* Add new fill primitive and use it to wrap text in JSX
This adds a new `fill` primitive that can be used to fill lines with as much code as possible before moving to a new line with the same indentation.
It is used here layout JSX children. This gives us nicer wrapping for JSX elements containings lots of text interspersed with tags.
* Quick fix for jsx whitespace regressions
* Fix a couple more bugs
* Tidy up the `fill` algorithm
Attempt to make the algorithm a little more regular, and improve the naming of variables to make it a little easier to understand (I hope!).
* Small tidy up of JSX whitespace declarations
* Remove unnecessary code
It turns out that `children` is only used in the case when the element is printed on a single line, in which case all the types of JSX whitespaces behave the same, so we don't need to special case leading/trailing/solitary whitespace.
* A little more tidy up based on PR feedback
* Fix up tests after rebasing
* Make it explicit that we keep multiple consecutive spaces
* Add an explanatory comment
* Fix broken snapshot in master
* Ignore existing commands when deciding whether content will fit when using fill
* Fix a bug where children would get incorrectly filled onto a line
* Tidy up JSX whitespace names
Right now, expressions inside of template literals are have the level of indentation of the start of the template literal. But oftentimes, expressions are nested inside of template literals and therefore the expression should have this level of nesting.
The heuristic i'm using to decide when to use the template literal nesting is if it's not the first line and if there isn't another expression before on the same line.
In #1257, I discovered that if there's a `""` doc at the end, it's not going to trim the previous one correctly. It also happens to fix a few existing things.
The idea is that if you reach the end of the `}` inside of a template literal, we have to flush the trailing comma, otherwise it would generate invalid code. We also need the same special case for JSX.
I don't like adding yet another type of document but it seems like the most elegant way to solve the problem.
Fixes#623
The reason why trailing comments on a line work with commas is because of a special `lineSuffix` document that delays printing the content until a \n is printed. But `lineSuffix` only worked for pure string. By making it work with arbitrary documents we can fix trailing commas with trailing comments.
Fixes#538
- doc-printer.js is now the direct implementation of the Wadler paper
- doc-builders.js are a lot of utils to generate the IR the above file needs
- doc-utils.js are small utils to traverse list of docs.
Karl O'Keeffe