Macro ecmascript::build_ast

macro_rules! build_ast {
    ([$($many:tt)+]) => { ... };
    (regex_lit /{$pattern:expr}/{$flags:expr}) => { ... };
    (regex_lit /{$pattern:expr}/) => { ... };
    (templ_el {$cooked:expr}) => { ... };
    (templ_el {$cooked:expr} {$raw:expr}) => { ... };
    (this) => { ... };
    (id $id:expr) => { ... };
    (null) => { ... };
    (true) => { ... };
    (false) => { ... };
    (num $lit:expr) => { ... };
    (str $lit:expr) => { ... };
    (array [$($elements:tt),*]) => { ... };
    (array_item $($expression:tt)+) => { ... };
    (...$($expression:tt)+) => { ... };
    (object [$($properties:tt),*]) => { ... };
    ([$($key:tt)+]: [$($value:tt)+]) => { ... };
    (get [$($key:tt)+] [$($value:tt)+]) => { ... };
    (set [$($key:tt)+] [$($value:tt)+]) => { ... };
    (function [$($params:tt),*] [$($body:tt),*]) => { ... };
    (function * [$($params:tt),*] [$($body:tt),*]) => { ... };
    (async function [$($params:tt),*] [$($body:tt),*]) => { ... };
    (async function * [$($params:tt),*] [$($body:tt),*]) => { ... };
    (function [$($params:tt),*] {$body:expr}) => { ... };
    (p_id $id:expr) => { ... };
    (call [$($id:tt)+] [$($args:tt)+]) => { ... };
    (yield) => { ... };
    (<$id:ident />) => { ... };
}

This macro makes constructing complicated syntax trees very easy. This can be useful for re-writing parts of the AST, or deriving a a syntax tree from other trees (eg. concatenating syntax trees).

Example

let my_wrapper_func = build_ast! {
  [array [
      [array_item true],
      [array_item false],
      [array_item null],
      [...[array [ [array_item num 1f64] ]]]
   ]]
};

Conventions

• we use [] to represent recursive calls to the macro

eg: call [id "my_func".to_string()] [ [id "a".to_string()] [true] [null] ] recursively expands to build_ast!(call build_ast!(...) [ build_ast!(...), build_ast!(...), build_ast!(...) ])

• we use {} to accept a rust expression