Programming-Idioms

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Idiom #196 Pass a sub-array

Given an integer array a of size n, pass the first, third, fifth and seventh, ... up to the m th element to a routine foo which sets all these elements to 42.

import std.range;
void foo(Range)(Range r) {
	r.fill(42);
}

foo(a.indexed(iota(0,m,2)));
! Caller:
  integer, dimension(n) :: a
  call foo(a(1:m:2))

! Callee:

  subroutine foo(a)
    integer, dimension(:), intent(inout) :: a
    a = 42
  end subroutine foo
Math
procedure foo(var L: Integer);
begin
  L := 42;
end;

begin
  for i := 0 to Min(m, n-1) do
    if not odd(i) then foo(a[i]);
end.
sub foo  {
    my ($A, @i) = @_;
    @$A[@i] = (42) x @i;
    return $A;
}
foo($A, grep { 0 == $_ % 2 } 0 .. $m);

def foo(data, r):
    for i in r: data[i] = 42
    return

foo(a, range(0, m+1, 2))
fn foo(el: &mut i32) {
    *el = 42;
}
a.iter_mut().take(m).step_by(2).for_each(foo);
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Idiom created by

tkoenig 
void foo(Range)(Range r) {
	r.fill(42);
}

foo(a.indexed(iota(0,m,2)));
! Caller:
  integer, dimension(n) :: a
  call foo(a(1:m:2))

! Callee:

  subroutine foo(a)
    integer, dimension(:), intent(inout) :: a
    a = 42
  end subroutine foo
procedure foo(var L: Integer);
begin
  L := 42;
end;

begin
  for i := 0 to Min(m, n-1) do
    if not odd(i) then foo(a[i]);
end.
sub foo  {
    my ($A, @i) = @_;
    @$A[@i] = (42) x @i;
    return $A;
}
foo($A, grep { 0 == $_ % 2 } 0 .. $m);

def foo(data, r):
    for i in r: data[i] = 42
    return

foo(a, range(0, m+1, 2))
fn foo(el: &mut i32) {
    *el = 42;
}
a.iter_mut().take(m).step_by(2).for_each(foo);