Migration of Empires

Dan Korostelev (@nadako)

Team before me

Team before me

• Settled with Haxe/OpenFL
• Made as3hx work
• Developed a "continous conversion" pipeline

Issues

• OpenFL HTML5 performance ✔️
• Flash/OpenFL behaviour inconsistencies ✔️
• Complex building pipeline 🤷
• Still AS3 source code 🤷‍♂️

Problems with as3hx

• OK for compiling, bad for developing
• Syntax-only AST
• Comments/whitespace are AST nodes
• Typing is very complicated
  • done on writing
  • no typed program representation
  • hard to transform the code

New converter: full-fidelity parsing

New converter: typed tree

New converter: SWC support

• Load signatures from the ABC bytecode
• ...into the same typed tree structure (dummy tokens)

• Thanks, format library!

New converter: Type annotations

• Override field, local and argument types
• Strict Array/Dictionary/Function types
• Supported in both AS3 and SWC

New converter: filters

• Adapt AS3 code for Haxe
• Insert missing type conversion
• Remove redundant code (e.g useless casts)

New converter: output

• Prints the filtered typed tree
• ...with the comments and whitespace

AS3

Haxe (formatted)

Encapsulated Reflection

• */Object -> ASAny/ASObject

• Overriden property access and type conversions

• Thanks, abstracts! \o/

It works! :)

• HTML5 via JS and OpenFL 
• Flash via SWF and SWC libs
• AS3 is only used for conversion

...converter is fully in Haxe/JVM

Using the Flash target

• Still relevant (payers on potatos) 
• Using original SWCs (for now)
• Had to fix compiler a bit
  • bytecode issues
  • flash properties
  • more interop (e.g. Vector)

Next step: full Haxe!

• Final touches on code conversion style
• Prepare dev environment
• Educate the teams
• Help other projects

Haxe 4

• Compiler cache finally reliable!
• IDE services work...
• ...but are slow :(

Thank you!

Questions?