[jackhill/mal.git] / cs / step8_macros.cs

using System;
using System.IO;
using System.Collections;
using System.Collections.Generic;
using Mal;
using MalVal = Mal.types.MalVal;
using MalString = Mal.types.MalString;
using MalSymbol = Mal.types.MalSymbol;
using MalInteger = Mal.types.MalInteger;
using MalList = Mal.types.MalList;
using MalVector = Mal.types.MalVector;
using MalHashMap = Mal.types.MalHashMap;
using MalFunction = Mal.types.MalFunction;
using Env = Mal.env.Env;

namespace Mal {
    class step8_macros {
        // read
        static MalVal READ(string str) {
            return reader.read_str(str);
        }

        // eval
        public static bool is_pair(MalVal x) {
            return x is MalList && ((MalList)x).size() > 0;
        }

        public static MalVal quasiquote(MalVal ast) {
            if (!is_pair(ast)) {
                return new MalList(new MalSymbol("quote"), ast);
            } else {
                MalVal a0 = ((MalList)ast)[0];
                if ((a0 is MalSymbol) &&
                    (((MalSymbol)a0).getName() == "unquote")) {
                    return ((MalList)ast)[1];
                } else if (is_pair(a0)) {
                    MalVal a00 = ((MalList)a0)[0];
                    if ((a00 is MalSymbol) &&
                        (((MalSymbol)a00).getName() == "splice-unquote")) {
                        return new MalList(new MalSymbol("concat"),
                                           ((MalList)a0)[1],
                                           quasiquote(((MalList)ast).rest()));
                    }
                }
                return new MalList(new MalSymbol("cons"),
                                   quasiquote(a0),
                                   quasiquote(((MalList)ast).rest()));
            }
        }

        public static bool is_macro_call(MalVal ast, Env env) {
            if (ast is MalList) {
                MalVal a0 = ((MalList)ast)[0];
                if (a0 is MalSymbol &&
                    env.find(((MalSymbol)a0).getName()) != null) {
                    MalVal mac = env.get(((MalSymbol)a0).getName());
                    if (mac is MalFunction &&
                        ((MalFunction)mac).isMacro()) {
                        return true;
                    }
                }
            }
            return false;
        }

        public static MalVal macroexpand(MalVal ast, Env env) {
            while (is_macro_call(ast, env)) {
                MalSymbol a0 = (MalSymbol)((MalList)ast)[0];
                MalFunction mac = (MalFunction) env.get(a0.getName());
                ast = mac.apply(((MalList)ast).rest());
            }
            return ast;
        }

        static MalVal eval_ast(MalVal ast, Env env) {
            if (ast is MalSymbol) {
                MalSymbol sym = (MalSymbol)ast;
                return env.get(sym.getName());
            } else if (ast is MalList) {
                MalList old_lst = (MalList)ast;
                MalList new_lst = ast.list_Q() ? new MalList()
                                            : (MalList)new MalVector();
                foreach (MalVal mv in old_lst.getValue()) {
                    new_lst.conj_BANG(EVAL(mv, env));
                }
                return new_lst;
            } else if (ast is MalHashMap) {
                var new_dict = new Dictionary<string, MalVal>();
                foreach (var entry in ((MalHashMap)ast).getValue()) {
                    new_dict.Add(entry.Key, EVAL((MalVal)entry.Value, env));
                }
                return new MalHashMap(new_dict);
            } else {
                return ast;
            }
        }


        static MalVal EVAL(MalVal orig_ast, Env env) {
            MalVal a0, a1, a2, res;
            MalList el;

            while (true) {

            //System.out.println("EVAL: " + printer._pr_str(orig_ast, true));
            if (!orig_ast.list_Q()) {
                return eval_ast(orig_ast, env);
            }

            // apply list
            MalVal expanded = macroexpand(orig_ast, env);
            if (!expanded.list_Q()) { return expanded; } 
            MalList ast = (MalList) expanded;

            if (ast.size() == 0) { return ast; }
            a0 = ast[0];

            String a0sym = a0 is MalSymbol ? ((MalSymbol)a0).getName()
                                           : "__<*fn*>__";

