From 8e9993e91da2cd28c5c1c3ce46bd2b1884ab91c6 Mon Sep 17 00:00:00 2001 From: Matthew Hall Date: Mon, 13 Mar 2023 18:43:40 +1300 Subject: Documentation for Some --- src/parcom.cr | 14 -------------- src/parcom/some.cr | 33 +++++++++++++++++++++++++++++++++ 2 files changed, 33 insertions(+), 14 deletions(-) create mode 100644 src/parcom/some.cr diff --git a/src/parcom.cr b/src/parcom.cr index c7dde7b..4f35420 100644 --- a/src/parcom.cr +++ b/src/parcom.cr @@ -119,20 +119,6 @@ module Parcom end end - class Some(T, V) < Parser(T, Array(V)) - @p : Assert(T, Array(V)) - - def initialize(p : Parser(T, V)) - @p = Many.new(p).assert { |arr| !arr.empty? } - end - - def parse(tokens : Tokens(T)) : Result(T, Array(V)) - @p.parse(tokens) - rescue ex : ParserFail - raise ParserFail.new("Some: #{ex.message}") - end - end - class Exactly(T, V) < Parser(T, Array(V)) @p : Sequence(T, V) diff --git a/src/parcom/some.cr b/src/parcom/some.cr new file mode 100644 index 0000000..a2e3563 --- /dev/null +++ b/src/parcom/some.cr @@ -0,0 +1,33 @@ +require "./parser.cr" +require "./assert.cr" +require "./many.cr" + +module Parcom + # `Some` is a `Parser` that repeatedly tries to parse with another parser. + # The `Some` 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 `Some` + # object will stop attempting to parse and will return the array of + # previous successes. + # + # `Some` will raise a `ParserFail` exception if the parser never succeeds + # or consumes input. For cases where parsing should allow for 0 successes, + # use `Many`. + class Some(T, V) < Parser(T, Array(V)) + @p : Assert(T, Array(V)) + + # Accepts the parser to use. + def initialize(p : Parser(T, V)) + @p = Many.new(p).assert { |arr| !arr.empty? } + end + + # Continuously parses with the wrapped parser, returns all successes. + # Fails if there are no successes. + def parse(tokens : Tokens(T)) : Result(T, Array(V)) + @p.parse(tokens) + rescue ex : ParserFail + raise ParserFail.new("Some: #{ex.message}") + end + end +end + -- cgit v1.2.1