lmodstring

README

The standard Lua string library is pretty pathetic in my opinion. Many simple operations are not possible without lots of complicated code and/or regular expressions. Of course this is probably because Lua is written in C, and C also has a pathetic string library (it doesn't even have an actual string type!).

I added some new string handling functions on top of the default. Some of these are similar to what Lua already has, but without the regular expression support, others fill critical holes in the default API, and a few are lazy conveniences.

Most of these functions assume strings are UTF-8, be careful.

You will only have these functions if you import the string module, see the package example.

If you do not want these extensions simply set the _NO_STRING_EXTS registry key to any non-false value before loading the string module. This can be done like so:

l.Push("_NO_STRING_EXTS")
l.Push(true)
l.SetTableRaw(lua.RegistryIndex)

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function string.count(str, sub)

Returns the number of non-overlapping occurrences of sub in str.

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function string.hasprefix(str, prefix)

Returns true if str starts with prefix.

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function string.hassuffix(str, suffix)

Returns true if str ends with suffix.

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function string.join(table, [sep])

Joins all the values in table with sep. If sep is not specified then it defaults to ", "

Yes, I know there is a function in the table module that does something similar.

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function string.replace(str, old, new, [n])

Replaces n occurrences of old with new in str. If n < 0 then there is no limit on replacements.

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function string.split(str, sep, [n])

Split str into n substrings at ever occurrence of sep.

• n > 0: at most n substrings; the last substring will be the unsplit remainder
• n == 0: the result is an empty table
• n < 0: all substrings

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function string.splitafter(str, sep, [n])

This is exactly like strings.split, except sep is retained as part of the substrings.

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function string.title(str)

Convert the first character of every word in str to it's title case.

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function string.trim(str, cut)

Returns str with any chars in cut removed from it's beginning and end.

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function string.trimprefix(str, prefix)

Returns str with prefix removed from it's start. str is returned unchanged if it does not start with prefix.

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function string.trimspace(str)

Returns str with all whitespace trimmed from it's beginning and end.

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function string.trimsuffix(str, suffix)

Returns str with suffix removed from it's end. str is returned unchanged if it does not end with suffix.

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function string.unquote(str)

If str begins and ends with a quote char (one of "'`) then it will be unquoted using the rules for the Go language. This includes escape sequence expansion.

Documentation

Index

• func Open(l *lua.State) int

Functions

func Open

func Open(l *lua.State) int

Open loads the "string" module when executed with "lua.(*State).Call".

It would also be possible to use this with "lua.(*State).Require" (which has some side effects that are inappropriate for a core library like this) or "lua.(*State).Preload" (which makes even less sense for a core library).

The following standard Lua functions/fields are not provided:

string.gmatch
string.gsub
string.match
string.pack
string.packsize
string.unpack

Additionally "string.find" does not allow pattern based searching.

The following non-standard functions are provided:

string.count
string.hasprefix
string.hassuffix
string.join (like table.concat, but not exactly)
string.replace
string.split
string.splitafter
string.title
string.trim
string.trimprefix
string.trimspace
string.trimsuffix
string.unquote

For more information about these extensions (including how to disable them) see the "README.md" file for this package (not the main "lua" package!).