From 87765d0a9cf5ed1742deeead5a8099162d8559f4 Mon Sep 17 00:00:00 2001
From: Pragmatic Software <pragma78@gmail.com>
Date: Sat, 11 Jul 2020 21:15:54 -0700
Subject: [PATCH] Progress on embedding Plang

---
 Plang            |   2 +-
 Plugins/Plang.pm | 131 ++++++++++++++++++++++++++++++++++++++++-------
 2 files changed, 114 insertions(+), 19 deletions(-)

diff --git a/Plang b/Plang
index 16e65fdc..80f9afa6 160000
--- a/Plang
+++ b/Plang
@@ -1 +1 @@
-Subproject commit 16e65fdcab9571ce0a2edbc492e83fc6e05ceb7f
+Subproject commit 80f9afa670d2e96cd4b70df69c052a490d499273
diff --git a/Plugins/Plang.pm b/Plugins/Plang.pm
index 13ca0613..3bba1e15 100644
--- a/Plugins/Plang.pm
+++ b/Plugins/Plang.pm
@@ -23,9 +23,18 @@ sub initialize {
     unshift @INC, $path if not grep { $_ eq $path } @INC;
     require "$path/Interpreter.pm";
 
+    # regset plang.debug 0-10 -- Plugin must be reloaded for this value to take effect.
     my $debug = $self->{pbot}->{registry}->get_value('plang', 'debug') // 0;
+
+    # create our Plang interpreter object
     $self->{plang} = Plang::Interpreter->new(embedded => 1, debug => $debug);
 
+    # register some built-in functions
+    $self->{plang}->{interpreter}->add_function_builtin('set',    [qw/channel keyword text/], \&set_factoid);
+    $self->{plang}->{interpreter}->add_function_builtin('get',    [qw/channel keyword/],      \&get_factoid);
+    $self->{plang}->{interpreter}->add_function_builtin('append', [qw/channel keyword text/], \&append_factoid);
+
+    # register the `plang` command
     $self->{pbot}->{commands}->register(sub { $self->cmd_plang(@_) }, "plang", 0);
 }
 
@@ -39,28 +48,114 @@ sub cmd_plang {
 
     my $usage = "plang <Plang code>; see https://github.com/pragma-/Plang";
 
-    my $getopt_error;
-    local $SIG{__WARN__} = sub {
-        $getopt_error = shift;
-        chomp $getopt_error;
-    };
+    return $usage if not length $context->{arguments};
 
-    my ($show_usage);
-    my @opt_args = $self->{pbot}->{interpreter}->split_line($context->{arguments}, strip_quotes => 1);
+    # run() returns result of the final statement
+    my $result = $self->run($context->{arguments});
 
-    Getopt::Long::Configure("bundling");
-    GetOptionsFromArray(
-        \@opt_args,
-        'h'   => \$show_usage
-    );
+    # check to see if we need to append final result to output
+    if (defined $result) {
+        if (ref $result->[0] eq 'ARRAY') {
+            foreach my $r (@$result) {
+                $self->{output} .= $r->[1] if defined $r->[1];
+            }
+        } else {
+            $self->{output} .= $result->[1] if defined $result->[1];
+        }
+    }
 
-    return $usage                         if $show_usage;
-    return "/say $getopt_error -- $usage" if defined $getopt_error;
-    $context->{arguments} = "@opt_args";
+    return length $self->{output} ? $self->{output} : "No output.";
+}
 
-    my $result = $self->{plang}->interpret_string($context->{arguments});
-    return "No output." if not defined $result;
-    return "/say $result";
+# run an embedded plang program
+sub run {
+    my ($self, $code) = @_;
+
+    # parse the code into an ast
+    my $ast = $self->{plang}->parse_string($code);
+    return if not defined $ast;
+
+    # create a new environment for a Plang program
+    my $context = $self->{plang}->{interpreter}->init_program;
+
+    # grab our program's statements
+    my $program    = $ast->[0];
+    my $statements = $program->[1];
+
+    $self->{output} = "";  # collect output of the embedded Plang program
+    my $result;            # result of the final statement
+
+    # interpret the statements
+    foreach my $node (@$statements) {
+        my $ins = $node->[0];
+
+        if ($ins eq 'STMT') {
+            $result = $self->{plang}->{interpreter}->statement($context, $node->[1]);
+            $result = $self->handle_statement_results($result);
+        }
+
+        last if $self->{error};
+    }
+
+    return $result; # return result of the final statement
+}
+use Data::Dumper;
+
+# handle a Plang statement result
+sub handle_statement_results {
+    my ($self, $results) = @_;
+
+    if (ref $results->[0] eq 'ARRAY') {
+        my $ret;
+        foreach my $result (@$results) {
+            $ret = $self->handle_statement_result($result);
+        }
+        return $ret;
+    } else {
+        return $self->handle_statement_result($results);
+    }
+}
+
+sub handle_statement_result {
+    my ($self, $result) = @_;
+
+    if ($result->[0] eq 'ERROR') {
+        $self->{output} .= $result->[1];
+        $self->{error} = 1;
+        return;
+    }
+
+    if ($result->[0] eq 'WARNING') {
+        $self->{output} .= $result->[1];
+        return;
+    }
+
+    if ($result->[0] eq 'STDOUT') {
+        $self->{output} .= $result->[1];
+        return;
+    }
+
+    return $result;
+}
+
+# our custom PBot built-in functions for Plang
+
+sub get_factoid {
+    my ($plang, $name, $arguments) = @_;
+    my ($channel, $keyword) = ($arguments->[0]->[1], $arguments->[1]->[1]);
+    return ['STRING', "get_factoid: channel: [$channel], keyword: [$keyword]"];
+}
+
+sub set_factoid {
+    my ($plang, $name, $arguments) = @_;
+    my ($channel, $keyword, $text) = ($arguments->[0]->[1], $arguments->[1]->[1], $arguments->[2]->[1]);
+    return ['STRING', "set_factoid: channel: [$channel], keyword: [$keyword], text: [$text]"];
+}
+
+sub append_factoid {
+    my ($plang, $name, $arguments) = @_;
+    my ($channel, $keyword, $text) = ($arguments->[0]->[1], $arguments->[1]->[1], $arguments->[2]->[1]);
+    return ['STRING', "append_factoid: channel: [$channel], keyword: [$keyword], text: [$text]"];
 }
 
 1;