OpenEuphoria

Re: Win32Lib Update

• Posted by Ralf Nieuwenhuijsen <nieuwen at XS4ALL.NL> Nov 28, 1998
• 1056 views

>The function reverse() is missing from v 0.15a.
>Here's my attempt at a reverse() function. Before you start a new thread, I
>know this one probably isn't the fastest and doesn't reverse sequences
>within sequences.
>But it is useful, short and clean, IMO.

Why not start a thread ? 

function reverse_flat (sequence s)
-- Reverses only the top level
sequence result

    result = {}
    for index = 1 to length(s) do
        result = prepend(result, s[index])
    end for

    return result
end function

-- The above is the most clean and fastest, as far as I can tell.

function reverse (object x)
-- Reverses all levels in the sequence
sequence result

    if atom (x) then
        return x
    end if

    result = {}
    for index = 1 to lenght(s) do
        result = prepend (result, reverse (s[index]))
    end for

return result
end function

-- This too is the fastest (and cleanest possible). I know I can avoid one
level of recursion, however Euphoria's
for-statement-block-containing-only-one-statement-optimization will be
missed. And for larger sequences (those who need the extra speed the most)
this will make a significant difference.

However, the above is all speculative, until some one starts benchmarking on
this.

Ralf