Parse integers

lib/emerald/parser.rb

@@ -23,7 +23,9 @@ def parse_node(source)
       when " "
         parse_whitespace(source)
       when /[a-zA-Z\-]/
-        parse_atom(source)
+        parse_atom(source,first_char)
+      when /\d+/
+        parse_atom(source, first_char)
       end
     end
 
@@ -34,8 +36,13 @@ def parse_whitespace(source)
       [nil, rest_of_source]
     end
 
-    def parse_atom(source)
-      pattern = /\A[a-z\-]+/
+    def parse_atom(source, non_whitespace_char)
+      case non_whitespace_char
+      when /\A[a-zA-Z\-]+/
+        pattern = /\A[a-zA-Z\-]+/
+      when /\d+/
+        pattern = /\d+/
+      end
       atom_value = pattern.match(source).to_s
       atom = Atom.new(atom_value)
       rest_of_source = drop(source, atom_value.size)

spec/emerald/parser_spec.rb

@@ -16,10 +16,17 @@
     end
 
     it "parses two atoms" do
-      source = "hello      world"
+      source = "hello      World"
       ast = Emerald::Parser.new(source).parse
       expect(ast).to eq([Emerald::Atom.new("hello"),
-                         Emerald::Atom.new("world")])
+                         Emerald::Atom.new("World")])
+    end
+
+    it "parses two atoms: a string and an integer" do
+      source = "hey 65"
+      ast = Emerald::Parser.new(source).parse
+      expect(ast).to eq([Emerald::Atom.new("hey"),
+                        Emerald::Atom.new("65")])
     end
   end
 end