Indentation Rules

Questions and Answers
1

This works:

let pb = 
      [
          ("a", stack[n (scale "phrygian" "0 [~ 3] . 8 5 4 . 4 -1 2 0") #  s "superpiano"]),
          ("b", stack[n (scale "phrygian" "0 [3] . 5 8 4 . 4 -3 2 0") #  s "superpiano"])
      ]
in
d7 $ ur 4 "a b a a" pb []

while this does not :

let pb = 
    [
        ("a", stack[n (scale "phrygian" "0 [~ 3] . 8 5 4 . 4 -1 2 0") #  s "superpiano"]),
        ("b", stack[n (scale "phrygian" "0 [3] . 5 8 4 . 4 -3 2 0") #  s "superpiano"])
    ]
in
d7 $ ur 4 "a b a a" pb []

Problem is, in my editor (VSCode), when I do a CR, it gives me the second version.
Does haskell expect 2 spaces indent instead of 4 and that might be the cause of the problem ?

2

You can use let to define more than one thing:

let a = 3
    b = 4
    c = 5

The variable names must line up, so this is an error:

let a = 3
     b = 4
    c = 5

A definition can go over one line, so this is ok:

let a = 
       3
    b = 4
    c = 5

However the second line must be indented further than the variable that's being defined. So this is OK:

let a = 
     3
    b = 4
    c = 5

But this isn't:

let a = 
    3
    b = 4
    c = 5

Neither is this:

let a = 
   3
    b = 4
    c = 5

So that's the problem with your second example - the [ and ] are on the same level at the thing that's being defined, and needs to be somewhere to the right of it.

3

Ok, thanks. I am not sure I would go to the extent to say that it makes sense :slight_smile: but at least I know the reason now. What's the most annoying is that the IDE is not aware of that ... Does this happens in Atom too ?

4

This is a good point, does anyone know how to set indentation rules for common editors specifically for tidal cycles?

5

It might be worth checking a haskell vscode plugin, see if that does better. If so maybe the behaviour could be brought across to the tidal plugin.
The emacs tidal plugin that I often use is based on top of the haskell one and is syntax-aware and gets the indentation mostly right