Unable to compile due to "out of scope error"

[0zAND1z]

Here's the code:

#![no_std]
#![allow(non_snake_case)]
#![feature(alloc)]
#![feature(use_extern_macros)]
#![feature(proc_macro_gen)]

extern crate pwasm_std;
extern crate pwasm_ethereum;
extern crate pwasm_abi;
extern crate pwasm_abi_derive;
/// Bigint used for 256-bit arithmetic

pub mod hello {
    // add code here
    use pwasm_ethereum;
    use pwasm_abi::types::*;

    // eth_abi is a procedural macros https://doc.rust-lang.org/book/first-edition/procedural-macros.html
    use pwasm_abi_derive::eth_abi;

    #[eth_abi(HelloEndpoint)]
    pub trait HelloInterface {
        /// The constructor
        fn constructor(&mut self);
        /// Total amount of tokens
        fn sayHello(&mut self) -> String;
    }

    pub struct HelloContract;

    impl HelloInterface for HelloContract {
        fn constructor (&mut self) {

        }

        fn sayHello(&mut self) -> String {
            println("Hallo!");
        }
    }
}

// Declares the dispatch and dispatch_ctor methods
use pwasm_abi::eth::EndpointInterface;

#[no_mangle]
pub fn call() {
    let mut endpoint = hello::HelloEndpoint::new(hello::HelloContract{});

    // Read http://solidity.readthedocs.io/en/develop/abi-spec.html#formal-specification-of-the-encoding for details
    pwasm_ethereum::ret(&endpoint.dispatch(&pwasm_ethereum::input()));
}

#[no_mangle]
pub fn deploy() {
    let mut endpoint = hello::HelloEndpoint::new(hello::HelloContract{});
    //
    endpoint.dispatch_ctor(&pwasm_ethereum::input());
}

The log while running ./build.sh:

error[E0433]: failed to resolve. Could not find `HelloEndpoint` in `hello`
  --> src/lib.rs:92:31
   |
92 |     let mut endpoint = hello::HelloEndpoint::new(hello::HelloContract{});
   |                               ^^^^^^^^^^^^^ Could not find `HelloEndpoint` in `hello`

error[E0433]: failed to resolve. Could not find `HelloEndpoint` in `hello`
   --> src/lib.rs:100:31
    |
100 |     let mut endpoint = hello::HelloEndpoint::new(hello::HelloContract{});
    |                               ^^^^^^^^^^^^^ Could not find `HelloEndpoint` in `hello`

error[E0412]: cannot find type `String` in this scope
  --> src/lib.rs:21:5
   |
21 |     #[eth_abi(TokenEndpoint)]
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^ not found in this scope
help: possible candidate is found in another module, you can import it into scope
   |
15 |     use pwasm_std::String;
   |

error[E0412]: cannot find type `String` in this scope
  --> src/lib.rs:36:35
   |
36 |         fn sayHello(&mut self) -> String {
   |                                   ^^^^^^ not found in this scope
help: possible candidate is found in another module, you can import it into scope
   |
15 |     use pwasm_std::String;
   |

error[E0425]: cannot find function `println` in this scope
  --> src/lib.rs:37:13
   |
37 |             println("Hallo!");
   |             ^^^^^^^ not found in this scope

warning: unused import: `pwasm_ethereum`
  --> src/lib.rs:15:9
   |
15 |     use pwasm_ethereum;
   |         ^^^^^^^^^^^^^^
   |
   = note: #[warn(unused_imports)] on by default

warning: unused import: `pwasm_abi::types::*`
  --> src/lib.rs:16:9
   |
16 |     use pwasm_abi::types::*;
   |         ^^^^^^^^^^^^^^^^^^^

warning: unused import: `pwasm_abi::eth::EndpointInterface`
  --> src/lib.rs:73:5
   |
73 | use pwasm_abi::eth::EndpointInterface;
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: aborting due to 5 previous errors

Some errors occurred: E0412, E0425, E0433.
For more information about an error, try `rustc --explain E0412`.
error: Could not compile `pwasm-tutorial-contract`.

To learn more, run the command again with --verbose.

[AchalaSB]

@fckt I'm facing same issue. How to solve this problem?

[lexfrl]

The problem is that the String type is not supported by the pwasm-abi. Try to use &[u8]

[AchalaSB]

Thanks for reverting. As per my knowledge the type u8 and its byte slice &[u8] will convert from String to integer type. (Sorry if I'm wrong) How Can I use &[u8] without using String type but String is not supported by pwasm-abi?

[lexfrl]

have you tried to convert String to &[u8]?

[AchalaSB]

I tried by changing String type to &[u8] as mentioned above. But getting an error

error: custom attribute panicked
  --> src/lib.rs:21:5
   |
21 |     #[eth_abi(HelloEndpoint)]
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: message: Unable to handle param of type Rptr(None, MutTy { ty: Slice(Path(None, Path { global: false, segments: [PathSegment { ident: Ident("u8"), parameters: AngleBracketed(AngleBracketedParameterData { lifetimes: [], types: [], bindings: [] }) }] })), mutability: Immutable }): not supported by abi

error: aborting due to previous error

error: Could not compile `pwasm-tutorial-contract`.

To learn more, run the command again with --verbose.

[lexfrl]

so, haven't you tried Vec<u8>?

[AchalaSB]

@fckt Writing a #![no_std] crate disables the standard library, including vec! and Vec But pwasm-std itself compiled with no_std. Removing #![no_std] gives following error

error: duplicate lang item in crate `pwasm_std`: `panic_impl`.
  |
  = note: first defined in crate `std`.

error: duplicate lang item in crate `pwasm_std`: `oom`.
  |
  = note: first defined in crate `std`.

error: aborting due to 2 previous errors

how can use both pwasm-std and Vec

[lexfrl]

use pwasm_abi::types::*; imports Vec as well. Take a look here for more examples

[AchalaSB]

I have used use pwasm_abi ::types :: *; already.

[AchalaSB]

@fckt Is Vec<u8> is compatible with web3provider? Im getting an error ‘Transaction Error. Exception thrown in contract code.’ while testing

If I use Vec<u8> to convert my string is it gives me array of characters ? or How it look like? Here's my code

fn sayHello(&mut self) -> Vec<u8> {
            use pwasm_std :: String;
            let s = String::from("this is a string");
            let v = Vec::from(s);
            v
        }

[0zAND1z]

Stale thread.