incstr

incstr

Increment strings or generate sequential string ids in node.js or browser

Usage

incstr

nextStr = incstr(str,
                 [alphabet=incstr.alphabet],
                 [numberlike=incstr.numberlike])

• str - string to increment;
• alphabet - alphabet to use (default 'A..Za..z0..9');
• numberlike - 'BA' after '9' instead of 'AA'(default false);
• default alphabet can be set through incstr.alphabet;
• default value for numberlike can be set through incstr.numberlike;
• works with strings of any length.

incstr.idGenerator

nextId = incstr.idGenerator(options)
id = nextId() // real generator would be too bulky "nextId.next().value"

Possible options:

• options.lastId;
• options.alphabet;
• options.numberlike;
• options.prefix;
• options.suffix.

lastId can also be accessed later through nextId.lastId property.

Note that nextId() is much faster than incstr() and safer because it verifies uniqueness of chars in the alphabet.

Examples

Pass a string to increment using default alphabet:

let i = incstr() // "A"
i = incstr(i) // "B"
...
i = incstr(i) // "9"
i = incstr(i) // "AA"
i = incstr(i) // "AB"

Pass a string and an alphabet to use:

incstr("ccc", "abc") // "aaaa"
incstr("cc", "ab") // throws ('c' is not in alphabet 'ab')
incstr("0", "01") // "1"
incstr("1", "01") // "00", note NOT "10"
incstr("1", "01", true) // "10", numberlike increment

Generate ids:

const nextId = incstr.idGenerator()
id1 = nextId() // 'A'
id2 = nextId() // 'B'

const nextId = incstr.idGenerator({alphabet:'ab', prefix:'id_', suffix:''})
nextId() // 'id_a'
nextId() // 'id_b'
nextId() // 'id_aa'

const nextId = incstr.idGenerator({lastId:'cc', alphabet:'abc', numberlike: true})
id = nextId() // 'baa'