You're right, I could have been clearer about saying it is a new AST and not a JavaScript/asm.js AST. That is what I meant. Bytecodes are for instruction sets

You're right, I could have been clearer about saying it is a new AST and not a JavaScript/asm.js AST. That is what I meant. Bytecodes are for instruction sets, not trees though. From wikipedia, "Bytecode, also known as p-code (portable code), is a form of instruction set designed for efficient execution by a software interpreter." There are no instructions to interpret since there is no instruction set defined. It is possible though that certain browsers may take the AST and create an instruction set for an interpreter or they may compile it to native code but that is entirely browser specific and has nothing to do with WebAssembly. https://github.com/WebAssembly/design/blob/master/TextFormat.md https://github.com/WebAssembly/design/blob/master/TextFormat... "Given that the code representation is actually an Abstract Syntax Tree, the syntax would contain nested statements and expressions (instead of the linear list of instructions most assembly languages have)."