shell-pipe-class.raku

use v6;

## agregation of STDERR
## filtering of STDERR for colour coding and ENV vars
## exception handling with STDERR stashing
## https://colabti.org/irclogger/irclogger_log/raku?date=2020-07-04#l268

subset Arrayish of Any where { .^can(‚push‘) && .^can(‚list‘) }

class Shell::Pipe {
    has @.pipees;
    has @.starters;
    has $.name is rw = "Shell::Pipe <anon>";
    method start {
        do for @.starters.reverse -> &c { |c }
    }
    method sink { note "sinking {self.gist}"; await self.start }
    method gist { 
        @.pipees.map(*.&gist-of-pipee).join(' ↦ ')
    }
    sub gist-of-pipee($e) {
        given $e { 
            when Proc::Async { .path.IO.basename }
            when Routine { .name }
            when Block { „Block({.file.IO.basename}:{.line})“ }
            when Arrayish { .?name // .WHAT.gist }
        }
    }
}

my multi infix:«|>»(Proc::Async:D $out, &c) { 
    my $pipe = Shell::Pipe.new;

    $pipe.pipees.append: $out, &c;

    $pipe
}

my multi infix:«|>»(Shell::Pipe:D $pipe, &c) { 
    $pipe.pipees.append: &c;

    $pipe
}

my multi infix:«|>»(Proc::Async:D $out, Proc::Async:D $in) { 
    my $pipe = Shell::Pipe.new;

    $pipe.pipees.append: $out, $in;
    $pipe.starters.append: -> { 
        $in.start, $out.start 
    }

    $in.bind-stdin: $out.stdout;

    $pipe
}

my multi infix:«|>»(Shell::Pipe:D $pipe, Proc::Async:D $in) { 
    my $out = $pipe.pipees.tail;
    $pipe.pipees.push: $in;

    given $out {
        when Proc::Async { 
            $in.bind-stdin: .stdout;
            $pipe.starters.push: -> { $in.start };
        }
        when Arrayish { 
            fail "Arrayish not at the tail or head of a pipe.";
        }
    }

    $pipe
}

my multi infix:«|>»(Proc::Async:D $out, Arrayish:D \a) { 
    my $pipe = Shell::Pipe.new;

    $pipe.pipees.push: $out;
    $pipe.pipees.push: a;

    $out.stdout.lines.tap(-> \e { a.push: e });
    $pipe.starters.push(-> { $out.start });

    $pipe
}

my multi infix:«|>»(Shell::Pipe:D $pipe, Arrayish:D \a) { 
    my $out = $pipe.pipees.tail;
    $pipe.pipees.push: a;

    $out.stdout.lines.tap(-> \e { a.push: e });

    $pipe
}

my multi infix:«|>»(Arrayish:D \a, Proc::Async:D $in) { 
    my $pipe = Shell::Pipe.new;

    $pipe.pipees.push: a;
    $pipe.pipees.push: $in;
    # FIXME workaround R#3778
    $in.^attributes.grep(*.name eq '$!w')[0].set_value($in, True);
    $pipe.starters.push: -> { 
        | $in.start, start {
            LEAVE try $in.close-stdin;
            $in.write: „$_\n“.encode for a.list;
        }
    }

    $pipe
}

my multi infix:«|>»(Supply:D \s, Proc::Async:D $in) {
    # TODO
}

my multi infix:«|>»(Supply:D \s, Shell::Pipe:D $in) {
    # TODO
}

my $find = Proc::Async.new('/usr/bin/find', '/tmp');
my $grep = Proc::Async.new('/bin/grep', 'a');
my $sort = Proc::Async.new('/usr/bin/sort');
my @a;
my @spy;
# 
# sub my-little-filter { $^a ~~ s/a/b/ }
# 
# my $pipe = $find \
#            |> @spy \
#            |> $grep \
#            |> &my-little-filter \
#            |> $sort \
#            |> { .uc } \
#            |> @a;
# 
# say $pipe;
@a = <3 b a 5 c>;
my $p = $find |> $sort |> @a;

say $p;