Higher-order functions: Difference between revisions

=={{header|CLU}}==

<lang clu>% Functions can be passed to other functions using the 'proctype'

% type generator. The same works for iterators, using 'itertype'

% Here are two functions

square = proc (n: int) returns (int) return (n*n) end square

cube = proc (n: int) returns (int) return (n*n*n) end cube

% Here is a function that takes another function

do_calcs = proc (from, to: int, title: string,

fn: proctype (int) returns (int))

po: stream := stream$primary_output()

stream$putleft(po, title, 8)

stream$puts(po, " -> ")

for i: int in int$from_to(from,to) do

stream$putright(po, int$unparse(fn(i)), 5)

end

stream$putc(po, '\n')

end do_calcs

start_up = proc ()

do_calcs(1, 10, "Squares", square)

do_calcs(1, 10, "Cubes", cube)

end start_up</lang>

{{out}}

<pre>Squares -> 1 4 9 16 25 36 49 64 81 100

Cubes -> 1 8 27 64 125 216 343 512 729 1000</pre>