Why doesn't line 5 contain an indentation error. I expected to get a parse error on compilation. I expected that the + on line 5 would have to be aligned under the * in line 4.
module Learn where
x = 10
* 5
+ y -- why isn't this incorrect indentation
myResult = x * 5
y = 10
It compiles because there's no block there to consider.
Indentation only matters after where, let, do, case of.
These keywords start a block of things, and it is important to understand whether a line continues the previous entry, starts a new entry, or ends the block.
case f 5 of
A -> foo
32 -- continues the previous entry
B -> 12 -- starts a new entry
+ bar 43 -- ends the case
After = we do not need to split a block into entries: there's only a single expression. Hence no indentation rules apply.
This compiles because the definition of x was all to the right of the beginning of x. It's not important where each line starts as long as those lines are indented to the right of x.
