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Package ldvalue

v2.0.1
Latest Go to latest

The latest major version is v2.

Published: Oct 8, 2020 | License: Apache-2.0 | Module: gopkg.in/launchdarkly/go-sdk-common.v2

Overview

Package ldvalue provides an abstraction of the LaunchDarkly SDK's general value type. LaunchDarkly supports the standard JSON data types of null, boolean, number, string, array, and object (map), for any feature flag variation or custom user attribute. The ldvalue.Value type can contain any of these.

This package also provides the helper types OptionalBool, OptionalInt, and OptionalString, which are safer alternatives to using pointers for optional values.

Index

type ArrayBuilder

type ArrayBuilder interface {
	// Add appends an element to the array builder.
	Add(value Value) ArrayBuilder
	// Build creates a Value containing the previously added array elements. Continuing to modify the
	// same builder by calling Add after that point does not affect the returned array.
	Build() Value
}

ArrayBuilder is a builder created by ArrayBuild(), for creating immutable arrays.

func ArrayBuild

func ArrayBuild() ArrayBuilder

ArrayBuild creates a builder for constructing an immutable array Value.

arrayValue := ldvalue.ArrayBuild().Add(ldvalue.Int(100)).Add(ldvalue.Int(200)).Build()

func ArrayBuildWithCapacity

func ArrayBuildWithCapacity(capacity int) ArrayBuilder

ArrayBuildWithCapacity creates a builder for constructing an immutable array Value.

The capacity parameter is the same as the capacity of a slice, allowing you to preallocate space if you know the number of elements; otherwise you can pass zero.

arrayValue := ldvalue.ArrayBuildWithCapacity(2).Add(ldvalue.Int(100)).Add(ldvalue.Int(200)).Build()

type ObjectBuilder

type ObjectBuilder interface {
	// Set sets a key-value pair in the object builder.
	Set(key string, value Value) ObjectBuilder
	// Build creates a Value containing the previously specified key-value pairs. Continuing to modify
	// the same builder by calling Set after that point does not affect the returned object.
	Build() Value
}

ObjectBuilder is a builder created by ObjectBuild(), for creating immutable JSON objects.

func ObjectBuild

func ObjectBuild() ObjectBuilder

ObjectBuild creates a builder for constructing an immutable JSON object Value.

objValue := ldvalue.ObjectBuild().Set("a", ldvalue.Int(100)).Set("b", ldvalue.Int(200)).Build()

func ObjectBuildWithCapacity

func ObjectBuildWithCapacity(capacity int) ObjectBuilder

ObjectBuildWithCapacity creates a builder for constructing an immutable JSON object Value.

The capacity parameter is the same as the capacity of a map, allowing you to preallocate space if you know the number of elements; otherwise you can pass zero.

objValue := ldvalue.ObjectBuildWithCapacity(2).Set("a", ldvalue.Int(100)).Set("b", ldvalue.Int(200)).Build()

type OptionalBool

type OptionalBool struct {
	// contains filtered or unexported fields
}

OptionalBool represents a bool that may or may not have a value. This is similar to using a bool pointer to distinguish between a false value and nil, but it is safer because it does not expose a pointer to any mutable value.

To create an instance with a bool value, use NewOptionalBool. There is no corresponding method for creating an instance with no value; simply use the empty literal OptionalBool{}.

ob1 := NewOptionalBool(1)
ob2 := NewOptionalBool(false) // this has a value which is false
ob3 := OptionalBool{}         // this does not have a value

This can also be used as a convenient way to construct a bool pointer within an expression. For instance, this example causes myIntPointer to point to the bool value true:

var myBoolPointer *int = NewOptionalBool(true).AsPointer()

This type is used in the Anonymous property of lduser.User, and for other similar fields in the LaunchDarkly Go SDK where a bool value may or may not be defined.

func NewOptionalBool

func NewOptionalBool(value bool) OptionalBool

NewOptionalBool constructs an OptionalBool that has a bool value.

