All: add keywords.

Also, fix nth and count to match cloure.

1 files changed, 5 insertions, 3 deletions

diff --git a/ruby/core.rb b/ruby/core.rb
index 6b127ba..d55100c 100644
--- a/ruby/core.rb
+++ b/ruby/core.rb
@@ -8,8 +8,10 @@ $core_ns = {
     :nil? =>      lambda {|a| a == nil},
     :true? =>     lambda {|a| a == true},
     :false? =>    lambda {|a| a == false},
+    :symbol =>    lambda {|a| a.to_sym},
     :symbol? =>   lambda {|a| a.is_a? Symbol},
-    :symbol? =>   lambda {|a| a.is_a? Symbol},
+    :keyword =>   lambda {|a| "\u029e"+a},
+    :keyword? =>  lambda {|a| (a.is_a? String) && "\u029e" == a[0]},
 
     :"pr-str" =>  lambda {|*a| a.map {|e| _pr_str(e, true)}.join(" ")},
     :str =>       lambda {|*a| a.map {|e| _pr_str(e, false)}.join("")},
@@ -44,11 +46,11 @@ $core_ns = {
     :sequential? => lambda {|a| sequential?(a)},
     :cons =>      lambda {|a,b| List.new(b.clone.insert(0,a))},
     :concat =>    lambda {|*a| List.new(a && a.reduce(:concat) || [])},
-    :nth =>       lambda {|a,b| a[b]},
+    :nth =>       lambda {|a,b| raise "nth: index out of range" if b >= a.size; a[b]},
     :first =>     lambda {|a| a[0]},
     :rest =>      lambda {|a| List.new(a.size > 0 && a.drop(1) || [])},
     :empty? =>    lambda {|a| a.size == 0},
-    :count =>     lambda {|a| a.size},
+    :count =>     lambda {|a| return 0 if a == nil; a.size},
     :conj =>      lambda {|*a| a[0].clone.conj(a.drop(1))},
     :apply =>     lambda {|*a| a[0][*a[1..-2].concat(a[-1])]},
     :map =>       lambda {|a,b| List.new(b.map {|e| a[e]})},