Macro merge_whitespace 

merge_whitespace!() { /* proc-macro */ }

This is a procedural macro that removes multiple consecutive whitespaces from a given string literal and replaces them with a single space. Quoted text will be ignored and kept as-is.

Example

let output = merge_whitespace!("Hello     World!\r\n      \"How        are\"         you?");
assert_eq!(output, r#"Hello World! "How are" you?"#);

If you want to keep quoted text as is, you can specify a quotation mark character. Everything within a pair of these markers is kept as-is:

let output = merge_whitespace!("Hello     World!\r\n      \"How        are\"         you?", quote_char = '"');
assert_eq!(output, "Hello World! \"How        are\" you?");

Return

The macro expands to the modified string literal.