upgrade risor engine to v2

README.md

@@ -20,7 +20,7 @@ go-polyscript democratizes different scripting engines by abstracting the loadin
 
 ## Engines Implemented
 
-- **Risor**: A Python-like scripting language designed for embedding in Go applications
+- **Risor**: A fast scripting language designed for embedding in Go applications
 - **Starlark**: Google's deterministic configuration language (used in Bazel, and others)
 - **Extism**: Pure Go runtime and plugin system for executing WASM
 
@@ -51,15 +51,15 @@ func main() {
 
 	script := `
 		// The ctx object from the Go inputData map
-		name := ctx.get("name")
+		let name = ctx.get("name")
 
-		p := "."
-		if ctx.get("excited") {
+		let p = "."
+		if (ctx.get("excited")) {
 			p = "!"
 		}
-		
-		message := "Hello, " + name + p
-		
+
+		let message = "Hello, " + name + p
+
 		// Return a map with our result
 		{
 			"greeting": message,

engines/README.md

@@ -69,8 +69,8 @@ data := map[string]any{
 }
 
 // Risor script access
-name := ctx["name"]           // "World"
-debug := ctx["config"]["debug"] // true
+let name = ctx["name"]           // "World"
+let debug = ctx["config"]["debug"] // true
 ```
 
 ### Starlark Engine: `ctx` Context Wrapper

engines/benchmarks/README.md

@@ -4,20 +4,29 @@ This directory contains benchmarking tools and historical benchmark records for
 
 ## Performance Optimization Patterns
 
+The numbers below are from `BenchmarkEvaluationPatterns`, `BenchmarkDataProviders`, and `BenchmarkEngineComparison` on an Apple M5 Max (darwin/arm64) using the trivial greeting script in [`benchmark_test.go`](./benchmark_test.go). Your absolute numbers will differ, but the relative deltas are the signal. See [`results/latest.txt`](./results/latest.txt) for the authoritative most-recent run.
+
 ### 1. Compile Once, Run Many Times
 
-The benchmarks show that pre-loading and parsing scripts is ~35% faster than recompiling for each execution:
+Reusing a compiled evaluator is **~2.25x faster** than recompiling the script on every call, and allocates **~44% less memory** / **~65% fewer objects**:
+
+| Pattern              |   ns/op | B/op    | allocs/op |
+|----------------------|--------:|--------:|----------:|
+| SingleExecution      |  48,323 | 120,751 |       713 |
+| CompileOnceRunMany   |  21,435 |  67,682 |       252 |
 
 ```go
 // COMPILATION PHASE (expensive, do once)
 evaluator, err := polyscript.FromRisorString(script, options...)
 
