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|
use std::io;
use std::env;
use std::io::Write;
use std::path::Path;
mod sexpr;
mod cexpr;
use cexpr::CExpr;
fn repl(verbose: bool) {
let stdin = io::stdin();
let mut stdout = io::stdout();
loop {
let raw_input = &mut String::new();
stdout.write(b"\ncasual> ").unwrap();
stdout.flush().unwrap();
stdin.read_line(raw_input).unwrap();
let raw_input = raw_input; // mutable to immutable reference
if raw_input.len() == 0 {
// end-of-line, aka Ctrl-D. Blank line will still have newline char
stdout.write(b"\nCiao!\n").unwrap();
return;
}
// TODO: use debug or something instead of "verbose"?
let tokens = match sexpr::sexpr_tokenize(&raw_input) {
Ok(tokens) => {
if verbose { println!("Tokens: {}", tokens.join(", ")); };
tokens
},
Err(e) => {
println!("couldn't tokenize: {}", e);
continue;
}
};
let ast = match sexpr::sexpr_parse(&tokens, 0) {
Ok((mut ast_list, _)) => {
if verbose {
for ast in &ast_list {
println!("AST: {}", sexpr::sexpr_repr(ast).unwrap());
};
};
// We're a REPL, so only one expression at a time
if ast_list.len() > 1 {
println!("one expression at a time on the REPL, please!");
continue;
} else if ast_list.len() == 0 {
sexpr::SExpr::SNull
} else {
let ast = ast_list.pop().unwrap();
ast
}
},
Err(e) => {
println!("couldn't parse: {}", e);
continue;
}
};
let expr = match CExpr::from_sexpr(&ast) {
Ok(v) => v,
Err(e) => {
println!("couldn't parse as math: {}", e);
continue;
},
};
match expr.to_sexpr() {
Ok(out) => println!("{}", sexpr::sexpr_repr(&ast).unwrap()),
Err(e) => {
println!("couldn't return to sexpr: {}", e);
continue;
},
}
}
}
fn usage() {
println!("usage:\tcasual [-h] [-v] [--no-repl] [<files>]");
println!("");
println!("Files will be loaded in order, then drop to REPL (unless \"--no-repl\" is passed).");
println!("Verbose flag (\"-v\") will result in lexed tokens and parsed AST \
being dumped to stdout (when on REPL).");
}
fn main() {
let mut verbose: bool = false;
let mut no_repl: bool = false;
let mut file_list = Vec::<String>::new();
for arg in env::args().skip(1) {
match &*arg {
"-v" | "--verbose" => { verbose = true; },
"--no-repl" => { no_repl = true; },
"-h" | "--help" => { usage(); return; },
_ if arg.starts_with("-") => {
println!("Unknown option: {}", arg);
println!("");
usage();
return;
},
_ => {
file_list.push(arg.clone());
}
}
}
for fname in file_list {
let fpath = Path::new(&fname);
if !fpath.is_file() {
println!("File not found (or not file): {}", fname);
return;
}
println!("Loading {}...", fname);
match sexpr::sexpr_parse_file(&fpath) {
Err(e) => {
println!("Error loading file: {}\n {}", fname, e);
return;
},
Ok(_) => ()
}
}
if !no_repl {
repl(verbose);
}
}
|
