Commit | Line | Data |
---|---|---|
9bbb8ccc | 1 | #! /usr/bin/env crystal run |
2 | ||
5185c56e | 3 | require "readline" |
9bbb8ccc | 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 | ||
97d0deb1 | 14 | module Mal |
15 | extend self | |
16 | ||
17 | def func_of(env, binds, body) | |
5185c56e | 18 | ->(args : Array(Mal::Type)) { |
97d0deb1 | 19 | new_env = Mal::Env.new(env, binds, args) |
20 | eval(body, new_env) | |
5185c56e | 21 | }.as(Mal::Func) |
97d0deb1 | 22 | end |
9bbb8ccc | 23 | |
97d0deb1 | 24 | def eval_ast(ast, env) |
5185c56e | 25 | return ast.map { |n| eval(n, env).as(Mal::Type) } if ast.is_a? Mal::List |
9bbb8ccc | 26 | |
97d0deb1 | 27 | val = ast.unwrap |
9bbb8ccc | 28 | |
97d0deb1 | 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 | |
5185c56e | 37 | val.each_with_object(Mal::List.new) { |n, l| l << eval(n, env) } |
97d0deb1 | 38 | when Mal::Vector |
5185c56e | 39 | val.each_with_object(Mal::Vector.new) { |n, l| l << eval(n, env) } |
97d0deb1 | 40 | when Array(Mal::Type) |
5185c56e | 41 | val.map { |n| eval(n, env).as(Mal::Type) } |
97d0deb1 | 42 | when Mal::HashMap |
5185c56e | 43 | val.each { |k, v| val[k] = eval(v, env) } |
97d0deb1 | 44 | val |
9bbb8ccc | 45 | else |
97d0deb1 | 46 | val |
9bbb8ccc | 47 | end |
9bbb8ccc | 48 | end |
9bbb8ccc | 49 | |
97d0deb1 | 50 | def read(str) |
51 | read_str str | |
9bbb8ccc | 52 | end |
53 | ||
97d0deb1 | 54 | macro pair?(list) |
55 | {{list}}.is_a?(Array) && !{{list}}.empty? | |
9bbb8ccc | 56 | end |
9bbb8ccc | 57 | |
97d0deb1 | 58 | def quasiquote(ast) |
59 | list = ast.unwrap | |
9bbb8ccc | 60 | |
97d0deb1 | 61 | unless pair?(list) |
62 | return Mal::Type.new( | |
63 | Mal::List.new << gen_type(Mal::Symbol, "quote") << ast | |
64 | ) | |
65 | end | |
9bbb8ccc | 66 | |
97d0deb1 | 67 | head = list.first.unwrap |
9bbb8ccc | 68 | |
97d0deb1 | 69 | case |
70 | # ("unquote" ...) | |
71 | when head.is_a?(Mal::Symbol) && head.str == "unquote" | |
72 | list[1] | |
5185c56e | 73 | # (("splice-unquote" ...) ...) |
97d0deb1 | 74 | when pair?(head) && (arg0 = head.first.unwrap).is_a?(Mal::Symbol) && arg0.str == "splice-unquote" |
5185c56e | 75 | tail = Mal::Type.new list[1..-1].each_with_object(Mal::List.new) { |e, l| l << e } |
97d0deb1 | 76 | Mal::Type.new( |
77 | Mal::List.new << gen_type(Mal::Symbol, "concat") << head[1] << quasiquote(tail) | |
78 | ) | |
9bbb8ccc | 79 | else |
5185c56e | 80 | tail = Mal::Type.new list[1..-1].each_with_object(Mal::List.new) { |e, l| l << e } |
97d0deb1 | 81 | Mal::Type.new( |
82 | Mal::List.new << gen_type(Mal::Symbol, "cons") << quasiquote(list.first) << quasiquote(tail) | |
83 | ) | |
9bbb8ccc | 84 | end |
85 | end | |
86 | ||
97d0deb1 | 87 | def macro_call?(ast, env) |
88 | list = ast.unwrap | |
89 | return false unless list.is_a? Mal::List | |
90c66423 | 90 | return false if list.empty? |
9bbb8ccc | 91 | |
97d0deb1 | 92 | sym = list.first.unwrap |
93 | return false unless sym.is_a? Mal::Symbol | |
9bbb8ccc | 94 | |
97d0deb1 | 95 | func = env.find(sym.str).try(&.data[sym.str]) |
