Community documentation for Janet

(buffer ;(interpose " " [:ant 'bee "cat" ``dog`` @`ewe`]))
# => @"ant bee cat dog ewe"

(= math/-inf (- math/-inf 1))
# =>
true

# note that 'not' works as an implementation of 'falsey?'
(map not     [ nil   false true  0     1     'a    :a    "a"   []    {}    (fn []) ])
# =>        @[ true  true  false false false false false false false false false   ]

(map truthy? [ nil   false true  0     1     'a    :a    "a"   []    {}    (fn []) ])
# =>        @[ false false true  true  true  true  true  true  true  true  true    ]

(doc-of file/read) # => file/read docs are shown

(def tmpfile (file/temp))

(doc-of (tmpfile :read)) # => also shows the file/read docs. 
# Note that we didn't have to use the file/read symbol here to get docs.

(buffer "dude, " "where's " "my " "car?") # => @"dude, where's my car?"

(map bytes?      [ 'ab   :ab   "ab"   @"ab"  [97 98]  @[97 98]  {0 97 1 98}  @{0 97 1 98}  ])
# =>            @[ true  true  true   true   false    false     false        false         ]

(map symbol?     [ 'ab   :ab   "ab"   @"ab"  [97 98]  @[97 98]  {0 97 1 98}  @{0 97 1 98}  ])
# =>            @[ true  false false  false  false    false     false        false         ]

(map keyword?    [ 'ab   :ab   "ab"   @"ab"  [97 98]  @[97 98]  {0 97 1 98}  @{0 97 1 98}  ])
# =>            @[ false true  false  false  false    false     false        false         ]

(map string?     [ 'ab   :ab   "ab"   @"ab"  [97 98]  @[97 98]  {0 97 1 98}  @{0 97 1 98}  ])
# =>            @[ false false true   false  false    false     false        false         ]

(map buffer?     [ 'ab   :ab   "ab"   @"ab"  [97 98]  @[97 98]  {0 97 1 98}  @{0 97 1 98}  ])
# =>            @[ false false false  true   false    false     false        false         ]

# use (dyn :args) to get the value of dynamic binding *args*
(let [args (dyn :args)]
  (if (= "-h" (get args 1))
    (print "Usage: janet args.janet [-h] ARGS..")
    (printf "command line arguments:\n %q" args)))

# Find all bindings (in the current environment) with "push" in the name.
(doc "push")

#    Bindings:
#
#    array/push buffer/push buffer/push-byte buffer/push-string
#    buffer/push-word
#
#    Dynamics:
#
#
#
#    Use (doc sym) for more information on a binding.

(os/dir ".")              # => @["foo" "bar"]
(os/rename "bar" "bar2")  # => nil
(os/dir ".")              # => @["bar2" "foo"]

(reduce string "ha" ["ha" "ha" "ha" "ha"]) # => "hahahahaha"

(accumulate string "ha" ["ha" "ha" "ha" "ha"]) # => @["haha" "hahaha" "hahahaha" "hahahahaha"]

# There is a list of formatters here: https://janet-lang.org/capi/writing-c-functions.html


(string/format "With terminal colors: %M" [:array {:key-in "struct"}]) # => "With terminal colors: (\e[33m:array\e[0m {\e[33m:key-in\e[0m \e[35m\"struct\"\e[0m})"

(defn greet-me [] (print "hey programmer!"))
(defn greet-stranger [] (print "hey stranger!"))

(varfn greet [] (greet-me))
(greet) # prints "hey programmer!"
(varfn greet [] (greet-stranger))
(greet) # prints "hey stranger!"

# kind of analogous to (def greet (fn [] (some-thunk))), but with built-in
# sugar to automatically update 'greet' if varfn is called with a name
# already bound

(int/u64 "18446744073709551615")
# => <core/u64 18446744073709551615>

(string/bytes "foo")  # => (102 111 111)
(string/from-bytes 102 111 111)  # => "foo"
(string/from-bytes (splice (string/bytes "foo")))  # => "foo"

(map (fn [x] x)        "foo")  # => @[102 111 111]
(map string/from-bytes "foo")  # => @["f" "o" "o"]

(defn string/explode [s] (map string/from-bytes s))
(string/explode "foo")  # => @["f" "o" "o"]

(frequencies ["a" "a" "b" "c" "d" "d"])
# => @{"c" 1 "d" 2 "a" 2 "b" 1}


(frequencies {:a "Bob"
              :b "Joe"
              :c "Mat"
              :d "Bob"})
# => @{"Bob" 2 "Joe" 1 "Mat" 1}

(frequencies "Hallo World")
# => @{108 3 114 1 100 1 87 1 97 1 32 1 111 2 72 1}