 WebAssembly text format

The WebAssembly text format is the readable textual encoding of WebAssembly modules. Parenthesized declarations describe the same structured program that can be encoded in binary. Symbolic identifiers such as $add help readers refer to definitions; numeric indices determine references in the underlying module.^[ref]

For example, (module (func (export "add") (param i32 i32) (result i32) local.get 0 local.get 1 i32.add)) declares and exports a function accepting two 32-bit integers. The local.get instructions push its arguments onto the operand stack; i32.add consumes them and produces the result. Inputs 3 and 4 give 7. The folded instruction (i32.add (local.get 0) (local.get 1)) is an alternative notation for the same instruction sequence.^[ref]

The parentheses of a folded instruction make operand grouping visible, but do not introduce a different arithmetic operation. Decoding either spelling yields the same instruction structure. Textual readability and runtime behavior are separate: indentation can help a human follow the WebAssembly module, while the declared types and instruction order govern execution.