Trace (Arraylist subroutine): Difference between revisions
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===Syntax terms=== | ===Syntax terms=== | ||
<table class="syntaxTable"> | <table class="syntaxTable"> | ||
<tr><th | <tr><th>al</th> | ||
<td>An <var>Arraylist</var> object. </td></tr> | <td>An <var>Arraylist</var> object. </td></tr> | ||
<tr><th>method</th> | <tr><th>method</th> | ||
Line 15: | Line 15: | ||
<tr><th>NumWidth</th> | <tr><th>NumWidth</th> | ||
<td>The number of bytes in the display of each item to use for the item number. This is an optional, but <var>[[Methods#Named parameters|NameRequired]]</var>, parameter; if you specify a value, the parameter name <var class="term">NumWidth</var> is required.<p> | <td>The number of bytes in the display of each item to use for the item number. This is an optional, but <var>[[Methods#Named parameters|NameRequired]]</var>, parameter; if you specify a value, the parameter name <var class="term">NumWidth</var> is required.<p> | ||
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 <var class="Term">NumWidth</var> must be a number between <code>-1</code> and <code>10</code> inclusive. If you specify a value of <code>0</code>, the item number is not displayed.</p><p>If <var class="term">NumWidth</var> is <code>-1</code>, the default, the method uses the minimum number of bytes required to show the item number. For example, one byte is required for item number 5, while five bytes are required for item number 98764.</p></td></tr> | 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 <var class="Term">NumWidth</var> value must be a number between <code>-1</code> and <code>10</code> inclusive. If you specify a value of <code>0</code>, the item number is not displayed.</p><p>If <var class="term">NumWidth</var> is <code>-1</code>, the default, the method uses the minimum number of bytes required to show the item number. For example, one byte is required for item number 5, while five bytes are required for item number 98764.</p></td></tr> | ||
<tr><th>Separator</th> | <tr><th>Separator</th> | ||
<td>A string, 15 characters or less, to be used to separate the item number from the item value. This is an optional, but <var>[[Methods#Named parameters|NameRequired]]</var> argument; if you specify a value, the parameter name <var class="term">Separator</var> is required.<p>The default value for <var>Separator</var> is a colon (<code> | <td>A string, 15 characters or less, to be used to separate the item number from the item value. This is an optional, but <var>[[Methods#Named parameters|NameRequired]]</var> argument; if you specify a value, the parameter name <var class="term">Separator</var> is required.<p>The default value for <var>Separator</var> is a colon (<code>:</code>). A blank always follows the <var class="term">Separator</var> string.</p></td></tr> | ||
<tr><th>Start</th> | <tr><th>Start</th> | ||
<td>The item number of the initial item in the output display. This is an optional, but <var>[[Methods#Named parameters|NameRequired]]</var>, argument; if you specify a value, the parameter name <var class="term">Start</var> is required.<p>The default value for <var>Start</var> is <code>1</code> | <td>The item number of the initial item in the output display. This is an optional, but <var>[[Methods#Named parameters|NameRequired]]</var>, argument; if you specify a value, the parameter name <var class="term">Start</var> is required.<p>The default value for <var>Start</var> is <code>1</code>, which makes item 1 in <var class="term">al</var> be the first item in the output display.</p></td></tr> | ||
<tr><th>MaxItems</th> | <tr><th>MaxItems</th> | ||
<td>The maximum number of items to display. A zero or negative value means to display all the items. This is an optional, but <var>[[Methods#Named parameters|NameRequired]]</var>, argument; if you specify a value, the parameter name <var class="term">MaxItems</var> is required.<p>The default value for <var>MaxItems</var> is <code>0</code> | <td>The maximum number of items to display. A zero or negative value means to display all the items. This is an optional, but <var>[[Methods#Named parameters|NameRequired]]</var>, argument; if you specify a value, the parameter name <var class="term">MaxItems</var> is required.<p>The default value for <var>MaxItems</var> is <code>0</code>, which displays all items from the <var class="term">Start</var> item to the end of <var class="term">al</var>.</p></td></tr> | ||
<tr><th>Label</th> | <tr><th>Label</th> | ||
<td>A literal string that gets output before each line. This is useful for "tagging" lines to make them more identifiable. This is an optional, but <var>[[Methods#Named parameters|NameRequired]]</var>, argument; if you specify a value, the parameter name <var class="term">Label</var> is required.<p>The default value for <var>Label</var> is | <td>A literal string that gets output before each line. This is useful for "tagging" lines to make them more identifiable. This is an optional, but <var>[[Methods#Named parameters|NameRequired]]</var>, argument; if you specify a value, the parameter name <var class="term">Label</var> is required.<p>The default value for <var>Label</var> is a null string, which displays no additional "tag" information.</p></td></tr> | ||
</table> | </table> | ||
Revision as of 23:15, 2 February 2011
Trace Arraylist (Arraylist class)
The Trace subroutine displays the contents of an Arraylist in a readable form on the currently selected trace stream. 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 user's standard output (terminal) destinations respectively.
Syntax
al:Trace[( [itemFunction], [NumWidth= number], [Separator= string], - [Start= number], [MaxItems= number], [Label= string])]
Syntax terms
al | An Arraylist object. |
---|---|
method | 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 (be that 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 method is ToString. |
NumWidth | The number of bytes in the display of each item to use for the item number. This is an optional, but NameRequired, 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 less, to be used to separate the item number from the item value. This is an optional, but NameRequired argument; if you specify a value, the parameter name Separator is required. The default value for Separator is a colon ( |
Start | The item number of the initial item in the output display. This is an optional, but NameRequired, 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, but NameRequired, 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, but NameRequired, 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.
- Audit and Print are the same as Trace except they send their output to the Model 204 audit trail or currently selected trace destinations, respectively.
Examples
For examples of Trace method calls, see Printing a collection.