8.12
3 Types
3.1 Type Instances
value
The undefined value.
The null value.
3.2 Additional Type Utilities
| (require ecmascript/types) | package: ecmascript |
3.2.1 Type Predicates
Returns #f if v is the undefined value, #t otherwise.
procedure
(undefined? v) → boolean?
v : any/c
Returns #t if v is the undefined value, #f otherwise.
Returns #t if v is the null value, #f otherwise.
Returns #t if v is a boolean value, #f otherwise.
Returns #t if v is a number, #f otherwise.
Returns #t if v is a string, #f otherwise.
procedure
(primitive-value? v) → boolean?
v : any/c
Returns #t if v is the undefined value, the null
value, a boolean, a number or a string.
procedure
(object? v) → boolean?
v : any/c
Returns #t if v is an ECMAScript object, #f otherwise.
3.2.2 Reference Type
struct
(struct reference (base name strict?) #:extra-constructor-name make-reference) base : (or/c object? (is-a?/c environment-record%) undefined?) name : string? strict? : boolean?
An ECMAScript reference.
3.2.3 Type Conversions
| (require ecmascript/convert) | package: ecmascript |
procedure
(to-primitive v [preferred]) → primitive-value?
v : value? preferred : (or/c 'number 'string #f) = #f
Converts v to a primitive value. If preferred is
'number or 'string, the conversion process may
return a value of that type. If v is already a primitive
value, it is returned unchanged.
procedure
(to-boolean v) → boolean?
v : value?
Converts v to a boolean value.
procedure
(to-number v) → number?
v : value?
Converts v to a number (possibly +nan.0).
procedure
(to-integer v) → number?
v : value?
Converts v to a number and returns the result of truncating
it to an integer.
procedure
(to-int32 v) → number?
v : value?
Converts v to a signed 32-bit integer.
procedure
(to-uint32 v) → number?
v : value?
Converts v to an unsigned 32-bit integer.
procedure
(to-uint16 v) → number?
v : value?
Converts v to an unsigned 16-bit integer.
procedure
(to-string v) → string?
v : value?
Returns a string representation of v.
procedure
v : (and/c value? (not/c undefined?) (not/c null?))
If v is an ECMAScript object, it is returned unchanged.
Otherwise, a new Boolean, Number or
String object is created with its value set to
v.