Karreidos

Kaleidoscope in Rust but somewhat modified.

Main differences from original Kaleidoscope:

• Function definition with fn instead of def
• Comment with // or /* */, not with #
• Loop statement with genarator-like syntax (for i <- 1..10, 1 { /* .. */ })
• Pipe operator />

Requirement

• LLVM version 15.x

How to use

You can open REPL with:

cargo build --release
./target/release/karreidos -i

then, you can write some codes like:

?>> extern fn cos(x); // from standard C library
?>> fn add(x, y) { x + y; }
?>> fn double(x) { x * 2; }
?>> fn func(arg) {
...     if arg < 10 {
...         let mut i = 10;
...         for mut v <- arg .. 100, 1 {
...             i = i + v;
...             v = v + 1; // number of repetition is not affected by this assignment
...         };
...         i /> add(3);
...     } else {
...         cos(arg);
...     }
...     /> double();
... }
...
?>> func(9);
[INFO] 9854  // (10 + sum(9..=99) + 3) * 2
?>> func(31.415926535);
[INFO] 2     // cos(10pi) * 2

Or you can generate LLVM-IR with source files:

./target/release/karreidos /path/to/src.krr -o /path/to/output.ll

with debug info (but incomplete feature):

./target/release/karreidos /path/to/src.krr --debug-info -o /path/to/output.ll

Also, you can emit object file or assembly:

./target/release/karreidos /path/to/src.krr --emit obj -o /path/to/output.out
./target/release/karreidos /path/to/src.krr --emit asm -o /path/to/output.s

specify target:

./target/release/karreidos /path/to/src.krr --emit asm --target=x86_64-unknown-linux-gnu /path/to/output.s

Grammer (BNF form) is available here. Note that redefining variable in the same scope (block) is prohibited.

?>> fn func() {
...     let i = 10;
...     let i = 10;
... }
...
[ERROR] Redefined("i", Variable)

To be implemented

• Kaleidoscope itself (except chapter 6).
• Language server protocol
• Port them using tree-sitter