@sagemath/pari-gmp

Quickstart

Install the package

$ npm i @sagemath/pari-gmp

Then use it from node.js as follows:

$ node
Welcome to Node.js v14.15.5.
> (async ()=>global.gp = await require('@sagemath/pari-gmp')())()
Promise { <pending> }
> gp('factor(2^128 + 1)')
'%1 = 5\n'
> gp('\\p100')
   realprecision = 105 significant digits (100 digits displayed)
'\n'
> gp('contfrac(Pi)')
'%4 = [3, 7, 15, 1, 292, 1, 1, 1, 2, 1, 3, 1, 14, 2, 1, 1, 2, 2, 2, 2, 1, 84, 2, 1, 1, 15, 3, 13, 1, 4, 2, 6, 6, 99, 1, 2, 2, 6, 3, 5, 1, 1, 6, 8, 1, 7, 1, 2, 3, 7, 1, 2, 1, 1, 12, 1, 1, 1, 3, 1, 1, 8, 1, 1, 2, 1, 6, 1, 1, 5, 2, 2, 3, 1, 2, 4, 4, 16, 1, 161, 45, 1, 22, 1, 2, 2, 1, 4, 1, 2, 24, 1, 2, 1, 3, 1, 2, 1, 1, 10, 2, 5]\n'

Now square a large number, which should take a few seconds, as compared to Javascript's built in BigInt, which takes "forever" (?). Pari without GMP is also reasonably fast, taking a second longer.

> t=new Date();gp('n=10^(10^7)-17; m=n*n; 0'); new Date() - t
2757
> t=new Date(); n=BigInt(10)**BigInt(10**7)-BigInt(17); m=n*n; new Date()-t
... I gave up after a minute

Build from source

You need to install emscripten. Then do

npm run build

This will download and build GMP, then download and build PARI linked against GMP for faster arithmetic.

Problems/TODO

Interrupting running code

Try gp(factor(2^2001+1)) and hit control+c to try to interrupt the running computation. It terminates the Node.js interpreter as well, and there is no way to catch this.

PARI packages

Some PARI commands require loading files from disk. E.g.,

polgalois(x^8+1)

We just need to include the correct files in the right place by including an option like

--embed-file ../root/pari@/usr/local/share/pari/

in the OPT variable in build-pari.sh.

Using with webpack5 in your browser

Make it easy to use this in frontend browser code bundled up using webpack.

Acknowledgement

• Bill Allombert has been very helpful.