Scope modifiers: Difference between revisions

=={{header|M2000 Interpreter}}==

We can use Global, Local to shadow any sane variable and give scope to new one.

We can use Static for simple variables, so we can find them in the next call.

By default every new variable/module/function/group is local if defined in a module or a function

In command line, in M2000 console every variable/module/function/group is global

Local variables are prefered by interpreter at reading/writing

We have to use <= to assign new values to global variables, or to member of groups inside a module inside a group. See ResetValues in Group Alfa.

<lang M2000 Interpreter>

Module Checkit {

M=1000

Function Global xz {

=9999

}

Module TopModule {

\\ clear vars and static vars

Clear

M=500

Function Global xz {

=10000

}

Module Kappa {

Static N=1

Global M=1234

x=1

z=1

k=1

Group Alfa {

Private:

x=10, z=20, m=100

Function xz {

=.x*.z+M

}7

Public:

k=50

Module AddOne {

.x++

.z++

.k++

Print .xz(), .m=100

}

Module ResetValues {

\\ use <= to change members, else using = we define local variables

.x<=10

.z<=20

}

}

' print 1465

Alfa.AddOne

Print x=1, z=1, k=1, xz()=10000

Print N ' 1 first time, 2 second time

N++

Push Alfa

}

Kappa

Drop ' drop one alfa

Kappa

Print M=500

' leave one alfa in stack of values

}

TopModule

Read AlfaNew

Try ok {

AlfaNew.AddOne

}

\\ we get an error because M global not exist now

\\ here M is Local.

If Error or Not Ok Then Print Error$ ' Uknown M in .xz() in AlfaNew.AddOne

Print M=1000, xz()=9999

For AlfaNew {

Global M=1234

.ResetValues

.AddOne ' now works because M exist as global, for this block

}

Print M=1000, xz()=9999

For This {

Local M=50

M++

Print M=51

}

Print M=1000

}

Checkit

List ' list of variables are empty

Modules ? ' list of modules show two: A and A.Checkit

Print Module$ ' print A

</lang>