A Value behaves like a Constant, but it can be changed.
TO is a parsing word that changes a Values. In Gforth
(not in Standard Forth) you can access (and change) a value also with
>body.
Here are some examples:
12 Value APPLES \ Define APPLES with an initial value of 12 34 TO APPLES \ Change the value of APPLES. TO is a parsing word 1 ' APPLES >body +! \ Increment APPLES. Non-standard usage. APPLES \ puts 35 on the top of the stack.
Value ( w "name" – ) core-ext “Value”
Define name with the initial value w; this value can be
changed with to name or ->name.
name execution: – w2
AValue ( w "name" – ) gforth-0.6 “AValue”
Like value, but defines a value for an address
(this only makes a difference in the cross-compiler).
2Value ( d "name" – ) double-ext “two-value”
fvalue ( r "name" – ) floating-ext “f-value”
Define name ( -- r1 ) where r1 initially is
r; this value can be changed with to name or
->name.
TO ( value "name" – ) core-ext “TO”
changes the value of name to value
+TO ( value "name" – ) gforth-1.0 “+TO”
increments the value of name by value
value! ( x xt-value – ) gforth-experimental “to-store”
Changes the value of xt-value to x
value+! ( n xt-value – ) gforth-experimental “value-plus-store”
Increments the value of xt-value by n