            switch (a0sym) {
            case "def!":
                a1 = ast[1];
                a2 = ast[2];
                res = EVAL(a2, env);
                env.set(((MalSymbol)a1).getName(), res);
                return res;
            case "let*":
                a1 = ast[1];
                a2 = ast[2];
                MalSymbol key;
                MalVal val;
                Env let_env = new Env(env);
                for(int i=0; i<((MalList)a1).size(); i+=2) {
                    key = (MalSymbol)((MalList)a1)[i];
                    val = ((MalList)a1)[i+1];
                    let_env.set(key.getName(), EVAL(val, let_env));
                }
                return EVAL(a2, let_env);
            case "quote":
                return ast[1];
            case "quasiquote":
                return EVAL(quasiquote(ast[1]), env);
            case "defmacro!":
                a1 = ast[1];
                a2 = ast[2];
                res = EVAL(a2, env);
                ((MalFunction)res).setMacro();
                env.set(((MalSymbol)a1).getName(), res);
                return res;
            case "macroexpand":
                a1 = ast[1];
                return macroexpand(a1, env);
            case "do":
                eval_ast(ast.slice(1, ast.size()-1), env);
                orig_ast = ast[ast.size()-1];
                break;
            case "if":
                a1 = ast[1];
                MalVal cond = EVAL(a1, env);
                if (cond == Mal.types.Nil || cond == Mal.types.False) {
                    // eval false slot form
                    if (ast.size() > 3) {
                        orig_ast = ast[3];
                    } else {
                        return Mal.types.Nil;
                    }
                } else {
                    // eval true slot form
                    orig_ast = ast[2];
                }
                break;
            case "fn*":
                MalList a1f = (MalList)ast[1];
                MalVal a2f = ast[2];
                Env cur_env = env;
                return new MalFunction(a2f, env, a1f,
                    args => EVAL(a2f, new Env(cur_env, a1f, args)) );
            default:
                el = (MalList)eval_ast(ast, env);
                var f = (MalFunction)el[0];
                MalVal fnast = f.getAst();
                if (fnast != null) {
                    orig_ast = fnast;
                    env = f.genEnv(el.rest());
                } else {
                    return f.apply(el.rest());
                }
                break;
            }

            }
        }

        // print
        static string PRINT(MalVal exp) {
            return printer._pr_str(exp, true);
        }

        // repl
        static MalVal RE(Env env, string str) {
            return EVAL(READ(str), env);
        }

        static void Main(string[] args) {
            string prompt = "user> ";
            
            // core.cs: defined using C#
            var repl_env = new env.Env(null);
            foreach (var entry in core.ns) {
                repl_env.set(entry.Key, entry.Value);
            }
            repl_env.set("eval", new MalFunction(a => EVAL(a[0], repl_env)));
            MalList _argv = new MalList();
            for (int i=1; i < args.Length; i++) {
                _argv.conj_BANG(new MalString(args[i]));
            }
            repl_env.set("*ARGV*", _argv);

            // core.mal: defined using the language itself
            RE(repl_env, "(def! not (fn* (a) (if a false true)))");
            RE(repl_env, "(def! load-file (fn* (f) (eval (read-string (str \"(do \" (slurp f) \")\")))))");
            RE(repl_env, "(defmacro! cond (fn* (& xs) (if (> (count xs) 0) (list 'if (first xs) (if (> (count xs) 1) (nth xs 1) (throw \"odd number of forms to cond\")) (cons 'cond (rest (rest xs)))))))");
            RE(repl_env, "(defmacro! or (fn* (& xs) (if (empty? xs) nil (if (= 1 (count xs)) (first xs) `(let* (or_FIXME ~(first xs)) (if or_FIXME or_FIXME (or ~@(rest xs))))))))");

            int fileIdx = 0;
            if (args.Length > 0 && args[0] == "--raw") {
                Mal.readline.mode = Mal.readline.Mode.Raw;
                fileIdx = 1;
            }
            if (args.Length > fileIdx) {
                RE(repl_env, "(load-file \"" + args[fileIdx] + "\")");
                return;
            }
            
