Block structure

[jeandrek]

do-it should have block structure

Possibilities:

• Make begin create a new scope (this will be bad if I add macros)
• Add a new block special form that introduces a new scope

[BookOwl]

How about a block special form that works just likes, begin, except that it creates a new scope?

[jeandrek]

That's what I meant by the second possibility.

[jeandrek]

I could leave popping the local variables to the end of the procedure, but then the rest of the procedure would be taking more stack space than necessary… I should add another item to the stack at the start of a block but rather than it starting at 0 have it start at the same, and run cleanup at the end of the block

[jeandrek]

I've implemented a block special form on the block branch and it works

EDIT: And I made for use block instead of begin

[jeandrek]

Added with #6