Module stringx
A module that contains many helpful string extensions.
Functions
| escape_pattern (s) | Escape a string so it can be used as a pattern. |
| isalpha (s) | Checks if a string contains only alphabetic characters. |
| isdigit (s) | Checks if a string contains only digits. |
| isalnum (s) | Checks if a string contains only alphanumeric characters. |
| isspace (s) | Checks if a string contains only spaces. |
| islower (s) | Checks if a string contains only lower-case characters. |
| isupper (s) | Checks if a string contains only upper-case characters. |
| at (s, i) | Return the single character at the given index. |
| shorten (s, len, show_tail) | Shortens a string to a given length, adding dots if necessary. |
| capitalize (s) | Capitalize the first word in a string. |
| chomp (s, final) | Strip a final value (default: newlines) from the end of a string |
| chop (s) | Remove the final character from the string. |
| delete (s, substr) | Remove all characters given from the string. |
| lstrip (s, chars) | Remove leading characters from a string, as given by the chars pattern. |
| rstrip (s, chars) | Remove trailing characters from a string, as given by the chars pattern. |
| strip (s, chars) | Remove leading and trailing characters from a string, as given by the chars pattern. |
| lfind (s, sub, first, last) | Finds the index of the first instance of sub in s |
| rfind (s, sub, first, last) | Finds the index of the last instance of sub in s |
| replace (s, old, new, count) | Replaces all instances of substring old replaced by new. |
| endswith (s, suffix, start, fin) | Returns true if s ends with the specified suffix, false otherwise. |
| startswith (s, suffix, start, fin) | Returns true if s starts with the specified suffix, false otherwise. |
| count (s, substr, start, fin) | Returns the number of occurences of the substring substr in the string given by s[start:fin]. |
| partition (s, sep) | Search the string s for a pattern, and returns the part before it, the match, and the part after it. |
| rpartition (s, sep) | Search the string s for a pattern, starting from the end, and return the part before it, the match, and the part after it. |
| ljust (s, i, padstr) | Left-justifies the string to the given width. |
| rjust (s, i, padstr) | Right-justifies the string to the given width. |
| zfill (s, width) | Pad a string with zeros on the left, to fill a field of the specified width. |
| patch () | Adds all the functions in this module to the 'string' table, so they can be used directly on strings. |
Functions
- escape_pattern (s)
-
Escape a string so it can be used as a pattern.
Parameters:
- s The string to escape
Returns:
-
A string with any special characters escaped, such that it can be
used as a pattern
- isalpha (s)
-
Checks if a string contains only alphabetic characters.
Parameters:
- s The string to check
Returns:
-
true or false
- isdigit (s)
-
Checks if a string contains only digits.
Parameters:
- s The string to check
Returns:
-
true or false
- isalnum (s)
-
Checks if a string contains only alphanumeric characters.
Parameters:
- s The string to check
Returns:
-
true or false
- isspace (s)
-
Checks if a string contains only spaces.
Parameters:
- s The string to check
Returns:
-
true or false
- islower (s)
-
Checks if a string contains only lower-case characters.
Parameters:
- s The string to check
Returns:
-
true or false
- isupper (s)
-
Checks if a string contains only upper-case characters.
Parameters:
- s The string to check
Returns:
-
true or false
- at (s, i)
-
Return the single character at the given index.
Parameters:
- s The string
- i The index
Returns:
-
A string of length 1 if successful, otherwise an empty string
- shorten (s, len, show_tail)
-
Shortens a string to a given length, adding dots if necessary.
Parameters:
- s The string to shorten
- len The maximum length to show
- show_tail Boolean indicating whether to show the start or end of the string (defaults to false, indicating show the start)
Returns:
-
A string of maximum length len
- capitalize (s)
-
Capitalize the first word in a string.
Parameters:
- s The string to capitalize
Returns:
-
The string, with the first letter capitalized
- chomp (s, final)
-
Strip a final value (default: newlines) from the end of a string
Parameters:
- s The string to chomp
- final The value to remove from the end of s
Returns:
-
The string, with any final characters removed
- chop (s)
-
Remove the final character from the string. If the string ends with a
newline pair (\r\n), then both characters are removed.