There is no corresponding method for creating an OptionalBool with no value; simply use the empty literal OptionalBool{}.

func NewOptionalBoolFromPointer

func NewOptionalBoolFromPointer(valuePointer *bool) OptionalBool

NewOptionalBoolFromPointer constructs an OptionalBool from a bool pointer. If the pointer is non-nil, then the OptionalBool copies its value; otherwise the OptionalBool has no value.

func (OptionalBool) AsPointer

func (o OptionalBool) AsPointer() *bool

AsPointer returns the OptionalBool's value as a bool pointer if it has a value, or nil otherwise.

The bool value, if any, is copied rather than returning to a pointer to the internal field.

func (OptionalBool) AsValue

func (o OptionalBool) AsValue() Value

AsValue converts the OptionalBool to a Value, which is either Null() or a boolean value.

func (OptionalBool) BoolValue

func (o OptionalBool) BoolValue() bool

BoolValue returns the OptionalBool's value, or false if it has no value.

func (OptionalBool) Get

func (o OptionalBool) Get() (bool, bool)

Get is a combination of BoolValue and IsDefined. If the OptionalBool contains a bool value, it returns that value and true; otherwise it returns false and false.

func (OptionalBool) IsDefined

func (o OptionalBool) IsDefined() bool

IsDefined returns true if the OptionalBool contains a bool value, or false if it has no value.

func (OptionalBool) MarshalJSON

func (o OptionalBool) MarshalJSON() ([]byte, error)

MarshalJSON converts the OptionalBool to its JSON representation.

The output will be either a JSON boolean or null. Note that the "omitempty" tag for a struct field will not cause an empty OptionalBool field to be omitted; it will be output as null. If you want to completely omit a JSON property when there is no value, it must be a bool pointer instead of an OptionalBool; use the AsPointer() method to get a pointer.

func (OptionalBool) MarshalText

func (o OptionalBool) MarshalText() ([]byte, error)

MarshalText implements the encoding.TextMarshaler interface.

func (OptionalBool) OrElse

func (o OptionalBool) OrElse(valueIfEmpty bool) bool

OrElse returns the OptionalBool's value if it has one, or else the specified fallback value.

func (OptionalBool) String

func (o OptionalBool) String() string

String is a debugging convenience method that returns a description of the OptionalBool. This is either "true", "false, or "[none]" if it has no value.

func (*OptionalBool) UnmarshalJSON

func (o *OptionalBool) UnmarshalJSON(data []byte) error

UnmarshalJSON parses an OptionalBool from JSON.

The input must be either a JSON number that is a boolean or null.

func (*OptionalBool) UnmarshalText

func (o *OptionalBool) UnmarshalText(text []byte) error

UnmarshalText implements the encoding.TextUnmarshaler interface.

This allows OptionalBool to be used with packages that can parse text content, such as gcfg.

func (OptionalBool) WriteToJSONBuffer

func (o OptionalBool) WriteToJSONBuffer(j *jsonstream.JSONBuffer)

WriteToJSONBuffer provides JSON serialization for OptionalBool with the jsonstream API.

The JSON output format is identical to what is produced by json.Marshal, but this implementation is more efficient when building output with JSONBuffer. See the jsonstream package for more details.

type OptionalInt

type OptionalInt struct {
	// contains filtered or unexported fields
}

OptionalInt represents an int that may or may not have a value. This is similar to using an int pointer to distinguish between a zero value and nil, but it is safer because it does not expose a pointer to any mutable value.

To create an instance with an int value, use NewOptionalInt. There is no corresponding method for creating an instance with no value; simply use the empty literal OptionalInt{}.

oi1 := NewOptionalInt(1)
oi2 := NewOptionalInt(0) // this has a value which is zero
oi3 := OptionalInt{}     // this does not have a value

This can also be used as a convenient way to construct an int pointer within an expression. For instance, this example causes myIntPointer to point to the int value 2:

var myIntPointer *int = NewOptionalInt("x").AsPointer()

This type is used in ldreason.EvaluationDetail.VariationIndex, and for other similar fields in the LaunchDarkly Go SDK where an int value may or may not be defined.

func NewOptionalInt

func NewOptionalInt(value int) OptionalInt

NewOptionalInt constructs an OptionalInt that has an int value.

