haydari
所属分类：工具库
开发工具：Crystal
文件大小：0KB
下载次数：0
上传日期：2016-03-11 19:43:57
上 传 者：
sh-1993
说明： 晶体编程语言的解析器组合子库。，
(Parser combinator library for crystal programming language.,)
文件列表:
.travis.yml (18, 2016-03-11)
LICENSE (1077, 2016-03-11)
samples/ (0, 2016-03-11)
samples/brainfuck.cr (1063, 2016-03-11)
samples/json.cr (1593, 2016-03-11)
samples/tutorial/ (0, 2016-03-11)
samples/tutorial/1-char.cr (207, 2016-03-11)
samples/tutorial/2-many-chars.cr (219, 2016-03-11)
shard.yml (88, 2016-03-11)
spec/ (0, 2016-03-11)
spec/dummy_classes/ (0, 2016-03-11)
spec/dummy_classes/input_parser.cr (1183, 2016-03-11)
spec/haydari/ (0, 2016-03-11)
spec/haydari/parser_input_spec.cr (1033, 2016-03-11)
spec/haydari/parser_spec.cr (803, 2016-03-11)
spec/haydari/parsers/ (0, 2016-03-11)
spec/haydari/parsers/char_spec.cr (957, 2016-03-11)
spec/haydari/parsers/many_spec.cr (562, 2016-03-11)
spec/haydari/parsers/not_spec.cr (331, 2016-03-11)
spec/haydari/parsers/or_spec.cr (848, 2016-03-11)
spec/haydari/parsers/plus_spec.cr (705, 2016-03-11)
spec/haydari/parsers/recurse_spec.cr (946, 2016-03-11)
spec/haydari/parsers/return_spec.cr (512, 2016-03-11)
spec/haydari/parsers/satisfy_char_spec.cr (582, 2016-03-11)
spec/haydari/parsers/satisfy_string_spec.cr (574, 2016-03-11)
spec/haydari/parsers/string_spec.cr (511, 2016-03-11)
spec/haydari/parsers/then_spec.cr (1063, 2016-03-11)
spec/haydari_spec.cr (49, 2016-03-11)
spec/spec_helper.cr (146, 2016-03-11)
src/ (0, 2016-03-11)
src/haydari.cr (2449, 2016-03-11)
src/haydari/ (0, 2016-03-11)
src/haydari/parser.cr (1927, 2016-03-11)
src/haydari/parser_error.cr (187, 2016-03-11)
src/haydari/parser_generator.cr (94, 2016-03-11)
src/haydari/parser_input.cr (1131, 2016-03-11)
src/haydari/parsers/ (0, 2016-03-11)
src/haydari/parsers/char_parser.cr (432, 2016-03-11)
... ...
# haydari (WIP)
Parser combinator library for crystal-lang,
## Installation
Add this to your application's `shard.yml`:
```yaml
dependencies:
haydari:
github: umurgdk/haydari
```
## TODO
- [ ] Support `IO` as `ParserInput`
## Usage
Parser combinators make easy to build complex parsers without dealing with so much hassle. Instead of trying to build one big monolithic parser, making small and composeable parsers and combining them together is way of writing parsers in parser combinators. Haydari gives you smallest parsers like *parse a character*, *parse a whitespace*, etc. and tons of combinators like *many*, *not*, *then* to give them a meaning.
### 1. Creating a parser
Let's start writing with simplest parser. Our parser going to read one **space** character and done.
```crystal
# samples/tutorial/1-char.cr
require "haydari"
class MyParser
include Haydari
defparser space, Char do
char(' ')
end
end
my_parser = MyParser.new.space
my_parser.run(" ")
puts "'#{my_parser.output}'" # prints a space character => ' '
```
Here `defparser` takes a **name** and a **type** of the value we're going to parse. Since we're using char parser it results in char value. As you can see calling space method is not running the parser, instead it builds a parser instance to run later on.
But why we get only **one** space character even we pass a string which has more than one space characters? `char` parser reads a character from it's input and then success or fail. `char` parser don't know anything about how many times it should try to parse or what to do next. But **combinators** does. There are lots of combinators builtin Haydari but most known one is called `many`. `many` takes a parser and tries to run that parser until it fails. Let's parse multiple space characters.
```crystal
# samples/tutorial/2-many-chars.cr
# notice Array(Char)
defparser space, Array(Char) do
many char(' ')
end
```
Now if we run our parser again output will be `'[' ', ' ', ' ']'`. First thing you should notice our parser's type is changed to `Array(Char)`. This is result of *many* combinator. *many* combinator takes a parser and run that parser until it fails and collect all the results. Because of that its value going to be array of values. You may expect `many char(' ')` to be resulted in `String`, but that's not true. Since *many* combinator could take any kind of parser, the parser you gave may not result into character.
### 2. Parsing comma separated array of strings
TBD
### JSON Parser
```crystal
require "haydari"
class JSONParser
include Haydari
alias JValue = String | Int32 | Bool | Nil | Array(JValue) | Hash(String, JValue)
alias KeyValue = {String, JValue}
defparser string_lit, String do
string("\"") >> none_of("\"\n").many.text << string("\"")
end
defparser bool_lit, Bool do
string("true").return(true) | string("false").return(false)
end
defparser contents, JValue do
string_lit | array_lit | object_lit | bool_lit | number
end
defparser comma, String do
ws.many >> string(",") << ws.many
end
defparser array_lit, Array(JValue) do
string("[") >> ws.many >> contents.sep(comma) << ws.many << string("]")
end
defparser key_value, KeyValue do
string_lit.then { |key|
ws.many >> string(":") >> ws.many >> contents.select { |value|
{key, value}
}
}
end
defparser object_lit, Hash(String, JValue) do
string("{") >> ws.many >> key_value.sep(comma).select { |kvs|
hash = Hash(String, JValue).new
kvs.each do |kv|
hash[kv[0]] = kv[1]
end
hash
} << ws.many << string("}")
end
def run(input)
puts typeof(object_lit)
parser = object_lit
if parser.run(input)
parser.output
else
raise "Failed!"
end
end
end
json_parser = JSONParser.new
hash = json_parser.run("{\"hello\" : \"world\", \"arr\":\n [1, 2, 3, true, {\"sub\" : \"gell\"}]}")
puts hash.inspect
```
## Development
TODO: Write development instructions here
## Contributing
1. Fork it ( https://github.com/umurgdk/haydari/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request
## Contributors
- umurgdk(https://github.com/umurgdk) Umur Gedik - creator, maintainer
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