IDE regular expressions: what changed

Revision 0 to 1. Removed lines have a minus sign; added lines have a plus sign.

Title: IDE regular expressions

New		Line
1	+	## Normal regular expression
2	+
3	+	Metacharacters:
4	+
5	+	` \ Quote the next metacharacter`\
6	+	` ^ Match the beginning of the line`\
7	+	` . Match any character (except newline). Example: 'a.c' matches 'abc', 'aBC', 'axc', 'a3c', 'a$c', etc.`\
8	+	` $ Match the end of the line (or before newline at the end)`\
9	+	` \| Alternation`\
10	+	` () Grouping. For example: (abc)+ matches 'abc' or 'abcabc' or 'abcabcabc' etc.`\
11	+	` [] Character class. For example [abc], [a-z], [a-zA-Z0-9_]`\
12	+	` [^] Reversed character class. For example [^a-z]`
13	+
14	+	Quantifiers:
15	+
16	+	` * Match 0 or more times`\
17	+	` + Match 1 or more times`\
18	+	` ? Match 1 or 0 times`\
19	+	` {n} Match exactly n times`\
20	+	` {n,} Match at least n times`\
21	+	` {n,m} Match at least n but not more than m times`
22	+
23	+	Curly brackets in any other context is treated as a regular character. The \`\`*is equivalent to {0,}, the \`\`+ to {1,} and the \`\`?'' to {0,1}.
24	+
25	+	By default, a quantifier is greedy, that means, it will match as many times as possible. To match the minimum number of times possible, append a \`\`?''.
26	+
27	+	` *? Match 0 or more times`\
28	+	` +? Match 1 or more times`\
29	+	` ?? Match 0 or 1 time`\
30	+	` {n}? Match exactly n times`\
31	+	` {n,}? Match at least n times`\
32	+	` {n,m}? Match at least n but not more than m times`
33	+
34	+	## Simple Syntax
35	+
36	+	Some IDE dialogs provide a checkbox to choose between simple syntax and regular expressions. The simple syntax is often shorter for common file name filters.
37	+
38	+	Technically it does this:
39	+
40	+	The following characters are replaced with
41	+	. -> \.
42	+	* -> .*
43	+	? -> .
44	+	, -> \|
45	+	; -> \|
46	+
47	+	Finally enclose by ^( )$
48	+
49	+	### Examples for simple syntax
50	+
51	+	- *.pas - matches all file names ending with .pas, like Unit1.pas or Some.txt.pas. Default is to match case sensitive. So it does not fit unit1.PAS.
52	+	- .pas;.pp;*p - matches all files like unit1.pas, 678.pp or %.p
53	+	- unit.pas - matches all files beginning with unit* and ending with .pas like unit1.pas and unit.pas.
54	+	- unit?.pas - matches all files beginning with unit, ending with .pas and exactly one like arbitrary character in between like unit1.pas and unit2.pas.
55	+
56	+	## Quoted symbols
57	+
58	+	The backslash '\\' can be used to treat special characters like '.' as normal character or to get some special ranges.
59	+
60	+	\. matches a point '.'
61	+	\d matches a number character '0'..'9'
62	+	\D matches a non number character
63	+	\s matches a space character ' ',#9,#10,#12,#13
64	+	\S matches a non space character
65	+	\w matches a word character 'a'..'z','A'..'Z','0'..'9','_'
66	+	\W matches a non word character
67	+	\b word boundary
68	+	\B not word boundary
69	+	\A begin of line
70	+	\Z end of line
71	+
72	+	## Search and Replace with regular expressions
73	+
74	+	The find dialogs support regular expressions for finding and replacing. Each found pattern grouped in round brackets can be used by a \$1, ..., \$9 variable
75	+
76	+	Example 1:
77	+
78	+	- Find expression: a(.*)c
79	+	- Replace expression: A\$1C
80	+	- Text: 'abc aLazc'
81	+
82	+	The \$1 will be replaced with the found text, that matches the first bracket.
83	+
84	+	- Result: 'AbC ALazC'
85	+
86	+	Example 2:
87	+
88	+	- Find expression: T(prefix)(\w+)
89	+	- Replace expression: T\$2Suffix
90	+	- Text: replaced from 'TprefixClass' to 'TClassSuffix'
91	+
92	+	You can also use the following special chars in the replace term
93	+
94	+	\n
95	+	Inserts a Linebreak
96	+
97	+	\l \u
98	+	Lower or Uppercases the next Char. Use this in front of \$n. \u\$1 Will insert the match from the first brackets, but with its first char made uppercase
99	+
100	+	\L \U
101	+	Lower or Uppercase the full text of the next \$n. The \$n must follow immediately
102	+
103	+	---
104	+	From the Free Pascal wiki, page "IDE regular expressions", as it stood on 2022-02-05 after a change by Trev, out of the wiki's dump of 2024-05-26. Copyright stays with the author who wrote it, according to the old wiki's [[Licensing]] page. If you have concerns about this material, [message the admin](/wiki-contact).

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