lambda_calculus | dependency implementation of the untyped lambda calculus | Dashboard library

by ljedrz Rust Version: 2.1 License: CC0-1.0

X-Ray Key Features Code Snippets(3)Community Discussions(4)Vulnerabilities Install Support

kandi X-RAY | lambda_calculus Summary

lambda_calculus is a Rust library typically used in Analytics, Dashboard applications. lambda_calculus has no bugs, it has no vulnerabilities, it has a Permissive License and it has low support. You can download it from GitHub.

lambda_calculus is a simple, zero-dependency implementation of pure lambda calculus in Safe Rust.

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Quality

Security

License

Reuse

Support

lambda_calculus has a low active ecosystem.

It has 48 star(s) with 4 fork(s). There are 2 watchers for this library.

It had no major release in the last 12 months.

There are 0 open issues and 6 have been closed. On average issues are closed in 3 days. There are no pull requests.

It has a neutral sentiment in the developer community.

The latest version of lambda_calculus is 2.1

Quality

lambda_calculus has no bugs reported.

Security

lambda_calculus has no vulnerabilities reported, and its dependent libraries have no vulnerabilities reported.

License

lambda_calculus is licensed under the CC0-1.0 License. This license is Permissive.

Permissive licenses have the least restrictions, and you can use them in most projects.

Reuse

lambda_calculus releases are available to install and integrate.

Installation instructions, examples and code snippets are available.

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lambda_calculus Key Features

No Key Features are available at this moment for lambda_calculus.

lambda_calculus Examples and Code Snippets

lambda_calculus,Examples,Showing β-reduction steps

Rust

Lines of Code : 22

License : Permissive (CC0-1.0)

Copy

use lambda_calculus::*;
use lambda_calculus::data::num::church::pred;

fn main() {
    let mut expr = app!(pred(), 1.into_church());

    println!("{} order β-reduction steps for PRED 1 are:", NOR);

    println!("{}", expr);
    while expr.reduce(NO

lambda_calculus,Examples,Comparing different numeral encodings

Rust

Lines of Code : 16

License : Permissive (CC0-1.0)

Copy

use lambda_calculus::*;

fn main() {
    println!("comparing different encodings of number 3 (De Bruijn indices):");
    println!("  Church encoding: {:?}", 3.into_church());
    println!("   Scott encoding: {:?}", 3.into_scott());
    println!(" Par

lambda_calculus,Examples,Comparing the number of steps for different reduction strategies

Rust

Lines of Code : 16

License : Permissive (CC0-1.0)

Copy

use lambda_calculus::*;
use lambda_calculus::data::num::church::fac;

fn main() {
    let expr = app(fac(), 3.into_church());

    println!("comparing normalizing orders' reduction step count for FAC 3:");
    for &order in [NOR, APP, HNO, HAP].i

Community Discussions

Trending Discussions on lambda_calculus

Understanding recurive let expression in lambda calculus with Haskell, OCaml and nix language

Java 8 lambda and alpha equivalence

Handling function application in λ expression with regex

Is the substitution model a good way of approximating how JavaScript evaluates pure code?

QUESTION

Understanding recurive let expression in lambda calculus with Haskell, OCaml and nix language

Asked 2020-Dec-06 at 23:22

I'm trying to understand how recursive set operate internally by comparing similar feature in another functional programming languages and concepts.

I can find it in wiki. In that, I need to know Y combinator, fixed point. I can get it briefly in wiki.

Then, now I start to apply this in Haskell.

Haskell

It is easy. But I want to know behind the scenes.

...

ANSWER

Answered 2020-Dec-05 at 13:54

I guess several things by myself.

In eagar evaluation language, I must declare before use it. So the order of declaration is simple.

Source https://stackoverflow.com/questions/65153327

QUESTION

Java 8 lambda and alpha equivalence

Asked 2017-Jul-21 at 12:42

I am wondering, is any nice way (if it is possible at all) to implement an alpha-equivalence comparison in Java-8?

