# Parselix
A parser combinator library for Elixir.
[](https://hex.pm/packages/parselix)
## Document
[Parselix Document](https://hexdocs.pm/parselix/)
## Features
* Attaching Metadata(position and token name)
* Evaluating While Parsing
* Recursive Parser
* Combining Small Parsers
* Editable Error Messages
* Documentable
## For what?
* To **parse** languages, data formats, and more.
* To **format** strings.
* To **validate** something such as mail address.
## Installation
Add `{:parselix, "~> x.x.x"}` to deps of your app.
## Example
### JSON
[See the json parser implementation by Parselix](https://github.com/ryo33/Parselix/blob/master/lib/parselix/prepared/json.ex).
### Function style
```elixir
@doc "Replaces error messages."
def error_message(parser, message) do
fn target, position ->
case parser.(target, position) do
{:error, _, _} -> {:error, message, position}
x -> x
end
end
end
```
```elixir
@doc "Parse lowercase characters."
def lowercases do
fn target, position do
parser = lowercase() |> many_1()
parser.(target, position)
end
end
```
### Function style with parser_body macro
```elixir
@doc "Parse uppercase characters."
def uppercases do
parser_body do
uppercase() |> many_1()
end
end
```
# Macro style
```elixir
@doc "Picks one value from the result of the given parser."
parser :pick, [parser, index] do
parser |> map(&Enum.at(&1, index))
end
```
```elixir
@doc "Parses the end of text."
parser :eof do
fn
"", position -> {:ok, :eof, "", position}
_, position -> {:error, "There is not EOF.", position}
end
end
```
# Private
```elixir
parserp :private_dump, [parser] do
parser |> map(fn _ -> :empty end)
end
```
## License
MIT
## Author
[ryo33](https://github.com/ryo33/ "ryo33's github page")
