Commit | Line | Data |
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4ef4b17c JM |
1 | use std::rc::Rc; |
2 | //use std::collections::HashMap; | |
3 | use fnv::FnvHashMap; | |
4 | use itertools::Itertools; | |
5 | ||
6 | #[macro_use] | |
7 | extern crate lazy_static; | |
8 | extern crate regex; | |
9 | extern crate itertools; | |
10 | extern crate fnv; | |
11 | ||
12 | extern crate rustyline; | |
13 | use rustyline::error::ReadlineError; | |
14 | use rustyline::Editor; | |
15 | ||
16 | #[macro_use] | |
17 | mod types; | |
18 | use types::{MalVal,MalArgs,MalRet,MalErr,error,format_error}; | |
19 | use types::MalVal::{Nil,Bool,Sym,List,Vector,Hash,Func,MalFunc}; | |
20 | mod reader; | |
21 | mod printer; | |
22 | mod env; | |
23 | use env::{Env,env_new,env_bind,env_get,env_set,env_sets}; | |
24 | #[macro_use] | |
25 | mod core; | |
26 | ||
27 | // read | |
28 | fn read(str: &str) -> MalRet { | |
29 | reader::read_str(str.to_string()) | |
30 | } | |
31 | ||
32 | // eval | |
33 | fn eval_ast(ast: &MalVal, env: &Env) -> MalRet { | |
34 | match ast { | |
35 | Sym(_) => Ok(env_get(&env, &ast)?), | |
36 | List(v,_) => { | |
37 | let mut lst: MalArgs = vec![]; | |
38 | for a in v.iter() { lst.push(eval(a.clone(), env.clone())?) } | |
39 | Ok(list!(lst)) | |
40 | }, | |
41 | Vector(v,_) => { | |
42 | let mut lst: MalArgs = vec![]; | |
43 | for a in v.iter() { lst.push(eval(a.clone(), env.clone())?) } | |
44 | Ok(vector!(lst)) | |
45 | }, | |
46 | Hash(hm,_) => { | |
47 | let mut new_hm: FnvHashMap<String,MalVal> = FnvHashMap::default(); | |
48 | for (k,v) in hm.iter() { | |
49 | new_hm.insert(k.to_string(), eval(v.clone(), env.clone())?); | |
50 | } | |
51 | Ok(Hash(Rc::new(new_hm),Rc::new(Nil))) | |
52 | }, | |
53 | _ => Ok(ast.clone()), | |
54 | } | |
55 | } | |
56 | ||
57 | fn eval(mut ast: MalVal, mut env: Env) -> MalRet { | |
58 | let ret: MalRet; | |
59 | ||
60 | 'tco: loop { | |
61 | ||
62 | ret = match ast.clone() { | |
63 | List(l,_) => { | |
64 | if l.len() == 0 { return Ok(ast); } | |
65 | let a0 = &l[0]; | |
66 | match a0 { | |
67 | Sym(ref a0sym) if a0sym == "def!" => { | |
68 | env_set(&env, l[1].clone(), eval(l[2].clone(), env.clone())?) | |
69 | }, | |
70 | Sym(ref a0sym) if a0sym == "let*" => { | |
71 | env = env_new(Some(env.clone())); | |
72 | let (a1, a2) = (l[1].clone(), l[2].clone()); | |
73 | match a1 { | |
74 | List(ref binds,_) | Vector(ref binds,_) => { | |
75 | for (b, e) in binds.iter().tuples() { | |
76 | match b { | |
77 | Sym(_) => { | |
78 | let _ = env_set(&env, b.clone(), | |
79 | eval(e.clone(), env.clone())?); | |
80 | }, | |
81 | _ => { | |
82 | return error("let* with non-Sym binding"); | |
83 | } | |
84 | } | |
85 | } | |
86 | }, | |
87 | _ => { | |
88 | return error("let* with non-List bindings"); | |
89 | } | |
90 | }; | |
91 | ast = a2; | |
92 | continue 'tco; | |
93 | }, | |
94 | Sym(ref a0sym) if a0sym == "do" => { | |
95 | match eval_ast(&list!(l[1..l.len()-1].to_vec()), &env)? { | |
96 | List(_,_) => { | |
97 | ast = l.last().unwrap_or(&Nil).clone(); | |
98 | continue 'tco; | |
99 | }, | |
100 | _ => error("invalid do form"), | |
