retroforth/doc/Hyperstatic.md
crc 5c5ccdff5e update a code fence style in the docs
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# Hyperstatic Global Environment
This now brings up an interesting subpoint. Retro provides a *hyper-
static global environment.* This can be difficult to explain, so let's
take a quick look at how it works:
~~~
#1000 'a var<n>
:scale (x-y) @a * ;
#3 scale putn
>>> 3000
#100 !a
#3 scale putn
>>> 300
#5 'a var<n>
#3 scale putn
>>> 300
@a putn
>>> 5
~~~
Output is marked with **\>\>\>**.
Note that we create two variables with the same name (*a*). The definition
for `scale` still refers to the old variable, even though we can no longer
directly manipulate it.
In a hyper-static global environment, functions continue to refer to the
variables and earlier functions that existed when they were defined. If
you create a new variable or function with the same name as an existing
one, it only affects future code.