Reimplement Tokens in terms of Sequence

1 files changed, 10 insertions, 11 deletions

diff --git a/src/parcom.cr b/src/parcom.cr
index 6fc6339..d7e6682 100644
--- a/src/parcom.cr
+++ b/src/parcom.cr
@@ -232,6 +232,8 @@ module Parcom
     def initialize(@ps : Iterable(Parser(T, V)))
     end
 
+    # TODO: this can probably be optimised more for Arrays
+    # TODO: might be better to use #zip
     def parse(tokens : TokenStream(T)) : Result(T, Array(V))
       parsed = [] of V
 
@@ -246,20 +248,17 @@ module Parcom
   end
 
   class Tokens(T) < Parser(T, Array(T))
-    def initialize(@expected : Iterable(T))
-    end
+    @p : Sequence(T, T)
 
-    # TODO: this can probably be optimised more for Arrays
-    # TODO: might be better to use #zip?
-    def parse(tokens : TokenStream(T)) : Result(T, Array(T))
-      parsed_tokens = [] of T
+    def initialize(expected : Iterable(T))
+      ps = [] of Parser(T, T)
+      expected.each { |t| ps << Token.new(t) }
 
-      @expected.each_with_index do |t, i|
-        r = Token.new(t).parse(tokens[i..])
-        parsed_tokens << r.value
-      end
+      @p = Sequence.new(ps)
+    end
 
-      Result.new(tokens[parsed_tokens.size..], parsed_tokens)
+    def parse(tokens : TokenStream(T)) : Result(T, Array(T))
+      @p.parse(tokens)
     end
   end