aboutsummaryrefslogtreecommitdiff
path: root/rust/src/step7_quote.rs
diff options
context:
space:
mode:
Diffstat (limited to 'rust/src/step7_quote.rs')
-rw-r--r--rust/src/step7_quote.rs341
1 files changed, 341 insertions, 0 deletions
diff --git a/rust/src/step7_quote.rs b/rust/src/step7_quote.rs
new file mode 100644
index 0000000..ae284d4
--- /dev/null
+++ b/rust/src/step7_quote.rs
@@ -0,0 +1,341 @@
+// support precompiled regexes in reader.rs
+#![feature(phase)]
+#[phase(plugin)]
+extern crate regex_macros;
+extern crate regex;
+
+use std::os;
+
+use types::{MalVal,MalRet,MalFunc,
+ Nil,False,Sym,List,Vector,Func,
+ _nil,symbol,string,list,malfunc};
+use env::{Env,env_new,env_bind,env_root,env_set,env_get};
+mod readline;
+mod types;
+mod reader;
+mod printer;
+mod env;
+mod core;
+
+// read
+fn read(str: String) -> MalRet {
+ reader::read_str(str)
+}
+
+// eval
+fn is_pair(x: MalVal) -> bool {
+ match *x {
+ List(ref lst) => lst.len() > 0,
+ _ => false,
+ }
+}
+
+fn quasiquote(ast: MalVal) -> MalVal {
+ if !is_pair(ast.clone()) {
+ return list(vec![symbol("quote"), ast])
+ }
+
+ match *ast.clone() {
+ List(ref args) => {
+ let ref a0 = args[0];
+ match **a0 {
+ Sym(ref s) => {
+ if s.to_string() == "unquote".to_string() {
+ let ref a1 = args[1];
+ return a1.clone();
+ }
+ },
+ _ => (),
+ }
+ if is_pair(a0.clone()) {
+ match **a0 {
+ List(ref a0args) => {
+ let a00 = a0args[0].clone();
+ match *a00 {
+ Sym(ref s) => {
+ if s.to_string() == "splice-unquote".to_string() {
+ return list(vec![symbol("concat"),
+ a0args[1].clone(),
+ quasiquote(list(args.slice(1,args.len()).to_vec()))])
+ }
+ },
+ _ => (),
+ }
+ },
+ _ => (),
+ }
+ }
+ let rest = list(args.slice(1,args.len()).to_vec());
+ return list(vec![symbol("cons"),
+ quasiquote(a0.clone()),
+ quasiquote(rest)])
+ },
+ _ => _nil(), // should never reach
+ }
+}
+
+fn eval_ast(ast: MalVal, env: Env) -> MalRet {
+ let ast2 = ast.clone();
+ match *ast2 {
+ //match *ast {
+ Sym(ref sym) => {
+ env_get(env.clone(), sym.clone())
+ },
+ List(ref a) => {
+ let mut ast_vec : Vec<MalVal> = vec![];
+ for mv in a.iter() {
+ let mv2 = mv.clone();
+ match eval(mv2, env.clone()) {
+ Ok(mv) => { ast_vec.push(mv); },
+ Err(e) => { return Err(e); },
+ }
+ }
+ Ok(list(ast_vec))
+ },
+ _ => {
+ Ok(ast)
+ }
+ }
+}
+
+fn eval(mut ast: MalVal, mut env: Env) -> MalRet {
+ 'tco: loop {
+
+ //println!("eval: {}, {}", ast, env.borrow());
+ //println!("eval: {}", ast);
+ let ast2 = ast.clone();
+ let ast3 = ast.clone();
+ match *ast2 {
+ List(_) => (), // continue
+ _ => return eval_ast(ast2, env),
+ }
+
+ // apply list
+ match *ast2 {
+ List(ref args) => {
+ if args.len() == 0 {
+ return Ok(ast3);
+ }
+ let ref a0 = *args[0];
+ match *a0 {
+ Sym(ref a0sym) => {
+ match a0sym.as_slice() {
+ "def!" => {
+ let a1 = (*args)[1].clone();
+ let a2 = (*args)[2].clone();
+ let res = eval(a2, env.clone());
+ match res {
+ Ok(r) => {
+ match *a1 {
+ Sym(ref s) => {
+ env_set(&env.clone(), s.clone(), r.clone());
+ return Ok(r);
+ },
+ _ => {
+ return Err("def! of non-symbol".to_string())
+ }
+ }
+ },
+ Err(e) => return Err(e),
+ }
+ },
+ "let*" => {
+ let let_env = env_new(Some(env.clone()));
+ let a1 = (*args)[1].clone();
+ let a2 = (*args)[2].clone();
+ match *a1 {
+ List(ref binds) | Vector(ref binds) => {
+ let mut it = binds.iter();
+ while it.len() >= 2 {
+ let b = it.next().unwrap();
+ let exp = it.next().unwrap();
+ match **b {
+ Sym(ref bstr) => {
+ match eval(exp.clone(), let_env.clone()) {
+ Ok(r) => {
+ env_set(&let_env, bstr.clone(), r);
+ },
+ Err(e) => {
+ return Err(e);
+ },
+ }
+ },
+ _ => {
+ return Err("let* with non-symbol binding".to_string());
+ },
+ }
+ }
+ },
+ _ => return Err("let* with non-list bindings".to_string()),
