Import std.data.json

JsonReader

std.data.json

class

Public Class JsonReader

Reads a JSON document's tokens, one each time Next is called, from text or from UTF-8 bytes, which it copies: an object's as BEGIN_OBJECT, then each KEY and its value, then END_OBJECT, and an array's as BEGIN_ARRAY, its values, and END_ARRAY. A byte order mark before the JSON is left out. It reads arrays and objects nested in each other up to depth deep.

Examples

Local reader = JsonReader(r"[1, 2, 3]")
Local sum: Int64 = 0
Local token = Try reader.Next()
While token != JsonToken.END
    If token == JsonToken.INT Then sum += reader.GetInt64()
    token = Try reader.Next()
End While

Expect(sum == 6)

std/data/json.fb, line 79

@PanicsAtCaller Public New(text: String, depth: Int = DEPTH) constructor #

A JsonReader of text, which nests up to depth deep. Panics unless depth is 1 or more.
@PanicsAtCaller Public New(bytes: UInt8[], depth: Int = DEPTH) constructor #

A JsonReader of bytes, UTF-8 JSON, which nests up to depth deep.
Public Method Next(): JsonToken Throws ParseError method #

The next token, END once the document's value is done, and END again after. Throws a ParseError where the text stops being JSON, with its line and column, each from 1: of SYNTAX for what can't be there, UNEXPECTED_END for text that ends early, and OUT_OF_RANGE for a number past a Double's range, or arrays and objects nested too deep.
@PanicsAtCaller Public Property Token: JsonToken property #

The token Next gave last.
Public Property Depth: Int property #

How many arrays and objects are open after the token: 0 for a document's lone value, 1 after its BEGIN_ARRAY or BEGIN_OBJECT and for each value in it, and 0 again after its END_ARRAY or END_OBJECT.
Public Property Line: Int property #

The line, from 1, where the token starts.
Public Property Column: Int property #

The column, from 1, in code points, where the token starts.
@PanicsAtCaller Public Method GetString(): String method #

A KEY's or a STRING's text. Panics for another token.
@PanicsAtCaller Public Method GetInt64(): Int64 method #

An INT's integer. Panics for another token.
@PanicsAtCaller Public Method GetUInt64(): UInt64 method #

A UINT's integer, or an INT's that isn't negative. Panics for another token.
@PanicsAtCaller Public Method GetDouble(): Double method #

A number as a Double: a DOUBLE's, or the nearest to an INT's or UINT's. Panics for another token.
@PanicsAtCaller Public Method GetBool(): Bool method #

A BOOL token's value. Panics for another token.
Public Method Skip() Throws ParseError method #

Reads past the value whose first token Next gave last, to its END_OBJECT or END_ARRAY when it's an object or an array. Throws as Next does.

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