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1 | #! /usr/bin/env crystal run |
2 | |
3 | require "./readline" |
4 | require "./reader" |
5 | require "./printer" |
6 | require "./types" |
7 | require "./env" |
8 | require "./core" |
9 | require "./error" |
10 | |
11 | # Note: |
12 | # Employed downcase names because Crystal prohibits uppercase names for methods |
13 | |
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14 | module Mal |
15 | extend self |
16 | |
17 | def func_of(env, binds, body) |
18 | -> (args : Array(Mal::Type)) { |
19 | new_env = Mal::Env.new(env, binds, args) |
20 | eval(body, new_env) |
21 | } as Mal::Func |
22 | end |
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23 | |
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24 | def eval_ast(ast, env) |
25 | return ast.map{|n| eval(n, env) as Mal::Type} if ast.is_a? Mal::List |
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26 | |
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27 | val = ast.unwrap |
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28 | |
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29 | Mal::Type.new case val |
30 | when Mal::Symbol |
31 | if e = env.get(val.str) |
32 | e |
33 | else |
34 | eval_error "'#{val.str}' not found" |
35 | end |
36 | when Mal::List |
37 | val.each_with_object(Mal::List.new){|n, l| l << eval(n, env)} |
38 | when Mal::Vector |
39 | val.each_with_object(Mal::Vector.new){|n, l| l << eval(n, env)} |
40 | when Array(Mal::Type) |
41 | val.map{|n| eval(n, env)} |
42 | when Mal::HashMap |
43 | val.each{|k, v| val[k] = eval(v, env)} |
44 | val |
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45 | else |
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46 | val |
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47 | end |
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48 | end |
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49 | |
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50 | def eval_invocation(list, env) |
51 | f = eval(list.first, env).unwrap |
52 | case f |
53 | when Mal::Closure |
54 | f.fn.call eval_ast(list[1..-1].each_with_object(Mal::List.new){|i, l| l << i}, env) |
55 | when Mal::Func |
56 | f.call eval_ast(list[1..-1].each_with_object(Mal::List.new){|i, l| l << i}, env) |
57 | else |
58 | eval_error "expected function as the first argument" |
59 | end |
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60 | end |
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61 | |
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62 | def read(str) |
63 | read_str str |
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64 | end |
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65 | |
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66 | macro invoke_list(l, env) |
67 | f = eval({{l}}.first, {{env}}).unwrap |
68 | args = eval_ast({{l}}[1..-1].each_with_object(Mal::List.new){|i, l| l << i}, {{env}}) |
69 | case f |
70 | when Mal::Closure |
71 | ast = f.ast |
72 | {{env}} = Mal::Env.new(f.env, f.params, args) |
73 | next # TCO |
74 | when Mal::Func |
75 | return f.call args |
76 | else |
77 | eval_error "expected function as the first argument" |
78 | end |
79 | end |
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80 | |
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81 | def eval(ast, env) |
82 | # 'next' in 'do...end' has a bug in crystal 0.7.1 |
83 | # https://github.com/manastech/crystal/issues/659 |
84 | while true |
85 | list = ast.unwrap |
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86 | |
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87 | return eval_ast(ast, env) unless list.is_a? Mal::List |
88 | return gen_type Mal::List if list.empty? |
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89 | |
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90 | head = list.first.unwrap |
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91 | |
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92 | unless head.is_a? Mal::Symbol |
93 | invoke_list(list, env) |
94 | end |
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95 | |
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96 | return Mal::Type.new case head.str |
97 | when "def!" |
98 | eval_error "wrong number of argument for 'def!'" unless list.size == 3 |
99 | a1 = list[1].unwrap |
100 | eval_error "1st argument of 'def!' must be symbol" unless a1.is_a? Mal::Symbol |
101 | env.set(a1.str, eval(list[2], env)) |
102 | when "let*" |
103 | eval_error "wrong number of argument for 'def!'" unless list.size == 3 |
104 | |
105 | bindings = list[1].unwrap |
106 | eval_error "1st argument of 'let*' must be list or vector" unless bindings.is_a? Array |
107 | eval_error "size of binding list must be even" unless bindings.size.even? |
108 | |
109 | new_env = Mal::Env.new env |
110 | bindings.each_slice(2) do |binding| |
111 | key, value = binding |
112 | name = key.unwrap |
113 | eval_error "name of binding must be specified as symbol" unless name.is_a? Mal::Symbol |
114 | new_env.set(name.str, eval(value, new_env)) |
115 | end |
116 | |
117 | ast, env = list[2], new_env |
118 | next # TCO |
119 | when "do" |
120 | if list.empty? |
121 | ast = Mal::Type.new nil |
122 | next |
123 | end |
124 | |
125 | eval_ast(list[1..-2].each_with_object(Mal::List.new){|i,l| l << i}, env) |
126 | ast = list.last |
127 | next # TCO |
128 | when "if" |
129 | ast = unless eval(list[1], env).unwrap |
130 | list.size >= 4 ? list[3] : Mal::Type.new(nil) |
131 | else |
132 | list[2] |
133 | end |
134 | next # TCO |
135 | when "fn*" |
136 | params = list[1].unwrap |
137 | unless params.is_a?(Mal::List) || params.is_a?(Mal::Vector) |
138 | eval_error "'fn*' parameters must be list" |
139 | end |
140 | Mal::Closure.new(list[2], params, env, func_of(env, params, list[2])) |
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141 | else |
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142 | invoke_list(list, env) |
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143 | end |
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144 | end |
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145 | end |
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146 | |
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147 | def print(result) |
148 | pr_str(result, true) |
149 | end |
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150 | |
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151 | def rep(str) |
152 | print(eval(read(str), $repl_env)) |
153 | end |
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154 | end |
155 | |
156 | $repl_env = Mal::Env.new nil |
157 | Mal::NS.each{|k,v| $repl_env.set(k, Mal::Type.new(v))} |
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158 | $repl_env.set("eval", Mal::Type.new -> (args: Array(Mal::Type)){ Mal.eval(args[0], $repl_env) }) |
159 | Mal.rep "(def! not (fn* (a) (if a false true)))" |
160 | Mal.rep "(def! load-file (fn* (f) (eval (read-string (str \"(do \" (slurp f) \")\")))))" |
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161 | $argv = Mal::List.new |
162 | $repl_env.set("*ARGV*", Mal::Type.new $argv) |
163 | |
164 | unless ARGV.empty? |
165 | if ARGV.size > 1 |
166 | ARGV[1..-1].each do |a| |
167 | $argv << Mal::Type.new(a) |
168 | end |
169 | end |
170 | |
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171 | Mal.rep "(load-file \"#{ARGV[0]}\")" |
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172 | exit |
173 | end |
174 | |
175 | while line = my_readline("user> ") |
176 | begin |
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177 | puts Mal.rep(line) |
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178 | rescue e |
179 | STDERR.puts e |
180 | end |
181 | end |