Obviously these two lambda-s are alpha-equivalent. Let us suppose that for some circumstances we want to detect this fact. How it can be achieved?

...

ANSWER

Answered 2017-Jun-28 at 13:18

_{I'm going out on a limb with this answer, but it may be worth mentioning this:}

There is no way to do this. As Brian Goetz pointed out in an answer to a related question, there are no specified, reliable ways of obtaining the "contents" of a lambda, in that sense.

But (and now comes the vague, handwaving part) :

There is no way to do this yet.

It might be possible to do this in the future. Maybe not with Java 9, but later. The Project Panama has ambituous goals, among them, giving the developer a deeper access to lambdas, aiding in further (runtime) optimizations, translations and processing.

And recently, Radosław Smogura posted in the mailing list :

I try to capture lambda expression to get them as expression tree during runtime. I’m able to do it for simple lambdas like (o) -> (var == var) && ((varX == varX) && (someField + 1 == 1)), so later user can use (missing) API to examine tree.

Right now tree can be accessed with code like this:

Source https://stackoverflow.com/questions/44802800

QUESTION

Handling function application in λ expression with regex

Asked 2017-May-24 at 15:58

Hello there !

I will start by giving a short, simplified definition of λ-expressions.
A λ-expression can be either :

A variable (here, let's say it's a lower-case letter [a-z]) (or any simple operation with variables (like a*b or (a+b)*c))
A function (or abstraction). It has the following syntax : (λx.e) where x is a dummy variable (can be any lower-case letter) and e is a λ-expression (eventually containing xs). It can be read as : function λ : x -> e(x)
A function application. It has the following syntax : (f e) (note that I want the space and both parenthesis) where f and e are both λ-expressions. It can be read as : f(e). The reduction operation basically means evaluating f(e)

Here is a link if you want to know more about Lambda Calculus

Now, I am trying to find a regex that does a reduction operation on a function application. In other words, in the abstraction, I want to replace each dummy variable (except the one preceding the .) by the following expression and give the resulting expression.

Here are some examples :
(For typing purpose, let's replace λ by \ in the string)
string => result after one reduction
((\x.x) a) => a
((\x.x) (\y.y)) => (\y.y)
(((\x.(\y.x+y)) a) b) => ((\y.a+y) b)
((\y.a+y) b) => a+b
((\x.x) (f g)) => (f g)
((\x.x) ((\y.y) a)) => ((\x.x) a) OR ((\y.y) a) (depends on what you think is easier to do. My guess would be the first one)

It can be done with multiple substitutions, but I would prefer no more than 2.
The language I am using is Powershell, so the regex must support .NET flavour (it does mean that recursion is not allowed...)
I am pretty sure there is something to do with balancing groups, but I can't find a working regex...
Also, there certainly are better solutions than using regex, but I want to do that with regex, no code here.
I will add more examples when I think of good ones.

Edit 1 :

All I managed to do so far is matching the expression and capture each sub-expression with the following regex :

...

ANSWER

Answered 2017-May-24 at 15:58

Ok I figured it out. It's a pretty long regex, so try to understand it at your own risk ;)
Here it goes :

Source https://stackoverflow.com/questions/44134560

QUESTION

Is the substitution model a good way of approximating how JavaScript evaluates pure code?

Asked 2017-May-22 at 18:32

Say this is my program:

...

ANSWER

Answered 2017-May-22 at 18:32

Is the substitution model a good way of approximating how JavaScript evaluates pure code?

Of course !

Source https://stackoverflow.com/questions/44119575

Community Discussions, Code Snippets contain sources that include Stack Exchange Network

Vulnerabilities

No vulnerabilities reported

Install lambda_calculus

Include the library by adding the following to your Cargo.toml:.
backslash_lambda: changes the display of lambdas from λ to \
encoding: builds the data encoding modules; default feature

Support

For any new features, suggestions and bugs create an issue on GitHub. If you have any questions check and ask questions on community page Stack Overflow .

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