Polymorphic AST eval

Interface / virtual-method dispatch through nine AST node types under heavy traversal load.

Runtime Compile time

Runtime · median per inner-loop window

median of 7 runs

Native Gocompiled

2.06 ms0.06×

Pipitbytecode VM

31.9 msbaseline

CPython 3.14bytecode VM

51.9 ms1.63×

PyPy 7.3tracing JIT

86.2 ms2.70×

Ttengobytecode VM

119 ms3.73×

Sscriggobytecode VM

unsupported in scriggo

n/a

Mmvmbytecode VM

240 ms7.52×

YyaegiAST walker

1.10 s34.5×

Full statistics

Runner	N	Compile	Runtime	P95	Stddev	RSS	vs pipit	Status
Native Gocompiled	7	108 ms	2.06 ms	2.07 ms	7.40 µs	1.62 GiB	0.06×	OK
Pipitbytecode VM	7	1.92 ms	31.9 ms	33.8 ms	741 µs	591 MiB	1.00×	OK
CPython 3.14bytecode VM	7	742 µs	51.9 ms	52.7 ms	553 µs	n/a	1.63×	OK
PyPy 7.3tracing JIT	7	555 µs	86.2 ms	100 ms	6.82 ms	n/a	2.70×	OK
tengobytecode VM	7	344 µs	119 ms	125 ms	3.01 ms	1.69 GiB	3.73×	OK
scriggobytecode VM	0	n/a	n/a	n/a	n/a	n/a	n/a	unsupported
mvmbytecode VM	7	620 µs	240 ms	256 ms	6.40 ms	1.69 GiB	7.52×	OK
yaegiAST walker	7	654 µs	1.10 s	1.13 s	21.8 ms	1.69 GiB	34.5×	OK

Workload & symmetry rules

Workload

Build an expression tree from a deterministic LCG that mixes nine node kinds (Add, Sub, Mul, Mod, Const, Var, IfPos, Min, Max), each as a distinct struct/class satisfying a single-method contract: Node.Eval(env) uint32. Walk the tree repeatedly and accumulate the fold.

Symmetry rules

Real interface dispatch in Go (Eval(env) method on a Node interface) and class-based duck typing in Python.
No tagged-union switch shortcut; every Eval call must go through dynamic dispatch.

Why this benchmark exists

A direct measurement of the interpreter's interface / virtual-method dispatch path. Bench 05 is similar but uses a tagged-int switch; this one forces real virtual dispatch.

Source code

pipit / Go
pipit_source.go
native Go
native_main.go
CPython / PyPy
cpython.py
tengo
script.tengo