Function spaces

pub fn spaces<Input>() -> impl Parser<Input, Output = ()>
where
    Input: Stream<Token = char>,

Skips over zero or more spaces according to std::char::is_whitespace.

This includes space characters, tabs and newlines.

use combine::Parser;
use combine::parser::char::spaces;
assert_eq!(spaces().parse(""), Ok(((), "")));
assert_eq!(spaces().parse("   "), Ok(((), "")));