https://github.com/objectionary/demu
A command line tool for DeMutabilization of EO programs
https://github.com/objectionary/demu
code-optimization eolang java oop
Last synced: 7 months ago
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A command line tool for DeMutabilization of EO programs
- Host: GitHub
- URL: https://github.com/objectionary/demu
- Owner: objectionary
- License: mit
- Created: 2022-12-08T13:14:40.000Z (almost 3 years ago)
- Default Branch: master
- Last Pushed: 2024-11-07T17:23:15.000Z (about 1 year ago)
- Last Synced: 2024-11-07T18:29:09.485Z (about 1 year ago)
- Topics: code-optimization, eolang, java, oop
- Language: Java
- Homepage:
- Size: 58.6 KB
- Stars: 4
- Watchers: 2
- Forks: 1
- Open Issues: 10
-
Metadata Files:
- Readme: README.md
- License: LICENSE.txt
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# DeMu
It's a well known fact that programs with immutable objects much easy to
maintain, test and use, but the main benefit form immutable objects is that they
allow performing
more [aggressive optimizations [1]](https://dl.acm.org/doi/10.1145/583810.583833)
and apply more valuable analysis. **DeMu** is exactly the tool for removing
mutable objects like `memory` and `cage`
from [EO](https://github.com/objectionary/eo) programs. Actually, DeMu is
acronym for **De-Muatabilization**.
## Methodology
There isn't single formal methodology or algorithm for converting mutable
objects into immutable, but we can use some separate methods to achieve this.
### Using SSA form for simple cases
We actually can
apply [SSA [2]](http://www1.cse.wustl.edu/~cytron/cs531/Resources/Papers/valnum.pdf)
form for `eo` programs. This approach can immediately remove some usages of
mutable objects. Let's consider the following example:
```eo
[] > example
cage 0 > index
seq > @
index.write 1
stdout
sprintf
"%s"
index
TRUE
```
After applying SSA form we get something like the next:
```eo
[] > example
seq > @
stdout
sprintf
"%s"
1
TRUE
```
And as you can see - we removed usage of `cage` from the result program.
The relation between SSA form and Dataflow Languages (like `EO` and,
particularly, Functional Programming Languages) is quite well described in
that [article [3]](https://www.cs.princeton.edu/~appel/papers/ssafun.pdf).
### Using recursion for loops
The second method is to convert loops into recursive calls.
## Related articles and links
1. [Immutability specification and its applications](https://dl.acm.org/doi/10.1145/583810.583833)
2. [Global Value Numbers and Redundant Computations](http://www1.cse.wustl.edu/~cytron/cs531/Resources/Papers/valnum.pdf)
3. [SSA is Functional Programming](https://www.cs.princeton.edu/~appel/papers/ssafun.pdf)
## How to Contribute
Fork repository, make changes, send us a pull request. We will review your
changes and apply them to the `master` branch shortly, provided they don't
violate our quality standards. To avoid frustration, before sending us your pull
request please run full Maven build:
```bash
$ mvn clean install -Pqulice
```
You will need Maven 3.3+ and Java 8+.