lyng/bytecode_migration_plan.md

Bytecode migration plan (compiler -> frames/bytecode)

This is a step-by-step checklist to track remaining non-bytecode paths in the compiler. Mark items as you implement them. Priorities are ordered by expected simplicity.

Priority 1: Quick wins (local changes)

• Implement bytecode emission for DelegatedVarDeclStatement.
  • References: lynglib/src/commonMain/kotlin/net/sergeych/lyng/bytecode/BytecodeCompiler.kt:3284, lynglib/src/commonMain/kotlin/net/sergeych/lyng/Compiler.kt:1667
• Implement bytecode emission for DestructuringVarDeclStatement.
  • References: lynglib/src/commonMain/kotlin/net/sergeych/lyng/bytecode/BytecodeCompiler.kt:3285, lynglib/src/commonMain/kotlin/net/sergeych/lyng/Compiler.kt:1667
• Ensure ExtensionPropertyDeclStatement is handled in both value and no-value bytecode paths.
  • References: lynglib/src/commonMain/kotlin/net/sergeych/lyng/bytecode/BytecodeCompiler.kt:3332

Priority 2: Conservative wrapper guards to relax

• Allow wrapping BreakStatement / ContinueStatement / ReturnStatement where bytecode already supports them.
  • References: lynglib/src/commonMain/kotlin/net/sergeych/lyng/Compiler.kt:1608
• Revisit containsLoopControl as a hard blocker for wrapping (once label handling is verified).
  • References: lynglib/src/commonMain/kotlin/net/sergeych/lyng/Compiler.kt:1542

Priority 3: Medium complexity statements

• Implement bytecode support for TryStatement.
  • References: lynglib/src/commonMain/kotlin/net/sergeych/lyng/Compiler.kt:1698, lynglib/src/commonMain/kotlin/net/sergeych/lyng/bytecode/BytecodeCompiler.kt:3290
• Expand WhenStatement condition coverage (remove "unsupported condition" paths).
  • References: lynglib/src/commonMain/kotlin/net/sergeych/lyng/Compiler.kt:1699

Priority 4: Ref-level blockers

• Support dynamic member access in bytecode (FieldRef / MethodCallRef on ObjDynamic).
  • References: lynglib/src/commonMain/kotlin/net/sergeych/lyng/Compiler.kt:1735
• Implement bytecode for qualified/captured member refs:
  • QualifiedThisMethodSlotCallRef
  • QualifiedThisFieldSlotRef
  • ClassScopeMemberRef
  • References: lynglib/src/commonMain/kotlin/net/sergeych/lyng/Compiler.kt:1759

Priority 5: Wrapping policy improvements

• Allow partial script wrapping (wrap supported statements even when others are unsupported).
  • References: lynglib/src/commonMain/kotlin/net/sergeych/lyng/Compiler.kt:1333
• Re-evaluate tooling paths that disable bytecode:
  • CompileTimeResolution.dryRun (resolution-only)
  • LyngLanguageTools.analyze (diagnostics/mini-ast)
  • References: lynglib/src/commonMain/kotlin/net/sergeych/lyng/resolution/CompileTimeResolution.kt:67, lynglib/src/commonMain/kotlin/net/sergeych/lyng/tools/LyngLanguageTools.kt:97