cl-interpret: Write an example for driving the interpreter

This commit is contained in:
John 2024-07-29 15:42:05 -05:00
parent ecebefe218
commit b17164b68b

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@ -0,0 +1,55 @@
//! A bare-minimum harness to evaluate a Conlang program
use std::{error::Error, path::PathBuf};
use cl_interpret::{convalue::ConValue, env::Environment};
use cl_lexer::Lexer;
use cl_parser::{inliner::ModuleInliner, Parser};
fn main() -> Result<(), Box<dyn Error>> {
let mut args = std::env::args();
let prog = args.next().unwrap();
let Some(path) = args.next().map(PathBuf::from) else {
println!("Usage: {prog} `file.cl` [ args... ]");
return Ok(());
};
let parent = path.parent().unwrap_or("".as_ref());
let code = std::fs::read_to_string(&path)?;
let code = Parser::new(Lexer::new(&code)).file()?;
let code = match ModuleInliner::new(parent).inline(code) {
Ok(code) => code,
Err((code, ioerrs, perrs)) => {
for (p, err) in ioerrs {
eprintln!("{}:{err}", p.display());
}
for (p, err) in perrs {
eprintln!("{}:{err}", p.display());
}
code
}
};
let mut env = Environment::new();
env.eval(&code)?;
let main = "main".into();
if env.get(main).is_ok() {
let args = args
.flat_map(|arg| {
Parser::new(Lexer::new(&arg))
.expr()
.map(|arg| env.eval(&arg))
})
.collect::<Result<Vec<_>, _>>()?;
match env.call(main, &args)? {
ConValue::Empty => {}
retval => println!("{retval}"),
}
}
Ok(())
}