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| author | Matthew Hall <hallmatthew314@gmail.com> | 2023-03-19 23:02:29 +1300 |
|---|---|---|
| committer | Matthew Hall <hallmatthew314@gmail.com> | 2023-03-19 23:02:29 +1300 |
| commit | 9734fa2d530b9496b70a388a117ea57fe5730772 (patch) | |
| tree | 78a42db1e64e5148edfa96cb2a451a17ef362485 /src | |
| parent | 2ef8841e9c7a48eea0f66cfe09d8fe996f43c2b2 (diff) | |
Remove old files
Diffstat (limited to 'src')
27 files changed, 0 insertions, 950 deletions
diff --git a/src/__OLD_parcom.cr b/src/__OLD_parcom.cr deleted file mode 100644 index ddb2e50..0000000 --- a/src/__OLD_parcom.cr +++ /dev/null @@ -1,84 +0,0 @@ -require "./parcom/*" - -module Parcom - VERSION = "0.1.0" - - # A ParserFail exception should be raised by `Parser#parse` when - # a parse attempt is unsuccessful. - # Raising this exception in the `#parse` method of a Parser "Foo" - # usually follows this pattern to allow for error tracing: - # - # ``` - # class Foo(T, V) < Parser(T, V) - # def parse(tokens : Tokens(T)) : Result(T, V) - # helper.parse(tokens) - # rescue ex : ParserFail - # raise ParserFail.new("Foo: #{ex.message}") - # end - # ``` - class ParserFail < Exception - end - - # `Tokens` is an `Array` wrapper struct to store the input - # stream of one or more `Parser` objects. - # A `Tokens` can be created from any `Iterable`, along with - # `String` objects using a special constructor. - struct Tokens(T) - getter tokens - - # Constructs a `Tokens(Char)` from a `String`. - def self.from_string(s : String) : Tokens(Char) - Tokens.new(s.chars) - end - - # Constructs a `Tokens` from an `Iterable`. - def initialize(ts : Iterable(T)) - if ts.responds_to?(:to_a) - @tokens = ts.to_a - else - @tokens = [] of T - ts.each { |t| @tokens << t } - end - end - - # Exposes `Array#[](Int)`. - def [](index : Int) : T - @tokens[index] - end - - # Exposes `Array#[](Int, Int)`, but wraps the returned array in a new `Tokens`. - def [](start : Int, count : Int) : Tokens(T) - Tokens.new(@tokens[start, count]) - end - - # Exposes `Array#[](Range)`, but wraps the returned array in a new `Tokens`. - def [](range : Range) : Tokens(T) - Tokens.new(@tokens[range]) - end - - # Like `#[]`, but returns `nil` instead of raising an `IndexError`. - def []?(*args) - self.[](*args) - rescue IndexError - nil - end - - # Exposes `Array#empty?`. - def empty? : Bool - @tokens.empty? - end - end - - # A `Result` stores a `Tokens` object and a parsed value, - # and is effectively used to store the state of a parser chain. - # This is used instead of a `Tuple` or `NamedTuple` because: - # 1. This is more idiomatic than a `Tuple`. - # 2. Crystal does not support generic named tuples. - struct Result(T, V) - getter tokens, value - - def initialize(@tokens : Tokens(T), @value : V) - end - end -end - diff --git a/src/__OLD_parcom/alt.cr b/src/__OLD_parcom/alt.cr deleted file mode 100644 index dedd41d..0000000 --- a/src/__OLD_parcom/alt.cr +++ /dev/null @@ -1,28 +0,0 @@ -require "./parser.cr" - -module Parcom - # `Alt` is a `Parser` that accepts two other parsers and tries - # to parse with one of them. - # If the first (left) parser succeeds, its result is returned. - # If the first parser fails, it will try the second (right) parser. - class Alt(T, V) < Parser(T, V) - # Accepts the two parsers to try to parse with. - def initialize(@p1 : Parser(T, V), @p2 : Parser(T, V)) - end - - # Tries to parse using both parsers. - # - # It will initially try to parse with the first