Dhall: A Non-Repetitive Alternative to YAML

#1

Post by ff_ » Thu, Jul 04, 2019, 3:30 PM UTC

Dhall: A Non-Repetitive Alternative to YAML
dhall-lang.org

Re: Dhall: A Non-Repetitive Alternative to YAML

#2

Post by _j7tr » Thu, Jul 04, 2019, 5:46 PM UTC

What's with the commas at the start of lines?

Re: Dhall: A Non-Repetitive Alternative to YAML

#3

Post by edoceo » Thu, Jul 04, 2019, 5:48 PM UTC

_j7tr wrote: post #2

What's with the commas at the start of lines?

Makes it easier when commenting out. Use this trick for SQL and JS too (to prevent trailing comma issue)

Re: Dhall: A Non-Repetitive Alternative to YAML

#4

Post by jbaum98 » Thu, Jul 04, 2019, 5:49 PM UTC

_j7tr wrote: post #2

What's with the commas at the start of lines?

This is a common convention in some languages, most often functional languages in my experience. I associate it most with OCaml.

So it's not so surprising to see it here, seeing as Dhall is written in Haskell.

Re: Dhall: A Non-Repetitive Alternative to YAML

#5

Post by dymk » Thu, Jul 04, 2019, 5:52 PM UTC

edoceo wrote: post #3

_j7tr wrote: post #2

What's with the commas at the start of lines?

Makes it easier when commenting out. Use this trick for SQL and JS too (to prevent trailing comma issue)

I don't get why you'd build a language in 2019 which disallows a trailing comma in lists.

Re: Dhall: A Non-Repetitive Alternative to YAML

#6

Post by nikolay » Thu, Jul 04, 2019, 5:54 PM UTC

Dhall keeps popping up on HN. Here what I don't like about it:

- Why use '=' instead of ':' for attributes? If you used ':', then '=' could be variable assignment and eliminate the need for 'let'.

- Why is there a need for commas?

- Why quote via ticks?! Gee!

- What's with the '{-' and '-}' for comments?! It's like its author decided to differ at any price!

In general, good ideas, but it's too weird and unnecessarily deviates from common syntax.

Re: Dhall: A Non-Repetitive Alternative to YAML

#7

Post by duijf » Thu, Jul 04, 2019, 6:00 PM UTC

nikolay wrote: post #6

Dhall keeps popping up on HN. Here what I don't like about it: - Why use '=' instead of ':' for attributes? If you used ':', then '=' could be variable assignment and eliminate the need for 'let'. - Why is there a need for commas? - Why quote via ticks?! Gee! - What's with the '{-' and '-}' for comments?! It's like its author decided to differ at any price ! In general, good ideas, but it's too weird and unnecessaril…

Dhall heavily borrows both ideas and syntax from the ML family of languages. E.g. Haskell, OCaml, Elm, Purescript

Colons are used for type signatures.

Commas are presumably required because you can have multi line and nested records. (don't quote me on this, not a parser expert)

The comment syntax is from Haskell.

Not saying this syntax is familiar to everyone, but it is familiar to some. The lineage of the syntax might help you understand where the language is coming from

Re: Dhall: A Non-Repetitive Alternative to YAML

#8

Post by NuSkooler » Thu, Jul 04, 2019, 6:01 PM UTC

Still much prefer HJSON (http://hjson.org/) for stuff that people might need to touch.

If it's truly for end-users (read: non-admin/dev types), you probably shouldn't have them touching configuration files _at all_.

Re: Dhall: A Non-Repetitive Alternative to YAML

#9

Post by dymk » Thu, Jul 04, 2019, 6:03 PM UTC

duijf wrote: post #7

nikolay wrote: post #6

Dhall keeps popping up on HN. Here what I don't like about it: - Why use '=' instead of ':' for attributes? If you used ':', then '=' could be variable assignment and eliminate the need for 'let'. - Why is there a need for commas? - Why quote via ticks?! Gee! - What's with the '{-' and '-}' for comments?! It's like its author decided to differ at any price ! In general, good ideas, but it's too weird and unnecessaril…

Dhall heavily borrows both ideas and syntax from the ML family of languages. E.g. Haskell, OCaml, Elm, Purescript Colons are used for type signatures. Commas are presumably required because you can have multi line and nested records. (don't quote me on this, not a parser expert) The comment syntax is from Haskell. Not saying this syntax is familiar to everyone , but it is familiar to some. The lineage of the syntax m…

Weird that it's billed as an alternative to YAML, but effectively has zero roots or influence from YAML. Looks more like an alternative to... whatever configuration language is popular in ML language projects?

Re: Dhall: A Non-Repetitive Alternative to YAML

#10

Post by andybak » Thu, Jul 04, 2019, 6:03 PM UTC

Immediate response?

I hate commas at the start of lines and I would prefer not to have curly braces in a human editable/readable format.

Neither reason is terribly rational but my first impressions weren't great.