aboutsummaryrefslogtreecommitdiff
path: root/src/__OLD_parcom/token_seq.cr
diff options
context:
space:
mode:
Diffstat (limited to 'src/__OLD_parcom/token_seq.cr')
-rw-r--r--src/__OLD_parcom/token_seq.cr38
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
+