2025-02-14: Fuzion February Update

Last month, the stability of the fz was improved significantly when handling faulty input source files. Furthermore, there was significant cleanup in code related to the Fuzion Intermediate Representation which will lead to the ability to safe the IR into a file for later use by tools like code generators or analysers.

• General

  • FOSDEM had a talk on Fuzion: Effects Everywhere: Error Handling and Design-By-Contract in Fuzion, a video recording and slides are available, check it out if you where not there!

  • The GreenCode project has started where Tokiwa Software GmbH is one of 26 partners from 9 European countries working software optimisation to manage and improve energy efficiency. Main goals for us is to use Fuzion with its effect handlers to model, control and reduce resource usage.

• Base library

  • New base library features

    • A new feature expanding_array provides an efficient immutable but extensible array. This is now used internally to implement an efficient partially sorted map ps_map, fix #4637 (#4651)

      This permits efficiently adding elements to an array similar to Java's ArrayList as follows:

      for  a := (container.expanding_array String).empty, a.add "😜"*i
           i in 1..6
      else
        say a
                  

    • Added Sequence.dedup and Sequence.unique to remove (adjacent) duplicates in a Sequence, fix #4552, workaround for #4628 (#4629)

    • Added Sequence.scan that takes a function instead of a Monoid (#4644)

    • Added Sequence.sliding and Sequence.group_map_reduce (#4655)

    • Added features like codepoint.is_ascii_digit for existing sets (#4635)

    • Added ffi convenience features: null, is_null (#4533)

  • Changes to the following standard library features

    • buffered.writer no uses mutate type parameter from buffered (#4595)

    • Avoid as_list in Sequence.as_array if array backed (#4653)

    • Changed io.out/io.err to be ref features io.Out/io.Err which avoids then need for Print_Handler when defining a different effect handler (#4590)

    • change impl of Print_Handler and print_effect (#4579)

    • Let mutable_tree_map inherit from Mutable_Map and add features (#4638)

    • Move type parameter from io.buffered.reader to io.buffered (#4492)

    • orderable provide implementation for type.equality (#4675)

    • unify string representation of maps (#4646)

    • modules: Move declaration outside of String as a workaround for #4619 (#4620)

• Parser

  • Fix OpExpr to parse expressions like x?? && y?? correctly (#4678)

  • Fix confusing error on wrong indentation (#4674)

• Front end

  • Fix crash when processing

    count(n) =>
      if true then count 1
      else         count 2
    
    _ := [3].map count |> sum
                

    constraintAssignableFrom return false for void unless constraint… (#4618)

  • Fix crash when processing

    o array i32->i32 := [-]      # array of unary function `i -> -i`
    say (o[0].call 3)
                

    InlineArray.propagateExpectedType fix check condition (#4606)

  • Fix crash when processing

    m 3
    m(a A) => if A : i32 then
    m(B type, b B) =>
                

    check for duplicate feature when adding type parameter (#4612)

  • Suppress subsequent errors: fix #4418 (#4605)

  • fix bug when inner feature inherits from outer feature and outer has type parameters (#4688)

  • fix handling of type constraints in inherited preconditions that resulted in unjustified errors: fix Context.exterior and comparison of type parameters (#4652)

  • Enable partial application of type feature as in m.map String.from_codepoints: fix resolving of unresolved type universe (#4663)

  • remove strange subsequent errors reported in feature that with arg types inferred from call site if there is no such call site (#4607)

  • Improve type inference for Lazy value in expressions like o := true.as_option 42 (#4669)

  • Fixed to eager partial application: do not wrap function argument into a lambda, fix #4609 (#4616)

  • remove uses of ast.Context anywhere but ast (#4627)

  • Fix partial application when calling infix operator, fix #4687 (#4689)

  • In assignment f := ... (x,y) -> ... f ..., the declared field f is now accessible within the lambda: fe: fix field on left side should be visible in lambda (#4608)

  • re-enable partial application for expr in parentheses, e.g., ("hi" |> say) (#4615)

  • fix crashes of `fz` command:

    • after reporting justified errors: fix initialValueFromCall in case of errors (#4611)

    • fix calling type on partial not resulting in error (#4625)

    • after failure to infer type parameter (#4610)

    • fix field for result not added in nested match/if expr (#4525)

    • Relax precondition for AbstractFeature.cotype (#4594)

    • fe: fix index out of bounds in SourceModule.inScope (#4613)

    • fe: fix soundness issue in checkLegalQualThisType (#4660)

• DFA

  • Do not remove fields used in compare_and_*, mark complete value as read (#4679)

  • Report error when replacing effect that is not instated (#4599)

• FUIR

  • implement clazz is array in fuir (#4602)

  • cache result field (#4664)

  • do not create new clazzes when lookupDone==true (#4643)

  • do not create outerRef clazz when lookupDone (#4665)

  • fix instability in clazz._id (#4648)

  • improve robustness of clazz_array_u8, etc. (#4578)

  • normalise outer clazzes of fields to always be values (#4585)

  • record which sites and code where used by DFA (#4666)

  • Remove fuir field index (#4588)

• All back end

  • native: sys.process, sys.pipe convert to native (#4575)

• C back end

  • be/c: add -CInclude, -CLink options (#4582)

  • posix.c: remove telldir/seekdir which are not POSIX (#4569)

• Windows

  • be/win: fix compilation of fuzion.dll (#4591)

• Build tools

  • do not fix fz output to UTF8 encoding (#4636)

  • makefile: do rm -rf $(@D) when rebuilding modules (#4593)

  • makefile: Fix path to src directory for javadoc (#4574)

  • scripts: fix line.separator (#4573)

  • scripts: use any POSIX shell instead of bash (#4571)

• Tests

  • add regression tests (#4697, #4614, #4673, #4604)

  • test file io using Unicode (#4708)

• Documentation

  • Added version and hash at the bottom of the API doc pages (#4703)

  • Don't show 'Private Constructor' annotation for arguments (#4670)

  • Fixed links to Fuzion source files (#4698)

Cheers,

--The Fuzion Team.