file_regex breaks sublime build

Question

This regex works in the SublimeText search field:

([^\/]+\.java)

If I use that regex in a .sublime-build file:

• \. is highlighted in red, and
• the build system is not recognised.

When I comment out the line "file_regex": "([^\/]+\.java)" the build system is recognised.

{
  "cmd": ["gradle" , "build"],
  "working_dir": "${project_path}",
  "file_regex": "([^\/]+\.java)"
}

Question: Why does the regex that works in search not work in the .sublime-build file?

Answer 1

The .sublime-build file uses the JSON file format.

You need to escape your backslash for JSON to handle it and pass the backslash on to regex.

Like this:

"file_regex": "([^\/]+\\.java)"

Since the build system is going to be used in the Python underlying Sublime Text let's reassure ourselves that Python is going to read this as we expect.

Test Python code:

import re

builddict = {
  "cmd": ["gradle" , "build"],
  "working_dir": "${project_path}",
  "file_regex": "([^\/]+\\.java)"
}

re_pattern = builddict['file_regex']
prog = re.compile(re_pattern)

teststrings = ['aaa.java', 'aaajava']

for teststring in teststrings:
    result = prog.search(teststring)

    if result is None:
        print(teststring + ' no match')
    else:
        print(teststring + ' matched')

Output:

aaa.java matched
aaajava no match

I assume that meets your desired output?