On: Making Coffeescript’s Whitespace More Significant

[tomp]

Which programming language do you prefer then? Don't say C, because in C, whitespace obviously is significant:

  int a = 1;

vs.

  inta=1;

other languages, like CoffeeScript and Python, simply take it to the next level.

[agscala → tomp]

I think your example is a little too much. Whitespace isn't significant in C. When talking about programming languages, I don't think whitespace refers to spaces between tokens. It's mostly a reference to indentation.

[masklinn → agscala]

> Whitespace isn't significant in C.

As demonstrated, it is.

> When talking about programming languages, I don't think whitespace refers to spaces between tokens.

But that makes no sense, it is whitespace, and it has semantic significance (hence being significant). Whitespace was not significant in older versions of Fortran, and that allowed you to write

    DO30I=10,100

which was interpreted as

    DO 30 I = 10, 100

that is non-significant whitespace.

Ruby has long struggled with how it interpreted its whitespace, for a long time

   sin (x) + y

would be interpreted as

   sin(x + y)

for instance, rather than

    syn(x) + y

how is that not significant whitespace?

[tordek → masklinn]

But that makes no sense, it is whitespace, and it has semantic significance (hence being significant). Whitespace was not significant in older versions of Fortran, and that allowed you to write

    DO30I=10,100

which was interpreted as

    DO 30 I = 10, 100

An amusing bug I saw in Expert C Programming mentioned how somebody once typed e dot instead of a comma, and

    DO 30 I = 10. 100

ended up interpreted as a simple real assignment:

    DO30I = 10.1

[rayiner → agscala]

He has a point. Whitespace is definitely significant to C's lexer, if not it's parser. When people say "significant whitespace" they're implicitly talking about "implicitly significant to the parser as well as the lexer."

[PLejeck → tomp]

When we say whitespace, we usually mean multiple spaces at the start of a line, something known as "indentation" ;)

[cube13 → tomp]

Whitespace does not control program flow in C. It only is used to separate tokens. It is not used to control program flow(like coffeescript and python).

Note that:

  int a = 0;

and

  int a=0;

and

  int                       a             =       0;

are all equivalent.

[thedufer → tomp]

s/whitespace/indentation/

You know that's what is being discussed.