            // repl loop
            while (true) {
                string line;
                try {
                    line = Mal.readline.Readline(prompt);
                    if (line == null) { break; }
                } catch (IOException e) {
                    Console.WriteLine("IOException: " + e.Message);
                    break;
                }
                try {
                    Console.WriteLine(PRINT(RE(repl_env, line)));
                } catch (Mal.types.MalContinue) {
                    continue;
                } catch (Exception e) {
                    Console.WriteLine("Error: " + e.Message);
                    Console.WriteLine(e.StackTrace);
                    continue;
                }
            }
        }
    }
}
Commit	Line	Data
faa20db2 JM	1	using System;
	2	using System.IO;
	3	using System.Collections;
	4	using System.Collections.Generic;
	5	using Mal;
	6	using MalVal = Mal.types.MalVal;
	7	using MalString = Mal.types.MalString;
	8	using MalSymbol = Mal.types.MalSymbol;
	9	using MalInteger = Mal.types.MalInteger;
	10	using MalList = Mal.types.MalList;
	11	using MalVector = Mal.types.MalVector;
	12	using MalHashMap = Mal.types.MalHashMap;
	13	using MalFunction = Mal.types.MalFunction;
	14	using Env = Mal.env.Env;
	15
	16	namespace Mal {
8cb5cda4	17	class step8_macros {
faa20db2 JM	18	// read
	19	static MalVal READ(string str) {
	20	return reader.read_str(str);
	21	}
	22
	23	// eval
	24	public static bool is_pair(MalVal x) {
	25	return x is MalList && ((MalList)x).size() > 0;
	26	}
	27
	28	public static MalVal quasiquote(MalVal ast) {
	29	if (!is_pair(ast)) {
	30	return new MalList(new MalSymbol("quote"), ast);
	31	} else {
	32	MalVal a0 = ((MalList)ast)[0];
	33	if ((a0 is MalSymbol) &&
	34	(((MalSymbol)a0).getName() == "unquote")) {
	35	return ((MalList)ast)[1];
	36	} else if (is_pair(a0)) {
	37	MalVal a00 = ((MalList)a0)[0];
	38	if ((a00 is MalSymbol) &&
	39	(((MalSymbol)a00).getName() == "splice-unquote")) {
	40	return new MalList(new MalSymbol("concat"),
	41	((MalList)a0)[1],
	42	quasiquote(((MalList)ast).rest()));
	43	}
	44	}
	45	return new MalList(new MalSymbol("cons"),
	46	quasiquote(a0),
	47	quasiquote(((MalList)ast).rest()));
	48	}
	49	}
	50
	51	public static bool is_macro_call(MalVal ast, Env env) {
	52	if (ast is MalList) {
	53	MalVal a0 = ((MalList)ast)[0];
	54	if (a0 is MalSymbol &&
	55	env.find(((MalSymbol)a0).getName()) != null) {
	56	MalVal mac = env.get(((MalSymbol)a0).getName());
	57	if (mac is MalFunction &&
	58	((MalFunction)mac).isMacro()) {
	59	return true;
	60	}
	61	}
	62	}
	63	return false;
	64	}
	65
	66	public static MalVal macroexpand(MalVal ast, Env env) {
	67	while (is_macro_call(ast, env)) {
	68	MalSymbol a0 = (MalSymbol)((MalList)ast)[0];
	69	MalFunction mac = (MalFunction) env.get(a0.getName());
	70	ast = mac.apply(((MalList)ast).rest());
	71	}
	72	return ast;
	73	}
	74
	75	static MalVal eval_ast(MalVal ast, Env env) {
	76	if (ast is MalSymbol) {
	77	MalSymbol sym = (MalSymbol)ast;
	78	return env.get(sym.getName());
	79	} else if (ast is MalList) {
	80	MalList old_lst = (MalList)ast;
	81	MalList new_lst = ast.list_Q() ? new MalList()
82	: (MalList)new MalVector();
83	foreach (MalVal mv in old_lst.getValue()) {
84	new_lst.conj_BANG(EVAL(mv, env));
85	}
86	return new_lst;
87	} else if (ast is MalHashMap) {
88	var new_dict = new Dictionary<string, MalVal>();
89	foreach (var entry in ((MalHashMap)ast).getValue()) {
90	new_dict.Add(entry.Key, EVAL((MalVal)entry.Value, env));
91	}
92	return new MalHashMap(new_dict);
93	} else {
94	return ast;
95	}
96	}
97
98
99	static MalVal EVAL(MalVal orig_ast, Env env) {
100	MalVal a0, a1, a2, res;
101	MalList el;
102
103	while (true) {
104
105	//System.out.println("EVAL: " + printer._pr_str(orig_ast, true));
106	if (!orig_ast.list_Q()) {
107	return eval_ast(orig_ast, env);
108	}
109
110	// apply list
111	MalVal expanded = macroexpand(orig_ast, env);
112	if (!expanded.list_Q()) { return expanded; }
113	MalList ast = (MalList) expanded;
114
115	if (ast.size() == 0) { return ast; }
116	a0 = ast[0];
117