96 | return false unless func && func.macro? | |
9bbb8ccc | 97 | |
97d0deb1 | 98 | true |
99 | end | |
9bbb8ccc | 100 | |
97d0deb1 | 101 | def macroexpand(ast, env) |
102 | while macro_call?(ast, env) | |
97d0deb1 | 103 | # Already checked in macro_call? |
5185c56e OR |
104 | list = ast.unwrap.as(Mal::List) |
105 | func_sym = list[0].unwrap.as(Mal::Symbol) | |
97d0deb1 | 106 | func = env.get(func_sym.str).unwrap |
9bbb8ccc | 107 | |
97d0deb1 | 108 | case func |
109 | when Mal::Func | |
110 | ast = func.call(list[1..-1]) | |
111 | when Mal::Closure | |
112 | ast = func.fn.call(list[1..-1]) | |
113 | else | |
114 | eval_error "macro '#{func_sym.str}' must be function: #{ast}" | |
115 | end | |
116 | end | |
9bbb8ccc | 117 | |
97d0deb1 | 118 | ast |
119 | end | |
9bbb8ccc | 120 | |
97d0deb1 | 121 | macro invoke_list(l, env) |
122 | f = eval({{l}}.first, {{env}}).unwrap | |
123 | args = eval_ast({{l}}[1..-1].each_with_object(Mal::List.new){|i, l| l << i}, {{env}}) | |
124 | case f | |
125 | when Mal::Closure | |
126 | ast = f.ast | |
127 | {{env}} = Mal::Env.new(f.env, f.params, args) | |
128 | next # TCO | |
129 | when Mal::Func | |
130 | return f.call args | |
131 | else | |
132 | eval_error "expected function as the first argument: #{f}" | |
133 | end | |
134 | end | |
9bbb8ccc | 135 | |
97d0deb1 | 136 | def eval(ast, env) |
137 | # 'next' in 'do...end' has a bug in crystal 0.7.1 | |
138 | # https://github.com/manastech/crystal/issues/659 | |
139 | while true | |
90c66423 JM |
140 | list = ast.unwrap |
141 | ||
142 | return eval_ast(ast, env) unless list.is_a? Mal::List | |
143 | return ast if list.empty? | |
97d0deb1 | 144 | |
145 | ast = macroexpand(ast, env) | |
146 | ||
147 | list = ast.unwrap | |
148 | ||
b1165f91 | 149 | return eval_ast(ast, env) unless list.is_a? Mal::List |
97d0deb1 | 150 | return ast if list.empty? |
151 | ||
152 | head = list.first.unwrap | |
153 | ||
154 | return invoke_list(list, env) unless head.is_a? Mal::Symbol | |
155 | ||
156 | return Mal::Type.new case head.str | |
5185c56e OR |
157 | when "def!" |
158 | eval_error "wrong number of argument for 'def!'" unless list.size == 3 | |
159 | a1 = list[1].unwrap | |
160 | eval_error "1st argument of 'def!' must be symbol: #{a1}" unless a1.is_a? Mal::Symbol | |
161 | env.set(a1.str, eval(list[2], env)) | |
162 | when "let*" | |
163 | eval_error "wrong number of argument for 'def!'" unless list.size == 3 | |
164 | ||
165 | bindings = list[1].unwrap | |
166 | eval_error "1st argument of 'let*' must be list or vector" unless bindings.is_a? Array | |
167 | eval_error "size of binding list must be even" unless bindings.size.even? | |
168 | ||
169 | new_env = Mal::Env.new env | |
170 | bindings.each_slice(2) do |binding| | |
171 | key, value = binding | |
172 | name = key.unwrap | |
173 | eval_error "name of binding must be specified as symbol #{name}" unless name.is_a? Mal::Symbol | |
174 | new_env.set(name.str, eval(value, new_env)) | |
175 | end | |
176 | ||
