From c575115f920ce352af164198e3460ee44dd82d31 Mon Sep 17 00:00:00 2001
From: MadMaurice <madmaurice@zom.bi>
Date: Sat, 3 Apr 2021 18:09:20 +0200
Subject: [PATCH] Add short notation for lists: '(1 2) == (list 1 2)

---
 lib/Minilisp.pm | 30 ++++++++++++++++++++++++++++++
 t/lists.t       |  6 ++++++
 2 files changed, 36 insertions(+)

diff --git a/lib/Minilisp.pm b/lib/Minilisp.pm
index 9c29af1..dfce759 100644
--- a/lib/Minilisp.pm
+++ b/lib/Minilisp.pm
@@ -11,6 +11,7 @@ use constant {
   STRING => 4,
   NUMBER => 5,
   KEYWORD => 6,
+  LIST => 7,
 };
 
 sub tokenize {
@@ -34,6 +35,10 @@ sub tokenize {
         {
           push @tokens, { type => RPAREN };
         }
+      elsif($str =~ s/^'\(//) # short notation for lists
+        {
+          push @tokens, { type => LIST }, { type => LPAREN };
+        }
       elsif($str =~ s/^'([^\s()"]+)//)
         {
           push @tokens, {
@@ -346,6 +351,10 @@ sub parser_expr {
     {
       return parser_call($ts);
     }
+  elsif($tok->{type} == LIST)
+    {
+      return parser_list($ts);
+    }
   elsif($tok->{type} == IDENT)
     {
       return sub {
@@ -373,6 +382,27 @@ sub parser_expr {
     }
 }
 
+sub parser_list {
+  my $ts = shift;
+
+  my $tok = shift @$ts;
+  die "Missing ( after ' for list" unless $tok->{type} == LPAREN;
+
+  my @elements;
+  while ($ts->[0]->{type} != RPAREN)
+    {
+      push @elements, parser_expr($ts);
+    }
+
+  shift @$ts; # Drop RPAREN
+
+  return sub {
+    my $ctx = shift;
+
+    return [ map { $_->($ctx) } @elements ];
+  }
+}
+
 my %macros;
 
 sub parser_call {
diff --git a/t/lists.t b/t/lists.t
index 806115d..fb30cf5 100644
--- a/t/lists.t
+++ b/t/lists.t
@@ -28,3 +28,9 @@
           (= 5 (car lst)))
   (expect "cdr gives rest of list"
           (equal (list 1 2) (cdr lst))))
+
+(expect "short notation equals list created with list function"
+        (equal '(1 2) (list 1 2)))
+
+(expect "short notation can create empty lists"
+        (zerop (length '())))