-// EXECUTION PHASE (inexpensive, do many times)
+// EXECUTION PHASE (cheap, do many times)
 result1, _ := evaluator.Eval(ctx1)
 result2, _ := evaluator.Eval(ctx2)
 result3, _ := evaluator.Eval(ctx3)
 ```
 
+The single-execution path pays parser + compiler + globals-validation cost per call. If you're running the same script more than once, create the evaluator once and hold onto it.
+
 ### 2. Data Preparation Separation
 
 For distributed architectures, separate data preparation from evaluation to improve system architecture design:
@@ -32,19 +41,32 @@ result, _ := evaluator.Eval(enrichedCtx)
 
 ### 3. Provider Performance Comparison
 
-The benchmarks show performance differences between `data.Provider` implementations:
+On `BenchmarkDataProviders` (Risor engine), all three `data.Provider` implementations land within ~3.5% of each other — raw provider throughput is **not** a meaningful selection criterion. Choose based on data flow shape, not speed:
 
-- **StaticProvider**: Fastest overall (~5-10% faster than other providers) - use when input data is static
-- **ContextProvider**: Needed for request-specific data that varies per execution
-- **CompositeProvider**: Small overhead but enables both static configuration and dynamic request data
+| Provider           |   ns/op | B/op   | allocs/op |
+|--------------------|--------:|-------:|----------:|
+| StaticProvider     |  22,354 | 67,382 |       251 |
+| ContextProvider    |  21,604 | 66,283 |       243 |
+| CompositeProvider  |  21,966 | 67,382 |       253 |
+
+- **StaticProvider** — data is fixed at evaluator creation (config, constants, feature flags).
+- **ContextProvider** — data varies per-call; carried via `context.Context`.
+- **CompositeProvider** — the backing store for the 2-step pattern (static config + dynamic per-request data).
 
 ### 4. Script Engine Performance Characteristics
 
-Performance characteristics vary significantly by implementation:
+On the same greeting script, `BenchmarkEngineComparison` shows Starlark is **~5.4x faster** than Risor for raw per-call overhead on small scripts, with **~8.6x less memory** and **~3.5x fewer allocations**:
+
+| Engine    |   ns/op | B/op   | allocs/op |
+|-----------|--------:|-------:|----------:|
+| Risor     |  22,121 | 67,382 |       251 |
+| Starlark  |   4,119 |  7,806 |        71 |
+
+Caveats: the benchmark script is trivial (two variables + a map literal), so this measures per-call VM setup more than real work. Interpret by use case, not by the numbers alone:
 
-- **Risor**: Generally fastest for general-purpose scripting with good Go interoperability
-- **Starlark**: Optimized for configuration processing with Python-like syntax
-- **Extism/WASM**: Best for security isolation with pre-compiled modules
+- **Starlark** — lowest per-call overhead; deterministic, Python-like, designed for configuration. Limited language capabilities (no loops as iteration, no stdlib I/O). Best when you have many fast, simple evaluations.
+- **Risor** — richer stdlib (`math`, `rand`, `regexp` in v2), TypeScript-aligned syntax (arrow functions, `try/catch`, optional chaining), friendlier for general scripting and data munging. Pays a higher fixed per-call cost.
+- **Extism/WASM** — language-agnostic isolation via pre-compiled modules. Choose when you need to run untrusted code, support multiple languages, or get true sandbox isolation.
 
 ## Running Benchmarks
 

engines/benchmarks/benchmark_test.go

@@ -43,9 +43,9 @@ var quietHandler = slog.NewJSONHandler(io.Discard, &slog.HandlerOptions{Level: s
 func BenchmarkEvaluationPatterns(b *testing.B) {
 	// Simple script for benchmarking
 	scriptContent := `
-		name := ctx["name"]
-		message := "Hello, " + name + "!"
-		
+		let name = ctx["name"]
+		let message = "Hello, " + name + "!"
+
 		{
 			"greeting": message,
 			"length": len(message)
@@ -110,9 +110,9 @@ func BenchmarkEvaluationPatterns(b *testing.B) {
 func BenchmarkDataProviders(b *testing.B) {
 	// Simple script for benchmarking
 	scriptContent := `
-		name := ctx["name"]
-		message := "Hello, " + name + "!"
-		
+		let name = ctx["name"]
+		let message = "Hello, " + name + "!"
+
 		{
 			"greeting": message,
 			"length": len(message)
@@ -168,8 +168,8 @@ func BenchmarkDataProviders(b *testing.B) {
 		// For CompositeProvider use case, we can prepare the context separately
 		// We access the name directly from the context
 		compositeScript := `
-			name := ctx["name"]
-			message := "Hello, " + name + "!"
+			let name = ctx["name"]
+			let message = "Hello, " + name + "!"
 			{
 				"greeting": message,
 				"length": len(message)
@@ -214,9 +214,9 @@ func BenchmarkEngineComparison(b *testing.B) {
 
 	// Risor script
 	risorScript := `
-		name := ctx["name"]
-		message := "Hello, " + name + "!"
-		
+		let name = ctx["name"]
+		let message = "Hello, " + name + "!"
+
 		{
 			"greeting": message,
 			"length": len(message)

engines/benchmarks/results/benchmark_2026-04-11_15-27-36.json

@@ -0,0 +1,45 @@
+{"Time":"2026-04-11T15:27:47.928167-04:00","Action":"start","Package":"github.com/robbyt/go-polyscript/engines/benchmarks"}
+{"Time":"2026-04-11T15:27:47.93643-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Output":"goos: darwin\n"}
+{"Time":"2026-04-11T15:27:47.93651-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Output":"goarch: arm64\n"}
+{"Time":"2026-04-11T15:27:47.936515-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Output":"pkg: github.com/robbyt/go-polyscript/engines/benchmarks\n"}
+{"Time":"2026-04-11T15:27:47.936522-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Output":"cpu: Apple M5 Max\n"}
+{"Time":"2026-04-11T15:27:47.936529-04:00","Action":"run","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkEvaluationPatterns"}
+{"Time":"2026-04-11T15:27:47.936533-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkEvaluationPatterns","Output":"=== RUN   BenchmarkEvaluationPatterns\n"}
+{"Time":"2026-04-11T15:27:47.936537-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkEvaluationPatterns","Output":"BenchmarkEvaluationPatterns\n"}
+{"Time":"2026-04-11T15:27:47.936661-04:00","Action":"run","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkEvaluationPatterns/SingleExecution"}
+{"Time":"2026-04-11T15:27:47.936678-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkEvaluationPatterns/SingleExecution","Output":"=== RUN   BenchmarkEvaluationPatterns/SingleExecution\n"}
+{"Time":"2026-04-11T15:27:47.936684-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkEvaluationPatterns/SingleExecution","Output":"BenchmarkEvaluationPatterns/SingleExecution\n"}
+{"Time":"2026-04-11T15:27:49.62027-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkEvaluationPatterns/SingleExecution","Output":"BenchmarkEvaluationPatterns/SingleExecution-18         \t   24763\t     47300 ns/op\t  120751 B/op\t     713 allocs/op\n"}
+{"Time":"2026-04-11T15:27:49.620349-04:00","Action":"run","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkEvaluationPatterns/CompileOnceRunMany"}
+{"Time":"2026-04-11T15:27:49.620367-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkEvaluationPatterns/CompileOnceRunMany","Output":"=== RUN   BenchmarkEvaluationPatterns/CompileOnceRunMany\n"}
+{"Time":"2026-04-11T15:27:49.620371-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkEvaluationPatterns/CompileOnceRunMany","Output":"BenchmarkEvaluationPatterns/CompileOnceRunMany\n"}
+{"Time":"2026-04-11T15:27:51.18472-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkEvaluationPatterns/CompileOnceRunMany","Output":"BenchmarkEvaluationPatterns/CompileOnceRunMany-18      \t   59836\t     21618 ns/op\t   67682 B/op\t     252 allocs/op\n"}
+{"Time":"2026-04-11T15:27:51.184786-04:00","Action":"run","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkDataProviders"}
+{"Time":"2026-04-11T15:27:51.1848-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkDataProviders","Output":"=== RUN   BenchmarkDataProviders\n"}
+{"Time":"2026-04-11T15:27:51.184817-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkDataProviders","Output":"BenchmarkDataProviders\n"}
+{"Time":"2026-04-11T15:27:51.25881-04:00","Action":"run","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkDataProviders/StaticProvider"}
+{"Time":"2026-04-11T15:27:51.258855-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkDataProviders/StaticProvider","Output":"=== RUN   BenchmarkDataProviders/StaticProvider\n"}
+{"Time":"2026-04-11T15:27:51.258882-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkDataProviders/StaticProvider","Output":"BenchmarkDataProviders/StaticProvider\n"}
+{"Time":"2026-04-11T15:27:52.772376-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkDataProviders/StaticProvider","Output":"BenchmarkDataProviders/StaticProvider-18               \t   57315\t     21799 ns/op\t   67382 B/op\t     251 allocs/op\n"}
+{"Time":"2026-04-11T15:27:52.772435-04:00","Action":"run","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkDataProviders/ContextProvider"}
+{"Time":"2026-04-11T15:27:52.77244-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkDataProviders/ContextProvider","Output":"=== RUN   BenchmarkDataProviders/ContextProvider\n"}
+{"Time":"2026-04-11T15:27:52.772445-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkDataProviders/ContextProvider","Output":"BenchmarkDataProviders/ContextProvider\n"}
