Built-in Types

Source: src/lib/BuiltInTypes.ts and src/lib/BuiltInTypeCompiler.ts.

2.1 Type List

Category	Type	Description
String	string	Any string
	ascii_string	ASCII string
	latin_string	Latin charset string
	hex_string	Hex string
Integer	int	Signed integer
	int8 / int16 / int32 / int64	Fixed-width integers (int64 is validated with integer semantics in JS)
	safe_int	JavaScript safe integer range
Unsigned Integer	uint	Unsigned integer
	uint8 / uint16 / uint32 / uint64	Fixed-width unsigned integers
	safe_uint	JavaScript safe unsigned integer range
Number	number	Any number
	float	Floating-point / integer (number)
	ufloat	Non-negative number
	numeric	A number, or a string that can be parsed as a number
Decimal String	decimal	Decimal string, supports (M,D)
	udecimal	Unsigned decimal string, supports (M,D)
Boolean	boolean	true / false
	true / false	Boolean literals
	true_value / false_value	Truthy / falsy
Structure	array	Any array
	struct	Any object structure
Special	null	null
	undefined / void / optional	undefined (synonyms)
	required	Not undefined
	any	Any value (always passes)

2.2 Argument Rules

Numeric range arguments

Applies to: int, float, number, numeric.

WARNING

uint and its fixed-width variants (uint8, uint16, uint32, uint64, safe_uint) do not support range arguments. If you need to constrain the range of an unsigned integer, use ["$.and", "uint", "|value between min max"] or numeric filters.

Syntax and examples:

// Signed integer range
compiler.compile({ rule: 'int(-10, 20)' });   // -10 to 20
compiler.compile({ rule: 'int(-10,)' });      // >= -10
compiler.compile({ rule: 'int(,20)' });       // <= 20

// Floating-point range
compiler.compile({ rule: 'float(0.0, 1.0)' });
compiler.compile({ rule: 'number(1.5, 99.9)' });

// Numeric-string range
compiler.compile({ rule: 'numeric(-100, 100)' });

String length arguments

Applies to: string, ascii_string, latin_string, hex_string.

Syntax and examples:

// Fixed length
compiler.compile({ rule: 'string(8)' });      // exactly 8 characters

// Length range
compiler.compile({ rule: 'string(1, 32)' });  // 1 to 32 characters

// Minimum length
compiler.compile({ rule: 'string(3,)' });     // at least 3 characters

Practical usage:

// Username: 3–16 ASCII characters
const isUsername = compiler.compile({ rule: 'ascii_string(3,16)' });

// Verification code: exactly 6 digits (combined with regex)
const isCaptcha = compiler.compile({ rule: ['$.and', 'string(6)', '~=/^\\d{6}$/'] });

Decimal arguments

Applies to: decimal, udecimal (exact decimal numbers represented as strings).

Syntax:

• decimal(M): total digits must not exceed M
• decimal(M,D): total digits M, with D fractional digits

Examples:

// Money amount: up to 10 digits total, 2 digits after decimal point
compiler.compile({ rule: 'decimal(10,2)' });  // "12345678.90"

// Unsigned money amount
compiler.compile({ rule: 'udecimal(12,4)' });

// Integer form (fractional digits = 0)
compiler.compile({ rule: 'decimal(8,0)' });   // "-1234567"

NOTE

The compiler option ignoreInvalidArgs controls what happens when you pass arguments to types that do not accept arguments (such as boolean, any, void, uint8, etc.):

• Default true: ignore extra arguments (for backward compatibility)
• Set to false: throw SyntaxError (recommended for new projects to catch invalid rules earlier)

You can pass this option via createInlineCompiler(opts) and createCompiler(lang, opts). See API Reference for details.