V7 VS decimal.js

I used such a succinct AST structure to implement a JavaScript parser and interpreter for a severely memory constrained environment (embedded): V7 (https://github.com/cesanta/v7)

We later switched to a ast->bytecode compilation step but for a while the implicit AST was directly traversed during interpretation.

Nice! A few years ago I took a stab at this problem space with https://github.com/cesanta/v7 ; with fun tricks like in-place compacting GC, stdlib JS object graph "frozen" in rom etc

https://github.com/cesanta/v7

Languages are not all equal nor do they all function in the same way, and that's not my opinion.

Javascript syntax itself is one thing, and you can certainly feel free to Javascriptify some C++ libraries and make it all look a certain way for specific tasks, while managing things behind the scenes, up to a point... but there is no getting around the fact that SOMEONE and some languages are needed to implement low level systems functionality.

the power of Cython or the Python C FFI is that it allows you to script/glue modular native code.

You then state "C++14 may have been ratified 7 years ago but it's not the target code your build chain spits out"

no, a C++ COMPILER spits out assembler code that then gets assembled and linked into an executable.

The C++ or C code corresponds directly to a given set of assembler instructions which correspond directly to CPU instructions.

You claim that Python programming of microcontrollers is mainstream, but this is not true nor possible. Python SCRIPTING of code modules (that cannot be written in Python) is certainly one way to assemble a system from pre-built legos.

If you refer to knowing what I'm talking about as gatekeeping and egoism, might I suggest that you insist less forcefully in the correctness of incorrect things you state? we could be done with this spat in short order if YOU would refrain from speaking falsehoods. lies.untrue things.

I look forward to your lisp c compiler. make sure that it's 100% lisp from the bottom up, or I'll consider you're having ceded my point. Consider that the lisp you author in has a garbage collection system that lisp cannot have written originally, nor has any semantics for the underlying memory structures of, but hey, I guess if one is committed to pretending that all languages are equal for all tasks, who am I to question ones self-identification with a given language.

ii) Third-Party Libraries There are various libraries like math.js, decimal.js, big.js that solve the problem. Each library functions according to its documentation. This approach is comparatively better.

Desperate for a solution, I stumbled upon Decimal.js, a JavaScript library that provides arbitrary-precision decimal arithmetic. I was intrigued, so I decided to give it a try.

I too wish JS had a dedicated Decimal Type, but there is plenty of 3rd party libraries available like decimal.js

For your particular example though, if we keep in mind that the input data to be validated is JSON-serializable, only a string could possibly accommodate the precision expected of a decimal from among the JSON-serializable JS primitives. You could use one or more regex patterns to describe the allowable permutations. The resultant schema would be cross-platform since it doesn't use custom keywords - nice! You can also use unions if you want to say that integers, NaN, and Infinity are also allowed per the docs there.

i've used Decimal.js to account for floating point issues in JS before. maybe this will help? I realize its not native and is a 3rd party lib - but its intent is to handle floating point issues and precision. That kinds sounds like the tree you're barking up right now. maybe it will help.

In the example provided, the name of the library is literally Decimal.js: https://mikemcl.github.io/decimal.js/

I'm working on a project where users will enter numbers like 9,999,999,999.99999 (up to 15 digits, up to 5 of them decimal) and we are having a problem with Numbers losing precision beyond certain number of digits (a typical issue for IEEE Standard 754 Floating Point Numbers, the 0.1 + 0.2 problem). I've solved this problem in a few projects before with the help of decimal.js or bignumber,js . In those cases, we kept user-input as strings and used a few custom-made numeric textbox widgets to accommodate this. Unfortunately, those widgets were proprietary... Now I need one again, but can't find anything. Do they exist?

Looks good! I love the idea of the embedded calculator

I noticed that it doesn't handle remainder/modulo (%) equations:

"10 % 2" results in: "Left hand side of addition cannot be a percentage."

It does look like decimal.js can handle that: https://mikemcl.github.io/decimal.js/#mod

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...

https://github.com/MikeMcl/decimal.js/ great library