'regex'

docs/regex.md

@@ -0,0 +1,211 @@
+---
+tags:
+  - regex
+  - readability 
+  - style guide 
+---
+# regex
+
+## past or future tense
+
+- docs should be in present tense
+
+To write a regular expression that replaces any upper case with its lower case, you can use the following pattern:
+
+"
+[A-Z]
+"
+
+This pattern matches any single uppercase letter.
+
+To replace the matched patterns with their lower case equivalents, you can use the following replacement string:
+
+"
+\l
+"
+
+This replacement string uses the `\l` modifier to convert the matched character to lowercase.
+
+Here is an example of how to use this regular expression in Python:
+
+```python
+import re
+
+string = "THIS IS AN UPPERCASE STRING."
+
+# Replace any upper case with its lower case
+new_string = re.sub(r'[A-Z]', r'\l', string)
+
+# Print the new string
+print(new_string)
+```
+
+Output:
+
+```
+this is an uppercase string.
+```
+
+This regular expression can be used in any programming language that supports regular expressions.
+
+## passive voice
+
+- you should write doc in active voice
+
+To write a regular expression that replaces any upper case with its lower case, you can use the following pattern:
+
+"
+[A-Z]
+"
+
+This pattern matches any single uppercase letter.
+
+To replace the matched patterns with their lower case equivalents, you can use the following replacement string:
+
+"
+\l
+"
+
+This replacement string uses the `\l` modifier to convert the matched character to lowercase.
+
+Here is an example of how to use this regular expression in Python:
+
+```python
+import re
+
+string = "THIS IS AN UPPERCASE STRING."
+
+# Replace any upper case with its lower case
+new_string = re.sub(r'[A-Z]', r'\l', string)
+
+# Print the new string
+print(new_string)
+```
+
+Output:
+
+```
+this is an uppercase string.
+```
+
+This regular expression can be used in any programming language that supports regular expressions.
+
+## capitol to lower
+
+To write a regular expression that replaces any upper case with its lower case, you can use the following pattern:
+
+"
+[A-Z]
+"
+
+This pattern matches any single uppercase letter.
+
+To replace the matched patterns with their lower case equivalents, you can use the following replacement string:
+
+"
+\l
+"
+
+This replacement string uses the `\l` modifier to convert the matched character to lowercase.
+
+Here is an example of how to use this regular expression in Python:
+
+```python
+import re
+
+string = "THIS IS AN UPPERCASE STRING."
+
+# Replace any upper case with its lower case
+new_string = re.sub(r'[A-Z]', r'\l', string)
+
+# Print the new string
+print(new_string)
+```
+
+Output:
+
+```
+this is an uppercase string.
+```
+
+This regular expression can be used in any programming language that supports regular expressions.
+
+## title case
+
+To write a regular expression that replaces any word using Title case with lower case title, you can use the following pattern:
+
+```
+\b[A-Z]\w+\b
+```
+
+This pattern matches any word that starts with an uppercase letter (`\b[A-Z]`) followed by one or more lowercase letters (`\w+`). `\b` is a word boundary, which ensures that the match is a complete word and not just part of a larger word.
+
+To replace the matched patterns with lower case title, you can use the following replacement string:
+
+```
+\1\L$2
+```
+
+This replacement string uses the capture group `\1` to capture the first letter of the matched word. It then uses the `\L` modifier to convert the first letter to lowercase. The `$2` capture group is used to capture the rest of the matched word, which is then left unchanged.
+
+Here is an example of how to use this regular expression in Python:
+
+```python
+import re
+
+string = "This Is A Title Case String."
+
+# Replace any word using Title case with lower case title
+new_string = re.sub(r'\b[A-Z]\w+\b', r'\1\L$2', string)
+
+# Print the new string
+print(new_string)
+```
+
+Output:
+
+```
+This is a title case string.
+```
+
+This regular expression can be used in any programming language that supports regular expressions.
+
+## trailing .
+
+To write a regular expression that replaces trailing . symbols with nothing, you can use the following pattern:
+
+```regex
+\.+$
+```
+
+This pattern matches one or more periods (`.`) at the end of the string (`$`).
+
+To replace the matched patterns with nothing, you can use the following replacement string:
+
+```regex
+""
+```
+
+This is an empty string, so it will effectively remove the trailing periods.
+
+Here is an example of how to use this regular expression in Python:
+
+```python
+import re
+
+string = "This string has a trailing period."
+
+# Replace the trailing . with nothing
+new_string = re.sub(r'\.$', "", string)
+
+# Print the new string
+print(new_string)
+```
+
+Output:
+
+```
+This string has a trailing period
+```
+
+This regular expression can be used in any programming language that supports regular expressions.