Regex hangs the browser

[tdhooper]

interactive-shader-format-js/src/MetadataExtractor.js

Line 11 in bfaf801

const results = regex.exec(rawFragmentShader);

I'm trying to run some non-ISF shaders through the parser which cause this line to hang the browser. Instead of doing this validity check and grabbing the metadata block with an expensive regex, why not use the startIndex and endIndex endpoints you define later?

If you're wondering why I'm trying to parse non-ISF shaders, consider a live-update application where someone makes a typo, or in my case where I'm supporting multiple shader metadata formats, and only want to invoke ISF if it's a valid ISF shader.

[msfeldstein]

How do you get it to hang? I tried deleting the whole comment section on interactiveshaderformat.com and it seems to work (error) just fine but not hang

[tdhooper]

Here's the part of my shader which is causing it to hang, try pasting this into interactiveshaderformat.com

float mHead(vec3 p) {

    p = pp;
    p += vec3(-.165,.0715,-.346);
    float eyeball = length(p) - .088;
    if (isMap) isEye = eyeball < d;
    d = min(d, eyeball);


    // ear
    p = pp;
    p += vec3(-.405,.12,.10);
    pR(p.xy, -.12);
    pR(p.xz, .35);
    pR(p.yz, -.3);
    vec3 pe = p;

    // base
    float ear = p.s + smoothstep(-.05, .1, p.y) * .015 - .005;
    float earback = -ear - mix(.001, .025, smoothstep(.3, -.2, p.y));

    // inner
    pR(p.xz, -.5);
    float iear = ellip(p.zy - vec2(.01,-.03), vec2(.045,.05));
    iear = smin(iear, length(p.zy - vec2(.04,-.09)) - .02, .09);
    float ridge = iear;
    iear = smin(iear, length(p.zy - vec2(.1,-.03)) - .06, .07);
    ear = smax2(ear, -iear, .04);
    earback = smin(earback, iear - .04, .02);

    // ridge
    p = pe;
    pR(p.xz, .2);
    ridge = ellip(p.zy - vec2(.01,-.03), vec2(.045,.055));
    ridge = smin3(ridge, -pRi(p.zy, .2).x - .01, .015);
    ridge = smax3(ridge, -ellip(p.zy - vec2(-.01,.1), vec2(.12,.08)), .02);

    float ridger = .01;

    ridge = max(-ridge, ridge - ridger);

    ridge = smax2(ridge, abs(p.x) - ridger/2., ridger/2.);

    ear = smin(ear, ridge, .045);



    return d;
}