Does return only return a single 256 bit word?

[nejucomo]

Note: The example uses serpent on the develop branch with revision c9563cff.

The following example tries to return a long text string. An examination of the LLL output makes it seem as if only 32 bytes are returned in the expression (return (ref '_temp_131) 32). Am I misreading this LLL expression?

$ cat > long_string_return.se
return text("This is 53 characters, which is longer than 256 bits.")

$ serpent compile_to_lll !$
serpent compile_to_lll long_string_return.se
(return 0
  (lll
    (seq
      (set '_temp_131
        (with '_temp17_str (alloc 85)
          (seq
            (mstore (get '_temp17_str) 53)
            (mstore (add (get '_temp17_str) 32)
              38178759162904981153227459547417441039765882805204013944776380134389117973280
            )
            (mstore (add (get '_temp17_str) 64)
              49046669650839314774563824355363137219616139645592700948219339121638676365312
            )
            (add (get '_temp17_str) 32)
          )
        )
      )
      (return (ref '_temp_131) 32)
    )
    0
  )
)

[vbuterin]

Need "return(text("This is 53 characters, which is longer than 256 bits."):str)". Yeah, I've been trying to tiptoe the line between being minimalistic and having a type system and it sometimes leads to weird consequences like that.

[ethers]

@nejucomo: pls close or reopen if still an issue

[nejucomo]

@ethers The answer isn't yet quite clear enough. Is this understanding correct:

• The grammar production return <expr> :str will return a long-string assuming that <expr> evaluates to a long string value.
• The <expr> in this case is the literal text("This is 53 characters, which is longer than 256 bits.") .

What happens if <expr> does not evaluate to a long string value? eg: return 42 :str ?

[ethers]

Hi @nejucomo I haven't tried return 42 :str
Something would not work somewhere, and the error provided may not be clear at all, so at this stage developer does have to be more careful about the types. If you prefer better typing, try Solidity, but when you opened this issue I would not have been surprised if Solidity wasn't able to do better than Serpent in this regard (returning a string). Serpent has its quirks but you may find it can still do some things that Solidity does not yet support.