Ruby: add step3

1 files changed, 28 insertions, 0 deletions

diff --git a/ruby/env.rb b/ruby/env.rb
new file mode 100644
index 0000000..dfd5ec9
--- /dev/null
+++ b/ruby/env.rb
@@ -0,0 +1,28 @@
+class Env
+    attr_accessor :data
+    def initialize(outer=nil, binds=[], exprs=[])
+        @data = {}
+        @outer = outer
+    end
+
+    def find(key)
+        if @data.key? key
+            return self
+        elsif @outer
+            return @outer.find(key)
+        else
+            return nil
+        end
+    end
+
+    def set(key, value)
+        @data[key] = value
+        return value
+    end
+
+    def get(key)
+        env = find(key)
+        raise "'" + key.to_s + "' not found" if not env
+        env.data[key]
+    end
+end