package closure;

import basic;
import array;

// a function mapping an operation element-wise over a sequence
function map( sequence, oper )
{
    local result = #[];

    local el;
    for (el in sequence)
        array.push( result, oper( el ) );
    return result;
}

/*
 * return the sequence obtained by applying the
 * exponentiation operator (x**y) to each element
 */
function pow( sequence, y )
{
    /*
     * We pass a closure referencing our argument y
     * as the operation.
     */
    return map( sequence,
                function( x )
                {
                    return x ** y;
                } );
}

private aSeq       = #[1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
private squareSeq  = pow( aSeq, 2 );
private cubeSeq    = pow( aSeq, 3 );

basic.print( "Original sequence: ", aSeq, "\n" );
basic.print( "sequence ** 2    : ", squareSeq, "\n" );
basic.print( "sequence ** 3    : ", cubeSeq, "\n" );