parser. - # If it fails, it will try to parse with the second parser. - def parse(tokens : Tokens(T)) : Result(T, V) - @p1.parse(tokens) - rescue ex1 : ParserFail - begin - @p2.parse(tokens) - rescue ex2 : ParserFail - raise ParserFail.new("Alt (#{ex1.message}), (#{ex2.message})") - end - end - end -end - diff --git a/src/__OLD_parcom/any_token.cr b/src/__OLD_parcom/any_token.cr deleted file mode 100644 index 1f65bfc..0000000 --- a/src/__OLD_parcom/any_token.cr +++ /dev/null @@ -1,18 +0,0 @@ -require "./parser.cr" - -module Parcom - # `AnyToken` is a `Parser` that consumes exactly one token from - # the input stream and returns it. - # It fails if the input stream is empty. - class AnyToken(T) < Parser(T, T) - # Parses the first token in the input, fails if the input is empty. - def parse(tokens : Tokens(T)) : Result(T, T) - if tokens.empty? - raise ParserFail.new("AnyToken: input was empty") - else - Result.new(tokens[1..], tokens[0]) - end - end - end -end - diff --git a/src/__OLD_parcom/assert.cr b/src/__OLD_parcom/assert.cr deleted file mode 100644 index 5a3e621..0000000 --- a/src/__OLD_parcom/assert.cr +++ /dev/null @@ -1,45 +0,0 @@ -require "./parser.cr" - -module Parcom - # `Assert` is a `Parser` that runs another `Parser` and then - # performs a test on its result. The parser will then either fail if - # the result does not pass the test, or forward it on if it does. - # - # Example: - # ``` - # letter = Assert.new(AnyToken(Char).new) { |x| x.letter? } - # non_letter = Assert.new(AnyToken(Char).new) { |x| !x.letter? } - # input = Tokens.from_string("hi") - # letter.parse(input) # this succeeds - # non_letter.parse(input) # this fails - # ``` - # - # `Assert` instance can also be created by calling - # `Parser#assert` on any parser: - # ``` - # # This parser is identical to the above example. - # letter = AnyToken.new(Char).assert { |x| x.letter? } - # ``` - class Assert(T, V) < Parser(T, V) - # Accepts the parser to run and a `Bool`-retuning block - # containing the test to perform on the other parser's result. - def initialize(@p : Parser(T, V), &block : V -> Bool) - @f = block - end - - # Runs the parser it was initialized with, and returns that parser's - # result if it passes the provided test. Raises `ParserFail` otherwise. - def parse(tokens : Tokens(T)) : Result(T, V) - result = @p.parse(tokens) - rescue ex : ParserFail - raise ParserFail.new("Assert (pre-assertion): #{ex.message}") - else - unless @f.call(result.value) - raise ParserFail.new("Assert: predicate failed for <#{result.value}>") - end - - return result - end - end -end - diff --git a/src/__OLD_parcom/at_least.cr b/src/__OLD_parcom/at_least.cr deleted file mode 100644 index 2fb8dcf..0000000 --- a/src/__OLD_parcom/at_least.cr +++ /dev/null @@ -1,29 +0,0 @@ -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 - diff --git a/src/__OLD_parcom/at_most.cr b/src/__OLD_parcom/at_most.cr deleted file mode 100644 index b70164f..0000000 --- a/src/__OLD_parcom/at_most.cr +++ /dev/null @@ -1,29 +0,0 @@ -require "./parser.cr" -require "./map.cr" -require "./exactly.cr" -require "./optional.cr" - -module Parcom - # `AtMost` is a `Parser` that tries to parse with another parser a specific - # number of times. The results of each successful parse are returned in an - # array. If the specific number of parses succeed, the parsing stops, even - # if it is possible to keep parsing. If the parser is never successful, it - # succeeds with an empty array. - class AtMost(T, V) < Parser(T, Array(V)) - @p : Map(T, Array(V?), Array(V)) - - # Accepts the number of parsing attempts, and the parser to use. - def initialize(i : Int, p : Parser(T, V)) - @p = Exactly.new(i, Optional.new(p)).map(&.compact) - end - - # Tries to parse up to the given number of times. - # If the parser never succeeds, returns an empty array. - def parse(tokens : Tokens(T)) : Result(T, Array(V)) - @p.parse(tokens) - rescue ex : ParserFail - raise ParserFail.new("AtMost: #{ex.message}") - end - end -end - diff --git a/src/__OLD_parcom/between.cr b/src/__OLD_parcom/between.cr deleted file mode 100644 index 05519e4..0000000 --- a/src/__OLD_parcom/between.cr +++ /dev/null @@ -1,37 +0,0 @@ -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 - diff --git a/src/__OLD_parcom/eof.cr b/src/__OLD_parcom/eof.cr deleted file mode 100644 index 650da56..0000000 --- a/src/__OLD_parcom/eof.cr +++ /dev/null @@ -1,23 +0,0 @@ -require "./parser.cr" - -module Parcom - # `EOF` is a `Parser` succeeds if the input stream is empty. - # - # This parser retuns `nil` when successful because there is no - # other meaningful value to return. - # - # This parser is also one of the few cases where it is ideal to not - # modify or take from the input stream, as it should be empty anyway. - class EOF(T) < Parser(T, Nil) - # Succeeds is the input stream is empty and returns `nil`. - # Raises a `ParserFail` exception when the input is not empty. - def parse(tokens : Tokens(T)) : Result(T, Nil) - if tokens.empty? - Result.new(tokens, nil) - else - raise ParserFail.new("Eof: input was not empty") - end - end - end -end - diff --git a/src/__OLD_parcom/exactly.cr b/src/__OLD_parcom/exactly.cr deleted file mode 100644 index a34fd0d..0000000 --- a/src/__OLD_parcom/exactly.cr +++ /dev/null @@ -1,28 +0,0 @@ -require "./parser.cr" - -module Parcom - # `Exactly` is a `Parser` that tries to parse 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 - # OR greater than the specified number, the parser fails. - class Exactly(T, V) < Parser(T, Array(V)) - @p : Sequence(T, 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)) - i = i.negative? ? 0 : i - # put `i` copies of `p` into an array - ps = ([p] of Parser(T, V)) * i - @p = Sequence.new(ps) - end - - # Tries to parse the given number of times. - def parse(tokens : Tokens(T)) : Result(T, Array(V)) - @p.parse(tokens) - rescue ex : ParserFail - raise ParserFail.new("Exactly: #{ex.message}") - end - end -end - diff --git a/src/__OLD_parcom/first_of.cr b/src/__OLD_parcom/first_of.cr deleted file mode 100644 index c4077eb..0000000 --- a/src/__OLD_parcom/first_of.cr +++ /dev/null @@ -1,40 +0,0 @@ -require "./parser.cr" - -module Parcom - # `FirstOf` is a `Parser` that accepts multiple parsers, and tries to parse - # with all of them, in order. As soon as one of the parsers succeeds, - # that parser's result is returned. If none of the parsers are successful, - # the parsing fails. - class FirstOf(T, V) < Parser(T, V) - @p : Parser(T, V) - - # Accepts the parsers to use. Raises an `ArgumentError` if - # no parsers are provided. - def initialize(ps : Iterable(Parser(T, V))) - ps_iter = ps.each - p = ps_iter.next - - if p.is_a?(Iterator::Stop) - raise ArgumentError.new("FirstOf requires atleast one parser, got none") - end - - # Combine all the parsers into one by wrapping them with `Alt`. - @p = p - - loop do - p = ps_iter.next - break if p.is_a?