There is no corresponding method for creating an OptionalInt with no value; simply use the empty literal OptionalInt{}.

func NewOptionalIntFromPointer

func NewOptionalIntFromPointer(valuePointer *int) OptionalInt

NewOptionalIntFromPointer constructs an OptionalInt from an int pointer. If the pointer is non-nil, then the OptionalInt copies its value; otherwise the OptionalInt has no value.

func (OptionalInt) AsPointer

func (o OptionalInt) AsPointer() *int

AsPointer returns the OptionalInt's value as an int pointer if it has a value, or nil otherwise.

The int value, if any, is copied rather than returning to a pointer to the internal field.

func (OptionalInt) AsValue

func (o OptionalInt) AsValue() Value

AsValue converts the OptionalInt to a Value, which is either Null() or a number value.

func (OptionalInt) Get

func (o OptionalInt) Get() (int, bool)

Get is a combination of IntValue and IsDefined. If the OptionalInt contains an int value, it returns that value and true; otherwise it returns zero and false.

func (OptionalInt) IntValue

func (o OptionalInt) IntValue() int

IntValue returns the OptionalInt's value, or zero if it has no value.

func (OptionalInt) IsDefined

func (o OptionalInt) IsDefined() bool

IsDefined returns true if the OptionalInt contains an int value, or false if it has no value.

func (OptionalInt) MarshalJSON

func (o OptionalInt) MarshalJSON() ([]byte, error)

MarshalJSON converts the OptionalInt to its JSON representation.

The output will be either a JSON number or null. Note that the "omitempty" tag for a struct field will not cause an empty OptionalInt field to be omitted; it will be output as null. If you want to completely omit a JSON property when there is no value, it must be an int pointer instead of an OptionalInt; use the AsPointer() method to get a pointer.

func (OptionalInt) MarshalText

func (o OptionalInt) MarshalText() ([]byte, error)

MarshalText implements the encoding.TextMarshaler interface.

func (OptionalInt) OrElse

func (o OptionalInt) OrElse(valueIfEmpty int) int

OrElse returns the OptionalInt's value if it has one, or else the specified fallback value.

func (OptionalInt) String

func (o OptionalInt) String() string

String is a debugging convenience method that returns a description of the OptionalInt. This is either a numeric string, or "[none]" if it has no value.

func (*OptionalInt) UnmarshalJSON

func (o *OptionalInt) UnmarshalJSON(data []byte) error

UnmarshalJSON parses an OptionalInt from JSON.

The input must be either a JSON number that is an integer or null.

func (*OptionalInt) UnmarshalText

func (o *OptionalInt) UnmarshalText(text []byte) error

UnmarshalText implements the encoding.TextUnmarshaler interface.

This allows OptionalInt to be used with packages that can parse text content, such as gcfg.

func (OptionalInt) WriteToJSONBuffer

func (o OptionalInt) WriteToJSONBuffer(j *jsonstream.JSONBuffer)

WriteToJSONBuffer provides JSON serialization for OptionalInt with the jsonstream API.

The JSON output format is identical to what is produced by json.Marshal, but this implementation is more efficient when building output with JSONBuffer. See the jsonstream package for more details.

type OptionalString

type OptionalString struct {
	// contains filtered or unexported fields
}

OptionalString represents a string that may or may not have a value. This is similar to using a string pointer to distinguish between an empty string and nil, but it is safer because it does not expose a pointer to any mutable value.

