Search code examples
rustrust-wasmbinary-size

rust wasm convert enum type to string without std or fmt


Is there a stable way to convert rust enum types to strings (and from strings to enum types) without the use of std or fmt?

The reason I am asking is because std appears to account for and 'bloat' the final binary size by around 33% (using cargo bloat) - leaving me with an executable almost 1MB in size for some very simple code.

Note I've already done all cargo.toml profile.release optimizations as outlined here: https://rustwasm.github.io/docs/book/reference/code-size.html


Solution

  • Maybe this is silly but I've just took out std/fmt and used impl on the enum and did the same thing. binary size hasn't decreased yet but I haven't removed all std / fmt from all dependencies yet. Makes me feel silly for using std / fmt in the first place since it's the same amount of work either way. I think the only difference is if my MYType enum were used inside the &format! macro I'd just need to call .to_string()

    pub enum MyType {A, B, /*etc...*/ }
    
    impl MyEnumType 
    {
       pub fn print(&self)
       {
          match &self 
          {
             MyEnumType::A => web_sys::console::log_1("a"),
             MyEnumType::B => web_sys::console::log_1("b"),
             /*etc... */ 
          }
       }
    
       pub fn from_str(input: &String) -> Result<MyEnumType, String> 
       {
          match input.as_str() 
          {
            "A" => Ok(MyEnumType::A),
            "a" => Ok(MyEnumType::A),
            "B" => Ok(MyEnumType::B),
            "b" => Ok(MyEnumType::B),
            /* etc*/ 
             _  => Err("bad string".to_string()),
          }
        }
    
        pub fn to_string(&self) -> String 
        {
          match &self 
          {         
            MyEnumType::A => "a".to_string(),   
            MyEnumType::B => "b".to_string(),   
            /* etc ... */
          }
        }
      }