Prevent hint from overlapping cursor

Signed-off-by: Morten Hustveit <morten.hustveit@gmail.com>
draw-gl-30.cc: Ran clang-format --style=Google

Signed-off-by: Morten Hustveit <morten.hustveit@gmail.com>
Find single character expression at end of line

There was an off-by-one error that would prevent these expressions from being
found.

Signed-off-by: Morten Hustveit <morten.hustveit@gmail.com>
Avoid parsing the end of words as expressions

The last valid expression in the word "apple" is the letter "e".

Signed-off-by: Morten Hustveit <morten.hustveit@gmail.com>