Unlike Value, which can contain a value of any JSON-compatible type, OptionalString either contains a string or nothing. To create an instance with a string value, use NewOptionalString. There is no corresponding method for creating an instance with no value; simply use the empty literal OptionalString{}.

os1 := NewOptionalString("this has a value")
os2 := NewOptionalString("") // this has a value which is an empty string
os2 := OptionalString{} // this does not have a value

This can also be used as a convenient way to construct a string pointer within an expression. For instance, this example causes myStringPointer to point to the string "x":

var myStringPointer *string = NewOptionalString("x").AsPointer()

func NewOptionalString

func NewOptionalString(value string) OptionalString

NewOptionalString constructs an OptionalString that has a string value.

There is no corresponding method for creating an OptionalString with no value; simply use the empty literal OptionalString{}.

func NewOptionalStringFromPointer

func NewOptionalStringFromPointer(valuePointer *string) OptionalString

NewOptionalStringFromPointer constructs an OptionalString from a string pointer. If the pointer is non-nil, then the OptionalString copies its value; otherwise the OptionalString has no value.

func (OptionalString) AsPointer

func (o OptionalString) AsPointer() *string

AsPointer returns the OptionalString's value as a string pointer if it has a value, or nil otherwise.

The string value, if any, is copied rather than returning to a pointer to the internal field.

func (OptionalString) AsValue

func (o OptionalString) AsValue() Value

AsValue converts the OptionalString to a Value, which is either Null() or a string value.

func (OptionalString) Get

func (o OptionalString) Get() (string, bool)

Get is a combination of StringValue and IsDefined. If the OptionalString contains a string value, it returns that value and true; otherwise it returns an empty string and false.

func (OptionalString) IsDefined

func (o OptionalString) IsDefined() bool

IsDefined returns true if the OptionalString contains a string value, or false if it has no value.

func (OptionalString) MarshalJSON

func (o OptionalString) MarshalJSON() ([]byte, error)

MarshalJSON converts the OptionalString to its JSON representation.

The output will be either a JSON string or null. Note that the "omitempty" tag for a struct field will not cause an empty OptionalString field to be omitted; it will be output as null. If you want to completely omit a JSON property when there is no value, it must be a string pointer instead of an OptionalString; use the AsPointer() method to get a pointer.

func (OptionalString) MarshalText

func (o OptionalString) MarshalText() ([]byte, error)

MarshalText implements the encoding.TextMarshaler interface.

Marshaling an empty OptionalString{} will return nil, rather than a zero-length slice.

func (OptionalString) OnlyIfNonEmptyString

func (o OptionalString) OnlyIfNonEmptyString() OptionalString

OnlyIfNonEmptyString returns the same OptionalString unless it contains an empty string (""), in which case it returns an OptionalString that has no value.

func (OptionalString) OrElse

func (o OptionalString) OrElse(valueIfEmpty string) string

OrElse returns the OptionalString's value if it has one, or else the specified fallback value.

func (OptionalString) String

func (o OptionalString) String() string

String is a debugging convenience method that returns a description of the OptionalString. This is either the same as its string value, "[empty]" if it has a string value that is empty, or "[none]" if it has no value.

Since String() is used by methods like fmt.Printf, if you want to use the actual string value of the OptionalString instead of this special representation, you should call StringValue():

s := OptionalString{}
fmt.Printf("it is '%s'", s) // prints "it is '[none]'"
fmt.Printf("it is '%s'", s.StringValue()) // prints "it is ''"

func (OptionalString) StringValue

func (o OptionalString) StringValue() string

StringValue returns the OptionalString's value, or an empty string if it has no value.

func (*OptionalString) UnmarshalJSON

func (o *OptionalString) UnmarshalJSON(data []byte) error

UnmarshalJSON parses an OptionalString from JSON.

The input must be either a JSON string or null.

func (*OptionalString) UnmarshalText

func (o *OptionalString) UnmarshalText(text []byte) error

UnmarshalText implements the encoding.TextUnmarshaler interface.

This allows OptionalString to be used with packages that can parse text content, such as gcfg.

If the byte slice is nil, rather than zero-length, it will set the target value to an empty OptionalString{}. Otherwise, it will set it to a string value.

func (OptionalString) WriteToJSONBuffer

func (o OptionalString) WriteToJSONBuffer(j *jsonstream.JSONBuffer)

WriteToJSONBuffer provides JSON serialization for OptionalString with the jsonstream API.

