Which is the right regular expression to use for Numbers and Strings?

Question

I am trying to create simple IDE and coloring my JTextPane based on

• Strings (" ")
• Comments (// and /* */)
• Keywords (public, int ...)
• Numbers (integers like 69 and floats like 1.5)

The way i color my source code is by overwritting the insertString and removeString methods inside the StyledDocument.

After much testing, i have completed comments and keywords.

Q1: As for my Strings coloring, I color my strings based on this regular expression:

Pattern strings = Pattern.compile("\"[^\"]*\"");
Matcher matcherS = strings.matcher(text);

while (matcherS.find()) {
    setCharacterAttributes(matcherS.start(), matcherS.end() - matcherS.start(), red, false);
}

This works 99% of the time except for when my string contains a specific kind of string where there is a "\ inside the code. This messes up my whole color coding. Can anyone correct my regular expression to fix my error?

Q2: As for Integers and Decimal coloring, numbers are detected based on this regular expression:

Pattern numbers = Pattern.compile("\\d+");
Matcher matcherN = numbers.matcher(text);
while (matcherN.find()) {
    setCharacterAttributes(matcherN.start(), matcherN.end() - matcherN.start(), magenta, false);
}

By using the regular expression "\d+", I am only handling integers and not floats. Also, integers that are part of another string are matched which is not what i want inside an IDE. Which is the correct expression to use for integer color coding?

Below is a screenshot of the output:

Thank you for any help in advance!

Answer 1

For the strings, this is probably the fastest regex -

"\"[^\"\\\\]*(?:\\\\.[^\"\\\\]*)*\""

Formatted:

 " [^"\\]* 
 (?: \\ . [^"\\]* )*
 "

For integers and decimal numbers, the only foolproof expression I know of is
this -

"(?:\\d+(?:\\.\\d*)?|\\.\\d+)"

Formatted:

 (?:
      \d+ 
      (?: \. \d* )?
   |  \. \d+ 
 )

As a side note, If you're doing each independently from the start of
the string you could be possibly overlapping highlights.