FindToken (StringTokenizer function): Difference between revisions
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{{Template:StringTokenizer:FindToken subtitle}} | {{Template:StringTokenizer:FindToken subtitle}} | ||
This callable method returns a Boolean value that indicates whether | This callable method returns a <var>Boolean value</var> that indicates whether | ||
it finds a specified token. | it finds a specified token. | ||
The value is <code>True</code> if the token is found; | The value is <code>True</code> if the token is found; | ||
otherwise it is <code>False</code>. | otherwise it is <code>False</code>. | ||
The search starts from the tokenizing position, | The search starts from the tokenizing position, | ||
the value of which is returned by [[NextPosition (StringTokenizer property)|NextPosition]]. | the value of which is returned by <var>[[NextPosition (StringTokenizer property)|NextPosition]]</var>. | ||
If the token is found, the position in | If the token is found, the position in | ||
the string is advanced past the found token, and [[CurrentToken (StringTokenizer function)|CurrentToken]] | the string is advanced past the found token, and <var>[[CurrentToken (StringTokenizer function)|CurrentToken]]</var> | ||
will return the found token. | will return the found token. | ||
Otherwise, [[AtEnd (StringTokenizer function)|AtEnd]] is set to <code>True</code>, and <var>CurrentToken</var> | Otherwise, <var>[[AtEnd (StringTokenizer function)|AtEnd]]</var> is set to <code>True</code>, and <var>CurrentToken</var> | ||
is set to the last token at the end of the string. | is set to the last token at the end of the string. | ||
The delimiters that are involved in determining the tokens | The delimiters that are involved in determining the tokens | ||
are set initially by the [[New (StringTokenizer constructor)|New]] constructor | are set initially by the <var>[[New (StringTokenizer constructor)|New]]</var> constructor | ||
that instantiates the <var>StringTokenizer</var> object. | that instantiates the <var>StringTokenizer</var> object. | ||
The delimiters can be modified by the [[Spaces (StringTokenizer property)|Spaces]], | The delimiters can be modified by the <var>[[Spaces (StringTokenizer property)|Spaces]]</var>, | ||
[[Quotes (StringTokenizer property)|Quotes]], and [[TokenChars (StringTokenizer property)|TokenChars]] properties. | <var>[[Quotes (StringTokenizer property)|Quotes]]</var>, and <var>[[TokenChars (StringTokenizer property)|TokenChars]]</var> properties. | ||
==Syntax== | ==Syntax== | ||
{{Template:StringTokenizer:FindToken syntax}} | {{Template:StringTokenizer:FindToken syntax}} | ||
===Syntax terms=== | ===Syntax terms=== | ||
<table class="syntaxTable"> | <table class="syntaxTable"> | ||
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For more information about <var>Boolean</var> enumerations, see [[Enumerations#Using_Boolean_enumerations|"Using Boolean Enumerations"]].</td></tr> | For more information about <var>Boolean</var> enumerations, see [[Enumerations#Using_Boolean_enumerations|"Using Boolean Enumerations"]].</td></tr> | ||
<tr><th>stringTokenizer</th> | <tr><th>stringTokenizer</th> | ||
<td>A <var>StringTokenizer</var> object expression. </td></tr> | <td>A <var>StringTokenizer</var> object expression. </td></tr> | ||
<tr><th>string</th> | <tr><th>string</th> | ||
<td>A string that is the token to be located.</td></tr> | <td>A string that is the token to be located.</td></tr> | ||
| Line 36: | Line 40: | ||
<ul> | <ul> | ||
<li>For a new <var>StringTokenizer</var> instance, issuing <var>FindToken</var>, | <li>For a new <var>StringTokenizer</var> instance, issuing <var>FindToken</var>, | ||
[[NextToken (StringTokenizer function)|NextToken]], or [[SkipTokens (StringTokenizer subroutine)|SkipTokens]] is | <var>[[NextToken (StringTokenizer function)|NextToken]]</var>, or <var>[[SkipTokens (StringTokenizer subroutine)|SkipTokens]]</var> is required before <var>[[CurrentToken (StringTokenizer function)|CurrentToken]]</var> may be issued without error. | ||
