[Library] cJson.ahk for AHKv2 (version 2.0.0)

[geek]

cJson.ahk

The first and only AutoHotkey JSON library to use embedded compiled C for high performance.


Compatibility

This library is compatible with AutoHotkey v2.0 U64 and U32.


Using cJson

Converting an AHK Object to JSON:

Code: Select all

#Include <JSON>

; Create an object with every supported data type
obj := ["abc", 123, {true: true, false: false, null: ""}, [JSON.true, JSON.false, JSON.null]]

; Convert to JSON
MsgBox JSON.Dump(obj) ; Expect: ["abc", 123, {"false": 0, "null": "", "true": 1}, [true, false, null]]

Converting JSON to an AHK Object:

Code: Select all

#Include <JSON>

; Create some JSON
str := '["abc", 123, {"true": 1, "false": 0, "null": ""}, [true, false, null]]'
obj := JSON.Load(str)

; Convert using default settings
MsgBox (
	str "`n"
	"`n"
	"obj[1]: " obj[1] " (expect abc)`n"
	"obj[2]: " obj[2] " (expect 123)`n"
	"`n"
	"obj[3]['true']: " obj[3]['true'] " (expect 1)`n"
	"obj[3]['false']: " obj[3]['false'] " (expect 0)`n"
	"obj[3]['null']: " obj[3]['null'] " (expect blank)`n"
	"`n"
	"obj[4][1]: " obj[4][1] " (expect 1)`n"
	"obj[4][2]: " obj[4][2] " (expect 0)`n"
	"obj[4][3]: " obj[4][3] " (expect blank)`n"
)

; Convert Bool and Null values to objects instead of native types
JSON.BoolsAsInts := false
JSON.NullsAsStrings := false
obj := JSON.Load(str)
MsgBox obj[4][1] == JSON.True ; 1
MsgBox obj[4][2] == JSON.False ; 1
MsgBox obj[4][3] == JSON.Null ; 1

Notes

Data Types

AutoHotkey does not provide types that uniquely identify all the possible values
that may be encoded or decoded. To work around this problem, cJson provides
magic objects that give you greater control over how things are encoded. By
default, cJson will behave according to the following table:

Code: Select all

| Value         | Encodes as            | Decodes as            |
|---------------|---------------------- |---------------------- |
| `true`        | `1`                   | `1` *                 |
| `false`       | `0`                   | `0` *                 |
| `null`        | N/A                   | `""` *                |
| `0.1` †       | `0.10000000000000001` | `0.10000000000000001` |
| `JSON.True`   | `true`                | N/A                   |
| `JSON.False`  | `false`               | N/A                   |
| `JSON.Null`   | `null`                | N/A                   |

* To avoid type data loss when decoding true and false, the class property JSON.BoolsAsInts can be set := false. Once set, boolean true and false will decode to JSON.True and JSON.False respectively. Similarly, for Nulls JSON.NullsAsStrings can be set := false. Once set, null will decode to JSON.Null.

† In AutoHotkey, numbers with a fractional component are represented internally as double-precision floating point values. Floating point values are effectively a base-2 fraction, and just like how not all base-10 fractions can convert cleanly into base-10 decimals (see: 2/3 to 0.333...) not all base-2 fractions can convert cleanly into base-10 decimals. This results in situations where you write a simple base-10 decimal of 0.1, but it shows as a really ugly 0.10000000000000001 when your code displays it. Although AutoHotkey v1 used a bunch of tricks to hide this imprecision, such as by rounding aggressively to six places and by storing decimal values written in your code as strings until used for calculation, AutoHotkey v2 does not try to hide this. Similarly, cJson does not either.

Roadmap

• Allow changing the indent style for pretty print mode.
• Export differently packaged versions of the library (e.g. JSON, cJson, and Jxon) for better compatibility.
• Add methods to extract values from the JSON blob without loading the full object into memory.
• Add methods to replace values in the JSON blob without fully parsing and reformatting the blob.
• Integrate with a future MCLib-hosted COM-based hash-table style object for even greater performance.

---

Download cJson.ahk

[geek]

This library is not related to the cJson library by Mono919 found here viewtopic.php?f=83&t=113464. I do not endorse that library, neither is that library necessarily an endorsement of this one.

I do wish they had not stepped on the name I had already picked years earlier, but this is the situation we are in.

[geek]

This library (both the AHKv1 and AHKv2 versions) is available within the AutoHotkey.wiki code runner sandbox, so you can try it before downloading. Check out the cJson page on the wiki here: https://autohotkey.wiki/libraries:json:cjson

[Qriist]

Well done! Thank you for implementing NullsAsStrings! <3

[william_ahk]

Finally!!!

[oldbrother]

Thanks a lot!ii

[MysticDude]

Woah, this is awesome. Thanks!

I've been using jsongo from GroggyOtter, measured cJson to be over 12 times faster on some data I am working with