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Diffstat (limited to 'src/__OLD_parcom/at_least.cr')
| -rw-r--r-- | src/__OLD_parcom/at_least.cr | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/src/__OLD_parcom/at_least.cr b/src/__OLD_parcom/at_least.cr new file mode 100644 index 0000000..2fb8dcf --- /dev/null +++ b/src/__OLD_parcom/at_least.cr @@ -0,0 +1,29 @@ +require "./parser.cr" +require "./map.cr" +require "./exactly.cr" + +module Parcom + # `AtLeast` is a `Parser` that tries to parser 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 + # the specified number, the parser fails. + class AtLeast(T, V) < Parser(T, Array(V)) + @p : Map(T, {Array(V), Array(V)}, Array(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)) + @p = (Exactly.new(i, p) + Many.new(p)).map do |tup| + tup[0] + tup[1] + end + end + + # Tries to parse the given number of times, or more. + def parse(tokens : Tokens(T)) : Result(T, Array(V)) + @p.parse(tokens) + rescue ex : ParserFail + raise ParserFail.new("AtLeast: #{ex.message}") + end + end +end + |