(Iterator::Stop) - @p = @p | p - end - end - - # Tries to parse with each of the given parsers. Either returns the first - # successful result or fails if no parsers succeed. - def parse(tokens : Tokens(T)) : Result(T, V) - @p.parse(tokens) - rescue ex : ParserFail - raise ParserFail.new("FirstOf: #{ex.message}") - end - end -end - diff --git a/src/__OLD_parcom/flunk.cr b/src/__OLD_parcom/flunk.cr deleted file mode 100644 index 00a0bd6..0000000 --- a/src/__OLD_parcom/flunk.cr +++ /dev/null @@ -1,12 +0,0 @@ -require "./parser.cr" - -module Parcom - # `Flunk` is a `Parser` that always fails. - class Flunk(T, V) < Parser(T, V) - # Always raises `ParserFail` - def parse(tokens) : Result(T, V) - raise ParserFail.new("Flunk: parsing failed") - end - end -end - diff --git a/src/__OLD_parcom/left.cr b/src/__OLD_parcom/left.cr deleted file mode 100644 index 201f497..0000000 --- a/src/__OLD_parcom/left.cr +++ /dev/null @@ -1,26 +0,0 @@ -require "./parser.cr" -require "./map.cr" - -module Parcom - # `Left` is a `Parser` that tries to parse with two different - # parsers in succession and fails if either of the two parsers fails. - # This parser behaves the same as `Plus`, but only returns the result - # of the first parser. - class Left(T, V, U) < Parser(T, V) - @p : Map(T, {V, U}, V) - - # Accepts the two parsers to use, in order. - def initialize(p1 : Parser(T, V), p2 : Parser(T, U)) - @p = (p1 + p2).map(&.first) - end - - # Tries to parse with the two given parsers, and returns the - # result of the first parser if they both succeed. - def parse(tokens : Tokens(T)) : Result(T, V) - @p.parse(tokens) - rescue ex : ParserFail - raise ParserFail.new("Left: #{ex.message}") - end - end -end - diff --git a/src/__OLD_parcom/many.cr b/src/__OLD_parcom/many.cr deleted file mode 100644 index a734c63..0000000 --- a/src/__OLD_parcom/many.cr +++ /dev/null @@ -1,36 +0,0 @@ -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 - diff --git a/src/__OLD_parcom/map.cr b/src/__OLD_parcom/map.cr deleted file mode 100644 index 34961b5..0000000 --- a/src/__OLD_parcom/map.cr +++ /dev/null @@ -1,30 +0,0 @@ -require "./parser.cr" - -module Parcom - # `Map` is a `Parser` that tries to parse using another parser, - # and then changing the result of that parser to a different value. - # - # Example: - # ``` - # # Where `Digits` is some parser that returns an array of digit characters - # parse_i32 = Digits.new.map { |x| x.join.to_i32 } - # result = parse_i32.parse(Tokens.from_string("1234")) - # result.value # => 1234 (Int32) - # ``` - class Map(T, V, U) < Parser(T, U) - # Accepts the parser to use and the function to apply to the result. - def initialize(@p : Parser(T, V), &block : V -> U) - @f = block - end - - # Tries to parse with the given parser and applies the - # function to the result if successful. - def parse(tokens : Tokens(T)) : Result(T, U) - result = @p.parse(tokens) - Result.new(result.tokens, @f.call(result.value)) - rescue ex : ParserFail - raise ParserFail.new("Map: #{ex.message}") - end - end -end - diff --git a/src/__OLD_parcom/optional.cr b/src/__OLD_parcom/optional.cr deleted file mode 100644 index b368d4e..0000000 --- a/src/__OLD_parcom/optional.cr +++ /dev/null @@ -1,40 +0,0 @@ -require "./parser.cr" - -module Parcom - # `Optional` is a `Parser` that tries to parse with another parser, - # but does not fail the parser chain if the wrapped parser fails. - # If the wrapped parser fails, an `Optional` will not modify the input - # stream, and return `nil` instead. - # - # Example: - # ``` - # digit = Satisfy(Char).new { |c| c.digit? } - # digits = Many.new(digit) - # plus_sign = Optional.new(Token.new('+')) - # positive_int = plus_sign >> digits - # - # input1 = Tokens.from_string("+12345") - # input2 = Tokens.from_string("12345") - # - # # Both of these has the same result - # positive_int.parse(input1) - # positive_int.parse(input2) - # ``` - class Optional(T, V) < Parser(T, V?) - # Accepts the parser to use. - def initialize(@p : Parser(T, V)) - end - - # Tries to parse with the given parser, succeeds with `nil` - # instead of failing. This parser does not consume input if - # the wrapped parser fails. - def parse(tokens : Tokens(T)) : Result(T, V?) - r = @p.parse?(tokens) - - new_tokens = r.nil? ? tokens : r.tokens - new_value = r.nil? ? nil : r.value - Result.new(new_tokens, new_value) - end - end -end - diff --git a/src/__OLD_parcom/parser.cr b/src/__OLD_parcom/parser.cr deleted file mode 100644 index ca350df..0000000 --- a/src/__OLD_parcom/parser.cr +++ /dev/null @@ -1,87 +0,0 @@ -require "../parcom.cr" - -module Parcom - # `Parser` is the base class of all parser objects and contains - # a handful of helper methods that can allow for cleaner syntax. - # - # The generic type `T` represents the type of tokens a parser will - # operate on (usually `Char`). - # The generic type `V` represents the type of value that a parser - # will return when parsing is successful. - abstract class Parser(T, V) - # Accepts a `Tokens(T)` and either retuns a `Result(T, V)`, or raises a - # `ParserFail` exception with a message providing context of where - # in the chain the parsing failed. - # - # The `V` in the returned `Result` is arbitrary, but the `Tokens(T)` in - # the returned result MUST contain the parser's input, with some tokens - # removed from the front proprtional to what was parsed. - # - # Example: - # ``` - # hello = ParsesHello.new # inherits from Parser(Char, String) - # input = Tokens.from_string("Hello world!") - # - # result = hello.parse(input) - # result.value # => "Hello" - # result.tokens # => [' ', 'w', 'o', 'r', 'l', 'd', '!'] - # - # bad_input = Tokens.from_string("Good evening world!") - # hello.parse(bad_input) # raises ParserFail - # ``` - abstract def parse(tokens : Tokens(T)) : Result(T, V) - - # Same as `#parse`, but returns `nil` instead of raising `ParserFail`. - def parse?(tokens : Tokens(T)) : Result(T, V)? - self.parse(tokens) - rescue ParserFail - return nil - end - - # Constructs an `Alt` parser with `self` and `other`. - def |(other : Parser(T, V)) : Alt(T, V) - Alt.new(self, other) - end - - # Constructs a `Plus` parser with `self` and `other`. - def +(other : Parser(T, U)) : Plus(T, V, U) forall U - Plus.new(self, other) - end - - # Constructs a `Left` parser with `self` and `other`. - def <<(other : Parser(T, U)) : Left(T, V, U) forall U - Left.new(self, other) - end - - # Constructs a `Right` parser with `self` and `other`. - def >>(other : Parser(T, U)) : Right(T, V, U) forall U - Right.new(self, other) - end - - # Constructs an `Assert` parser with `self` and the given block. - def assert(&block : V -> Bool) : Assert(T, V) - Assert.new(self, &block) - end - - # Constructs an `Assert` parser with `self` and the given proc. - def assert(f : V -> Bool) : Assert(T, V) - Assert.new(self, &f) - end - - # Constructs a `Map` parser with `self` and the given block. - def map(&block : V -> U) : Map(T, V, U) forall U - Map.new(self, &block) - end - - # Constructs a `Map` parser with `self` and the given proc. - def map(f : V -> U) : Map(T, V, U) forall U - Map.new(self, &f) - end - - # Constructs