https://github.com/nunorc/reducer

a simple tool for reducing expressions to a simpler form in Haskell
https://github.com/nunorc/reducer

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a simple tool for reducing expressions to a simpler form in Haskell

README

# Reducer

A simple tool developed in Haskell to reduce a sequence of elements,
represented by strings, to a simple expression by finding repeating patterns.

For a live demo visit: http://reducer.nrc.pt.

## Example

### Using ghci

Using ghci, to reduce the sequence `["a","a","b","c","a","b","c"]`:

*Reducer> let (expr,patterns) = reduce ["a","a","b","c","a","b","c"]

The final reduced expression is:

*Reducer> expr
["a","P0","P0"]

And the patterns found are:

*Reducer> patterns
[("P0",["a","b","c"])]

### Using the command line

You can use the *main.hs* program to build a GraphViz representation of the reduced
expression. The input expression should be stored in a JSON file:

$ cat ex/input.json
["a","a","b","c","a","b","c"]

run the program using for example *runhaskell*, giving as argument the input file,
and saving the output to a new file:

$ runhaskell main.hs ex/input.json > ex/expr.dot

Now use the *dot* tool from GraphViz to create a *PNG* file for example:

$ dot -Tpng ex/expr.dot > ex/expr.png

You should see something similar to the image below:

![Example](ex/expr.png)

## About

Developed by: Almeida, J.J, Oliveira, J.N., and Carvalho, N.R.