[RPL/2] self compiling ?

[DEMAINE Benoit-Pierre]

BERTRAND Joël wrote:
> 	Nope. An RPL/2 is a compound type that contains a void pointer and a 
> type (3 characters). The only difference between a list and an 
> expression (algebraic or RPN expression) is this type : "RPN" for RPN 
> expression, "ALG" for algebraic and "LST" for list. But there is a 
> fondamental difference between an expression and a list. You cannot use 
> all intrinsic functions in an expression. Thus, RPL/2 has to analyze 
> expression syntax _before_ conversion to avoid all syntax errors. It has 
> to analyze semantic of expression too (you can use loops, conditional 
> statement and these code structures have to be well written. For 
> example, you cannot start your expression with THEN or END...). I think 
> it is better to modify by approprate functions a preexistant expression 
> than trying to transform a list in expression (that requires a lot of 
> cpu time in validation process).

The Metakernel did not take time to perform all these checks. Checks
were performed when exiting the editor; not when using commands like
lst->prg. When the resulting object was not consistent, in the worst
case, machine rebooted (cause in the worst case, the return stack get's
empty too early).

My beloved function was "->obj" . Of course, those dangerous things were
informal, in the hidden lib, and removed in the HP49. Thats why I prefer
an HP48GX with MTK over a HP49 ^^

-- 
 >o_/ DEMAINE Benoit-Pierre (aka DoubleHP) http://benoit.demaine.info/
If computing were an exact science, IT engineers would not have work \_o<

"So all that's left, Is the proof that love's not only blind but deaf."
(FAKE TALES OF SAN FRANCISCO, Arctic Monkeys)