Many and Some

1 files changed, 23 insertions, 0 deletions

diff --git a/src/parcom/parser.cr b/src/parcom/parser.cr
index fcfe292..8ee3f68 100644
--- a/src/parcom/parser.cr
+++ b/src/parcom/parser.cr
@@ -241,6 +241,29 @@ module Parcom
       p1 = self
       (p1 + p2).map(&.last).named("#{p1.name} >> #{p2.name}")
     end
+
+    # Creates a new parser from `self` that parses with `self` as many times
+    # as possible. If it never succeeds, returns an empty list.
+    def many : Parser(T, Array(U))
+      p = self
+      Parser(T, Array(U)).new("Many: #{p.name}") do |tokens|
+        values = [] of U
+        r = p.parse?(tokens)
+        until r.nil?
+          break unless tokens != r.tokens
+          tokens = r.tokens
+          values << r.value
+          r = p.parse?(tokens)
+        end
+        Result.new(tokens, values)
+      end
+    end
+
+    # Creates a new parser from `self` that parses with `self` as many times
+    # as possible. Raises `ParserFail` it never succeeds.
+    def some : Parser(T, Array(U))
+      many.assert { |arr| !arr.empty? }.named("Some: #{@name}")
+    end
   end
 end