required before [[CurrentToken (StringTokenizer function)|CurrentToken]] may be issued without error. | |||
<li>The <var>NextToken</var> and [[PeekToken (StringTokenizer function)|PeekToken]] | <li>The <var>NextToken</var> and <var>[[PeekToken (StringTokenizer function)|PeekToken]]</var> | ||
functions also return the next token. | functions also return the next token. | ||
Like <var>FindToken</var>, <var>NextToken</var> | Like <var>FindToken</var>, <var>NextToken</var> | ||
advances the tokenizing position to the character or position following that token. | advances the tokenizing position to the character or position following that token. | ||
PeekToken, however, does not advance the tokenizing position. | <var>PeekToken</var>, however, does not advance the tokenizing position. | ||
</ul> | </ul> | ||
==Examples== | ==Examples== | ||
The following code fragment shows a <var>FindToken</var> call that locates its target, | The following code fragment shows a <var>FindToken</var> call that locates its target, | ||
then a <var>FindToken</var> call that does not locate its target: | then a <var>FindToken</var> call that does not locate its target: | ||
| Line 63: | Line 67: | ||
</p> | </p> | ||
'''Note:''' | '''Note:''' | ||
Using the PrintText statement is described in [[Targeted Text statements| | Using the PrintText statement is described in [[Targeted Text statements|"Targeted Text statements"]]. | ||
Printing an enumeration value is described in [[Enumerations#printenum|ToString property "Usage notes"]]. | |||
in [[Enumerations# | |||
==See also== | ==See also== | ||
{{Template:StringTokenizer:FindToken footer}} | {{Template:StringTokenizer:FindToken footer}} | ||
Revision as of 22:07, 5 July 2012
Search for specified token (StringTokenizer class)
This callable method returns a Boolean value that indicates whether
it finds a specified token.
The value is True if the token is found;
otherwise it is False.
The search starts from the tokenizing position,
the value of which is returned by NextPosition.
If the token is found, the position in
the string is advanced past the found token, and CurrentToken
will return the found token.
Otherwise, AtEnd is set to True, and CurrentToken
is set to the last token at the end of the string.
The delimiters that are involved in determining the tokens are set initially by the New constructor that instantiates the StringTokenizer object. The delimiters can be modified by the Spaces, Quotes, and TokenChars properties.
Syntax
[%boolean =] stringTokenizer:FindToken( string) Throws MismatchedQuote
Syntax terms
| %boolean | An enumeration object of type Boolean to contain the returned value of FindToken. For more information about Boolean enumerations, see "Using Boolean Enumerations". |
|---|---|
| stringTokenizer | A StringTokenizer object expression. |
| string | A string that is the token to be located. |
Usage notes
- For a new StringTokenizer instance, issuing FindToken, NextToken, or SkipTokens is required before CurrentToken may be issued without error.
- The NextToken and PeekToken functions also return the next token. Like FindToken, NextToken advances the tokenizing position to the character or position following that token. PeekToken, however, does not advance the tokenizing position.
Examples
The following code fragment shows a FindToken call that locates its target, then a FindToken call that does not locate its target:
%tok = new(tokenchars='-') %tok:string = 'Content-Transfer-Encoding: 7bit' PrintText {~} is {%tok:findToken('Transfer')} PrintText {~} is {%tok:findToken('8bit')} PrintText {~} is {%tok:AtEnd} PrintText {~} is {%tok:currentToken}
The result is:
%tok:findToken('Transfer') is True %tok:findToken('8bit') is False %tok:AtEnd is True %tok:currentToken is 7bit
Note: Using the PrintText statement is described in "Targeted Text statements". Printing an enumeration value is described in ToString property "Usage notes".