Trace (Arraylist subroutine)
Trace Arraylist (Arraylist class)
The Trace subroutine displays the contents of an Arraylist in a readable form on the currently selected trace stream. That stream can be the user's standard output, the Model 204 audit trail, an internal trace table, or a combination of these (as described for the User Language Trace statement). The listed item values are displayed in ascending order by their position and, by default, are preceded by their item number, a colon and a blank space (': ').
Trace is identical to Audit and Print, except their output is sent to the Model 204 audit trail (like the User Language Audit statement) and to the user's standard output (terminal) destination, respectively.
Syntax
al:Trace[( [itemFunction], [NumWidth= number], [Separator= string], - [Start= number], [MaxItems= number], [Label= string])]
Syntax terms
| al | An Arraylist object. |
|---|---|
| itemFunction | The method that is to be applied to al items to produce the trace output. The method must take no parameters and produce an intrinsic (Float, String, Fixed or Unicode) value. It may be a system or user-written method, a class variable or property, a local method, or a method variable.
The default value of itemFunction is ToString. |
| NumWidth | The number of bytes in the display of each item to use for the item number. This is an optional, name required, parameter; if you specify a value, the parameter name, NumWidth, is required.
Item numbers are right-justified within the indicated number of bytes, and they are truncated on the left if the length of the item number exceeds the space allocated for it. The NumWidth value must be a number between If NumWidth is |
| Separator | A string, 15 characters or fewer, to be used to separate the item number from the item value. This is an optional, name required, argument; if you specify a value, the parameter name, Separator, is required.
The default value for Separator is a colon (:). A blank always follows the Separator string. |
| Start | The item number of the initial item in the output display. This is an optional, name required, argument; if you specify a value, the parameter name, Start, is required.
The default value for Start is |
| MaxItems | The maximum number of items to display. A zero or negative value means to display all the items. This is an optional, name required, argument; if you specify a value, the parameter name, MaxItems, is required.
The default value for MaxItems is |
| Label | A literal string that gets output before each line. This is useful for "tagging" lines to make them more identifiable. This is an optional, name required, argument; if you specify a value, the parameter name, Label, is required.
The default value for Label is a null string, which displays no additional "tag" information. |
Usage notes
- All errors in Trace result in request cancellation.
Examples
For examples of the Trace method calls, see "Printing a collection".