Commit | Line | Data |
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c3023f26 JM |
1 | function step7_quote(varargin), main(varargin), end |
2 | ||
3 | % read | |
4 | function ret = READ(str) | |
5 | ret = reader.read_str(str); | |
6 | end | |
7 | ||
8 | % eval | |
9 | function ret = is_pair(ast) | |
c4033aab | 10 | ret = iscell(ast) && length(ast) > 0; |
c3023f26 JM |
11 | end |
12 | ||
13 | function ret = quasiquote(ast) | |
14 | if ~is_pair(ast) | |
15 | ret = {types.Symbol('quote'), ast}; | |
16 | elseif isa(ast{1},'types.Symbol') && ... | |
17 | strcmp(ast{1}.name, 'unquote') | |
18 | ret = ast{2}; | |
19 | elseif is_pair(ast{1}) && isa(ast{1}{1},'types.Symbol') && ... | |
20 | strcmp(ast{1}{1}.name, 'splice-unquote') | |
21 | ret = {types.Symbol('concat'), ... | |
22 | ast{1}{2}, ... | |
23 | quasiquote(ast(2:end))}; | |
24 | else | |
25 | ret = {types.Symbol('cons'), ... | |
26 | quasiquote(ast{1}), ... | |
27 | quasiquote(ast(2:end))}; | |
28 | end | |
29 | end | |
30 | ||
31 | function ret = eval_ast(ast, env) | |
32 | switch class(ast) | |
33 | case 'types.Symbol' | |
34 | ret = env.get(ast); | |
35 | case 'cell' | |
36 | ret = {}; | |
37 | for i=1:length(ast) | |
38 | ret{end+1} = EVAL(ast{i}, env); | |
39 | end | |
40 | otherwise | |
41 | ret = ast; | |
42 | end | |
43 | end | |
44 | ||
45 | function ret = EVAL(ast, env) | |
46 | while true | |
47 | if ~iscell(ast) | |
48 | ret = eval_ast(ast, env); | |
49 | return; | |
50 | end | |
51 | ||
52 | % apply | |
53 | if isa(ast{1},'types.Symbol') | |
54 | a1sym = ast{1}.name; | |
55 | else | |
56 | a1sym = '_@$fn$@_'; | |
57 | end | |
58 | switch (a1sym) | |
59 | case 'def!' | |
60 | ret = env.set(ast{2}, EVAL(ast{3}, env)); | |
61 | return; | |
62 | case 'let*' | |
63 | let_env = Env(env); | |
64 | for i=1:2:length(ast{2}) | |
65 | let_env.set(ast{2}{i}, EVAL(ast{2}{i+1}, let_env)); | |
66 | end | |
67 | env = let_env; | |
68 | ast = ast{3}; % TCO | |
69 | case 'quote' | |
70 | ret = ast{2}; | |
71 | return; | |
72 | case 'quasiquote' | |
73 | ast = quasiquote(ast{2}); % TCO | |
74 | case 'do' | |
75 | el = eval_ast(ast(2:end-1), env); | |
76 | ast = ast{end}; % TCO | |
77 | case 'if' | |
78 | cond = EVAL(ast{2}, env); | |
79 | if strcmp(class(cond), 'types.Nil') || ... | |
80 | (islogical(cond) && cond == false) | |
81 | if length(ast) > 3 | |
82 | ast = ast{4}; % TCO | |
83 | else | |
84 | ret = types.nil; | |
85 | return; | |
86 | end | |
87 | else | |
88 | ast = ast{3}; % TCO | |
89 | end | |
90 | case 'fn*' | |
91 | fn = @(varargin) EVAL(ast{3}, Env(env, ast{2}, varargin)); | |
92 | ret = Function(fn, ast{3}, env, ast{2}); | |
93 | return; | |
94 | otherwise | |
95 | el = eval_ast(ast, env); | |
96 | f = el{1}; | |
97 | args = el(2:end); | |
98 | if isa(f, 'Function') | |
99 | env = Env(f.env, f.params, args); | |
100 | ast = f.ast; % TCO | |
101 | else | |
102 | ret = f(args{:}); | |
103 | return | |
104 | end | |
105 | end | |
106 | end | |
107 | end | |
108 | ||
109 | ||
110 | function ret = PRINT(ast) | |
111 | ret = printer.pr_str(ast, true); | |
112 | end | |
113 | ||
114 | % REPL | |
115 | function ret = rep(str, env) | |
116 | ret = PRINT(EVAL(READ(str), env)); | |
117 | end | |
118 | ||
119 | function main(args) | |
120 | repl_env = Env(false); | |
121 | ||
122 | % core.m: defined using matlab | |
123 | ns = core.ns(); ks = ns.keys(); | |
124 | for i=1:length(ks) | |
125 | k = ks{i}; | |
126 | repl_env.set(types.Symbol(k), ns(k)); | |
127 | end | |
128 | repl_env.set(types.Symbol('eval'), @(a) EVAL(a, repl_env)); | |
129 | repl_env.set(types.Symbol('*ARGV*'), args(2:end)); | |
130 | ||
131 | % core.mal: defined using the langauge itself | |
132 | rep('(def! not (fn* (a) (if a false true)))', repl_env); | |
133 | rep('(def! load-file (fn* (f) (eval (read-string (str "(do " (slurp f) ")")))))"', repl_env); | |
134 | ||
135 | if ~isempty(args) | |
136 | rep(strcat('(load-file "', args{1}, '")'), repl_env); | |
137 | quit; | |
138 | end | |
139 | ||
140 | %cleanObj = onCleanup(@() disp('*** here1 ***')); | |
141 | while (true) | |
142 | line = input('user> ', 's'); | |
143 | if strcmp(strtrim(line),''), continue, end | |
144 | try | |
145 | fprintf('%s\n', rep(line, repl_env)); | |
146 | catch err | |
147 | fprintf('Error: %s\n', err.message); | |
148 | fprintf('%s\n', getReport(err, 'extended')); | |
149 | end | |
150 | end | |
151 | end |