Stack overflow when running a recursive programming language grammar

[TheOnlyTails]

I'm trying to write a grammar for a custom general-purpose programming language using pest, and while I've managed to write the grammar, running it always results in a fatal runtime error: stack overflow.
Here is the grammar I'm using, together with the test file I'm running it on (though it fails on smaller examples too).

[tomtau]

have you tried stepping through it in a debugger: https://github.com/pest-parser/awesome-pest/blob/main/debugger.md ?

[TheOnlyTails]

From what I can see, it had a problem with the order of the float_literal alternatives which I fixed, but for some reason, when trying to parse an identifier as an expr, such as a, it goes into an infinite loop.