将 Str 转换为 Enums 列表列表
原标题：converting list of Str into list of Enums
I have an enum definition in a module AAA:
enum RDProcDebug ;
class Debug {
method foo(RDProcDebug @ds) {
for @ds { say .key ~ => ~ .value }
}
}
In Raku programs, this works well, eg
use AAA;
my RDProcDebug $rp .= new;
$r.foo(AstBlock, BlockType);
But now I need to supply the names of the debug elements from the command line, which can only supply Str, eg
$ RDOpts= AstBlock BlockType raku myprog
# and in myprog
if %*ENV:exists {
$rp.debug( %*ENV ); # this does not work
}
So how do I convert a list of Str into a list of type enum RDProcDebug ?
最佳回答
Okay, so you want to pass those enum values from the command line, but there you only get strings. I get it. Here s what you can do:
First, grab that RDOpts from your environment and split it into separate words.
my @debug-options = %*ENV.split(/s+/);
Now here s the neat part. Raku has a trick to look up enum values by their name. It looks a bit weird, but it works like this:
my @debug-values = @debug-options.map({ RDProcDebug::{$_} });
What this does is check for each string in your list if there s a matching enum value. If all goes well, you ll end up with a list of actual RDProcDebug values. You can now just pass it to your debug method:
$rp.debug(@debug-values);
All together you would get something like this:
if %*ENV {
my @debug-options = %*ENV.split(/s+/);
my @debug-values = @debug-options.map({ RDProcDebug::{$_} });
$rp.debug(@debug-values);}
Oh yeah, one more thing: if someone types in a wrong name, you ll get an error. You might want to do something about that..
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