# Working With Strings

Strings in RETRO are NULL terminated sequences of values
representing characters. Being NULL terminated, they can't
contain a NULL (ASCII 0).

The character words in RETRO are built around ASCII, but
strings can contain UTF8 encoded data if the host platform
allows. Words like `s:length` will return the number of bytes,
not the number of logical characters in this case.

## Searching

RETRO provides two words for searching within a string.

`s:contains-char?` 
`s:contains-string?`
`s:index-of`
`s:index-of-string`

## Comparisons

`s:eq?`
`s:case`

## Extraction

`s:left`
`s:right`
`s:substr`

## Joining

`s:append`
`s:prepend`

## Tokenization

`s:tokenize`
`s:tokenize-on-string`
`s:split`
`s:split-on-string`

## Conversions

`s:to-lower`
`s:to-upper`
`s:to-number`

## Cleanup

`s:chop`
`s:trim`
`s:trim-left`
`s:trim-right`

## Lifetime

`s:keep`
`s:temp`

## Combinators

`s:for-each`
`s:filter`
`s:map`

## Other

`s:evaluate`
`s:copy`
`s:reverse`
`s:hash`
`s:length`
`s:replace`
`s:format`
`s:empty`