ arrays language collections ]
      references ["https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach"]
      examples [ (each number [ 1 2 3 ] (console.log number))
                 (each (letter index) `[ a b c d ]
                       (set letters letter index)
                       (pipe letter (.to-upper-case) (console.log))) ])

(macro each (item array ...body)
       (var node this
            args (if (node? item 'expression) item [item]))
       `(|> @array
            (.for-each (lambda @{ node& args& body& }))))


(docs "returns true if `haystack` includes `needle`.  `haystack` can be a string or array/list."
      tags [arrays collections]
      examples [ (includes? 'hello 'h) (includes? `[ Veni vidi vici] 'vidi) ])
(macro includes? (haystack needle)
       `(pipe @haystack (.index-of @needle) (!= -1)))

(docs "returns true if `haystack` does NOT include `needle`.
`haystack` can be a string or array/list"
      tags [arrays collections]
      examples [ (excludes? 'hello 10) (excludes? `[ Veni vidi vici] 'attenti) ])
(macro excludes? (haystack needle)
       `(pipe @haystack (.index-of @needle) (= -1)))