type-functions.sc

using import ..pijul.utils.va

#inline va-pos (val args...)
    va-lifold none
        inline "#hidden" (i key arg result)
            dump i key arg result
            static-if (not (none? result)) result
            elseif (arg == val) i
            else result
        args...

inline first (a b)
    static-if (none? a) b
    else a

inline last (a b)
    static-if (none? b) a
    else b

inline only-one (a b)
    static-if (none? a) b
    elseif (none? b) a
    else
        static-error "Only one is allowed"

inline va-pos-finder (test select)
    inline va-pos-finder (val args...)
        va-lifold none
            inline (i key arg result)
                define next
                    static-if (test val arg) i
                select result next
            args...

inline va-find-pos (val test select args...)
    (va-pos-finder test select)
        val args...

inline va-finder (test select)
    inline va-pos-finder (val args...)
        va-lfold none
            inline (key arg result)
                define next
                    static-if (test val arg) arg
                select result next
            args...

inline va-find (val test select args...)
    (va-finder test select)
        val args...

let args... = 1 2:u32 3.0

inline dispatcher-maker (args...)
    let types... =
        va-map typeof args...
    let finder =
        va-pos-finder (do >=) only-one
    _
        inline (type)
            let pos =
                finder type types...
            static-if (none? pos)
                static-error "No argument of specified type found"
            va@ pos args...
        inline (type)
            va-map
                inline (arg)
                    static-if ((typeof arg) <= type) arg
                args...
        inline (type)
            let pos =
                finder type types...
            not (none? pos)

let this these has? =
    dispatcher-maker args...

print
    has? u32

print
    has? real

print
    has? i8

print
    this u32

sugar type-dispatcher (body...)
    qq
        fn (...)
            let this these has? =
                dispatcher-maker ...

            unquote-splice body...

run-stage;

define integer-printer
    type-dispatcher
        print
            static-if (has? i32)
                ..
                    tostring (this i32)
                    ":i32"
            else
                this integer

integer-printer 1
integer-printer 2:u32
print 1
print 2:u32

define sum-numbers-and-concatenate-strings
    type-dispatcher
        _
            + 0
                these integer
            .. ""
                these string

let num str =
    sum-numbers-and-concatenate-strings
        \ 1 2 "Hello" 3 " " 4 5 "world" "!"

print num
print str