Object, Bracket & Array Syntax

Each note of a notation is validated against ECMAScript variable syntax, array-index notation, and object-bracket notation. Invalid notes never match — and most methods throw a NotationError rather than fail silently.

Property Keys

Standard identifiers use dot notation. Non-standard keys (digits, dashes, symbols, reserved characters) must use bracket notation with quotes:

Incorrect	Correct
x[y]	x["y"]
x.1	x['1']
x.y-z	x["y-z"]
x.@	x['@']

Notation.isValid('x.y-z');     // » false
Notation.isValid('x["y-z"]');  // » true

Array Indices

Brackets with a number address array items:

• [0].x — the x property of the first item of a root array.
• x[1] — the second item of the x property of a root object.

const data = { tags: ['a', 'b', 'c'] };
Notation.create(data).get('tags[1]');   // » "b"

Wildcards

Wildcards are glob-only — valid in filter() and the NotationGlob class, but not in regular notation.

Pattern	Meaning
*	all properties of an object
[*]	all items of an array
x[*]	all items of x (an array)
x.*	all properties of x (an object)
x['*']	a literal * key — not a wildcard (valid regular notation)

Notation.isValid('x.*');    // » false (glob only)
NotationGlob.isValid('x.*'); // » true

Wildcard Equivalence

For non-negated globs, trailing wildcards are redundant — they all normalize to the bare notation:

x  =  x.*  =  x.*.*
[0]  =  [0][*]

Negated versions are not equivalent — the trailing wildcard changes what’s removed:

• !x — remove x entirely.
• !x.* — empty x’s first-level properties, but keep x (as {}).
• !x.*.* — empty only the second-level properties of x.

!x  ≠  !x[*]
![*]  ≠  ![*].*

This distinction drives filtering and data integrity — worth internalizing before you write negated globs.