call

call function with given list of parameters

Parameters

call function :string :literal :function
     params :block

Attributes

external:stringpath to external library
expect:typeexpect given return type

Returns

  • :any

Examples

copy
multiply: function [x y][
    x * y
]

call 'multiply [3 5]          ; => 15

copy
call $[x][x+2] [5]            ; 7

copy
; Calling external (C code) functions

; compile with:
; clang -c -w mylib.c
; clang -shared -o libmylib.dylib mylib.o

; #include 
;
; void sayHello(char* name){
;    printf("Hello %s!\n", name);
; }
;
; int doubleNum(int num){
;    return num * 2;
;}

; call an external function directly
call.external: "mylib" 'sayHello ["John"]

; map an external function to a native one
doubleNum: function [num][
    ensure -> integer? num
    call .external: "mylib"
        .expect:   :integer
        'doubleNum @[num]
]

loop 1..3 'x [
    print ["The double of" x "is" doubleNum x]
]

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