README.md

# ![Elixir](https://hexdocs.pm/ex_unit/assets/logo.png) GenFST

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GenFST implements a generic finite state transducer with
customizable rules expressed in a DSL.

A finite-state transducer (FST) is a finite-state machine 
with two memory tapes, following the terminology for Turing 
machines: an input tape and an output tape.

A FST will read a set of strings on the input tape and 
generates a set of relations on the output tape. An FST 
can be thought of as a translator or relater between strings in a set.

In morphological parsing, an example would be inputting a string of letters 
into the FST, the FST would then output a string of 
[morphemes](https://en.wikipedia.org/wiki/Morphemes).

## Example

Here we implement a simple morphological parser for English language. This
morphological parser recognize different inflectional morphology of the verbs.

```elixir
defmodule MorphologicalParser do
  use GenFST

  rule ["play", {"s", "^s"}]
  rule ["act", {"s", "^s"}]

end
assert MorphologicalParser.parse("acts") == "act^s"
```

For example if we pass the third-person singluar tense of the verb _act_,
`MorphologicalParser.parse("acts")`, the morphological parser will output
`"act^s"`. The semantic of rule definition is given at `rule/1`.


## Installation

The package can be installed by adding `gen_fst` to your list of 
dependencies in `mix.exs`:

```elixir
def deps do
  [{:gen_fst, "~> 0.1.0"}]
end
```

## Documentation

The docs for this project can be found at [https://hexdocs.pm/gen_fst](https://hexdocs.pm/gen_fst).