For TPRC 2023

lib/assign/Array.pm

@@ -98,12 +98,19 @@ sub gen_code {
         my $def = $elem->{def} // '';
         $def &&= " // $def";
 
-        push @$code,
-            ($elem->sigil eq '@')
-                ? "$var $oper \@$from\[$i..\@$from-1\]$def;" :
-            ($elem->{cast})
-                ? "$var $oper \[\@$from\[$i..\@$from-1\]\]$def;" :
-            "$var $oper $from\->[$i]$def;";
+        if ($elem->sigil eq '@' || $elem->{cast}) {
+            my $begin = $i;
+            my $end = abs(@$elems - $i);
+            $i = - $end;
+
+            push @$code,
+                ($elem->sigil eq '@')
+                ? "$var $oper \@$from\[$begin..\@$from-$end\]$def;"
+                : "$var $oper \[\@$from\[$begin..\@$from-$end\]\]$def;";
+        }
+        else {
+            push @$code, "$var $oper $from\->[$i]$def;";
+        }
 
         $i++;
     }

lib/assign/Hash.pm

@@ -5,6 +5,7 @@ use assign::Struct;
 use base 'assign::Struct';
 
 use assign::Types;
+use assign::Array;
 
 use XXX;
 
@@ -17,13 +18,38 @@ sub parse_elem {
         my $type = ref($tok);
         next if $type eq 'PPI::Token::Whitespace';
 
+        if ($type eq 'PPI::Token::Word') {
+            $self->parse_fat_comma;
+            $self->parse_whitespaces;
+
+            my $str = $tok->content;
+            my $v = shift(@$in);
+            if ($v && ref($v) eq 'PPI::Structure::Constructor') {
+                my $deepkey = "{$str}";
+                if ($v->braces eq '[]') {
+                    my $struct = assign::Array->new(node => $v, deepkey => $deepkey)->parse;
+                    push @$elems, $struct;
+                }
+                elsif ($v->braces eq '{}') {
+                    my $struct = assign::Hash->new(node => $v, deepkey => $deepkey)->parse;
+                    push @$elems, $struct;
+                }
+                else {
+                    XXX $v, "Expecting [...] or {...}";
+                }
+            }
+
+            return 1;
+        }
+
         if ($type eq 'PPI::Token::Symbol') {
             my $str = $tok->content;
             if ($str =~ /^\$\w+$/) {
                 push @$elems, assign::var->new($str);
                 return 1;
             }
         }
+
         XXX $tok, "unexpected token";
     }
     return 0;
@@ -35,21 +61,27 @@ sub gen_code {
     my $code = [ @$init ];
     my $elems = $self->{elems};
 
-    if ($decl) {
+    if ($decl && (my @to_declares = grep $_->can("val"), @$elems)) {
         push @$code,
             "$decl(" .
             join(', ',
-                map $_->val,
-                @$elems
-            ) .
-            ');';
+                 map $_->val,
+                 @to_declares
+            ) . ');'
     }
 
     for my $elem (@$elems) {
         my $type = ref $elem;
-        my $var = $elem->val;
-        (my $key = $var) =~ s/^\$//;
-        push @$code, "$var $oper $from\->{$key};";
+        if ( $type eq 'assign::Hash' ||  $type eq 'assign::Array' ) {
+            my $_from = $from . ($elem->{deepkey} ?  "->" . $elem->{deepkey} : "");
+            push @$code, $elem->gen_code($decl, $oper, $_from, $init);
+        }
+        else {
+            my $var = $elem->val;
+            (my $key = $var) =~ s/^\$//;
+            my $deepkey = $elem->{deepkey};
+            push @$code, "$var $oper $from\->$deepkey\{$key\};";
+        }
     }
 
     return join "\n", @$code;

lib/assign/Struct.pm

@@ -7,6 +7,7 @@ sub new {
     my $class = shift;
     bless {
         elems => [],
+        deepkey => "",
         @_,
     }, $class;
 }
@@ -37,7 +38,7 @@ sub parse {
 
