Thread by @hillelogram

One of my favorite things with learning about new programming languages is seeing all the "small ideas" that could easily be picked up by other languages. Here are some examples:

D has a special "unittest" block as part of the language syntax, instead of relegating it to a framework. You can have the unittests checked on every program run if you want

dlang.org/spec/unittest.…

In Eiffel you can mark any method as "obsolete". JVM and .NET do something similar as an attribute, I think it's neat how in Eiffel it's a part of the language semantics

eiffel.org/doc/eiffel/ET-…

Clojure vars can have arbitrary metadata, which doesn't effect value comparison. So you can distinguish between data that's important for the program execution and data you're tracking to help out the developer

clojure.org/reference/meta…

In Chapel, variables and constants can be made into `configs`, which makes them changeable with CLI flags. ie if you have `config var foo = 1;`, you can run `./program --foo=17`

chapel-lang.org/docs/primers/v…

Powershell functions can have an explicit `Param` block where you define attributes for each function parameter, like default values, help docs, validation constraints, etc.

docs.microsoft.com/en-us/powershe…

Ruby has a few interesting bits. Method names can end in `?` or `!`, and by convention `name?` returns a boolean value and `name!` is a "dangerous method"

docs.ruby-lang.org/en/3.1/syntax/…

Ruby also has `backtick syntax` to run shell commands, which makes replacing a bash script with a ruby one super easy, though that's now considered an antipattern

hilman.io/blog/2016/01/s…

Frink has special syntax for date values. You can write `# 2001-08-12 #` to mean the *date* 2001-08-12, instead of writing something annoying like `Date(2001, 7, 12)` an remembering that months start at 0

frinklang.org/#DateTimeHandl…

I like small ideas because other languages can more easily explore them. It's easier to add date literals to a language than it is to add a borrow checker

Oh, one I forgot from #jlang! J has extended numeric notation:

3e3 = 3000
(1r2 + 1r7) = 9r14
3p2 = 3π²

e is especially nice because you can literally write avogadros number as 6.02e23

code.jsoftware.com/wiki/Vocabular…