RegexReplaceCorresponding (Stringlist function): Difference between revisions
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<td>A regex in '''%regList''' is invalid.<i>nnn</i>, the absolute value of the return minus 1000, gives the 1-based position of the character being scanned when the error was discovered. The value for an error occurring at end-of-string is the length of the string + 1. Prior to Version 7.0 of the <var class=product>Sirius Mods</var>, an invalid regex results in a Status value of <tt>.-1</tt>.</td></tr> | <td>A regex in '''%regList''' is invalid.<i>nnn</i>, the absolute value of the return minus 1000, gives the 1-based position of the character being scanned when the error was discovered. The value for an error occurring at end-of-string is the length of the string + 1. Prior to Version 7.0 of the <var class=product>Sirius Mods</var>, an invalid regex results in a Status value of <tt>.-1</tt>.</td></tr> | ||
</table> | </table> | ||
<p class="code"><blockquote> If you omit this argument and a negative Status value is to be returned, the run is cancelled.</blockquote></td></tr> | |||
</p> | |||
</table> | </table> | ||
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In the following code fragment, the second item in regex list '''%regList''' is the first to match the input string '''inStr'''. The subexpression in that item performs no special capturing function -- the parentheses are for grouping only. Since <tt>.%opt='g'</tt> is specified, three replacements are made (using the corresponding, second, item in '''%repList'''): | In the following code fragment, the second item in regex list '''%regList''' is the first to match the input string '''inStr'''. The subexpression in that item performs no special capturing function -- the parentheses are for grouping only. Since <tt>.%opt='g'</tt> is specified, three replacements are made (using the corresponding, second, item in '''%repList'''): | ||
< | <p class="code">... | ||
... | |||
%regList = new | %regList = new | ||
text to %regList | text to %regList | ||
Line 86: | Line 86: | ||
Print 'Output<var>String</var>: ' %outStr | Print 'Output<var>String</var>: ' %outStr | ||
... | ... | ||
</ | </p> | ||
The result would be: | The result would be: | ||
< | <p class="code">Status from ReplaceCorresponding is 3 | ||
Status from ReplaceCorresponding is 3 | |||
Output<var>String</var>: &&1&&2&&d | Output<var>String</var>: &&1&&2&&d | ||
</ | </p> | ||
[[Category:Stringlist methods|RegexReplaceCorresponding function]] | [[Category:Stringlist methods|RegexReplaceCorresponding function]] |
Revision as of 15:47, 20 January 2011
Replace substrings that match regex with items in a Stringlist (Stringlist class)
This method searches a given string for matches to one of multiple regular expressions contained in a list, and it replaces found matches with or according to a string contained in a list that corresponds to the regex list. The method is available as of Version 6.9 of the Sirius Mods. The regex list items are treated as mutually exclusive alternatives, and the function stops as soon as an item matches and the replacement is made. A "global" option is also available to continue searching and replacing within the given string using the matching regex item until no more matches are found. RegexReplaceCorresponding uses the rules of regular expression matching (information about which is provided in Regex processing). RegexReplaceCorresponding accepts two required and two optional arguments, and it returns a string. Specifying an invalid argument results in request cancellation.
Syntax
%outString = sl:RegexReplaceCorresponding( inString, replacementList, - [Options= string], - [Status= %output]) Throws InvalidRegex
Syntax terms
outStr | A string set to the value of inStr with each matched substring replaced by the value of the replacementList item that corresponds to the matching %regList item. | ||||||||||||
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%regList | A Stringlist object whose items are interpreted as regular expressions and applied to the inStr value. | ||||||||||||
inStr | The input string, to which the regular expressions in %regList are applied. | ||||||||||||
replacementList | A Stringlist, each of whose items is a potential replacement string for the substring of inStr that is matched by the corresponding item of %regList. Except when the .A option is specified (as described below for the Options argument), you can include .$0 markers in replacementList items as placeholders for the substring of inStr that the item matches. .xxx$0 is an example of a valid replacement string, and .xxx concatenated with the portion of inStr that gets matched (by the corresponding %regList item) constitute the replacement string. Any character after the dollar sign other than a zero is an error. Multiple zeroes (as many as 9) are permitted; a digit following such a string of zeroes must be escaped. You can also use the format .$m0, where m is one of the following modifiers:
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Options= string | The Options argument (name required) is an optional string of options. The options are single letters, which may be specified in uppercase or lowercase, in any combination, and separated by blanks or not separated. For more information about these options, see Regex processing.
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Status= num | The Status argument (name required) is optional; if specified, it is set to an integer code. These values are possible:
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Usage notes
- It is strongly recommended that you protect your environment from regex processing demands on PDL and STBL space by setting, say, .UTABLE LPDLST 3000 and .UTABLE LSTBL 9000. For further discussion of this, see User Language.
- Items in %regList must not exceed 6124 bytes. However, the inStr value and items in replacementList may exceed 6124 bytes.
- For information about additional methods and $functions that support regular expressions, see Regex processing.
Examples
In the following code fragment, the second item in regex list %regList is the first to match the input string inStr. The subexpression in that item performs no special capturing function -- the parentheses are for grouping only. Since .%opt='g' is specified, three replacements are made (using the corresponding, second, item in %repList):
... %regList = new text to %regList abcx a(bc?) abcd end text %repList = new text to %repList & && &&& end text %inStr = 'abc1abc2abcd' %opt='g' %outStr = %regList:RegexReplaceCorresponding (%inStr, %repList, Options=%opt, Status=%st) Print 'Status from ReplaceCorresponding is ' %st Print 'OutputString: ' %outStr ...
The result would be:
Status from ReplaceCorresponding is 3 OutputString: &&1&&2&&d