101 | } | |
102 | }, | |
103 | Sym(ref a0sym) if a0sym == "if" => { | |
104 | let cond = eval(l[1].clone(), env.clone())?; | |
105 | match cond { | |
106 | Bool(false) | Nil if l.len() >= 4 => { | |
107 | ast = l[3].clone(); | |
108 | continue 'tco; | |
109 | }, | |
110 | Bool(false) | Nil => Ok(Nil), | |
111 | _ if l.len() >= 3 => { | |
112 | ast = l[2].clone(); | |
113 | continue 'tco; | |
114 | }, | |
115 | _ => Ok(Nil) | |
116 | } | |
117 | }, | |
118 | Sym(ref a0sym) if a0sym == "fn*" => { | |
119 | let (a1, a2) = (l[1].clone(), l[2].clone()); | |
120 | Ok(MalFunc{eval: eval, ast: Rc::new(a2), env: env, | |
121 | params: Rc::new(a1), is_macro: false, | |
122 | meta: Rc::new(Nil)}) | |
123 | }, | |
124 | _ => { | |
125 | match eval_ast(&ast, &env)? { | |
126 | List(ref el,_) => { | |
127 | let ref f = el[0].clone(); | |
128 | let args = el[1..].to_vec(); | |
129 | match f { | |
130 | Func(_,_) => f.apply(args), | |
131 | MalFunc{ast: mast, env: menv, params, ..} => { | |
132 | let a = &**mast; | |
133 | let p = &**params; | |
134 | env = env_bind(Some(menv.clone()), p.clone(), args)?; | |
135 | ast = a.clone(); | |
136 | continue 'tco; | |
137 | }, | |
138 | _ => error("attempt to call non-function"), | |
139 | } | |
140 | }, | |
141 | _ => { | |
142 | error("expected a list") | |
143 | } | |
144 | } | |
145 | } | |
146 | } | |
147 | }, | |
148 | _ => eval_ast(&ast, &env), | |
149 | }; | |
150 | ||
151 | break; | |
152 | ||
153 | } // end 'tco loop | |
154 | ||
155 | ret | |
156 | } | |
157 | ||
158 | ||
159 | fn print(ast: &MalVal) -> String { | |
160 | ast.pr_str(true) | |
161 | } | |
162 | ||
163 | fn rep(str: &str, env: &Env) -> Result<String,MalErr> { | |
164 | let ast = read(str)?; | |
165 | let exp = eval(ast, env.clone())?; | |
166 | Ok(print(&exp)) | |
167 | } | |
168 | ||
169 | fn main() { | |
170 | // `()` can be used when no completer is required | |
171 | let mut rl = Editor::<()>::new(); | |
172 | if rl.load_history(".mal-history").is_err() { | |
6c4cc8ad | 173 | eprintln!("No previous history."); |
4ef4b17c JM |
174 | } |
175 | ||
176 | // core.rs: defined using rust | |
177 | let repl_env = env_new(None); | |
178 | for (k, v) in core::ns() { | |
179 | env_sets(&repl_env, k, v); | |
180 | } | |
181 | ||
182 | // core.mal: defined using the language itself | |
183 | let _ = rep("(def! not (fn* (a) (if a false true)))", &repl_env); | |
184 | ||
185 | // main repl loop | |
186 | loop { | |
187 | let readline = rl.readline("user> "); | |
188 | match readline { | |
189 | Ok(line) => { | |
190 | rl.add_history_entry(&line); | |
191 | rl.save_history(".mal-history").unwrap(); | |
192 | if line.len() > 0 { | |
193 | match rep(&line, &repl_env) { | |
194 | Ok(out) => println!("{}", out), | |
195 | Err(e) => println!("Error: {}", format_error(e)), | |
196 | } | |
197 | } | |
198 | }, | |
199 | Err(ReadlineError::Interrupted) => continue, | |
200 | Err(ReadlineError::Eof) => break, | |
201 | Err(err) => { | |
202 | println!("Error: {:?}", err); | |
203 | break | |
204 | } | |
205 | } | |
206 | } | |
207 | } | |
208 | ||
209 | // vim: ts=2:sw=2:expandtab |