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authorMatthew Hall <hallmatthew314@gmail.com>2023-03-13 19:31:28 +1300
committerMatthew Hall <hallmatthew314@gmail.com>2023-03-13 19:31:28 +1300
commit48ea163f12653a709b575f4c26b8348ef53ae0d5 (patch)
treef8e8777e878840d14c1a7f68a81259e3c9e14c35
parent8e9993e91da2cd28c5c1c3ce46bd2b1884ab91c6 (diff)
Documentation for sequence
-rw-r--r--src/parcom.cr21
-rw-r--r--src/parcom/sequence.cr33
2 files changed, 33 insertions, 21 deletions
diff --git a/src/parcom.cr b/src/parcom.cr
index 4f35420..b6e6c3b 100644
--- a/src/parcom.cr
+++ b/src/parcom.cr
@@ -81,27 +81,6 @@ module Parcom
end
end
- class Sequence(T, V) < Parser(T, Array(V))
- def initialize(@ps : Iterable(Parser(T, V)))
- end
-
- # TODO: this can probably be optimised more for Arrays
- # TODO: might be better to use #zip
- def parse(tokens : Tokens(T)) : Result(T, Array(V))
- parsed = [] of V
-
- @ps.each do |p|
- r = p.parse(tokens)
- parsed << r.value
- tokens = r.tokens
- end
-
- Result.new(tokens, parsed)
- rescue ex : ParserFail
- raise ParserFail.new("Sequence: #{ex.message}")
- end
- end
-
class TokenSeq(T) < Parser(T, Array(T))
@p : Sequence(T, T)
diff --git a/src/parcom/sequence.cr b/src/parcom/sequence.cr
new file mode 100644
index 0000000..6a05cde
--- /dev/null
+++ b/src/parcom/sequence.cr
@@ -0,0 +1,33 @@
+require "./parser.cr"
+
+module Parcom
+ # `Sequence` is a `Parser` that combines multiple parsers and
+ # tries to parse all of them in succession. If all of the parsers
+ # succeed, the values parsed are returned in an array, in the order
+ # they were parsed in. If any of the parsers fail,
+ # the `Sequence` also fails.
+ class Sequence(T, V) < Parser(T, Array(V))
+ # Accepts the parsers to use.
+ def initialize(@ps : Iterable(Parser(T, V)))
+ end
+
+ # Tries each parser in order, and returns their results.
+ # Fail if any of the wrapped parsers fail.
+ # TODO: this can probably be optimised more for Arrays
+ # TODO: might be better to use #zip
+ def parse(tokens : Tokens(T)) : Result(T, Array(V))
+ parsed = [] of V
+
+ @ps.each do |p|
+ r = p.parse(tokens)
+ parsed << r.value
+ tokens = r.tokens
+ end
+
+ Result.new(tokens, parsed)
+ rescue ex : ParserFail
+ raise ParserFail.new("Sequence: #{ex.message}")
+ end
+ end
+end
+