B __compile activates compiling features of bind. A procedure X is internally modified in an arbitrary manner by setting true __compile X bind. However, it is guaranteed that the modified X has the same effect as X when executed. Furthermore the procedure X is set to read-only to mark the applied changes.

An initial pass iteratively creates new optimization opportunities, thus:

2 3 5 7 11 mul mul mul mul ==> 2310

Idea: Use the syntax of Forth for compiling or optimizing:

: 2dup 2 copy ;

which corresponds to:

/2dup { 2 copy } bind def

First, examples of poor performance are needed.

In the first phase, only very simple linear optimizations of performance will be carried out.

Simple Sequences

Substitution of elementary sequences to simplify using unregistered operators.

1 --sub-- ==> --__isI-- --__----
1 --add-- ==> --__isI-- --__++--

0 --add-- ==>
0 --eq--  ==> --__eq0--

This is related to the PostScript idea of "Idiom Recognition". Examples in Forth would be:

2 --copy--        ==>  --__2dup--
--exec-- --pop--  ==>  --__nip--
3 2 --roll--      ==>  --__rot--
3 1 --roll--      ==>  --__-rot--

Constant Expressions

The equivalent of constexpr in C++.

Numbers

The following example evaluations should be converted at the time of __compile:

1 1 --add--      ==>  2
1.2 2.0 --sub--  ==>  -0.8
1.0 2.0 --mul--  ==>  2.0

Constant Boolean Values

true false or                 ==> true
bool {x x} {x x} --ifelse--   ==>  x x
bool {x x} --if--             ==>  x x | {}

Polymorphic Constants

literal1 literal2 --exch--   ==>  literal2 literal1

exec

{x y z} --exec--   ==> x y z

cvx, cvlit

[ x ] --cvx--   ==> { x }

Constant Strings

(A) (A) ?

Immediately Evaluated Names

As described in the Red Book.

Knowledge of the Stack

If __compile in a procedure knows which operands will be produced, it can actually drop some of the stack checks.

Single-Element Procedures

Replacement by the single operator with the extension of if, ifelse, repeat, etc. to support this as well.

Vocabularies preparse to ksn

Like make with a timestamp.

Loose Compile / Relaxed Mode

Mode in which fewer range checks and case defaults are included.
e.g., the main interpreter loop or especially type checks of many operators
Possibly make relaxed mode switchable on and off, leaving it up to the script author?

int32 and UTF

In the course of considering UTF, also introduce 32-bit integers for loops, indices, characters, etc.