json

README

JSON

A single, platform-agnostic JSON codec for Go that optimizes WebAssembly binary size by using zero reflection. It relies on fmt.Fielder for struct encoding/decoding, which is typically generated by ormc.

Architecture

• Zero Reflection: Uses type switches and fmt.Fielder instead of the reflect package.
• Platform-Agnostic: Identical behavior on all platforms (WASM, Linux, macOS, etc.).
• TinyGo Compatible: Optimized for minimal binary size and memory usage.

Usage

Structs

Structs MUST implement fmt.Fielder to be supported. This is normally handled by generating code with ormc.

package main

import (
    "github.com/tinywasm/fmt"
    "github.com/tinywasm/json"
)

// User implements fmt.Fielder (typically via ormc)
type User struct {
    Name string
}

func (u *User) Schema() []fmt.Field {
    return []fmt.Field{{Name: "Name", Type: fmt.FieldText, JSON: "name"}}
}
func (u *User) Values() []any   { return []any{u.Name} }
func (u *User) Pointers() []any { return []any{&u.Name} }

func main() {
    u := User{Name: "Alice"}

    var out string
    if err := json.Encode(&u, &out); err != nil {
        panic(err)
    }
    // out: {"name":"Alice"}

    var result User
    if err := json.Decode(out, &result); err != nil {
        panic(err)
    }
}

Primitives and Collections

Supports string, int, float64, bool, []byte, []string, []int, []any, and map[string]any.

API

Encode(input any, output any) error

• input: fmt.Fielder, primitives, or known collections.
• output: *[]byte, *string, or io.Writer.

Decode(input any, output any) error

• input: []byte, string, or io.Reader.
• output: fmt.Fielder, *string, *int64, *float64, *bool, *map[string]any, or *[]any.

---

Contributing

License

See LICENSE for details.

Documentation

Index

• func Decode(input any, output any) error
• func Encode(input any, output any) error

Functions

func Decode

func Decode(input any, output any) error

Decode parses JSON into a Go value. input: []byte | string | io.Reader. output: fmt.Fielder | *string | *int64 | *float64 | *bool | *map[string]any | *[]any.

func Encode

func Encode(input any, output any) error

Encode converts a Go value to JSON. input: any supported type (fmt.Fielder, primitives, known collections). output: *[]byte | *string | io.Writer.