toy

toy is a simple programming language that is made for fun.

goals

• easy to learn
• helpful errors
• performant (not the case right now)
• great tooling

architecture

• frontend
  • lexer
  • parser
  • ast
  • hir
  • mir
• middle
  • optimisations
• backend
  • jit compiler
  • register based vm
• tooling
  • cli
  • lsp server
  • vscode extension

todo

• bugs

  • defining a variable should return unit type, not the value assigned
    • not sure if this is a bug yet since we don't have functions yet so ignore
  • hover for variables doesn't show type in blocks
  • infer has some stuff in there which is not related to type inference
  • string consts not working properly in jit

• improvements

  • rename int to Int, float to Float, bool to Bool, string to String

  • handle postfix operators in parser better

    • should be the same as prefix operators

  • is_bracket_index_not_list() uses speculative (re)lexing to check if [...] contains a comma (ie list) or not (ie index/slice)

    • maybe do this in a cleaner way?
    • feels weird to re lex

  • i think slices and range expressions are a bit weird and buggy

    • need to review
    • they should be the same
    • they should both produce a slice? type
    • is this valid 10..9 or error? 10..10?

  • tests for runtime vs jit consistency

    • make sure they produce the same results for same inputs

• more helpful warnings

  • let/var statements are not in this language, omit and use := instead
  • doc comments which are not attached to anything
    • suggest attaching them to the next function/variable definition/doccomment
  • unused variables (naming convention: _varname to ignore warning)
  • unused functions (naming convention: _funcname to ignore warning)
  • shadowing variables
  • unreachable code

• clean up

  • maybe make cli just a cli and move all the logic elsewhere
  • review docs
    • make it read better
    • add more examples
    • unsure if i should make the docs have useful examples or just focus on language features

• tiered execution

  • interpret code first
  • profile hot paths
  • jit compile hot paths

• garbage collection improvements

  • but what?

• structs

• tuples

• enums

• traits / interfaces

• exceptions / error handling

  • try/catch
  • result type
  • option type

• pattern matching

• generics

• modules

  • import / export system

  • public / private visibility

  • scripts / application / libraries

    • scripts are single file programs
      • can be run directly without a build step
    • applications are multi file programs with a main entry point
      • can be built into an executable
    • libraries are multi file programs without a main entry point
      • can be built into a library file to be used by other programs
      • can be published to git repo

  • build system

    • portable build with embedded interpreter/jit
    • cross-compilation support

• extern functions / ffi

  • ability to call functions from other languages (e.g. c, rust)
  • define functions in other languages and call them from toy

• std lib

  • basic i/o
    • stdin
    • stdout
    • stderr
  • string manipulation
  • result / option types
  • type conversion
  • math functions
  • date/time functions
  • random
  • collections
    • arrays
    • hash maps
    • sets
  • file i/o
  • networking

• concurrency

  • async/await
  • threads
  • channels

• tree sitter?

• improve playground

  • ??

• good repl

  • lots of bugs right now
  • ? for help
  • keybind to exit
  • h to show history
  • autocompletion
  • multiline editing
  • some way to see variables defined in the repl
  • should use vm probably

• performance

  • look at hot paths and jit
  • optimise memory usage
  • parallel parsing
    • do we need cs-tree instead of rowan?
  • parallel gc?