Cactus Environment Machine

Installing

cabal install

Make sure ~/.cabal/bin/ is in your PATH variable.

Usage

cem {options} file.lc

Examples

cem test/hello.lc # compiles hello world program in test/
cem -g test/noprelude/fib.lc
cem -ld test/hello.lc

Flags

• -l: Put before any other flag, uses the libraries: lib/prelude.lc lib/os.lc lib/church.lc
• -t: Trace. Dumps term for every machine step. Useful for debugging.
• -r: Runs in virtual machine.
• -g: Visualization tool. Also probably want to use without libs.
• -a: Controlf low analysis (0CFA). Very slow, probably want to use without -l
• -f: Free variable analysis.

Syntax

See lc and sugar from IO.hs for parser syntax. Essentially a list of let bindings followed by an lc expression.

Required haskell libraries

Should be installed automatically with install

• graphviz
• parsec
• probably others

Issues

• VM doesn't have argc and argv implemented
• GC doesn't grow heap when needed, default large (400M)
• writeFd and readFd max out at a single page size, to read or write more must use multiple calls