In MLState s new programming language Opa, is it possible to create a global variable?
Opa is a functional language so there are no global variables in the language. However, one can achieve a similar behavior with Mutable. At top-level one declares the value with:
global_var = Mutable.make(initial_value)
where initial_value is the initial value for the variable (of some type t). Then one can retrieve the value with:
global_var.get()
and set it with:
global_var.set(new_value)
More information in the Opa API overview.
Note however, that this mechanism should be used only in special situations; the primary device of encapsulating state in Opa are its distributed sessions (see the Opa manual for more on that subject).
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In MLState s new programming language Opa, is it possible to create a global variable?