Excel LAMBDA examples of function chaining

excel-lambda-PIPE.txt

IFOMITTED = LAMBDA(arg, then, IF(ISOMITTED(arg), then, arg));

// Functions for common mathematical operators
MULTIPLY = LAMBDA(x, y, x*y);
ADD = LAMBDA(x, y, x+y);
SUBTRACT = LAMBDA(x, y, x-y);
DIVIDE = LAMBDA(x, y, x/y);

// Apply a series of functions to an array
PIPE =LAMBDA(array, functions, operator, [init], 
    REDUCE(IFOMITTED(init, array), functions, LAMBDA(a, b, operator(a , b(array))))
);

// Currently arrays of functions are composed with HSTACK or VSTACK
pipe_usage_example 
    =PIPE(
        SEQUENCE(10), 
        HSTACK(LAMBDA(x, MAX(x)), LAMBDA(x, SUM(x))), 
        MULTIPLY, 
        1
    );

/* Typed arrays would simplify this dramatically 
Additionally, allowing passage of mathematical operators 
as functions (3rd arg) would be huge! */
/* 
//This doesn't work!
dream_pipe_usage_example =PIPE(SEQUENCE(10), {MAX, SUM}, *, 1);
*/