When variables are referenced within a JMP script, JMP resolves the storage location of the variable using a specific set of rules. If the variable is referenced by a qualified name, then the resolution is based on the specific qualification specification. If the variable is referenced by an unqualified name, the situation is a bit more complex. JMP looks through a hierarchy of scopes representing the point of execution with the executing script. This section describes the rules that are used to resolve named variable references.
By default, variable name resolution in JMP 9 and later worked the same way as in JMP 8 and earlier, allowing your current JSL scripts to be executed unchanged. For JMP 9 and later, the difference between qualified and unqualified variable named references is important to understand.
A qualified named reference uses the : and :: operators to provide specific information about where a referenced variable resides, or where it is created. Examples of qualified named references include the following:
:var
::globalvar
datatable:var
nsref:var
"nsname":var
An unqualified named reference provides no explicit information to completely identify where a variable resides or where it is created. No scoping operator (: or ::) is specified in the reference. To change the behavior of JMP when resolving unqualified named variable references, use the Names Default To Here(1) function. For more information about variable name resolution, see the “Rules for Name Resolution”.
JMP applies rules in sequence to resolve variable references. See “Rules for Resolving Names”.