The JSON output format is identical to what is produced by json.Marshal, but this implementation is more efficient when building output with JSONBuffer. See the jsonstream package for more details.

type Value

type Value struct {
	// contains filtered or unexported fields
}

Value represents any of the data types supported by JSON, all of which can be used for a LaunchDarkly feature flag variation or a custom user attribute.

You cannot compare Value instances with the == operator, because the struct may contain a slice. Value has an Equal method for this purpose; reflect.DeepEqual will also work.

Value instances are immutable when used by code outside of this package.

func ArrayOf

func ArrayOf(items ...Value) Value

ArrayOf creates an array Value from a list of Values.

This requires a slice copy to ensure immutability; otherwise, an existing slice could be passed using the spread operator, and then modified. However, since Value is itself immutable, it does not need to deep-copy each item.

func Bool

func Bool(value bool) Value

Bool creates a boolean Value.

func CopyArbitraryValue

func CopyArbitraryValue(valueAsInterface interface{}) Value

CopyArbitraryValue creates a Value from an arbitrary interface{} value of any type.

If the value is nil, a boolean, an integer, a floating-point number, or a string, it becomes the corresponding JSON primitive value type. If it is a slice of values ([]interface{} or []Value), it is deep-copied to an array value. If it is a map of strings to values (map[string]interface{} or map[string]Value), it is deep-copied to an object value.

If it is a pointer to any of the above types, then it is dereferenced and treated the same as above, unless the pointer is nil, in which case it becomes Null().

For all other types, the value is marshaled to JSON and then converted to the corresponding Value type (unless marshalling returns an error, in which case it becomes Null()). This is somewhat inefficient since it involves parsing the marshaled JSON.

func CopyObject

func CopyObject(m map[string]Value) Value

CopyObject creates a Value by copying an existing map[string]Value.

If you want to copy a map[string]interface{} instead, use CopyArbitraryValue.

func Float64

func Float64(value float64) Value

Float64 creates a numeric Value from a float64.

func Int

func Int(value int) Value

Int creates a numeric Value from an integer.

Note that all numbers are represented internally as the same type (float64), so Int(2) is exactly equal to Float64(2).

func Null

func Null() Value

Null creates a null Value.

func Parse

func Parse(jsonData []byte) Value

Parse returns a Value parsed from a JSON string, or Null if it cannot be parsed.

This is simply a shortcut for calling json.Unmarshal and disregarding errors. It is meant for use in test scenarios where malformed data is not a concern.

func Raw

func Raw(value json.RawMessage) Value

Raw creates an unparsed JSON Value.

func String

func String(value string) Value

String creates a string Value.

func (Value) AsArbitraryValue

func (v Value) AsArbitraryValue() interface{}

AsArbitraryValue returns the value in its simplest Go representation, typed as interface{}.

This is nil for a null value; for primitive types, it is bool, float64, or string (all numbers are represented as float64 because that is Go's default when parsing from JSON).

Arrays and objects are represented as []interface{} and map[string]interface{}. They are deep-copied, which preserves immutability of the Value but may be an expensive operation. To examine array and object values without copying the whole data structure, use getter methods: Count, Keys, GetByIndex, TryGetByIndex, GetByKey, TryGetByKey.

func (Value) AsOptionalString

func (v Value) AsOptionalString() OptionalString

AsOptionalString converts the value to the OptionalString type, which contains either a string value or nothing if the original value was not a string.

func (Value) AsPointer

func (v Value) AsPointer() *Value

AsPointer returns either a pointer to a copy of this Value, or nil if it is a null value.

This may be desirable if you are serializing a struct that contains a Value, and you want that field to be completely omitted if the Value is null; since the "omitempty" tag only works for pointers, you can declare the field as a *Value like so:

type MyJsonStruct struct {
    AnOptionalField *Value `json:"anOptionalField,omitempty"`
}
s := MyJsonStruct{AnOptionalField: someValue.AsPointer()}

func (Value) AsRaw

func (v Value) AsRaw() json.RawMessage

AsRaw returns the value as a json.RawMessage.

