Future milestone goals

[doctorjei]

I want to suggest some usability features to add in order to make this editor effectively faster (as much as possible) than traditional editors while also helping new learners.

The Setup / Context

Bold: typed / committed characters
Italic: phantom characters (become real with 'tab')
Underline: placeholders
Cursor: |

Consider a user who types a d on an empty line. This is probably a definition for a function. We should provide the following response in the editor:

d|ef functionname():
    pass

From here, there are four major possibilities (maybe more, we can talk about it if so):

1. The next phantom character [e], or a phantom character in the current set [ef] otherwise invalid here [none]
   --> Commit up to typed phantom character

2. Another valid identifier character or SPACE
   --> This is (part of) a variable / identifier name. If SPACE, they've finished typing the identifier. (Terrible name...)

3. Tab <-- perhaps ENTER too?
   --> Commit all phantom characters in this set (autocomplete)

4. A syntactically invalid character
   --> Error highlighting or similar
   --> Also, we might want to experiment later with something that makes this impossible - maybe another study

Example Progression

Let's consider a progression as follows.

↓↓↓ (typed or tab is hit to "complete")

def |functionname():
    pass

↓↓↓ (user types any character or characters that are not part of the phantom characters)

def foobar|():
    pass

↓↓↓ (user types open-paren)

def foobar(|):
    pass

↓↓↓ (user types colon)

def foobar():
    |pass

...etc.

Alternatively, let's say it proceeds as follows instead...

def foobar|():
    pass

↓↓↓ (user types >)

def foobar() -> |None:
    pass

... or this:

def foobar|():
    pass

↓↓↓ (user types -)

def foobar() -|> None:
    pass

In other words, I think, as much as possible, we should try to find ways minimize effort and mitigate / avoid syntax errors by providing 1) clear display of the most likely code the user wants, 2) no interruption of a "typical" typing practice (within reason), and 3) painless recovery from an incorrect prediction. (I know this is a lot - that's why it's for the future!)