177 | ast, env = list[2], new_env | |
178 | next # TCO | |
179 | when "do" | |
180 | if list.empty? | |
181 | ast = Mal::Type.new nil | |
182 | next | |
183 | end | |
184 | ||
185 | eval_ast(list[1..-2].each_with_object(Mal::List.new) { |i, l| l << i }, env) | |
186 | ast = list.last | |
187 | next # TCO | |
188 | when "if" | |
189 | ast = unless eval(list[1], env).unwrap | |
190 | list.size >= 4 ? list[3] : Mal::Type.new(nil) | |
9bbb8ccc | 191 | else |
5185c56e OR |
192 | list[2] |
193 | end | |
194 | next # TCO | |
195 | when "fn*" | |
196 | params = list[1].unwrap | |
197 | unless params.is_a? Array | |
198 | eval_error "'fn*' parameters must be list or vector: #{params}" | |
9bbb8ccc | 199 | end |
5185c56e OR |
200 | Mal::Closure.new(list[2], params, env, func_of(env, params, list[2])) |
201 | when "quote" | |
202 | list[1] | |
203 | when "quasiquote" | |
204 | ast = quasiquote list[1] | |
205 | next # TCO | |
206 | when "defmacro!" | |
207 | eval_error "wrong number of argument for 'defmacro!'" unless list.size == 3 | |
208 | a1 = list[1].unwrap | |
209 | eval_error "1st argument of 'defmacro!' must be symbol: #{a1}" unless a1.is_a? Mal::Symbol | |
210 | env.set(a1.str, eval(list[2], env).tap { |n| n.is_macro = true }) | |
211 | when "macroexpand" | |
212 | macroexpand(list[1], env) | |
213 | else | |
214 | invoke_list(list, env) | |
215 | end | |
97d0deb1 | 216 | end |
9bbb8ccc | 217 | end |
9bbb8ccc | 218 | |
97d0deb1 | 219 | def print(result) |
220 | pr_str(result, true) | |
221 | end | |
9bbb8ccc | 222 | |
97d0deb1 | 223 | def rep(str) |
5185c56e | 224 | print(eval(read(str), REPL_ENV)) |
97d0deb1 | 225 | end |
9bbb8ccc | 226 | end |
227 | ||
5185c56e OR |
228 | REPL_ENV = Mal::Env.new nil |
229 | Mal::NS.each { |k, v| REPL_ENV.set(k, Mal::Type.new(v)) } | |
230 | REPL_ENV.set("eval", Mal::Type.new ->(args : Array(Mal::Type)) { Mal.eval(args[0], REPL_ENV) }) | |
97d0deb1 | 231 | Mal.rep "(def! not (fn* (a) (if a false true)))" |
e6d41de4 | 232 | Mal.rep "(def! load-file (fn* (f) (eval (read-string (str \"(do \" (slurp f) \"\nnil)\")))))" |
97d0deb1 | 233 | Mal.rep "(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)))))))" |
9bbb8ccc | 234 | |
5185c56e OR |
235 | argv = Mal::List.new |
236 | REPL_ENV.set("*ARGV*", Mal::Type.new argv) | |
9bbb8ccc | 237 | |
238 | unless ARGV.empty? | |
239 | if ARGV.size > 1 | |
240 | ARGV[1..-1].each do |a| | |
5185c56e | 241 | argv << Mal::Type.new(a) |
9bbb8ccc | 242 | end |
243 | end | |
244 | ||
245 | begin | |
97d0deb1 | 246 | Mal.rep "(load-file \"#{ARGV[0]}\")" |
9bbb8ccc | 247 | rescue e |
248 | STDERR.puts e | |
249 | end | |
250 | exit | |
251 | end | |
252 | ||
5185c56e | 253 | while line = Readline.readline("user> ", true) |
9bbb8ccc | 254 | begin |
97d0deb1 | 255 | puts Mal.rep(line) |
dd7a4f55 JM |
256 | rescue e : Mal::RuntimeException |
257 | STDERR.puts "Error: #{pr_str(e.thrown, true)}" | |
9bbb8ccc | 258 | rescue e |
dd7a4f55 | 259 | STDERR.puts "Error: #{e}" |
9bbb8ccc | 260 | end |
261 | end |