+{"Time":"2026-04-11T15:27:54.349074-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkDataProviders/ContextProvider","Output":"BenchmarkDataProviders/ContextProvider-18              \t   59300\t     21286 ns/op\t   66278 B/op\t     243 allocs/op\n"}
+{"Time":"2026-04-11T15:27:54.349117-04:00","Action":"run","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkDataProviders/CompositeProvider"}
+{"Time":"2026-04-11T15:27:54.349122-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkDataProviders/CompositeProvider","Output":"=== RUN   BenchmarkDataProviders/CompositeProvider\n"}
+{"Time":"2026-04-11T15:27:54.349126-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkDataProviders/CompositeProvider","Output":"BenchmarkDataProviders/CompositeProvider\n"}
+{"Time":"2026-04-11T15:27:55.948097-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkDataProviders/CompositeProvider","Output":"BenchmarkDataProviders/CompositeProvider-18            \t   58492\t     21914 ns/op\t   67382 B/op\t     253 allocs/op\n"}
+{"Time":"2026-04-11T15:27:55.948161-04:00","Action":"run","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkEngineComparison"}
+{"Time":"2026-04-11T15:27:55.948169-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkEngineComparison","Output":"=== RUN   BenchmarkEngineComparison\n"}
+{"Time":"2026-04-11T15:27:55.948198-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkEngineComparison","Output":"BenchmarkEngineComparison\n"}
+{"Time":"2026-04-11T15:27:56.028991-04:00","Action":"run","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkEngineComparison/RisorEngine"}
+{"Time":"2026-04-11T15:27:56.029037-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkEngineComparison/RisorEngine","Output":"=== RUN   BenchmarkEngineComparison/RisorEngine\n"}
+{"Time":"2026-04-11T15:27:56.029043-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkEngineComparison/RisorEngine","Output":"BenchmarkEngineComparison/RisorEngine\n"}
+{"Time":"2026-04-11T15:27:57.521117-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkEngineComparison/RisorEngine","Output":"BenchmarkEngineComparison/RisorEngine-18               \t   55202\t     22296 ns/op\t   67382 B/op\t     251 allocs/op\n"}
+{"Time":"2026-04-11T15:27:57.521171-04:00","Action":"run","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkEngineComparison/StarlarkEngine"}
+{"Time":"2026-04-11T15:27:57.521237-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkEngineComparison/StarlarkEngine","Output":"=== RUN   BenchmarkEngineComparison/StarlarkEngine\n"}
+{"Time":"2026-04-11T15:27:57.521247-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkEngineComparison/StarlarkEngine","Output":"BenchmarkEngineComparison/StarlarkEngine\n"}
+{"Time":"2026-04-11T15:27:59.194638-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Test":"BenchmarkEngineComparison/StarlarkEngine","Output":"BenchmarkEngineComparison/StarlarkEngine-18            \t  351516\t      4261 ns/op\t    7808 B/op\t      71 allocs/op\n"}
+{"Time":"2026-04-11T15:27:59.194849-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Output":"PASS\n"}
+{"Time":"2026-04-11T15:27:59.225755-04:00","Action":"output","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Output":"ok  \tgithub.com/robbyt/go-polyscript/engines/benchmarks\t11.297s\n"}
+{"Time":"2026-04-11T15:27:59.225792-04:00","Action":"pass","Package":"github.com/robbyt/go-polyscript/engines/benchmarks","Elapsed":11.298}

engines/benchmarks/results/benchmark_2026-04-11_15-27-36.txt

@@ -0,0 +1,13 @@
+goos: darwin
+goarch: arm64
+pkg: github.com/robbyt/go-polyscript/engines/benchmarks
+cpu: Apple M5 Max
+BenchmarkEvaluationPatterns/SingleExecution-18         	   24620	     48323 ns/op	  120751 B/op	     713 allocs/op
+BenchmarkEvaluationPatterns/CompileOnceRunMany-18      	   59073	     21435 ns/op	   67682 B/op	     252 allocs/op
+BenchmarkDataProviders/StaticProvider-18               	   56025	     22354 ns/op	   67382 B/op	     251 allocs/op
+BenchmarkDataProviders/ContextProvider-18              	   59650	     21604 ns/op	   66283 B/op	     243 allocs/op
+BenchmarkDataProviders/CompositeProvider-18            	   58615	     21966 ns/op	   67382 B/op	     253 allocs/op
+BenchmarkEngineComparison/RisorEngine-18               	   55406	     22121 ns/op	   67382 B/op	     251 allocs/op
+BenchmarkEngineComparison/StarlarkEngine-18            	  338401	      4119 ns/op	    7806 B/op	      71 allocs/op
+PASS
+ok  	github.com/robbyt/go-polyscript/engines/benchmarks	11.202s

engines/benchmarks/results/latest.txt

@@ -1 +1 @@
-benchmark_2025-11-08_16-24-33.txt
+benchmark_2026-04-11_15-27-36.txt