Scripting Guide - SAS

198 Programming Methods Chapter 8
Advanced Scoping and Namespaces
Table 8.4 Functions for manipulating lists or expressions (Continued)
Function Syntax Explanation
Substitut
e
Substitut
e Into
R =
Substitute(list|exp
r, Expr(pattern),
Expr(replacement),
...)
Substitute
Into(list|expr,
Expr(pattern),
Expr(replacement),
...)
Finds all matches to the pattern in the list or expression, and
replaces them with the replacement expression. Each pattern
must be a name. The second and third arguments are
evaluated before they are applied, so most of the time you
must quote them with an Expr function. To delay evaluating
an argument, use Name Expr instead of Expr. You can list
multiple pattern-replacement pairs for multiple substitutions
in one statement.
Substitute in place.
Advanced Scoping and Namespaces
Scripts that are used in production environments need to use more advanced scoping techniques to avoid
collisions between scripts. JMP provides three progressively more advanced techniques:
• The Names Default To Here() function. If you have simple scripting needs, this single command
might be sufficient. See “Names Default To Here” on page 198.
• Scopes that are pre-defined by JMP. See “Scoped Names” on page 201.
• Namespaces that you can create for your scripts. See “Namespaces” on page 204.
Names Default To Here
If you write production scripts, you need to insulate the script from the current user environment.
Otherwise, the variables that you use might interact with variables used by the user and by other scripts. The
way to do this is to keep your names in a local environment, which you can do by setting an execution mode
with the statement:
Names Default To Here(1);
Unqualified names in a script with the Names Default To Here mode turned on are private to that script.
However, the names persist as long as the script persists, or as long as objects created by or holding the script
are still active. We recommend that all production scripts start with Names Default To Here(1) unless
there is a specific reason not to do so. When the script uses an unqualified name in this mode, that name is
resolved in the local namespace.
To refer to global variables, scope the name specifically as a global variable (for example, ::global_name).
To refer to columns in a data table, scope with name specifically as a data table column (for example,
:column_name).