Why the interpreter complains about multiple statements inside an arrow function?

[slishnevsky]

Hello.

I was wondering why the interpreter complains about multiple statements inside an arrow function:

Code: Select all

  SetTimer(() => {
    color := PixelGetColor(270, 360)
    ShowMessageBox('Uploading "' filename '"...')
  }, 1000)

image.png (12.98 KiB) Viewed 130 times

[vmech]

@slishnevsky
Because braces are not allowed for fat arrow function definition. Use parentheses instead. And separate expressions inside with commas.

[lexikos]

Arrow functions require an expression. You cannot use a statement inside an expression.

Of course, color := PixelGetColor(270, 360) and ShowMessageBox('Uploading "' filename '"...') are also valid expressions, so you can just follow vmech's advice. If you need a control flow statement, you can't use an arrow function.

However, v2.1-alpha.3+ permits function definition expressions, where you just write a proper function definition inline (without =>, and optionally omitting the name).

[william_ahk]

However, v2.1-alpha.3+ permits function definition expressions, where you just write a proper function definition inline (without =>, and optionally omitting the name).

That's fantastic!