Rice

Rice is a minimal embeddable scripting language for Go applications.

• Dynamic-typing
• Functional programming support
• Lightweight standard library
• Single-threaded execution
• Built-in profiler
• Verbose error-reporting

⚠️ Rice is under development and subject to changes without prior notice; there is currently no backward compatibility. Try at your own risk.

Playground

Try Rice directly in your browser: https://rice-playground.vercel.app/

LLM prompt

An official LLM prompt is available to be attached to LLM conversations. It provides full syntax and standard library guide to the LLM models. Battle-tested on Claude, Gemini, GPT, DeepSeek, MiMo models.

Download here llm-prompt.md

Language Tour

1. Data types

list.new().append(
    # Primitives
    123,         # integer
    123.456,     # float
    true,        # bool
    "Xin chao!", # string
    null,        # null
    
    # Composites
    list.new(),  # list
    set.new(),   # set
    map.new(),   # map
    {            # map (as an Object)
      name: "Vi",
      "age": 9
    },
    func() {     # function
       return
    }
)

2. Functional programming

strings.join("\n", ...map.new()
    .put(
        "Fruit 1", "Apple",
        "Fruit 2", "Banana",
        "Fruit 3", "Cherry",
        "Fruit 4", "Durian",
        "Fruit 5", "Elderberry"
    )
    .filter(func(entry){
        typeof(entry[1]) == "String" && entry[1].toLower().include("a")
    })
    .entries()
    .sort(func(a,b){a[1]<b[1]})
    .map(func(entry){entry[0]+": "+entry[1]}))

3. First-class expression

const yes = if typeof(true) == "Bool" {
    const res = "Yes";

    res # The last expression is the code-block's value
} else {
    "No"
};

Guides

The language guides cover everything from basic syntax to embedding Rice in Go — whether you want to learn the language or integrate Rice.

Benchmarks

Run on Intel® Core™ i3-10105 @ 3.70 GHz, Go 1.24, Windows 11. Benchmarks executed via exec/bench_test.go with go test -bench=. -benchmem.

Benchmark	Ops/sec	ns/op	B/op	allocs/op	Description
Fibonacci(20)	16	60,194,989	28 MB	395,701	Recursive function call overhead — fib(20)
ForLoop(10000)	88	11,334,590	1.8 MB	149,627	Tight C-style for-loop, 0..9999 sum
Arithmetic(5000)	140	7,166,243	1.3 MB	117,771	Integer arithmetic in a loop (add/mul/div)
RecursionDeep(15)	137	7,292,346	2.5 MB	34,993	Moderately deep recursion — fib(15)
StringConcat(1000)	832	1,202,009	704 KB	14,525	String concatenation loop, 1000 iterations
Functional	14,946	66,921	18 KB	312	List filter + map on 5-element dataset

Tools

1. Error stacktrace

RuntimeError: unresolved reference "missing" (2:22)
 | 		const f = func() { missing };
 | .....................^
└─ at <root> (4:63-5:68)
    while cannot eval script statement #3
└─ at func() (4:63-5:68)
    while func()
└─ at func() (3:54-3:58)
    while cannot eval declaration value
    while unresolved reference "missing"

RuntimeError.Bind(source) fills line/column and a caret snippet from the script text. Frames() and Unwrap() expose the same chain for host code. Single-step the VM with Interpreter.Debug() / Step() / Position() when built with -tags rice_debug.

2. Profiling

[Root] taken 461.492ms (100.00%) at 0:0
  └─[Call] taken 284.887ms (61.73%) at 106:3869
    └─[Block] taken 284.887ms (100.00%) at 8:371
      └─[ForLoop] taken 284.887ms (100.00%) at 12:458
        └─[Block] (x10000) taken 270.419ms (94.92%) at 12:490
          └─[Call] (x10000) taken 227.73ms (84.21%) at 13:516
            └─[Call] (x10000) taken 219.667ms (96.46%) at 13:516
              └─[Call] (x10000) taken 203.129ms (92.47%) at 13:516
                └─[Call] (x10000) taken 172.021ms (84.69%) at 13:516
                  └─[Call] (x10000) taken 141.024ms (81.98%) at 13:516
                    └─[Call] (x10000) taken 54.31ms (38.51%) at 13:516
                      └─[Call] (x10000) taken 14.978ms (27.58%) at 13:516
                    └─[Call] (x10000) taken 26.054ms (18.48%) at 15:592
                └─[Call] (x10000) taken 24.048ms (11.84%) at 17:699
          └─[Call] (x10000) taken 26.863ms (9.93%) at 21:818
      └─[Call] taken 0s (0.00%) at 9:394
      └─[Call] taken 0s (0.00%) at 10:434
...

3. REPL/CLI

go run ./cmd/rice run script.rice
go run ./cmd/rice run script.ricebc
go run ./cmd/rice repl [--debug]
go run ./cmd/rice build -o out.ricebc script.rice
go run ./cmd/rice disasm script.rice
go run ./cmd/rice check script.rice

run compiles a .rice script or loads a .ricebc module, then executes it. repl keeps globals across lines (--debug prints tokens, checksum, and AST). build writes a portable module; disasm prints the listing; check compiles and exits 0 or 1.

FAQ

1. What is the file extension of Rice script? Simply, .rice
2. Does Rice support resource constraints? Time-bound limit is supported per user-defined function, native function and the overall script (via Go context)
3. What kind of interpreting Rice performs? A stack bytecode VM. The compiler emits a portable RICE module (see docs/bytecode.md).
4. How can I extend Rice with custom Go functions? Rice is designed to be highly extensible. You can expose your own Go functions and types to the environment

Roadmap

Features	Stage
Base	✅
REPL/CLI	✅
Profiler	✅
Bytecode VM	✅
LSP	❌
Playground	✅