Awesome

For The Graal

This is a fun absurd interpreter for a mini language.

The parser is implemented in Ruby using a s-expression parser SXP, the type checker/compiler is written in Java and the interpreter in JavaScript

Language

A program consists of a list of statements. Currently, there are functions, if statements, let statements and print statements.

The language supports numbers (double precision floating point), strings and bools.

Functions are defined using fun. They take in a name, a list of params, and a body. Params are a name/type pair. The function body is a list of statements.

(
  (fun foo ((n number) (b number)) 
    (
      (print (* n b))
    )
  )
)

Let statements are defined using let. They take in a name and an expression.

(
  (let a (* 25 (/ 30 10)))
)

Print statements are defined using print. They take in a single expression.

(
  (print "foobar")
)

If statements are defined using if. They take in a condition, and a then block with an optional else block.

(
  (if (< 10 20) (print "10 < 20"))
  (if (< 21 20) (print "21 < 20") (print "21 > 20"))
)

Running

Before running, you should have Graal with Ruby, JavaScript and Java all installed. Also, please make sure to run bundle install to install sxp.

Compiling is simply:

javac -Xlint:unchecked -classpath src/ src/Main.java

and running:

java -classpath src/ Main <source_file>

Where <source_file> is a file containing the source code. Check out examples/ for, well, examples.

javac and java must be the Graal versions, of course.

NOTE: You must run the code from the root directory as it loads files via relative paths.