amy3

Amy with simple polymorphic type and constant folding optimization.

Build

Clone:

$ git clone https://github.com/Meowcolm024/amy3.git

Build using stack (version 2.7.3+):

$ stack build

To run the generated JavaScript, you may also need to:

$ npm i deasync

Usage

To show help:

$ stack run -- -h                           
amy3 - The amy3 language interpreter/compiler

Usage: amy3-exe [TARGET...] [-i|--interpret] [-O|--optimize] [-o|--output FILE]
  amy3 is a subset of the Scala Programming Language. It can be directly
  interpreted or compiled to JavaScript

Available options:
  -i,--interpret           Interpret program
  -O,--optimize            Turn on optimization
  -o,--output FILE         Write output to FILE
  -h,--help                Show this help text

Interpret an example source file:

$ stack run -- -i examples/Hi.scala examples/Lib.scala
false
true
Maybe.Just(true)
input something: 

Compile and generate JavaScript from another example source file (tested under node v17.0.1):

$ stack run -- examples/What.scala --output=What.js
$ node What.js 
false
8002000
bye!

Difference

1. removed modules
2. removed abstract class and case class style, ADT, in favor of the enum syntax
3. need to supply a main function using @main
4. added parametric types for ADTs and functions
5. optional type signature for local bindings
6. constant folding optimization and redundent branch elimination

Known issues

The generated JavaScript program is not stable, it may exit will with max stack size reached, which is quite strange. This is probably related to the weired readline... (we may need to use error to force quit)

Primitives

The following functions are primitive functions:

// print string
print(s: String): Unit
// print string with new line
println(s: String): Unit
// read string from console
readLine(): String
// parse string to int
toInt(i: String): Int
// convert any type to string
toString(s: Any): String