a `Recover` parser with `self` and the given `V`. - def recover(default : V) : Recover(T, V) - Recover.new(self, default) - end - end -end - diff --git a/src/__OLD_parcom/peek.cr b/src/__OLD_parcom/peek.cr deleted file mode 100644 index 2b6f657..0000000 --- a/src/__OLD_parcom/peek.cr +++ /dev/null @@ -1,23 +0,0 @@ -require "./parser.cr" - -module Parcom - # `Peek` is a `Parser` that runs another `Parser` while - # leaving the input stream unmodified. - class Peek(T, V) < Parser(T, V) - # Accepts the parser to run. - def initialize(@p : Parser(T, V)) - end - - # Runs the parser it was initialized with, and returns - # that parser's result along with the original input. - # - # Re-raises a `ParserFail` exception if the other parser fails. - def parse(tokens : Tokens(T)) : Result(T, V) - result = @p.parse(tokens) - Result.new(tokens, result.value) - rescue ex : ParserFail - raise ParserFail.new("Peek: #{ex.message}") - end - end -end - diff --git a/src/__OLD_parcom/phrase.cr b/src/__OLD_parcom/phrase.cr deleted file mode 100644 index 1996fd4..0000000 --- a/src/__OLD_parcom/phrase.cr +++ /dev/null @@ -1,33 +0,0 @@ -require "./parser.cr" -require "./eof.cr" -require "./map.cr" - -module Parcom - # `Phrase` is a `Parser` that tries to parse with another parser, - # but will fail if any of the input has not been consumed. - # - # Example: - # ``` - # letter_a = Token.new('a') - # tokens = Tokens.from_string("aaa") - # one_a = Phrase(Char, Char).new(letter_a) - # result = one_a.parse(tokens) # This fails - # ``` - class Phrase(T, V) < Parser(T, V) - @p : Map(T, {V, Nil}, V) - - # Accepts the parser to parse with. - def initialize(p : Parser(T, V)) - @p = (p + EOF(T).new).map &.first - end - - # Tries to parse with the given parser, fails if there - # is any un-parsed input remaining. - def parse(tokens : Tokens(T)) : Result(T, V) - @p.parse(tokens) - rescue ex : ParserFail - raise ParserFail.new("Phrase: #{ex.message}") - end - end -end - diff --git a/src/__OLD_parcom/plus.cr b/src/__OLD_parcom/plus.cr deleted file mode 100644 index 53c9b4f..0000000 --- a/src/__OLD_parcom/plus.cr +++ /dev/null @@ -1,54 +0,0 @@ -require "./parser.cr" - -module Parcom - # `Plus` is a parser that tries to parse with two different - # parsers in succession and fails if either of the two parsers fails. - # The return type of this parser is `{V, U}`, where `V` is the return - # type of the first parser and `U` is the return type of the second. - # - # Example: - # ``` - # parse1 = Token.new('1') - # parse2 = Token.new('2') - # tokens = Tokens.from_string("12") - # result = (parse1 + parse2).parse(tokens) # succeeds - # result = (parse2 + parse1).parse(tokens) # fails, wrong order - # ``` - # - # `Plus` parsers can be chained together, but the resulting return type - # can become unweildly with too many combined parsers: - # ``` - # letter_a = Token.new('a') - # a5 = letter_a + letter_a + letter_a + letter_a + letter_a - # tokens = Tokens.from_string("aaaaa") - # a5.parse(tokens) # succeeds - # # `a5` has a return type of { { { {Char, Char}, Char}, Char}, Char} - # ``` - # - # If you need to parse more than two things in this manner, - # consider using `Many`, `Some`, `Sequence`, or `TokenSeq` instead. - class Plus(T, V, U) < Parser(T, {V, U}) - # Accepts the two parsers to use, in order. - def initialize(@p1 : Parser(T, V), @p2 : Parser(T, U)) - end - - # Tries to parse with the two given parsers, and returns - # their results in a tuple if the both succeed. - def parse(tokens : Tokens(T)) : Result(T, {V, U}) - begin - r1 = @p1.parse(tokens) - rescue ex : ParserFail - raise ParserFail.new("Plus (left): #{ex.message}") - end - - begin - r2 = @p2.parse(r1.tokens) - rescue ex : ParserFail - raise ParserFail.new("Plus (right): #{ex.message}") - end - - Result.new(r2.tokens, {r1.value, r2.value}) - end - end -end - diff --git a/src/__OLD_parcom/recover.cr b/src/__OLD_parcom/recover.cr deleted file mode 100644 index 378f8d6..0000000 --- a/src/__OLD_parcom/recover.cr +++ /dev/null @@ -1,27 +0,0 @@ -require "./parser.cr" -require "./optional.cr" -require "./map.cr" - -module Parcom - # `Recover` is a `Parser` that tries to parse with another parser, - # but does not fail the parser chain if the wrapped parser fails. - # If the wrapped parser fails, a `Recover` will not modify the input - # stream, and return an arbitrary value of type `V` instead. - class Recover(T, V) < Parser(T, V) - @p : Map(T, V?, V) - - # Accepts the parser to use, and the default value - # to return if the parser fails. - def initialize(p : Parser(T, V), default : V) - @p = Optional.new(p).map { |x| x.nil? ? default : x } - end - - # Tries to parse with the given parser, succeeds with the - # default value instead of failing. This parser does not - # consume input if the wrapped parser fails. - def parse(tokens : Tokens(T)) : Result(T, V) - @p.parse(tokens) - end - end -end - diff --git a/src/__OLD_parcom/right.cr b/src/__OLD_parcom/right.cr deleted file mode 100644 index a0489b1..0000000 --- a/src/__OLD_parcom/right.cr +++ /dev/null @@ -1,26 +0,0 @@ -require "./parser.cr" -require "./map.cr" - -module Parcom - # `Right` is a `Parser` that tries to parse with two different - # parsers in succession and fails if either of the two parsers fails. - # This parser behaves the same as `Plus`, but only returns the result - # of the second parser. - class Right(T, V, U) < Parser(T, U) - @p : Map(T, {V, U}, U) - - # Accepts the two parsers to use, in order. - def initialize(p1 : Parser(T, V), p2 : Parser(T, U)) - @p = (p1 + p2).map(&.last) - end - - # Tries to parse with the two given parsers, and returns the - # result of the second parser if they both succeed. - def parse(tokens : Tokens(T)) : Result(T, U) - @p.parse(tokens) - rescue ex : ParserFail - raise ParserFail.new("Left: #{ex.message}") - end - end -end - diff --git a/src/__OLD_parcom/satisfy.cr b/src/__OLD_parcom/satisfy.cr deleted file mode 100644 index 9734635..0000000 --- a/src/__OLD_parcom/satisfy.cr +++ /dev/null @@ -1,33 +0,0 @@ -require "./parser.cr" -require "./any_token.cr" -require "./assert.cr" - -module Parcom - # `Satisfy` is a `Parser` that parses a single token - # if that token passes a predefined test, similar - # to `Assert`. This class is effectively a shorthand - # for the following: - # ``` - # # These parsers are equivalent. - # letter_assert = Assert.new(AnyToken(Char).new) { |x| x.letter? } - # letter_satisfy = Satisfy(Char).new { |x| x.letter? } - # ``` - class Satisfy(T) < Parser(T, T) - @p : Assert(T, T) - - # Accepts the `Bool`-returning block containing the test - # to run on the parsed token. - def initialize(&block : T -> Bool) - @p = AnyToken(T).new.assert(&block) - end - - # Returns the first token of the input if that - # token passes the test. - def parse(tokens : Tokens(T)) : Result(T, T) - @p.parse(tokens) - rescue ex : ParserFail - raise ParserFail.new("Satisfy: #{ex.message}") - end - end -end - diff --git a/src/__OLD_parcom/sep_by.cr b/src/__OLD_parcom/sep_by.cr