intern-resources/readme.md
2023-10-06 18:57:47 -05:00

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# thunderstrike.ai intern resources
## rust
**Rust** is a strongly-typed <a href="https://en.wikipedia.org/wiki/Type_safety"><sup>[type safety]</sup></a>
systems programming language <a href="https://en.wikipedia.org/wiki/System_programming_language"><sup>[systems programming language]</sup></a>.
### In brief
<ul>
<li>Error handling is done with a special type that represents "the `Result` of this may be an error"</li>
<li>Null values are represented by special type that represents "this value is `Option`al"</li>
<li>Rust programs are incredibly fast and predictable</li>
</ul>
## purescript
**Purescript** is a strongly-typed <a href="https://en.wikipedia.org/wiki/Type_safety"><sup>[type safety]</sup></a>
purely functional <a href="https://en.wikipedia.org/wiki/Purely_functional_programming"><sup>[purely functional]</sup></a>
programming language that compiles to javascript (like typescript).
### In brief
<ul>
<li>Error handling is done with a special type that represents "`Either` it succeeded or failed"</li>
<li>Null values are represented by special type that represents "`Maybe` it's present or not"</li>
<li>
effectful code
<a href="https://en.wikipedia.org/wiki/Side_effect_(computer_science)"><sup>[side effect]</sup></a>
is isolated from non-effectful code. This makes programs much more consistent to run and reason about.
</li>
<li>everything is an expression</li>
<li>interacting with raw javascript is relatively painless</li>
</ul>
### Motivating example: React vs Halogen
You don't have to understand exactly how these examples work,
I'm providing them simply for you to glance over and get a feeling
for reading typescript/javascript vs purescript.
This app:
1. renders `"Loading..."` until either data or error
1. fetches data from a server
1. if ok, render items in a list. if error, render error span at the bottom of the page.
<details>
<summary><b>React (click to expand)</b></summary>
```typescript
type Item = {id: string, title: string, description: string}
export const App: () => React.Node = () => {
const [items, setItems] = React.useState<Array<Item> | undefined>(undefined)
const [error, setError] = React.useState<Error | undefined>(undefined)
React.useEffect(() => {
fetch('/api/item')
.then(rep => rep.json<Array<Item>>())
.then(items => setItems(items))
.catch(e => setError(e))
}, [])
return error !== undefined
? (<p class="error">{error.message}</p>)
: items === undefined
? (<p>Loading...</p>)
: items.map(item => {
return (
<div key={item.id}>
<p>{item.title}</p>
<span class="small">
{item.description}
</span>
</div>
)
})
}
```
</details>
<details>
<summary><b>Purescript Halogen (click to expand)</b></summary>
```haskell
type Item = { id :: String, title :: String, description :: String }
data State
= StateEmpty
| StateErrored Error
| StateGotItems (Array Item)
data Action = ActionInit
renderItem item = div [] [ p [] [text item.title]
, span
[className "small"]
[text item.description]
]
renderApp StateEmpty = p [] [text "Loading..."]
renderApp (StateErrored e) = p [className "error"] [text (message e)]
renderApp (StateGotItems items) = map renderItem items
action ActionInit = do
response <- fetch (URL "/api/item") {method: Get}
jsonString <- text response
itemsOrError <- readJSON jsonString
case itemsOrError of
Right items -> put (StateGotItems items)
Left error -> put (StateErrored error)
app = mkComponent
{ initialState: StateEmpty
, render: renderApp
, eval: mkEval ( defaultEval { handleAction = action, initialize: Just ActionInit } )
}
```
</details>
## Further reading
* [purescript website](https://www.purescript.org/)
* [purescript by example (free online book)](https://book.purescript.org/)
* [purescript in depth (free online book)](https://leanpub.com/purescript/read)
* [rust website](https://www.rust-lang.org/)
* [rust book (free online book)](https://doc.rust-lang.org/book/)