Rename Eof to EOF + documentation

2 files changed, 24 insertions, 11 deletions

diff --git a/src/parcom.cr b/src/parcom.cr
index f6d1e05..4612887 100644
--- a/src/parcom.cr
+++ b/src/parcom.cr
@@ -81,16 +81,6 @@ module Parcom
     end
   end
 
-  class Eof(T) < Parser(T, Nil)
-    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
-
   class Peek(T, V) < Parser(T, V)
     def initialize(@p : Parser(T, V))
     end
@@ -179,7 +169,7 @@ module Parcom
     @p : Map(T, {V, Nil}, V)
 
     def initialize(p : Parser(T, V))
-      @p = (p + Eof(T).new).map &.first
+      @p = (p + EOF(T).new).map &.first
     end
 
     def parse(tokens : Tokens(T)) : Result(T, V)
diff --git a/src/parcom/eof.cr b/src/parcom/eof.cr
new file mode 100644
index 0000000..650da56
--- /dev/null
+++ b/src/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
+