Second rewrite attempt, this one should work, monkaS

1 files changed, 28 insertions, 0 deletions

diff --git a/src/__OLD_parcom/exactly.cr b/src/__OLD_parcom/exactly.cr
new file mode 100644
index 0000000..a34fd0d
--- /dev/null
+++ b/src/__OLD_parcom/exactly.cr
@@ -0,0 +1,28 @@
+require "./parser.cr"
+
+module Parcom
+  # `Exactly` is a `Parser` that tries to parse with another parser
+  # a specific number of times. The results of each successful parse
+  # are returned in an array. If the number of successes is less than
+  # OR greater than the specified number, the parser fails.
+  class Exactly(T, V) < Parser(T, Array(V))
+    @p : Sequence(T, V)
+
+    # Accepts the number of parsing attempts, and the parser to use.
+    # If a negative int is given, it is treated as if it were `0`.
+    def initialize(i : Int, p : Parser(T, V))
+      i = i.negative? ? 0 : i
+      # put `i` copies of `p` into an array
+      ps = ([p] of Parser(T, V)) * i
+      @p = Sequence.new(ps)
+    end
+
+    # Tries to parse the given number of times.
+    def parse(tokens : Tokens(T)) : Result(T, Array(V))
+      @p.parse(tokens)
+    rescue ex : ParserFail
+      raise ParserFail.new("Exactly: #{ex.message}")
+    end
+  end
+end
+