118	String a0sym = a0 is MalSymbol ? ((MalSymbol)a0).getName()
119	: "__<fn>__";
120
121	switch (a0sym) {
122	case "def!":
123	a1 = ast[1];
124	a2 = ast[2];
125	res = EVAL(a2, env);
126	env.set(((MalSymbol)a1).getName(), res);
127	return res;
128	case "let*":
129	a1 = ast[1];
130	a2 = ast[2];
131	MalSymbol key;
132	MalVal val;
133	Env let_env = new Env(env);
134	for(int i=0; i<((MalList)a1).size(); i+=2) {
135	key = (MalSymbol)((MalList)a1)[i];
136	val = ((MalList)a1)[i+1];
137	let_env.set(key.getName(), EVAL(val, let_env));
138	}
139	return EVAL(a2, let_env);
140	case "quote":
141	return ast[1];
142	case "quasiquote":
143	return EVAL(quasiquote(ast[1]), env);
144	case "defmacro!":
145	a1 = ast[1];
146	a2 = ast[2];
147	res = EVAL(a2, env);
148	((MalFunction)res).setMacro();
149	env.set(((MalSymbol)a1).getName(), res);
150	return res;
151	case "macroexpand":
152	a1 = ast[1];
153	return macroexpand(a1, env);
154	case "do":
155	eval_ast(ast.slice(1, ast.size()-1), env);
156	orig_ast = ast[ast.size()-1];
157	break;
158	case "if":
159	a1 = ast[1];
160	MalVal cond = EVAL(a1, env);
161	if (cond == Mal.types.Nil \|\| cond == Mal.types.False) {
162	// eval false slot form
163	if (ast.size() > 3) {
164	orig_ast = ast[3];
165	} else {
166	return Mal.types.Nil;
167	}
168	} else {
169	// eval true slot form
170	orig_ast = ast[2];
171	}
172	break;
173	case "fn*":
174	MalList a1f = (MalList)ast[1];
175	MalVal a2f = ast[2];
176	Env cur_env = env;
177	return new MalFunction(a2f, env, a1f,
178	args => EVAL(a2f, new Env(cur_env, a1f, args)) );
179	default:
180	el = (MalList)eval_ast(ast, env);
181	var f = (MalFunction)el[0];
182	MalVal fnast = f.getAst();
183	if (fnast != null) {
184	orig_ast = fnast;
185	env = f.genEnv(el.rest());
186	} else {
187	return f.apply(el.rest());
188	}
189	break;
190	}
191
192	}
193	}
194
195	// print
196	static string PRINT(MalVal exp) {
197	return printer._pr_str(exp, true);
198	}
199
86b689f3	200	// repl
faa20db2 JM	201	static MalVal RE(Env env, string str) {
	202	return EVAL(READ(str), env);
	203	}
faa20db2 JM	204
	205	static void Main(string[] args) {
	206	string prompt = "user> ";
	207
8cb5cda4 JM	208	// core.cs: defined using C#
	209	var repl_env = new env.Env(null);
	210	foreach (var entry in core.ns) {
	211	repl_env.set(entry.Key, entry.Value);
faa20db2	212	}
8cb5cda4	213	repl_env.set("eval", new MalFunction(a => EVAL(a[0], repl_env)));
86b689f3 JM	214	MalList _argv = new MalList();
	215	for (int i=1; i < args.Length; i++) {
	216	_argv.conj_BANG(new MalString(args[i]));
	217	}
	218	repl_env.set("ARGV", _argv);
faa20db2	219
8cb5cda4	220	// core.mal: defined using the language itself
faa20db2 JM	221	RE(repl_env, "(def! not (fn* (a) (if a false true)))");
faa20db2 JM	222	RE(repl_env, "(def! load-file (fn* (f) (eval (read-string (str \"(do \" (slurp f) \")\")))))");
8cb5cda4 JM	223	RE(repl_env, "(defmacro! cond (fn* (& xs) (if (> (count xs) 0) (list 'if (first xs) (if (> (count xs) 1) (nth xs 1) (throw \"odd number of forms to cond\")) (cons 'cond (rest (rest xs)))))))");
8cb5cda4 JM	224	RE(repl_env, "(defmacro! or (fn* (& xs) (if (empty? xs) nil (if (= 1 (count xs)) (first xs) `(let* (or_FIXME ~(first xs)) (if or_FIXME or_FIXME (or ~@(rest xs))))))))");
faa20db2 JM	225
	226	int fileIdx = 0;
	227	if (args.Length > 0 && args[0] == "--raw") {
	228	Mal.readline.mode = Mal.readline.Mode.Raw;
	229	fileIdx = 1;
	230	}
	231	if (args.Length > fileIdx) {
86b689f3	232	RE(repl_env, "(load-file \"" + args[fileIdx] + "\")");
faa20db2 JM	233	return;
faa20db2 JM	234	}
86b689f3 JM	235
86b689f3 JM	236	// repl loop
faa20db2 JM	237	while (true) {
	238	string line;
	239	try {
	240	line = Mal.readline.Readline(prompt);
	241	if (line == null) { break; }
	242	} catch (IOException e) {
	243	Console.WriteLine("IOException: " + e.Message);
	244	break;
	245	}
	246	try {
	247	Console.WriteLine(PRINT(RE(repl_env, line)));
	248	} catch (Mal.types.MalContinue) {
	249	continue;
faa20db2 JM	250	} catch (Exception e) {
	251	Console.WriteLine("Error: " + e.Message);
	252	Console.WriteLine(e.StackTrace);
	253	continue;
	254	}
	255	}
	256	}
	257	}
	258	}