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:
└─Caused at <root> (at 0:0-0:0)
 ↑ cannot eval script statement #10 (at 97:2111-97:2166)
 └─Caused at CallExpr (at 97:2111-97:2166)
  ↑ cannot eval block statement #4 (at 89:1910-89:1931)
  ↑ cannot eval declaration value (at 89:1920-89:1931)
  └─Caused at CallExpr (at 89:1920-89:1931)
   ↑ cannot eval block statement #1 (at 54:1189-58:1344)
   ↑ iteration gets interrupted (at 54:1189-58:1344)
   ↑ cannot eval block statement #1 (at 56:1306-57:1334)
   ↑ cannot eval assignment value (at 56:1313-57:1334)
   ↑ cannot eval args[0] (at 56:1320-56:1324)
   ↑ cannot eval index (at 56:1322-56:1323)
   ↑ unresolved reference "j"

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

• The official REPL/CLI allows you to quickly try the language, discover the underlying process of lexing and parsing.

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? Currently, it features an AST tree-walking interpreter, and eventually switch to bytecode interpreter in near future
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	✅