If the value was originally created from a RawMessage, it returns the same value. For all other values, it converts the value to its JSON representation and returns that representation.

func (Value) BoolValue

func (v Value) BoolValue() bool

BoolValue returns the Value as a boolean.

If the Value is not a boolean, it returns false.

func (Value) Count

func (v Value) Count() int

Count returns the number of elements in an array or JSON object.

For values of any other type, it returns zero.

func (Value) Enumerate

func (v Value) Enumerate(fn func(index int, key string, value Value) bool)

Enumerate calls a function for each value within a Value.

If the input value is Null(), the function is not called.

If the input value is an array, fn is called for each element, with the element's index in the first parameter, "" in the second, and the element value in the third.

If the input value is an object, fn is called for each key-value pair, with 0 in the first parameter, the key in the second, and the value in the third.

For any other value type, fn is called once for that value.

The return value of fn is true to continue enumerating, false to stop.

func (Value) Equal

func (v Value) Equal(other Value) bool

Equal tests whether this Value is equal to another, in both type and value.

For arrays and objects, this is a deep equality test. This method behaves the same as reflect.DeepEqual, but is slightly more efficient.

func (Value) Float64Value

func (v Value) Float64Value() float64

Float64Value returns the value as a float64.

If the Value is not numeric, it returns zero.

func (Value) GetByIndex

func (v Value) GetByIndex(index int) Value

GetByIndex gets an element of an array by index.

If the value is not an array, or if the index is out of range, it returns Null().

func (Value) GetByKey

func (v Value) GetByKey(name string) Value

GetByKey gets a value from a JSON object by key.

If the value is not an object, or if the key is not found, it returns Null().

func (Value) IntValue

func (v Value) IntValue() int

IntValue returns the value as an int.

If the Value is not numeric, it returns zero. If the value is a number but not an integer, it is rounded toward zero (truncated).

func (Value) IsBool

func (v Value) IsBool() bool

IsBool returns true if the Value is a boolean.

func (Value) IsInt

func (v Value) IsInt() bool

IsInt returns true if the Value is an integer.

JSON does not have separate types for integer and floating-point values; they are both just numbers. IsInt returns true if and only if the actual numeric value has no fractional component, so Int(2).IsInt() and Float64(2.0).IsInt() are both true.

func (Value) IsNull

func (v Value) IsNull() bool

IsNull returns true if the Value is a null.

func (Value) IsNumber

func (v Value) IsNumber() bool

IsNumber returns true if the Value is numeric.

func (Value) IsString

func (v Value) IsString() bool

IsString returns true if the Value is a string.

func (Value) JSONString

func (v Value) JSONString() string

JSONString returns the JSON representation of the value.

func (Value) Keys

func (v Value) Keys() []string

Keys returns the keys of a JSON object as a slice.

The method copies the keys. If the value is not an object, it returns an empty slice.

func (Value) MarshalJSON

func (v Value) MarshalJSON() ([]byte, error)

MarshalJSON converts the Value to its JSON representation.

Note that the "omitempty" tag for a struct field will not cause an empty Value field to be omitted; it will be output as null. If you want to completely omit a JSON property when there is no value, it must be a pointer; use AsPointer().

func (Value) String

func (v Value) String() string

String converts the value to a string representation, equivalent to JSONString().

This is different from StringValue, which returns the actual string for a string value or an empty string for anything else. For instance, Int(2).StringValue() returns "2" and String("x").StringValue() returns "\"x\"", whereas Int(2).AsString() returns "" and String("x").AsString() returns "x".

This method is provided because it is common to use the Stringer interface as a quick way to summarize the contents of a value. The simplest way to do so in this case is to use the JSON representation.

func (Value) StringValue

func (v Value) StringValue() string

StringValue returns the value as a string.