+ }
+ ast = a2;
+ env = let_env.clone();
+ continue 'tco;
+ },
+ "quote" => {
+ return Ok((*args)[1].clone());
+ },
+ "quasiquote" => {
+ let a1 = (*args)[1].clone();
+ ast = quasiquote(a1);
+ continue 'tco;
+ },
+ "do" => {
+ let el = list(args.slice(1,args.len()-1).to_vec());
+ match eval_ast(el, env.clone()) {
+ Err(e) => return Err(e),
+ Ok(_) => {
+ let ref last = args[args.len()-1];
+ ast = last.clone();
+ continue 'tco;
+ },
+ }
+ },
+ "if" => {
+ let a1 = (*args)[1].clone();
+ let cond = eval(a1, env.clone());
+ if cond.is_err() { return cond; }
+ match *cond.unwrap() {
+ False | Nil => {
+ if args.len() >= 4 {
+ let a3 = (*args)[3].clone();
+ ast = a3;
+ env = env.clone();
+ continue 'tco;
+ } else {
+ return Ok(_nil());
+ }
+ },
+ _ => {
+ let a2 = (*args)[2].clone();
+ ast = a2;
+ env = env.clone();
+ continue 'tco;
+ },
+ }
+ },
+ "fn*" => {
+ let a1 = (*args)[1].clone();
+ let a2 = (*args)[2].clone();
+ return Ok(malfunc(a2, env.clone(), a1));
+ },
+ "eval" => {
+ let a1 = (*args)[1].clone();
+ match eval(a1, env.clone()) {
+ Ok(exp) => {
+ ast = exp;
+ env = env_root(&env);
+ continue 'tco;
+ },
+ Err(e) => return Err(e),
+ }
+ },
+ _ => ()
+ }
+ }
+ _ => (),
+ }
+ // function call
+ return match eval_ast(ast3, env.clone()) {
+ Err(e) => Err(e),
+ Ok(el) => {
+ match *el {
+ List(ref args) => {
+ // TODO: make this work
+ //match args.as_slice() {
+ // [&Func(f), rest..] => {
+ // (*f)(rest.to_vec())
+ // },
+ // _ => Err("attempt to call non-function".to_string()),
+ //}
+ let args2 = args.clone();
+ match *args2[0] {
+ Func(f) => f(args.slice(1,args.len()).to_vec()),
+ MalFunc(ref mf) => {
+ let mfc = mf.clone();
+ let alst = list(args.slice(1,args.len()).to_vec());
+ let new_env = env_new(Some(mfc.env.clone()));
+ match env_bind(&new_env, mfc.params, alst) {
+ Ok(_) => {
+ ast = mfc.exp;
+ env = new_env;
+ continue 'tco;
+ },
+ Err(e) => Err(e),
+ }
+ },
+ _ => Err("attempt to call non-function".to_string()),
+ }
+ }
+ _ => Err("Invalid apply".to_string()),
+ }
+ }
+ }
+ }
+ _ => return Err("Expected list".to_string()),
+ }
+
+ }
+}
+
+// print
+fn print(exp: MalVal) -> String {
+ exp.pr_str(true)
+}
+
+fn rep(str: String, env: Env) -> Result<String,String> {
+ match read(str) {
+ Err(e) => Err(e),
+ Ok(ast) => {
+ //println!("read: {}", ast);
+ match eval(ast, env) {
+ Err(e) => Err(e),
+ Ok(exp) => Ok(print(exp)),
+ }
+ }
+ }
+}
+
+fn main() {
+ // core.rs: defined using rust
+ let repl_env = env_new(None);
+ for (k, v) in core::ns().into_iter() { env_set(&repl_env, k, v); }
+ // see eval() for definition of "eval"
+ env_set(&repl_env, "*ARGV*".to_string(), list(vec![]));
+
+ // core.mal: defined using the language itself
+ let _ = rep("(def! not (fn* (a) (if a false true)))".to_string(),
+ repl_env.clone());
+ let _ = rep("(def! load-file (fn* (f) (eval (read-string (str \"(do \" (slurp f) \")\")))))".to_string(),
+ repl_env.clone());
+
+ // Invoked with command line arguments
+ let args = os::args();
+ if args.len() > 1 {
+ let mv_args = args.slice(2,args.len()).iter()
+ .map(|a| string(a.to_string()))
+ .collect::<Vec<MalVal>>();
+ env_set(&repl_env, "*ARGV*".to_string(), list(mv_args));
+ match rep("(load-file \"".to_string() + args[1] + "\")".to_string(),
+ repl_env.clone()) {
+ Ok(_) => {
+ os::set_exit_status(0);
+ return;
+ },
+ Err(str) => {
+ println!("Error: {}", str);
+ os::set_exit_status(1);
+ return;
+ },
+ }
+ }
+
+ loop {
+ let line = readline::mal_readline("user> ");
+ match line { None => break, _ => () }
+ match rep(line.unwrap(), repl_env.clone()) {
+ Ok(str) => println!("{}", str),
+ Err(str) => println!("Error: {}", str),
+ }
+ }
+}
generated by cgit v1.2.3 (git 2.25.1) at 2026-01-08 21:54:01 +0000