Add better burgers chapter

[feihong]

Overview

• Record types are like Js.t objects but their fields must be explicitly
  defined

  • Records and Js.t objects are both JavaScript objects during runtime

• You can get the fields out of a record using destructuring and pattern
  matching:

  • let destructuring:

    let {a, b, c} = record;

  • Switch expression branch pattern matching:

    switch (record) {
    | {a: "foo", b: "bar", c: 42} => "Magnifique!"
    | {a, b, c} => a ++ b ++ string_of_int(c)
    };

• It's common practice to group related types and functions into a submodule

• Try not to ignore record fields when pattern matching on records. Instead of

  | {a, b, _} =>

  Prefer

  | {a, b, c: _, d: _} =>

  Assuming c and d aren't used inside the branch.

• Try not to pattern match on tuples of more than 2 elements because it tends to
  be hard to read

[feihong]

Not sure if there's a better link that explains multiple argument functions

[jchavarri]

Looks awesome!

I wonder if the intro section with "Chapters and topics" should be updated? The table last item is "Styling with CSS":

melange-for-react-devs/docs/intro/index.md

Line 45 in b1e974a

| Styling with CSS | Styling the order confirmation using CSS | `mel.raw` extension node, `runtime_deps` field, `glob_files` term, `external`, `mel.module` attribute |

[feihong]

I wonder if the intro section with "Chapters and topics" should be updated? The table last item is "Styling with CSS"

I plan to update Chapters and topics table in a separate PR

[feihong]

I can't find our previous thread about this (maybe it was somewhere in this old PR?), but I decided to go with switch expression without the backticks since it's more of a concept than just syntax, same as how I write if-else, ternary, etc without the backticks.

In mainstream languages that have pattern matching (C#, Swift, Java) they've mostly settled on calling this "switch". Python is the only mainstream language I know of which uses "match". But since "switch" is kind of an overloaded term, maybe I should use "pattern match expression" instead?

[jchavarri]

nit: maybe this should be either

• bool
  or
• boolean
  ?

Same with int: either int or integer. 🤔

[feihong]

I opted to just put the field names and types in backticks in ad5f959

[jchavarri]

Suggested change

	- Records use `.` to access fields
	- Records use `.` to access fields, while `Js.t` values use `##`

[feihong]

Fixed in ad5f959

[jchavarri]

Suggested change

	- Records can be destructured and pattern matched)
	- Records can be destructured and pattern matched

[feihong]

Fixed in ad5f959

[jchavarri]

This is great 👍