Thread-safe cache
Is there a structure or library that I can use for a thread-safe cache? Keys will be strings.
Re: Structure of a web project
IMO, there is no need to think too much on the file organization, you will find how to organize them when the code size grow. One little trick I found useful is to add a --path to nim.cfg and create a common.nim that export frequently used packages. So that I can easily import packages with import common and less code to change when moving/renaming files. File structure: - src - core - foo.nim - bar.nim - common.nim - nim.cfg Run nim.cfg: --path:"src/core" Run common.nim import foo, bar export foo, bar Run
Re: Lambda syntax is awkward
Another technique also seen in std lib.
template twiceIt(input, body: untyped): untyped =
type T = typeof(input)
let fn = proc(n: T): T =
let it {.inject.} = n
`body`
fn(fn(input))
Run
let y = twiceIt 10:
echo "Gratuitous echo!"
return it * it
Run
Re: Lambda syntax is awkward
Python lambda is single line only. :)
Re: Structure of a web project
Just realized that the forum actually shares code, but the shared code is defined in the `frontend` module and imported by the main/root module. Maybe this is a possible answer, but doesn't seem completely intuitive to me.
Re: Lambda syntax is awkward
I wouldn't depend on the do notation. The reason it's experimental is that it doesn't fit the language and may be removed entirely eventually. Personally, I don't think this is too verbose: let fourthPower = twice(10, proc(n: int): int = echo "Gratuitous echo!" return n * n ) Run It would look very similar in JS. In Python it would simply not be possible.
Structure of a web project
I'm looking for ways/best practices on how to structure a dynamic web site I'm planning to do with nim. Looks like I'll be using `jester` for the backend, with `karax` for the frontend. Ideally they would live in the same repo and share some of the code, for instance the types. So, I'm looking for something like: - project root - core - be - fe Run where both `be` and `fe` would import `core`. I'm having troubles organizing this using `nimble`. I looked at the forum's repository, but it seems like it treats the frontend as a special case. Any advise?
Re: Lambda syntax is awkward
I actually prefer the "original problem" syntax. It's only like couple of characters of extra typing. The do, -> and => feel less clear.
Re: Lambda syntax is awkward
[https://github.com/Yardanico/nimpylib/blob/master/src/pylib.nim#L161](https://github.com/Yardanico/nimpylib/blob/master/src/pylib.nim#L161)
Re: Lambda syntax is awkward
Hm, not yet there, but arguably somewhat closer with `auto`: let plusTwo = twice(10) do (n:auto) -> auto: echo "Another gratuitious echo" n + 1 Run Maybe this is close enough that now it could be wrapped in some macro to shorten even more?
Re: Lambda syntax is awkward
Oh! I tried using `block` and wondered why it didn't work ... I didn't realize parens were necessary. The `do` notation seems an improvement; it resolves two of the three complaints I gave above. If it had better type-inference I'd love it. Maybe that's why it's still experimental? e.g. what I'd like to see is `let plusTwo = twice(10) do (n):`
Re: Uncle Bob - one syntax to rule them all?
Ironically I don't think Uncle Bob would like Nim at all, given our general preferance towards straightforward "get shit done" procedural code. For example in [this video](https://youtu.be/IRTfhkiAqPw?t=1179) the author critiques some of Bob's code and rewrites it in a simple procedural style. The resulting code is far more like what I would expect to see in a Nim codebase.
Re: Lambda syntax is awkward
There are some solutions, but all a little awkward. 1\. ["do" notation](https://nim-lang.org/docs/manual_experimental.html#do-notation), which I believe was moved to _experimental_ just before Nim 1.0, therefore might be changed or scrapped in a future Nim version. Personally I think it's even harder to read than the plain `proc` version. let plusTwo = twice(10) do (n:int) -> int: echo "Another gratuitious echo" n + 1 Run 2\. Sugar module with a [statement list expression](https://nim-lang.org/docs/manual.html#statements-and-expressions-statement-list-expression) where the last expression in the brackets is treated as the value. Not idiomatic, wouldn't recommend. let plusTwo2 = twice(10, n => ( echo "Another gratuitious echo"; n + 1 )) Run 3\. Sugar module with a [block expression](https://nim-lang.org/docs/manual.html#statements-and-expressions-block-expression). I almost like this one! Unfortunately if you remove the brackets, you get " _Error: expression expected, but found 'keyword block'_" let plusTwo3 = twice(10, n => (block: echo "Another gratuitious echo" n + 1 )) Run Does anyone know, is this a syntax limitation, or could the `=>` operator be modified to allow a block expression without brackets?
Lambda syntax is awkward
I'm finding Nim's syntax for calling lambdas awkward and verbose. proc twice[T](input: T, fn: proc(t: T):T):T = fn(fn(input)) let fourthPower = twice(10, proc(n: int): int = echo "Gratuitous echo!" return n * n ) Run * I have to declare parameter and return types. Even C++ lets me omit the return type! * The nested proc is still inside the outer proc's parentheses, so that has to be closed afterwards. * And a nitpick: the initial line ends with `=` not `:`, unlike all other statements that introduce nested blocks in a proc. **I 'm aware of the ``sugar`` module.** The `=>` macro makes this a lot better, but it only seems to work with single-line lambdas. let plusTwo = twice(10, (n) => n + 1) Run Every attempt I've made to use it in a multi-line lambda fails with syntax errors: let plusTwo = twice(10, (n) => echo "Another gratuitious echo" n + 1) # Error: expected: ')', but got: 'n' Run I like that templates and macros can be called with a block as a final parameter, but that feature is limited in that the block can't take any parameters and can't return a value. Is there something I've missed? Or are there proposals to improve this in the future? —Jens
Re: Uncle Bob - one syntax to rule them all?
> Nim's syntax seems very reasonable. I would use it as-is if there were just a > few more libraries like a SQL Server DB driver, XLSX file API. Maybe a few > more but nothing off the top of my head. There are but they are 1 man projects.
Re: Uncle Bob - one syntax to rule them all?
Just like a carpenter has a hammer, screwdrivers, tapes, wrenches, pliers, drills, saws for different purposes, developing is not about trying to hammer nails with a Swiss Army Knife but choosing the right tool for the right purposes.
