Pressing C+b searches the current
buffer and the current mode's keyword list for words beginning with
the one before the caret.
This serves as a very basic code completion feature, for example:
- When editing any kind of program source, enter the first few characters of
a previously-declared identifier name, invoke C+b, and save yourself
from having to type it out again.
- When editing Javadoc comments in Java source code,
enter "@" then press C+b to get a list of Javadoc tags.
- In a PHP file, enter a few characters and press C+b to see
a list of functions whose names start with what you entered.