deleted file mode 100644 index fa19027..0000000 --- a/src/__OLD_parcom/sep_by.cr +++ /dev/null @@ -1,38 +0,0 @@ -require "./parser.cr" -require "./map.cr" -require "./many.cr" - -module Parcom - # `SepBy` is a `Parser` that tries to parse one or more times with one - # parser, alternating with a second parser. - # - # Example: - # ``` - # letter_a = Token.new('a') - # letter_b = Token.new('b') - # p = SepBy(Char, Car, Char).new(letter_a, letter_b) - # tokens = Tokens.from_string("ababababa") - # - # result = p.parse(tokens) - # puts result.value # => ['a', 'a', 'a', 'a', 'a'] - # ``` - class SepBy(T, V, U) < Parser(T, Array(V)) - @p : Map(T, {V, Array(V)}, Array(V)) - - # Accepts the parser that parses the result values, and the - # parser that parses the sepatators. - def initialize(elem : Parser(T, V), sep : Parser(T, U)) - @p = (elem + Many(T, U).new(sep >> elem)).map do |tup| - [tup[0]] + tup[1] - end - end - - # Tries to parse, alternating the first and second parsers. - def parse(tokens : Tokens(T)) : Result(T, Array(V)) - @p.parse(tokens) - rescue ex : ParserFail - raise ParserFail.new("SepBy: #{ex.message}") - end - end -end - diff --git a/src/__OLD_parcom/sequence.cr b/src/__OLD_parcom/sequence.cr deleted file mode 100644 index 6a05cde..0000000 --- a/src/__OLD_parcom/sequence.cr +++ /dev/null @@ -1,33 +0,0 @@ -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 - diff --git a/src/__OLD_parcom/some.cr b/src/__OLD_parcom/some.cr deleted file mode 100644 index a2e3563..0000000 --- a/src/__OLD_parcom/some.cr +++ /dev/null @@ -1,33 +0,0 @@ -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 - diff --git a/src/__OLD_parcom/token.cr b/src/__OLD_parcom/token.cr deleted file mode 100644 index b4e1fef..0000000 --- a/src/__OLD_parcom/token.cr +++ /dev/null @@ -1,20 +0,0 @@ -require "./satisfy" - -module Parcom - # `Token` is a `Parser` that tries to parse a specific token - # from the input stream. - class Token(T) < Parser(T, T) - # Accepts the token that this parser will try to parse. - def initialize(@expected : T) - @p = Satisfy(T).new { |x| x == @expected } - end - - # Tries to parse the specified token from the input stream. - def parse(tokens : Tokens(T)) : Result(T, T) - @p.parse(tokens) - rescue ex : ParserFail - raise ParserFail.new("Token <#{@expected}>: #{ex.message}") - end - end -end - diff --git a/src/__OLD_parcom/token_seq.cr b/src/__OLD_parcom/token_seq.cr deleted file mode 100644 index 45900f9..0000000 --- a/src/__OLD_parcom/token_seq.cr +++ /dev/null @@ -1,38 +0,0 @@ -require "./parser.cr" -require "./sequence.cr" - -module Parcom - # `TokenSeq` is a `Parser` that attempts to parse a specific - # string of tokens. If the expected tokens are not at the start - # of the input stream, the parser fails. - # - # Example: - # ``` - # parse_test = TokenSeq(Char).new("test".chars) - # tokens = Tokens.from_string("testing") - # - # result = parse_test.parse(tokens) - # - # puts result.value # => ['t', 'e', 's', 't'] - # puts result.tokens # => ['i', 'n', 'g'] - # ``` - class TokenSeq(T) < Parser(T, Array(T)) - @p : Sequence(T, T) - - # Accepts the tokens to try and parse, in order. - def initialize(expected : Iterable(T)) - ps = [] of Parser(T, T) - expected.each { |t| ps << Token.new(t) } - - @p = Sequence.new(ps) - end - - # Tries to parse the list of tokens. - def parse(tokens : Tokens(T)) : Result(T, Array(T)) - @p.parse(tokens) - rescue ex : ParserFail - raise ParserFail.new("TokenSeq: #{ex.message}") - end - end -end - |
