Seriously. I can't believe this is not yet in Illustrator after 20 years. Basic AutoCAD like snapping is a necessity.
Besides this, you also need to be able to snap to a line extension BEFORE you drag a line out, for example to plot a new point with the pen tool that is co-linear with an existing line. I can't say how many times (probably in the tens of thousands) in my career when I have had to drag out a construction line extension just so i can start a new line that is co-linear, or at least starts co-linear with an existing line, and then delete the construction line when i am done.
Seriously. I can't believe this is not yet in Illustrator after 20 years. Basic AutoCAD like snapping is a necessity.
Besides this, you also need to be able to snap to a line extension BEFORE you drag a line out, for example to plot a new point with the pen tool that is co-linear with an existing line. I can't say how many times (probably in the tens of thousands) in my career when I have had to drag out a construction line extension just so i can start a new line that is co-linear, or at least starts co-linear with an existing line, and then delete the construction line when i am done.