README
¶
bari
bari is a JSON parser which works by emitting events for each interesting part of a JSON document.
For example, you will receive an event at the start of an object, for each string value, etc.
Use case
It is intended to be used when you want to parse a big JSON file (think gigabytes plus) and you can't afford the memory needed to load this using the standard JSON parser.
Usage
The parser works by emitting events into a channel. You are responsible for providing the channel, since you might want to buffer it.
Example code:
const data = `{"foo": "bar"}{"bar": true}`
parser := bari.NewParser(strings.NewReader(data))
ch := make(chan bari.Event)
go func() {
parser.Parse(ch)
close(ch)
}()
for ev := range ch {
fmt.Println(ev.Type, ev.Value)
}
The NewParser function takes a io.Reader, so it can read from a file, a network connection, or whatever else.
License
bari is licensed under the MIT, see the LICENSE file.
Documentation
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Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Event ¶
A Event represents a point of interest in a JSON document.
Events are emitted at the start of objects, arrays, and for each values. For example, given the following JSON data:
{"foo": "bar"}
The following events will be emitted in order:
ObjectStartEvent ObjectKeyEvent StringEvent "foo" ObjectValueEvent StringEvent "bar" ObjectEndEvent
type EventType ¶
type EventType uint
EventType is the type of event generated.
const ( // UnknownEvent is an invalid event. UnknownEvent EventType = iota // ObjectStartEvent is emitted at the start of a JSON object. ObjectStartEvent // ObjectKeyEvent is emitted at the start of a key of a JSON object. ObjectKeyEvent // ObjectValueEvent is emitted at the start of a value of a JSON object. ObjectValueEvent // ObjectEndEvent is emitted at the end of a JSON object. ObjectEndEvent // ArrayStartEvent is emitted at the start of a JSON array. ArrayStartEvent // ArrayEndEvent is emitted at the end of a JSON array. ArrayEndEvent // StringEvent is emitted for each string. StringEvent // NumberEvent is emitted for each number. The associated value will be either a float64 or a int64. NumberEvent // BooleanEvent is emitted for each boolean value. BooleanEvent // NullEvent is emitted for each null value. NullEvent // EOFEvent is emitted when parsing has stopped, either because the source input is finished or because there was an error. EOFEvent )
type ParseError ¶
A ParseError is attached to an event in case of a parsing error.
It contains additional information about where the error occurred in the input stream.
func (ParseError) Error ¶
func (p ParseError) Error() string
type Parser ¶
type Parser struct {
// contains filtered or unexported fields
}
A Parser reads and parses JSON documents from an input stream.
func (*Parser) Parse ¶
Parse starts parsing data from the input stream and emit events.
This method parses data until the input stream is empty.
Example (Multi) ¶
package main
import (
"fmt"
"strings"
"github.com/vrischmann/bari"
)
func main() {
const data = `{"foo": "bar"}{"bar": true}`
parser := bari.NewParser(strings.NewReader(data))
ch := make(chan bari.Event)
go func() {
parser.Parse(ch)
close(ch)
}()
for ev := range ch {
fmt.Println(ev.Type, ev.Value)
}
}
Output: ObjectStartEvent <nil> ObjectKeyEvent <nil> StringEvent foo ObjectValueEvent <nil> StringEvent bar ObjectEndEvent <nil> ObjectStartEvent <nil> ObjectKeyEvent <nil> StringEvent bar ObjectValueEvent <nil> BooleanEvent true ObjectEndEvent <nil>
Example (Single) ¶
package main
import (
"fmt"
"strings"
"github.com/vrischmann/bari"
)
func main() {
const data = `{"foo": "bar"}`
parser := bari.NewParser(strings.NewReader(data))
ch := make(chan bari.Event)
go func() {
parser.Parse(ch)
close(ch)
}()
for ev := range ch {
fmt.Println(ev.Type, ev.Value)
}
}
Output: ObjectStartEvent <nil> ObjectKeyEvent <nil> StringEvent foo ObjectValueEvent <nil> StringEvent bar ObjectEndEvent <nil>
Source Files