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-rw-r--r--src/__OLD_parcom/many.cr36
1 files changed, 36 insertions, 0 deletions
diff --git a/src/__OLD_parcom/many.cr b/src/__OLD_parcom/many.cr
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+++ b/src/__OLD_parcom/many.cr
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+require "./parser.cr"
+
+module Parcom
+ # `Many` is a `Parser` that repeatedly tries to parse with another parser.
+ # The `Many` object will collect all success values in an array, and return
+ # them with the final state of the input stream. If the wrapped parser ever
+ # fails or succeeds without parsing any input, the `Many` object will stop
+ # attempting to parse will will return the array of prrevious successes.
+ #
+ # `Many` will return an empty array if the parser never succeeds or consumes
+ # input. For cases where at least one parserr success is needed, use `Some`.
+ class Many(T, V) < Parser(T, Array(V))
+ # Accepts the parser to use.
+ def initialize(@p : Parser(T, V))
+ end
+
+ # Continuously parses with the wrapped parser, returns all successes.
+ # Parsing stops when the parser fails, or succeeds without consuming input.
+ def parse(tokens : Tokens(T)) : Result(T, Array(V))
+ parsed = [] of V
+
+ loop do
+ result = @p.parse?(tokens)
+ break unless !result.nil? && result.tokens != tokens
+
+ parsed << result.value
+ tokens = result.tokens
+ end
+
+ Result.new(tokens, parsed)
+ rescue ex : ParserFail
+ raise ParserFail.new("Many: #{ex.message}")
+ end
+ end
+end
+