v0.4.0-alpha "Diamond"

Release Notes

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WARNING: All Fe releases are alpha releases and only meant to share the development progress with developers and enthusiasts. It is NOT yet ready for production usage.

0.4.0-alpha "Diamond" (2021-04-28)

Features

• Support for revert messages in assert statements

  E.g

  assert a == b, "my revert statement"
  

  The provided string is abi-encoded as if it were a call
  to a function Error(string). For example, the revert string "Not enough Ether provided." returns the following hexadecimal as error return data:

  0x08c379a0                                                         // Function selector for Error(string)
  0x0000000000000000000000000000000000000000000000000000000000000020 // Data offset
  0x000000000000000000000000000000000000000000000000000000000000001a // String length
  0x4e6f7420656e6f7567682045746865722070726f76696465642e000000000000 // String data
  

(#288)

• Added support for augmented assignments.

  e.g.

  contract Foo:
      pub def add(a: u256, b: u256) -> u256:
          a += b
          return a
  
      pub def sub(a: u256, b: u256) -> u256:
          a -= b
          return a
  
      pub def mul(a: u256, b: u256) -> u256:
          a *= b
          return a
  
      pub def div(a: u256, b: u256) -> u256:
          a /= b
          return a
  
      pub def mod(a: u256, b: u256) -> u256:
          a %= b
          return a
  
      pub def pow(a: u256, b: u256) -> u256:
          a **= b
          return a
  
      pub def lshift(a: u8, b: u8) -> u8:
          a <<= b
          return a
  
      pub def rshift(a: u8, b: u8) -> u8:
          a >>= b
          return a
  
      pub def bit_or(a: u8, b: u8) -> u8:
          a |= b
          return a
  
      pub def bit_xor(a: u8, b: u8) -> u8:
          a ^= b
          return a
  
      pub def bit_and(a: u8, b: u8) -> u8:
          a &= b
          return a
  

(#338)

• A new parser implementation, which provides more helpful error messages
  with fancy underlines and code context. (#346)

• Added support for tuples with base type items.

  e.g.

  contract Foo:
      my_num: u256
  
      pub def bar(my_num: u256, my_bool: bool) -> (u256, bool):
          my_tuple: (u256, bool) = (my_num, my_bool)
          self.my_num = my_tuple.item0
          return my_tuple
  

(#352)

Bugfixes

• Properly reject invalid emit (#211)

• Properly tokenize numeric literals when they start with 0 (#331)

• Reject non-string assert reasons as type error (#335)

• Properly reject code that creates a circular dependency when using create or create2.

  Example, the follwing code is now rightfully rejected because it tries to create an
  instance of Foo from within the Foo contract itself.

  contract Foo:
    pub def bar()->address:
      foo:Foo=Foo.create(0)
  
      return address(foo)
  

(#362)

Internal Changes - for Fe Contributors

• AST nodes use Strings instead of &strs. This way we can perform incremental compilation on the AST. (#332)
• Added support for running tests against solidity fixtures.
  Also added tests that cover how solidity encodes revert reason strings. (#342)
• Refactoring of binary operation type checking. (#347)