Differences from K

        |              KLONG  **  A SIMPLE ARRAY LANGUAGE              |

                         Differences Between Klong and K
                                 By Nils M Holm
                              n m h @ t 3 x . o r g


        Klong is sufficiently similar to K to confuse you, so here is a
        summary of things that work differently in K. This list may not
        be complete. Please send additions via


        A single colon is used for quotation, so :x is like `x in K.

        Lists are LISP-like in Klong, but using square brackets:

        K List                        Klong List
        1 2 3 4 5                     [1 2 3 4 5]
        (1 2 3; 4 5 6; 7 8 9)         [[1 2 3] [4 5 6] [7 8 9]
        ((1 2; 3 4)                   [[[1 2] [3 4]] [[5 6] [7 8]]]
         (5 6; 7 8))

        Real numbers must have at least one digit before the ".", i.e.
        .0 is not a valid real number (but 0. is).

        Symbol names may contain dots, and system function begin with a
        dot, e.g.: .rn, .w, etc.


        Some verbs are different. They may differ in syntax, naming, or

        K Verb       K Syntax     Klong Syntax   Klong Verb
        ----------   ----------   ------------   --------------
        Amend        v:x          x::y           Define
        Item Amend   v[i;...]:x   x:=[y i...]    Amend
        Amend        v[i;...]:x   x:-[y i...]    Amend-in-Depth
        ?            ?            :#x            Char
        Cut/Drop     x_y          x:_y           Cut
        Where        &x           &x             Expand/Where
        Form         x$y          x:$y           Form
        Format       x$y          x$y            Format2
        ?            ?            x:@y           Index-in-Depth
        ?            ?            x:%y           Integer-Divide
        Enlist       ,x           ,x             List
        Reshape      x#y          x:^y           Reshape
        Rotate/Mod   x!y          x!y            Remainder
        Rotate/Mod   x!y          x:+y           Rotate
        Count        #x           #x             Size
        ?            ?            x:#y           Split
        Flip         +x           +x             Transpose

        There are also lots of K verbs that do not have any counterparts
        in Klong. They are not listed here.

        Unlike Amend, Define can only assign a value to a variable.

        The left side of Amend and Amend-in-Depth may be a list or array.
        Amend always returns a fresh copy and never alters values in
        situ. See [Amend] and [Amend-in-Depth] in the Reference Manual
        for examples.

        Cut may have an integer on its left side, e.g. 1:_[1 2 3].

        Form returns :undefined when it cannot decode its string

        Remainder returns the difference between the division result and
        the truncated (rounded to -infinity) division result.

        Size returns the magnitude (absolute value) of numbers and the
        code point of characters.


        Som adverbs also differ from their K counterparts:

        K Adverb     K syntax     Klong Syntax   Klong Adverb
        ----------   ----------   ------------   -----------------
        Each         x f'y        x f'y          Each2
        Each-Right   x f/:y       x f:\y         Each-Left
        Each-Pair    x f':y       x f:'y         Each-Pair
        Each-Left    y f\:x       x f:/y         Each-Right
        Over Dyad    f/x          f/x            Over
        Over Dyad    x f/y        x f/y          Over/Neutral
        Over Monad   f/x          f:~x           Converge
        Over Monad   x f/y        x f:~y         While
        Over Monad   x f/y        x f:*y         Iterate
        Scan Dyad    f\x          f\x            Scan-Over
        Scan Dyad    x f\y        x f\y          Scan-Over-Neutral
        Scan Monad   f\x          f\~x           Scan-Converging
        Scan Monad   f\x          x f\~x         Scan-While
        Scan Monad   f\x          x f\*x         Scan-Iterating

        Each-Pair combines elements in the opposite order, e.g.:
        -:'[1 2 3 4]  -->  (1-2),(2-3),(3-4)

        Each-Left and Each-Right are opposites in K and Klong, and in
        addition, arguments are expected in a different order in one
        case. Look closely!

        Scan-While collects only elements that satisfy the condition,
        e.g.: {x<10}{x+1}\~1  -->  [1 2 3 4 5 6 7 8 9]


        Dictionaries are always altered in situ.


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