Second rewrite attempt, this one should work, monkaS

1 files changed, 23 insertions, 0 deletions

diff --git a/src/__OLD_parcom/eof.cr b/src/__OLD_parcom/eof.cr
new file mode 100644
index 0000000..650da56
--- /dev/null
+++ b/src/__OLD_parcom/eof.cr
@@ -0,0 +1,23 @@
+require "./parser.cr"
+
+module Parcom
+  # `EOF` is a `Parser` succeeds if the input stream is empty.
+  #
+  # This parser retuns `nil` when successful because there is no
+  # other meaningful value to return.
+  #
+  # This parser is also one of the few cases where it is ideal to not
+  # modify or take from the input stream, as it should be empty anyway.
+  class EOF(T) < Parser(T, Nil)
+    # Succeeds is the input stream is empty and returns `nil`.
+    # Raises a `ParserFail` exception when the input is not empty.
+    def parse(tokens : Tokens(T)) : Result(T, Nil)
+      if tokens.empty?
+        Result.new(tokens, nil)
+      else
+        raise ParserFail.new("Eof: input was not empty")
+      end
+    end
+  end
+end
+