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-rw-r--r--src/parcom.cr18
-rw-r--r--src/parcom/between.cr37
2 files changed, 37 insertions, 18 deletions
diff --git a/src/parcom.cr b/src/parcom.cr
index 24fb76c..0170fdc 100644
--- a/src/parcom.cr
+++ b/src/parcom.cr
@@ -81,24 +81,6 @@ module Parcom
end
end
- class Between(T, V) < Parser(T, Array(V))
- @p : Map(T, {Array(V), Array(V)}, Array(V))
-
- def initialize(i : Int, j : Int, p : Parser(T, V))
- lower = i < j ? i : j
- upper = (i - j).abs
- @p = (Exactly.new(lower, p) + AtMost.new(upper, p)).map do |tup|
- tup[0] + tup[1]
- end
- end
-
- def parse(tokens : Tokens(T)) : Result(T, Array(V))
- @p.parse(tokens)
- rescue ex : ParserFail
- raise ParserFail.new("Between: #{ex.message}")
- end
- end
-
class FirstOf(T, V) < Parser(T, V)
@p : Parser(T, V)
diff --git a/src/parcom/between.cr b/src/parcom/between.cr
new file mode 100644
index 0000000..05519e4
--- /dev/null
+++ b/src/parcom/between.cr
@@ -0,0 +1,37 @@
+require "./parser.cr"
+require "./map.cr"
+require "./exactly.cr"
+require "./at_most.cr"
+
+module Parcom
+ # `Between` is a `Parser` that tries to parse with another parser a number
+ # of times within a specified range. The results of each successful parse
+ # are returned in an array. If the number of successful parses is out of
+ # the lower bound of the range, the parser fails. If the number of successful
+ # parses reaches thhe upper bound of the range, the parsing stops, even if it
+ # is possible to keep parsing.
+ class Between(T, V) < Parser(T, Array(V))
+ @p : Map(T, {Array(V), Array(V)}, Array(V))
+
+ # Accepts the lower and upper bounds for the number of parsing attempts,
+ # as well as the parser to use. This method works the same way whether or
+ # not the larger value is passed first or second. If a negative int value
+ # is given for either parameter, it is treated as `0`.
+ # TODO: Overload to allow for Range objects.
+ def initialize(i : Int, j : Int, p : Parser(T, V))
+ lower = i < j ? i : j
+ upper = (i - j).abs
+ @p = (Exactly.new(lower, p) + AtMost.new(upper, p)).map do |tup|
+ tup[0] + tup[1]
+ end
+ end
+
+ # Tries to parse a numebr of times within the given range.
+ def parse(tokens : Tokens(T)) : Result(T, Array(V))
+ @p.parse(tokens)
+ rescue ex : ParserFail
+ raise ParserFail.new("Between: #{ex.message}")
+ end
+ end
+end
+