1. Re: Stripped Perl?
From: Andy Kurnia
Re: EUPHORIA Digest - 21 Jun 1998 to 22 Jun 1998 (#1998-36)
>now let's talk about the clumsiness of "else" and short-circuited "or":
[clumsy code with unparenthesized compound boolean expressions snipped]
>Tell me how you would code the above if the "elsif" above with the
>current Euphoria version. Since I noted above x can be changed, you may
>not use
> elsif y[1] != GET_SUCCESS or not find(y[2], {2, 4, 6, 9, 11}) then
>which should work since get() always returns a 2-element sequence.
include input.e --(custom include with prompt input and value-checking)
integer y
constant x = {31,28,31,30,31,30,31,31,30,31,30,31}
while 1 do
y = InputPosInt( "Enter a month with less than 31 days (0 to quit): " )
if y < length( x ) then
if x[y] < 31 then
puts( 1, "Thank You.\n" )
process( y )
else
puts( 1, "That month has 31 days.\n" )
end if
else
puts( 1, "There aren't that many months in the year!\n" )
end if
end while
That's how I'd do it. Incidentally, InputPosInt() is a routine I wrote
awhile back that doesn't use get or value. It displays the prompt,
reads input with gets(), and converts it to an integer with and_bits().
If you enter an invalid value, it puts "Please enter a positive integer."
and loops until it either gets a 0 (and aborts) or a positive integer.
>Perl can do C-like commands like
> $i += 3;
> $j++;
Euphoria doesn't require us to look up every cryptic command in a set
of a dozen 900-page manuals in order to decipher illegible source code.
It's a high-level language. It can do i = i+3 and j = j+1, which
have the same effect and are more readable.
>Perl allows command output capturing, as in
> $diffout = `diff -w oldfile newfile 2>&1`;
> # 2>&1 in unix means stderr should be redirected to stdout
> if ($? >> 8) { # if errorlevel is not zero
> print "Changes:\n";
> print $diffout;
> }
> else {
> print "No changes\n";
> }
>etc. Euphoria, stuck with the 20k tracer installed in it, can't do that...
Not quite sure what that does, but I believe you mean something like...
system( "diff -w oldfile newfile >diffout.txt", 2 )
diffout = ReadFile( "diffout.txt" )
if diffout[1] != "No changes" then
--or whatever the output of diff is in that case
puts ( 1, "Changes:\n" )
puts ( 1, diffout )
else
puts ( 1, "No changes." )
end if
Of course, I'm assuming that diff is some sort of program and that
you've written that ReadFile() routine. Incidentally, the ability to
use the errorvalue of a program/os command is one thing currently
missing from Euphoria. (Next version, right Rob?) But it's just as
easy to write a program that gives some sort of text output as it is
to write one that returns an errorlevel.
Deciphering difficulties...
"if ($? >> 8) { # if errorlevel is not zero" --perl
$? = incomprehensible_symbol (errorlevel?),
>> = appendto pipe in DOS, some kind of stream direction in C++,
8 = 8
(incomprehensible_symbol appended to 8) : (errorlevel != 0)
append(8, incomprehensible_symbol) : (errorlevel != 0)
estimate of perl translation comment translation
"if append( 8, errorlevel ) then" : "if (errorlevel != 0) then"
The Euphoria version looks just like your comment, right? Needed
little or no translation from human thought. Code that looks the way
we think is generally better than code that translates into meaningless
stuff. If I knew perl, of course, maybe I could have gotten a proper
translation. But on the other hand, any programmer can understand the
Euphoria version of that basic statement, even if they've never heard of
Euphoria.
>Perl allows you to have a Perl code embedded as string, and execute it,
>and tell you if it worked or if it has an error.
That would be nice.
>Perl can check if a variable or a routine exists, is defined, or ... well,
>Euphoria has routine_id but no variable_id.
Variable_id(), a pointer to the variable, wouldn't be good, or necessary.
But a boolean function if_defined() that works for any user-defined symbol
(constants, variables, and routine names) would be useful.
>Perl can also be compiled
>for win32 etc if you get the source,
And have the right compiler (c?, c++?, ANSI or other?, what version?,
what compile switches?), and know how to use it, and edit the source to
run on your machine and change the headers and includes and, and...
Right? I've downloaded a few c programs that only came as source, and it
wasn't long before I just deleted 'em, rather than try to figure out how
to compile them on my compiler so that they'd work. Euphoria saves you all
that hassle and gives you the binaries, you don't even need to know c to
use Euphoria.
I'd guess that there's a pre-compiled version of Perl available somewhere
too, though.
>There is no debugging facility at all in Perl
Hmm...all that cryptic code and no way to debug it? Pbbt.
-100 points.
I'm not slamming Perl, I'm sure it's pretty powerful and has some
use. But Euphoria is not a stripped-down perl. It's a distinctly
different language with it's own strengths and weaknesses that
is at least the equal of Perl, IMO.
