Scripting Guide - SAS

Chapter 8 Programming Methods 201
Advanced Scoping and Namespaces
Note: Problems using this function are generally due to the mixing of unqualified and qualified references
to global variables. Always explicitly scoping a name prevents accessing an unintended variable.
Scoped Names
Specify where a name is to be resolved by using a scope in the form scope:name where scope indicates
how to resolve the name. For example, here:name indicates that the name should be resolved locally. Using
the Names Default To Here mode, here:name is equivalent to name. The scope instructs how to look up the
name.
The syntax is to use the colon scope operator:
scope:name
There are several types of scopes:
• Scope can be a resolution rule. For example, here:x means that x should be resolved to a name that is
local to the script. Global:x means that x should be resolved to a global name.
• Scope can be a namespace reference variable. For example. ref:a means that a should be resolved
within the namespace that ref refers to.
• Scope can be a data table reference to look up names as column names. For example, dt:height means
that height should be resolved as a column in the data table that dt refers to.
• Scope can be the name of a namespace that you created. For example, myNamespace:b where
myNamespace is a namespace that you created. "myNamespace":b is equivalent. See “Namespaces” on
page 204.
Examples of Scoping Column Formulas
The following examples demonstrate how to scope columns that contain formulas. In both scripts, x is a
global variable, local variable, and column name.
In the first script, the column name x is unscoped. the formula in the second column multiplies the value in
column x by 100. In this case, The result is a column with the values 100, 200, and 300.
::x=5;
New Table( "Test",
New Column( "x", Values( [1,2,3] ) ),
New Column( "y", Formula( 100*x ) ),
);
In the following script, the formula in column y assigns 500 to x and then adds 50 to x. Each cell in the
column contains the value 550.
::x=5;
New Table( "Test",
New Column( "x", Values( [1,2,3] ) ),
New Column( "y", Formula(Local( {x=500}, x+50 ) ) ),
);