Is steel scheme good as a system scripting language?

[amano-kenji]

Janet has been the best system scripting langauge for me.

By default, it uses /usr/lib(64)/janet as the directory for modules, but users can set janet's module path....

steel scheme doesn't set STEEL_HOME by default.

For a language to be used as a system scripting language, the defualt module directory must be provided.

[mattwparas]

I would argue that it does not have to be provided by default, assuming installation instructions are sufficient. The only reason I have not assumed a default yet is because I don't distribute (up to date) binaries - most if not all are building from source. Of course, at some point soon I will pick a default directory that can be overridden. The engine itself has support for adding other directories to search for modules, it just isn't directly exposed in the repl.

[mattwparas]

To address a few of those points:

• Steel takes about 20-30 ms to startup, however with some more effort I can get that down to < 10 ms. Just requires a little work I haven't had the time to allocate in the last few weeks
• Steel isn't as mature as Janet yet, like I said Janet has a few years on Steel
• The threading model in Steel does deep copy values when passing between threads. I will eventually have a notion of persistent data structures that are safe to share between threads, but as of now most values are not thread safe, which means we have to do a copy.
• "steel scheme should have something like PEG" - if you're willing to contribute something, I'm happy to accept contributions, but this is not high on my priority list.

I am not attempting to compete or siphon users from Janet. If Janet has a feature set that you appreciate, you should use that. If Steel does not have that feature set, and you would like it, please open an issue and describe what you'd like. If I think its a reasonable feature, I will consider adding it, and am always happy to accept contributions as well.

[amano-kenji]

Wait, steel scheme doesn't have regular expression, parsing expression grammar, or something else for text parsing?

[amano-kenji]

Which types does steel scheme use or plan to use as numbers?

[mattwparas]

I have not yet implemented the regex library, however the plan is to wrap the rust regex library https://docs.rs/regex/latest/regex/ and include it with the interpreter.

Steel will be implementing the full numeric tower, which currently includes integers (isize), floats (f64), big ints, and will eventually include rationals as well

[amano-kenji]

My recommendation is to skip regex and go straight to parsing expression grammar.

Raku's grammar is an evolution of regex, but parsing expression grammar is superior to even raku's grammar in my experiences.

After having used regex, raku grammar, and PEG, I think PEG is the best.

[amano-kenji]

I found https://github.com/kevinmehall/rust-peg, but I don't know how to write in Rust.

[amano-kenji]

Is the rational number based on big int? If it is, then it can be an arbitrary-precision decimal number.

In Raku, Rat type has arbitrary-size integer numerator and 64-bit denominator. Raku's FatRat type gives you arbitrary-size integer for denominator.

https://hackage.haskell.org/package/Decimal is expressed by arbitrary-size integer and 8-bit exponent. This means you can have precision up to 255 decimal places with Haskell's Decimal. Enough for financial calculation.

[novusnota]

+1 for PEG support, as an alternative or in addition to the regex