Hi JmageK,
> The previous mail quizzed me about, the (set (nth u 5) 1000) part.
> I understand it basically setting a value at a certain place like u[5] = 1000
> in c like languages. nth returns a list starting from count and set evaluates
> then sets the value of variable.
The important point to understand here is that a "variarle" in PicoLisp can
either be a symbol or a cell in a list.
>From doc/ref.html#fun, primary data types:
var - Variable: Either a symbol or a cons pair
> : (cdadr (cdadr incM))-> (0)
This returns a single cell, which may then destructively modified with 'set',
'inc', 'pop' or whatever function accepts a 'var' argument.
Internal background: 'set' gets a pointer to a part of a cell. For a list cell
this it
|
V
+-----+-----+
| CAR | CDR |
+-----+-----+
i.e. the CAR if a cell, while for a symbol it is
|
V
+-----+-----+ +-----+-----+
| | VAL | |'cba'|'fed'|
+-----+-----+ +-----+-----+
i.e. the VAL (value) of a symbol.
☺/ A!ex
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