Can this code be more succinct

Ruby
1

Hi All,

I like to use the following form for handling error situations:

( puts “ERROR: Long msg”;
exit) if some_boolean _expression

I want the multiple form because the error messages are often long and
sometimes multi-line.

Is there any way to improve it by getting rid of the parentheses?

Thanks in advance,
Richard

2

RichardOnRails wrote:

Is there any way to improve it by getting rid of the parentheses?
if some_boolean_expression
puts “ERROR: Long msg”
exit
end #SCNR

Seriously, though, what about this:

abort "ERROR: Long msg " +
“more message” if true

or

abort %{
line 1
line 2
} if true

3

RichardOnRails wrote:

Hi All,

I like to use the following form for handling error situations:

( puts “ERROR: Long msg”;
exit) if some_boolean _expression

I want the multiple form because the error messages are often long and
sometimes multi-line.

Is there any way to improve it by getting rid of the parentheses?

Thanks in advance,
Richard

Why use such a tortured construct in the first place? This is much
clearer:

if condition
puts <<-ENDOFSTRING
warning error warning error warning error warning error
warning error warning error warning error warning error
warning error warning error warning error warning error
warning error warning error warning error warning error
warning error warning error warning error warning error
ENDOFSTRING

exit
end

4

On Apr 28, 9:45 pm, RichardOnRails
[email protected] wrote:

Is there any way to improve it by getting rid of the parentheses?

Thanks in advance,
Richard

Thank you both for your generous, expert advice.

Here are two statements I now have in my app instead of my former,
convoluted and heavily parenthesizes statements:

http://www.pastie.org/462055

With gratitude,
Richard

5

I can’t help but feel that instead of getting more succint it seems to
become more and more verbose … :wink:

Except for the one-liner abort, which looks quite nice.

6

I can’t help but think this could be wrapped up in a nice, neat case
statement that is perhaps not more succinct but more readable.

case arg = ARGV[0]
when /^os$/
sym = arg.downcase
else
abort “ERROR: invalid arg #{arg}”
end

but I’m not sure whether the number of args check can be handled
inside the case. I tried a ‘when ARGV.size > 1’ but you can’t put a
full expression in a when statement.

7

On 4/30/09, Mark T. [email protected] wrote:

but I’m not sure whether the number of args check can be handled
inside the case. I tried a ‘when ARGV.size > 1’ but you can’t put a
full expression in a when statement.

there’s another form for case.
try this (untested),

arg = ARGV[0]
case
when ARGV.size > 1
abort “too many args ;-)”
when /^os$/ =~ arg
sym = arg.downcase
else
abort “ERROR: invalid arg #{arg}”
end

8

On 29.04.2009 05:38, RichardOnRails wrote:

sometimes multi-line.

http://www.pastie.org/462055

Frankly, I find this bit still quite convoluted, especially because of
the assignment in “unless”. How about:

arg = ARGV.shift || ‘os’
abort “ERROR:…” unless /\Aos\z/i =~ arg
abort “ERROR: multiple…” unless ARGV.empty?

Kind regards

robert

9

botp wrote:

On 4/30/09, Mark T. [email protected] wrote:

but I’m not sure whether the number of args check can be handled
inside the case. I tried a ‘when ARGV.size > 1’ but you can’t put a
full expression in a when statement.

there’s another form for case.
try this (untested),

arg = ARGV[0]
case
when ARGV.size > 1
abort “too many args ;-)”
when /^os$/ =~ arg
sym = arg.downcase
else
abort “ERROR: invalid arg #{arg}”
end

…but then instead of having to look up the format of a case statement,
you could just write:

val = “red”

if val == “blue”
puts “blue”
elsif val == “red”
abort “code red”
else
puts “not recognized”
end

puts “program terminating normally”

10

7stud – wrote:

…but then instead of having to look up the format of a case statement,
you could just write:

val = “red”

if val == “blue”
puts “blue”
elsif val == “red”
abort “code red”
else
puts “not recognized”
end

puts “program terminating normally”

…but then it is easier to type “when” than
“elseifif”. :slight_smile: