49 lines
1.4 KiB
Markdown
49 lines
1.4 KiB
Markdown
---
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layout: page
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published: true
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noToc: false
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noComments: false
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noDate: false
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title: Bytecode Format (Overview)
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subtitle: Reference for the bytecode format (split out from internals for convenience).
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description: Reference for the bytecode format (split out from internals for convenience).
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permalink: /documentation/bytecode-format/
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lang: en
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tags:
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- bytecode
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- convenience
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- format
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- internals
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- out
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- reference
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- split
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---
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This document summarizes the Fun bytecode format. For deep VM details, see [internals](./internals/).
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## Goals
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- Compact representation for fast loading and dispatch
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- Stable header with room for versioning
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## File layout (typical)
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1. Header
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- Magic number / signature
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- Format version
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- Flags (endianness, feature bits)
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- Offsets to sections
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2. Constants table
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- Literals: numbers, strings, compound constants
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3. Code section
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- Functions/procedures with instruction streams
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- Line/column mapping (optional for debugging)
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4. Auxiliary tables
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- Imports/exports, names, debug info (optional)
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## Instructions
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- Fixed-size or small-variant opcodes grouped by domain (math, logic, stack, call, control flow, etc.).
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- Operands encoded inline following the opcode (width varies by instruction).
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## Versioning and compatibility
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- The header's version field allows the VM to refuse or translate older/newer formats.
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- Keep additions backward-compatible when possible by appending sections or flags.
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