     while (1) {
         $self->parse_elem or last;
-        $self->parse_comma or last;
+        $self->parse_optional_comma or last;
     }
 
     return $self;
@@ -63,6 +64,61 @@ sub parse_comma {
     return 0;
 }
 
+sub parse_optional_comma {
+    my ($self) = @_;
+    my $in = $self->{in};
+    while (@$in) {
+        my $tok = shift(@$in);
+        my $type = ref($tok);
+        next if $type eq 'PPI::Token::Whitespace';
+
+        if ($type eq 'PPI::Token::Operator' and
+            $tok->content eq ','
+        ) {
+            return 1;
+        }
+        else {
+            unshift(@$in, $tok);
+            last;
+        }
+    }
+    return 0;
+}
+
+sub parse_fat_comma {
+    my ($self) = @_;
+
+    $self->parse_whitespaces;
+
+    my $in = $self->{in};
+    while (@$in) {
+        my $tok = shift(@$in);
+        my $type = ref($tok);
+
+        if ($type eq 'PPI::Token::Operator' and
+            $tok->content eq '=>'
+        ) {
+            return 1;
+        }
+        else {
+            XXX $tok, $in, "fat comma expected";
+        }
+    }
+    return 0;
+}
+
+sub parse_whitespaces {
+    my ($self) = @_;
+    my $in = $self->{in};
+    while (@$in) {
+        my $tok = shift(@$in);
+        next if ref($tok) eq 'PPI::Token::Whitespace';
+        unshift @$in, $tok;
+        last;
+    }
+    return 0;
+}
+
 sub get_var {
     my ($self, $var) = @_;
     my $def;

lib/assign/Types.pm

@@ -11,6 +11,7 @@ sub new {
     bless {
         var => $var,
         def => $def,
+        deepkey => "",
     }, $class;
 }
 

talk/Makefile

@@ -0,0 +1,15 @@
+SHELL := bash
+
+VROOM := \
+    vroom \
+    clean \
+
+default:
+ifdef s
+	vroom vroom --skip=$s
+else
+	vroom vroom
+endif
+
+$(VROOM):
+	vroom $@

talk/destructure.clj

@@ -0,0 +1,10 @@
+#!/usr/bin/env clojure
+
+(def people [
+  { :name "Ingy" :favs ["coffee" "yellow"] }
+  { :name "Gugod" :favs ["tea" "blue"] }])
+
+(defn about [{:keys [name] [color drink] :favs}]
+  (println (str name " wears " color " and drinks " drink ".")))
+
+(map about people)

talk/destructure.js

@@ -0,0 +1,11 @@
+#!/usr/bin/env node
+
+const people = [
+  { name: 'Ingy', favs: ['coffee', 'yellow'] },
+  { name: 'Gugod', favs: ['tea', 'blue'] },
+];
+
+people.forEach((person) => {
+  const { name, favs: [ drink, color ] } = person;
+  console.log(`${name} wears ${color} and drinks ${drink}.`);
+});

talk/destructure.pl

@@ -0,0 +1,19 @@
+#!/usr/bin/env perl
+
+use v5.16;
+
+use assign::0;
+
+my $people = [
+    { name => 'Ingy',  favs => ['coffee', 'yellow'] },
+    { name => 'Gugod', favs => ['tea', 'blue'] },
+];
+
+for my $person (@people) {
+    my {
+        $name,
+        favs => [ $drink, $color ],
+    } = $person;
+
+    say "$name wears $color and drinks $drink.";
+}

talk/destructure2.js

@@ -0,0 +1,10 @@
+#!/usr/bin/env node
+
+const people = [
+  { name: 'Ingy', favs: ['coffee', 'yellow'] },
+  { name: 'Gugod', favs: ['tea', 'blue'] },
+];
+
+people.forEach(({ name, favs: [ drink, color ] }) => {
+  console.log(`${name} wears ${color} and drinks ${drink}.`);
+});