v0.3.0-alpha "Calamine"

Release Notes

📄 Draft Spec
ℹ️ Getting Started

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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.

0.3.0-alpha "Calamine" (2021-03-24)

Features

• Add over/underflow checks for multiplications of all integers (#271)

• Add full support for empty Tuples. (#276)

  All functions in Fe implicitly return an empty Tuple if they have no other return value.
  However, before this change one was not able to use the empty Tuple syntax () explicitly.

  With this change, all of these are treated equally:

  contract Foo:
  
    pub def explicit_return_a1():
      return
  
    pub def explicit_return_a2():
      return ()
  
    pub def explicit_return_b1() ->():
      return
  
    pub def explicit_return_b2() ->():
      return ()
  
    pub def implicit_a1():
      pass
  
    pub def implicit_a2() ->():
      pass
  

• The JSON ABI builder now supports structs as both input and output. (#296)

• Make subsequently defined contracts visible.

  Before this change:

  # can't see Bar
  contract Foo:
     ...
  # can see Foo
  contract Bar:
     ...
  

  With this change the restriction is lifted and the following becomes possible. (#298)

  contract Foo:
      bar: Bar
      pub def external_bar() -> u256:
          return self.bar.bar()
  contract Bar:
      foo: Foo
      pub def external_foo() -> u256:
          return self.foo.foo()
  

• Perform checks for divison operations on integers (#308)

• Support for msg.sig to read the function identifier. (#311)

• Perform checks for modulo operations on integers (#312)

• Perform over/underflow checks for exponentiation operations on integers (#313)

Bugfixes

• Properly reject emit not followed by an event invocation (#212)

• Properly reject octal number literals (#222)

• Properly reject code that tries to emit a non-existing event. (#250)

  Example that now produces a compile time error:

  emit DoesNotExist()
  

• Contracts that create other contracts can now include __init__ functions.

  See #284 (#304)

• Prevent multiple types with same name in one module. (#317)

  Examples that now produce compile time errors:

  type bar = u8
  type bar = u16
  

  or

  struct SomeStruct:
      some_field: u8
  
  struct SomeStruct:
      other: u8
  

  or

  contract SomeContract:
      some_field: u8
  
  contract SomeContract:
      other: u8
  

  Prevent multiple fields with same name in one struct.

  Example that now produces a compile time error:

  struct SomeStruct:
      some_field: u8
      some_field: u8
  

  Prevent variable definition in child scope when name already taken in parent scope.

  Example that now produces a compile time error:

  pub def bar():
      my_array: u256[3]
      sum: u256 = 0
      for i in my_array:
          sum: u256 = 0
  

• The CLI was using the overwrite flag to enable Yul optimization.

  i.e.

  # Would both overwite output files and run the Yul optimizer. 
  $ fe my_contract.fe --overwrite
  

  Using the overwrite flag now only overwrites and optimization is enabled with the optimize flag. (#320)

• Ensure analyzer rejects code that uses return values for __init__ functions. (#323)

  An example that now produces a compile time error:

  contract C:
      pub def __init__() -> i32:
          return 0
  

• Properly reject calling an undefined function on an external contract (#324)

Internal Changes - for Fe Contributors

• Added the Uniswap demo contracts to our testing fixtures and validated their behaviour. (#179)
• IDs added to AST nodes. (#315)
• Failures in the Yul generation phase now panic; any failure is a bug. (#327)