Parameters:
- s The string to chop
Returns:
-
The string, with the final character (or newline pair) removed
- delete (s, substr)
-
Remove all characters given from the string.
Parameters:
- s The string to delete from
- substr Either a list-like table of strings or single string to remove
Returns:
-
The string with all input strings removed
- lstrip (s, chars)
-
Remove leading characters from a string, as given by the chars pattern.
Parameters:
- s The string to strip
- chars The pattern used to look for leading characters (default: %s+)
Returns:
-
A string with leading characters matching the pattern removed
- rstrip (s, chars)
-
Remove trailing characters from a string, as given by the chars pattern.
Parameters:
- s The string to strip
- chars The pattern used to look for trailing characters (default: %s+)
Returns:
-
A string with trailing characters matching the pattern removed
- strip (s, chars)
-
Remove leading and trailing characters from a string, as given by the chars
pattern.
Parameters:
- s The string to strip
- chars The pattern used to look for leading and trailing characters (default: %s+)
Returns:
-
A string with leading and trailing characters matching the pattern
removed
- lfind (s, sub, first, last)
-
Finds the index of the first instance of sub in s
Parameters:
- s The string to search
- sub The string to search for
- first The start index
- last The last index
Returns:
-
The index of the first instance, or nil if not found
- rfind (s, sub, first, last)
-
Finds the index of the last instance of sub in s
Parameters:
- s The string to search
- sub The string to search for
- first The start index
- last The last index
Returns:
-
The index of the last instance, or nil if not found
- replace (s, old, new, count)
-
Replaces all instances of substring old replaced by new.
Parameters:
- s The string to search
- old The substring to search for
- new The substring to replace with
- count (optional) If given, this function will only perform this number of replacements.
Returns:
-
The new string
- endswith (s, suffix, start, fin)
-
Returns true if s ends with the specified suffix, false otherwise.
Parameters:
- s The string to check
- suffix A string or list-like table of suffixes to check
- start (optional) The index to start checking at. Defaults to 1
- fin (optional) The index to stop checking at. Defaults to #s
Returns:
-
true or false
- startswith (s, suffix, start, fin)
-
Returns true if s starts with the specified suffix, false otherwise.
Parameters:
- s The string to check
- suffix A string or list-like table of suffixes to check
- start (optional) The index to start checking at. Defaults to 1
- fin (optional) The index to stop checking at. Defaults to #s
Returns:
-
true or false
- count (s, substr, start, fin)
-
Returns the number of occurences of the substring substr in the string given
by s[start:fin].
Parameters:
- s The string to check
- substr The substring to search for
- start The index at which to start searching (defaults to 1)
- fin The index at which to finish searching (defaults to #s)
Returns:
-
A number indicating the number of times the substring was found
- partition (s, sep)
-
Search the string s for a pattern, and returns the part before it, the
match, and the part after it. If not found, returns the input string and
two empty strings.
Parameters:
- s The string to partition
- sep The separator to partition by
Returns:
- The part before the separator, or the full string if no match
- The separator, or a blank string if not found
- The part after the separator, or a blank string if not found
- rpartition (s, sep)
-
Search the string s for a pattern, starting from the end, and return the
part before it, the match, and the part after it. If not found, returns the
input string and two empty strings.
Parameters:
- s The string to partition
- sep The separator to partition by
Returns:
- The part before the separator, or the full string if no match
- The separator, or a blank string if not found
- The part after the separator, or a blank string if not found
- ljust (s, i, padstr)
-
Left-justifies the string to the given width.
Parameters:
- s The string to left-justify
- i The width to justify to
- padstr The padding string to use (defaults to ' ')
Returns:
-
The newly justified string
- rjust (s, i, padstr)
-
Right-justifies the string to the given width.
Parameters:
- s The string to right-justify
- i The width to justify to
- padstr The padding string to use (defaults to ' ')
Returns:
-
The newly justified string
- zfill (s, width)
-
Pad a string with zeros on the left, to fill a field of the specified
width. The string is never truncated.
Parameters:
- s The string to pad
- width The width to pad to
- patch ()
- Adds all the functions in this module to the 'string' table, so they can be used directly on strings. Note that we exclude this function itself.