I finally found a solution to a problem that has bugged me for years:<\/p>\n
When editing PHP source code on my Mac, the code would occasionally break completely with an error message like \u201cPHP Fatal error: Cannot use [] for reading in \u2026 on line \u2026\u201d. The code on that line would look completely fine in the editor, say: \u201c$a[] = 1;\u201d<\/p>\n
Only when I\u2019d switch on \u201cShow Invisibles\u201d in TextWrangler, I\u2019d see some funny bullet in front of the equals sign. What looked like a regular space character was actually a non-breaking space (Unicode U+00A0, officially called \u201cNo-Break Space\u201d, \u201cc2 a0\u201d in a UTF-8 file\u2019s hexdump).<\/p>\n
It was inserted because I typed to fast (or too sloppily); I had been hitting the space bar while the Alt key was still pressed. (This wouldn\u2019t happen on a standard US keyboard, but the German keyboard layout requires the Alt key for typing square [ ] and curly brackets { }.)<\/p>\n
The superuser article How to disable the Option-Space key combination for non-breaking spaces?<\/a> had the solution: Install the free Karabiner (formerly named KeyRemap4MacBook)<\/a> (requires a reboot), search for \u201coption+space\u201d in its preferences and check the \u201cNon-Breaking Space to Normal Space\u201d option.<\/p>\n