/
Main.pm
150 lines (134 loc) Β· 5.54 KB
/
Main.pm
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# TODO:
# * Align number parsing to STD
# * Rakudo's .Numeric
# * complex numbers
# * Rakudo's grammar
# * val()
# * Strengthen val()
# * Make val() available globally
# * $?USAGE
# * Create $?USAGE at compile time
# * Make $?USAGE available globally
# * Command-line parsing
# * Allow both = and space before argument of double-dash args
# * Comma-separated list values
# * Allow exact Perl 6 forms, quoted away from shell
# * Fix remaining XXXX
my sub MAIN_HELPER($retval = 0) is hidden_from_backtrace {
# Do we have a MAIN at all?
my $m = callframe(1).my<&MAIN>;
return $retval unless $m;
# Temporary stand-in for magic val() routine
my sub hack-val ($v) {
# Convert to native type if appropriate
my $val;
if $v ~~ /^ 'Bool::'?'False' $/ { $val := Bool::False }
elsif $v ~~ /^ 'Bool::'?'True' $/ { $val := Bool::True }
elsif $v.Numeric.defined { $val := +$v }
else { return $v }
# Mix in original stringifications
my role orig-string[$orig] {
method Str () { $orig.Str }
multi method gist (Mu:D:) { $orig.gist }
};
return $val but orig-string[$v];
}
# Convert raw command line args into positional and named args for MAIN
my sub process-cmd-args (@args is copy) {
my (@positional-arguments, %named-arguments);
while (@args) {
my $passed-value = @args.shift;
if $passed-value ~~ /^ ( '--' | '-' | ':' ) ('/'?) (<-[0..9\.]> .*) $/ {
my ($switch, $negate, $arg) = (~$0, ?((~$1).chars), ~$2);
if $arg.index('=').defined {
my ($name, $value) = $arg.split('=', 2);
$value = hack-val($value);
$value = $value but False if $negate;
%named-arguments.push: $name => $value;
} else {
%named-arguments.push: $arg => !$negate;
}
} else {
@args.unshift($passed-value) unless $passed-value eq '--';
@positional-arguments.push: @args.map: &hack-val;
last;
}
}
$PROCESS::ARGFILES = IO::ArgFiles.new(:args(@args));
return @positional-arguments, %named-arguments;
}
# Generate $?USAGE string (default usage info for MAIN)
my sub gen-usage () {
my @help-msgs;
my $prog-name = $*PROGRAM_NAME eq '-e' ?? "-e '...'" !! $*PROGRAM_NAME;
for $m.candidates -> $sub {
my (@required-named, @optional-named, @positional, $docs);
for $sub.signature.params -> $param {
my $argument;
if $param.named {
my @names = $param.named_names.reverse;
$argument = @names.map({($^n.chars == 1 ?? '-' !! '--') ~ $^n}).join('|');
$argument ~= "=<{$param.type.^name}>" unless $param.type === Bool;
if $param.optional {
@optional-named.push("[$argument]");
}
else {
@required-named.push($argument);
}
}
else {
my $constraints = $param.constraint_list.map(*.gist).join(' ');
my $simple-const = $constraints && $constraints !~~ /^_block/;
$argument = $param.name ?? '<' ~ $param.name.substr(1) ~ '>' !!
$simple-const ?? $constraints !!
'<' ~ $param.type.^name ~ '>' ;
$argument = "[$argument ...]" if $param.slurpy;
$argument = "[$argument]" if $param.optional;
@positional.push($argument);
}
}
if $sub.WHY {
$docs = '-- ' ~ $sub.WHY.content
}
my $msg = join(' ', $prog-name, @required-named, @optional-named, @positional, $docs // '');
@help-msgs.push($msg);
}
my $usage = "Usage:\n" ~ @help-msgs.map(' ' ~ *).join("\n");
return $usage;
}
sub has-unexpected-named-arguments($signature, %named-arguments) {
my @named-params = $signature.params.grep: *.named;
return False if @named-params.grep: *.slurpy;
my %accepts-argument = @named-params.map({ .named_names }) Z=> 1 xx *;
for %named-arguments.keys -> $name {
return True if !%accepts-argument{$name}
}
return False;
}
# Process command line arguments
my ($p, $n) = process-cmd-args(@*ARGS).lol;
# Generate default $?USAGE message
my $?USAGE = gen-usage();
# Get a list of candidates that match according to the dispatcher
my @matching_candidates = $m.cando(Capture.new(list => $p, hash => $n));
# Sort out all that would fail due to binding
@matching_candidates .=grep: {!has-unexpected-named-arguments($_.signature, $n)};
# If there are still some candidates left, try to dispatch to MAIN
if +@matching_candidates {
return $m(|@($p), |%($n));
}
# We could not find the correct MAIN to dispatch to!
# Let's try to run a user defined USAGE sub
my $h = callframe(1).my<&USAGE>;
return $h() if $h;
# We could not find a user defined USAGE sub!
# Let's display the default USAGE message
if ($n<help>) {
$*OUT.say($?USAGE);
exit 1;
}
else {
$*ERR.say($?USAGE);
exit 2;
}
}