Second rewrite attempt, this one should work, monkaS

1 files changed, 38 insertions, 0 deletions

diff --git a/src/__OLD_parcom/token_seq.cr b/src/__OLD_parcom/token_seq.cr
new file mode 100644
index 0000000..45900f9
--- /dev/null
+++ b/src/__OLD_parcom/token_seq.cr
@@ -0,0 +1,38 @@
+require "./parser.cr"
+require "./sequence.cr"
+
+module Parcom
+  # `TokenSeq` is a `Parser` that attempts to parse a specific
+  # string of tokens. If the expected tokens are not at the start
+  # of the input stream, the parser fails.
+  #
+  # Example:
+  # ```
+  # parse_test = TokenSeq(Char).new("test".chars)
+  # tokens = Tokens.from_string("testing")
+  #
+  # result = parse_test.parse(tokens)
+  #
+  # puts result.value  # => ['t', 'e', 's', 't'] 
+  # puts result.tokens # => ['i', 'n', 'g']
+  # ```
+  class TokenSeq(T) < Parser(T, Array(T))
+    @p : Sequence(T, T)
+
+    # Accepts the tokens to try and parse, in order.
+    def initialize(expected : Iterable(T))
+      ps = [] of Parser(T, T)
+      expected.each { |t| ps << Token.new(t) }
+
+      @p = Sequence.new(ps)
+    end
+
+    # Tries to parse the list of tokens.
+    def parse(tokens : Tokens(T)) : Result(T, Array(T))
+      @p.parse(tokens)
+    rescue ex : ParserFail
+      raise ParserFail.new("TokenSeq: #{ex.message}")
+    end
+  end
+end
+