antfu / wenyan-ast Goto Github PK

This is a rewrite of wenyan-lang parser, with AST and source map support.

Note this is very working in progress. You will definitely face some glitches and bugs.

You can try it online: https://wyo.netlify.com

Features

• Written in Typescript, tokens and AST are well-typed.

• Source location supported

• Better error handling

• Macro expanding, importing, tokenizing finished in a single turn - Should be faster

• Tree shaking will be very straightforward to implement

Progress

• Tooling setup
• Tokenize
• 🚧Parse (Some of the syntax is not supported yet,try..catch for example)
• Speed Optimize
• Tree-shaking
• Back-compatible api

I am glad to tell you the overhaul now compiles most of the scripts correctly(the basic examples, draw_trees). :)

However, while I am doing compatibility testing, I found out this line in 算經

https://github.com/antfu/wenyan-overhaul/blob/87d52352b372d70d88f128144b269e3aed612e80/packages/stdlib/lib/%E7%AE%97%E7%B6%93.wy#L46

In the current compiler, it will compile to

    const _ans28 = 引 + 1;
    const _ans29 = 基;
    const _ans30 = 實;
    const _ans31 = 合(_ans29)(_ans30);
    const _ans32 = 造表列(_ans28)(_ans31);

I would say it make sense in some aspect, but it's hard to read and understand without having good knowledge about the compiler internal mechanisms. Which I think should not be advised.

I would suggest changing it to this

https://github.com/antfu/wenyan-overhaul/blob/d01080a3e7d92a78d930d8eadae36902227d5cc5/packages/stdlib/lib/%E7%AE%97%E7%B6%93.wy#L103

The new compiler does not maintain a "drifting" answers list (i forget what's its name in the code), instead, it makes the relationship of variables static during AST generation. (and there is no need for 噫 as well). So I am wondering if we should drop this "non-intuitive" mechanism in the new compiler? Or if there is any reason to have this mechanism please let me know. :)