diff --git a/lib/Minilisp.pm b/lib/Minilisp.pm
index de2c8ab..d871913 100644
--- a/lib/Minilisp.pm
+++ b/lib/Minilisp.pm
@@ -405,15 +405,25 @@ sub parser {
   }
 }
 
+sub parser_many_expr {
+  my $ts = shift;
+  my @exprs;
+
+  while (scalar(@$ts) && !peek_token($ts,RPAREN))
+    {
+      push @exprs, parser_expr($ts);
+    }
+
+  return @exprs;
+}
+
 sub parser_prog {
   my $ts = shift;
 
-  my @steps;
+  my @steps = parser_many_expr($ts);
 
-  while (scalar @$ts)
-    {
-      push @steps, parser_expr($ts);
-    }
+  die "Unexpected token " . $ts->[0]->{type} . " after end of program"
+    if scalar(@$ts);
 
   return sub {
     my $ctx = shift;
@@ -480,11 +490,7 @@ sub parser_list {
 
   slurp_token($ts, LPAREN, "Expected ( after ' for list");
 
-  my @elements;
-  while (!peek_token($ts,RPAREN))
-    {
-      push @elements, parser_expr($ts);
-    }
+  my @elements = parser_many_expr($ts);
 
   slurp_token($ts, RPAREN, "Expected ) after list");
 
@@ -514,12 +520,7 @@ sub parser_call {
 
   my $fn = parser_expr($ts);
 
-  my @params;
-
-  while (!peek_token($ts,RPAREN))
-    {
-      push @params, parser_expr($ts);
-    }
+  my @params = parser_many_expr($ts);
 
   slurp_token($ts, RPAREN, "Expecte ) after call");
 
@@ -643,12 +644,7 @@ $macros{if} = \&macro_if;
 sub macro_progn {
   my $ts = shift;
 
-  my @steps;
-
-  while (!peek_token($ts,RPAREN))
-    {
-      push @steps, parser_expr($ts);
-    }
+  my @steps = parser_many_expr($ts);
 
   return sub {
     my $ctx = shift;
@@ -782,11 +778,7 @@ $macros{set} = \&macro_set;
 sub macro_and {
   my $ts = shift;
 
-  my @operands_parsed;
-  while (!peek_token($ts,RPAREN))
-    {
-      push @operands_parsed, parser_expr($ts);
-    }
+  my @operands_parsed = parser_many_expr($ts);
 
   return sub {
     my $ctx = shift;
@@ -806,11 +798,7 @@ $macros{and} = \&macro_and;
 sub macro_or {
   my $ts = shift;
 
-  my @operands_parsed;
-  while (!peek_token($ts,RPAREN))
-    {
-      push @operands_parsed, parser_expr($ts);
-    }
+  my @operands_parsed = parser_many_expr($ts);
 
   return sub {
     my $ctx = shift;