varsize-string

Varsize-string is a JavaScript CommonJS (node.js) package for working
with strings where the different characters have different sizes.

Installation & Usage

With npm you can install and use the varsize-string like this:

``
$ npm install varsize-string --save
`

With the package being successfully installed you can create an instance like this:

`JavaScript
function charWidth(charCode, formerCharCode, inString, pos) {
/ in this example a-z (lower-case) is 0.8 the width of other characters /
return (charCode >= 97 && charCode <= 122 ) ? 0.8 : 1
}
var VarSizeString = require('varsize-string')
var str = new VarSizeString('ABCdef', charWidth)
var str2 = VarSizeString('abcDEF', charWidth) // You don't need to use new
`

Application


The most important application of varsize-string is in combination with
wcsize that identifies the size of strings rendered in a common terminal,
see wcstring for a shorthand combination of both.

It can also be used in a (visual) web context to correctly wrap or truncate strings.

Operations


On the instance you can apply a set of operations. Note that the following explanation uses size as an accumulated amount of width and width as a single-line size.

$3

Get the size of the widest line in the string.

$3

Get the size of the complete string.

$3

Analogous to String.indexOf. Looks for the first occurance of search. Optionally takes startOffset which is the size of characters that have to happen before the search takes place (default=0).

$3

Analogous to String.lastIndexOf. Looks for the last occurance of search.
Optionally takes endOffset which is the size offset from the end of the string from which to search for search.

$3

Analogous to String.substring. This method will return the fully visible characters between startSize and endSize. If endSize is not given it will assume a substring from startSize until the end of the string.
_However:_ Unlike String.substring, this method returns an object with the properties size and string in order to know the size of the substring.

Example:
`JavaScript
var vsstring = require('varsize-string')
vsstring('abcdef', charWidth).substring(0, 3) // {string: 'abc', size: 2.4}
`

$3


Equal to .substring(startSize, startSize + size).

$3

Truncates the string after a size. Will append the given suffix to the string if it does exceed the size.

$3

Removes the last character from the string and returns the new .size().

$3

Normalizes the string in order for all lines to fit within width.

Example:
`JavaScript
var vsstring = require('varsize-string')
vsstring('abcdef', charWidth).wrap(3) // 'abc\ndef'
vsstring('ab cd ef', charWidth).wrap(5) // 'ab cd\nef'
vsstring('ab cd ef', charWidth).wrap(3) // 'ab\ncd\nef'
`

#### Padding
The padding option takes a padding specification and applies it to the
wrapping process.

Example:

`JavaScript
var padding = {
first: {left: ' - ', right: ' '},
regular: {left: ' ', right: ' '}
}
vsstring('abcdefghijklmnop', charWidth).wrap(10, padding)
// - abcdef
// ghijkl
// mnop
`

There are a few shorthands to specifying the padding:

`JavaScript
padding = ' '
`

... is equals to ...

`JavaScript
{
first: ' ',
regular: ' '
}
`

... is equals to ...

`JavaScript
{
first: {left: ' ': right: undefined},
regular: {left: ' ': right: undefined}
}
`

Also you can preset left/right for both first and regular:

`JavScript
{
right: 'x',
first: {left: ' - '},
regular: {left: ' '}
}
`

... is equal to ...

`JavaScript
{
first: {left: ' - ', right: 'x'},
regular: {left: ' ', right: 'x'}
}
`

Note that the left/right presets override the first/regular specification:

`JavaScript
{
left: 'x',
first: '-',
regular: ' '
}
`

... is equal to ...

`JavaScript
{
first: {left: 'x', right: undefined},
regular: {left: 'x', right: undefined}
}
`

Also it supports a fallback to regular if first is missing:

`JavaScript
{
regular: {left: 'x', right: undefined}
}
`

... is equal to ...

`JavaScript
{
first: {left: 'x', right: undefined},
regular: {left: 'x', right: undefined}
}
`

$3


Turns a flexible padding definition into a clear padding definition. You can pass in an optional process variable to process the strings before they are being turned into varsizes-strings. You can also pass-in a width` to make sure that the padding will not exceed the width of, say, a wrapped string.