Speeding Up Auto-Completion
As you type an identifier, the auto-completion window pops up to propose matching identifier names. Every time you type a character, Source Insight considers the symbol data for that file to be “stale”. To give you the most accurate auto-completion results, Source Insight would need to reparse your file after each character you type. There is an option that controls this in the Preferences: Symbol Lookups dialog box.
The Parse locally before lookup option causes Source Insight to reparse before the auto-completion window appears. On a fast machine, or in a small file, the speed will be acceptable. However, turning this option off will result in a faster response.