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Overview

Edge Python is a Rust based bytecode interpreter weighing less than 70 KB, implementing adaptive instruction specialization to achieve performance approaching compiled native code.

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Concepts

  • Offset-based token representation: Tokens store (start, end, kind) as indices into source buffer, avoiding string copies and maintaining O(n) lexing.
  • Monolithic SSA bytecode emission: Single-pass codegen without AST. Variables versioned per assignment, phi-joined at control flow boundaries.
  • Inline opcode specialization: Generic bytecode replaced at runtime with type-specialized variants once operand types stabilize, enabling branch-free dispatch.
  • Template-driven code instantiation: Precompiled native code patches applied when hotspots detected, substituting runtime values without code generation overhead.
  • Adaptive bytecode metamorphosis: Instruction stream continuously rewritten based on execution profiles, allowing bytecode to evolve across runs.

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Compilation Pipeline

source -> offset-indexed tokens -> monolithic SSA bytecode -> [inline caching + type inference] -> template instantiation -> native execution
Γcompiler=Tpatch∘Sspecialize∘Eemit∘Pparse\Gamma_{compiler} = \mathcal{T}_{patch} \circ \mathcal{S}_{specialize} \circ \mathcal{E}_{emit} \circ \mathcal{P}_{parse}

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Architecture

├── Cargo.toml
├── README.md
├── src
│   ├── lib.rs
│   ├── main.rs
│   └── modules
│       ├── compiler.rs
│       ├── lexer.rs
│       ├── opcodes.rs
│       ├── parser.rs
│       └── vm.rs
└── tests

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Capabilities

typeskeywordsbuiltinlexical
intcontrol flowi/oidentation
floatfunctionstype conversionfstring
strclassesinspectionwalrus op
booloperatorsiterationcomments
listvariablesaggregationdocstrings
dictliteralsmathcomplex numbers
tuplealiasdebuggingunderscore
settry/exceptionreflection-
nonecontextadvances-
-async/await--
-module--
-pattern matching--
-type aliases--
-import--

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References

  • Structure and performance of efficient bytecode interpreters: dl.acm.org/doi/10.1145/1328195.1328197
  • Adaptive instruction specialization in interpreters: 2211.07633
  • Copy-and-patch JIT compilation: dl.acm.org/doi/10.1145/3485513
  • Simple and efficient construction of SSA form: dl.acm.org/doi/10.1007/978-3-642-37051-9_6