能否将WebAssembly文本格式（.wat）视为基于S表达式的编程语言？
Absolutely—though it’s important to clarify what kind of programming language it is. WAT is the human-readable text representation of WebAssembly (Wasm) binary modules. Unlike high-level languages like JavaScript or Rust, it’s a low-level, assembly-style language that maps directly to Wasm’s binary instruction set.
It has all the hallmarks of a programming language:
- A formal syntax and semantic rules
- Support for defining functions, variables, types, and control flow (like
ifblocks andloopconstructs) - The ability to express computational logic that can be compiled into executable code (Wasm binaries)
For example, here’s a simple WAT module that defines an addition function:
(module (func $add (param i32 i32) (result i32) local.get 0 local.get 1 i32.add ) (export "add" (func $add)) )
You can write this by hand, use tools like wat2wasm to compile it to a binary .wasm file, and then execute it in a browser or Wasm runtime. So while it’s not designed for general-purpose application development like Python or C#, it absolutely qualifies as a programming language.
Yes, WAT’s core syntax is built on S-expressions (symbolic expressions). If you’ve used languages like Lisp or Scheme, you’ll recognize the pattern: nearly all structural elements in WAT are expressed as nested parenthesized lists.
Take the module example above:
- The entire module is wrapped in
(module ...) - The function definition is
(func $add (param i32 i32) (result i32) ...) - Even instructions like integer addition are written as
(i32.add)(though WAT allows some syntactic sugar, like omitting parentheses for simple instructions in certain contexts)
The official WebAssembly specification explicitly notes that WAT uses an S-expression-based syntax for its human-readable form. The syntactic sugar (like writing i32.add instead of (i32.add) in some cases) is just a convenience for developers, but the underlying structure remains rooted in S-expressions.
内容的提问来源于stack exchange，提问作者Jason Yu