If the value is not a string, it returns an empty string.

This is different from String(), which returns a concise string representation of any value type.

func (Value) Transform

func (v Value) Transform(fn func(index int, key string, value Value) (Value, bool)) Value

Transform applies a transformation function to a Value, returning a new Value.

The behavior is as follows:

If the input value is Null(), the return value is always Null() and the function is not called.

If the input value is an array, fn is called for each element, with the element's index in the first parameter, "" in the second, and the element value in the third. The return values of fn can be either a transformed value and true, or any value and false to remove the element.

ldvalue.ArrayOf(ldvalue.Int(1), ldvalue.Int(2), ldvalue.Int(3)).Build().
    Transform(func(index int, key string, value Value) (Value, bool) {
        if value.IntValue() == 2 {
            return ldvalue.Null(), false
        }
        return ldvalue.Int(value.IntValue() * 10), true
    })
// returns [10, 30]

If the input value is an object, fn is called for each key-value pair, with 0 in the first parameter, the key in the second, and the value in the third. Again, fn can choose to either transform or drop the value.

ldvalue.ObjectBuild().Set("a", ldvalue.Int(1)).Set("b", ldvalue.Int(2)).Set("c", ldvalue.Int(3)).Build().
    Transform(func(index int, key string, value Value) (Value, bool) {
        if key == "b" {
            return ldvalue.Null(), false
        }
        return ldvalue.Int(value.IntValue() * 10), true
    })
// returns {"a": 10, "c": 30}

For any other value type, fn is called once for that value; if it provides a transformed value and true, the transformed value is returned, otherwise Null().

ldvalue.Int(2).Transform(func(index int, key string, value Value) (Value, bool) {
    return ldvalue.Int(value.IntValue() * 10), true
})
// returns numeric value of 20

For array and object values, if the function does not modify or drop any values, the exact same instance is returned without allocating a new slice or map.

func (Value) TryGetByIndex

func (v Value) TryGetByIndex(index int) (Value, bool)

TryGetByIndex gets an element of an array by index, with a second return value of true if successful.

If the value is not an array, or if the index is out of range, it returns (Null(), false).

func (Value) TryGetByKey

func (v Value) TryGetByKey(name string) (Value, bool)

TryGetByKey gets a value from a JSON object by key, with a second return value of true if successful.

If the value is not an object, or if the key is not found, it returns (Null(), false).

func (Value) Type

func (v Value) Type() ValueType

Type returns the ValueType of the Value.

func (*Value) UnmarshalJSON

func (v *Value) UnmarshalJSON(data []byte) error

UnmarshalJSON parses a Value from JSON.

func (Value) WriteToJSONBuffer

func (v Value) WriteToJSONBuffer(j *jsonstream.JSONBuffer)

WriteToJSONBuffer provides JSON serialization for Value with the jsonstream API.

The JSON output format is identical to what is produced by json.Marshal, but this implementation is more efficient when building output with JSONBuffer. See the jsonstream package for more details.

type ValueType

type ValueType int

ValueType indicates which JSON type is contained in a Value.

const (
	// NullType describes a null value. Note that the zero value of ValueType is NullType, so the
	// zero of Value is a null value.
	NullType ValueType = iota
	// BoolType describes a boolean value.
	BoolType ValueType = iota
	// NumberType describes a numeric value. JSON does not have separate types for int and float, but
	// you can convert to either.
	NumberType ValueType = iota
	// StringType describes a string value.
	StringType ValueType = iota
	// ArrayType describes an array value.
	ArrayType ValueType = iota
	// ObjectType describes an object (a.k.a. map).
	ObjectType ValueType = iota
	// RawType describes a json.RawMessage value. This value will not be parsed or interpreted as
	// any other data type, and can be accessed only by calling AsRaw().
	RawType ValueType = iota
)

func (ValueType) String

func (t ValueType) String() string

String returns the name of the value type.

Package Files

Documentation was rendered with GOOS=linux and GOARCH=amd64.

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