v0.8.0-alpha "Haxonite"

0.8.0-alpha "Haxonite" (2021-08-31)

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.

Features

• Support quotes, tabs and carriage returns in string literals and otherwise
  restrict string literals to the printable subset of the ASCII table. (#329)

• The analyzer now uses a query-based system, which fixes some shortcomings of the previous implementation.

  • Types can now refer to other types defined later in the file.
    Example:

  type Posts = Map<PostId, PostBody>
  type PostId = u256
  type PostBody = String<140>
  

  • Duplicate definition errors now show the location of the original definition.
  • The analysis of each function, type definition, etc happens independently, so an error in one
    doesn't stop the analysis pass. This means fe can report more user errors in a single run of the compiler. (#468)

• Function definitions are now denoted with the keyword fn instead of def. (#496)

• Variable declarations are now preceded by the let keyword. Example: let x: u8 = 1. (#509)

• Implemented support for numeric unary invert operator (~) (#526)

Bugfixes

• Calling self.__init__() now results in a nice error instead of a panic in the yul compilation stage. (#468)

• Fixed an issue where certain expressions were not being moved to the correct location. (#493)

• Fixed an issue with a missing return statement not properly detected.

  Previous to this fix, the following code compiles but it should not:

  contract Foo:
      pub fn bar(val: u256) -> u256:
          if val > 1:
              return 5
  

  With this change, the compiler rightfully detects that the code is missing
  a return or revert statement after the if statement since it is not
  guaranteed that the path of execution always follows the arm of the if statement. (#497)

• Fixed a bug in the analyzer which allowed tuple item accessor names with a leading 0,
  resulting in an internal compiler error in a later pass. Example: my_tuple.item001.
  These are now rejected with an error message. (#510)

• Check call argument labels for function calls.

  Previously the compiler would not check any labels that were used
  when making function calls on self or external contracts.

  This can be especially problematic if gives developers the impression
  that they could apply function arguments in any order as long as they
  are named which is not the case.

  contract Foo:
  
      pub fn baz():
          self.bar(val2=1, doesnt_even_exist=2)
    
      pub fn bar(val1: u256, val2: u256):
          pass
  

  Code as the one above is now rightfully rejected by the compiler. (#517)

Improved Documentation

• Various improvements and bug fixes to both the content and layout of the specification. (#489)

• Document all remaining statements and expressions in the spec.

  Also added a CI check to ensure code examples in the documentation
  are validated against the latest compiler. (#514)

Internal Changes - for Fe Contributors

• Separated Fe type traits between crates. (#485)