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 | |
9bbb8ccc | 90 | |
97d0deb1 | 91 | sym = list.first.unwrap |
92 | return false unless sym.is_a? Mal::Symbol | |
9bbb8ccc | 93 | |
97d0deb1 | 94 | func = env.find(sym.str).try(&.data[sym.str]) |
95 | return false unless func && func.macro? | |
9bbb8ccc | 96 | |
97d0deb1 | 97 | true |
98 | end | |
9bbb8ccc | 99 | |
97d0deb1 | 100 | def macroexpand(ast, env) |
101 | while macro_call?(ast, env) | |
97d0deb1 | 102 | # Already checked in macro_call? |
5185c56e OR |
103 | list = ast.unwrap.as(Mal::List) |
104 | func_sym = list[0].unwrap.as(Mal::Symbol) | |
97d0deb1 | 105 | func = env.get(func_sym.str).unwrap |
9bbb8ccc | 106 | |
97d0deb1 | 107 | case func |
108 | when Mal::Func | |
109 | ast = func.call(list[1..-1]) | |
110 | when Mal::Closure | |
111 | ast = func.fn.call(list[1..-1]) | |
112 | else | |
113 | eval_error "macro '#{func_sym.str}' must be function: #{ast}" | |
114 | end | |
115 | end | |
9bbb8ccc | 116 | |
97d0deb1 | 117 | ast |
118 | end | |
9bbb8ccc | 119 | |
97d0deb1 | 120 | macro invoke_list(l, env) |
121 | f = eval({{l}}.first, {{env}}).unwrap | |
122 | args = eval_ast({{l}}[1..-1].each_with_object(Mal::List.new){|i, l| l << i}, {{env}}) | |
123 | case f | |
124 | when Mal::Closure | |
125 | ast = f.ast | |
126 | {{env}} = Mal::Env.new(f.env, f.params, args) | |
127 | next # TCO | |
128 | when Mal::Func | |
129 | return f.call args | |
130 | else | |
131 | eval_error "expected function as the first argument: #{f}" | |
132 | end | |
133 | end | |
9bbb8ccc | 134 | |
97d0deb1 | 135 | def eval(ast, env) |
136 | # 'next' in 'do...end' has a bug in crystal 0.7.1 | |
137 | # https://github.com/manastech/crystal/issues/659 | |
138 | while true | |
139 | return eval_ast(ast, env) unless ast.unwrap.is_a? Mal::List | |
140 | ||
141 | ast = macroexpand(ast, env) | |
142 | ||
143 | list = ast.unwrap | |
144 | ||
b1165f91 | 145 | return eval_ast(ast, env) unless list.is_a? Mal::List |
97d0deb1 | 146 | return ast if list.empty? |
147 | ||
148 | head = list.first.unwrap | |
149 | ||
150 | return invoke_list(list, env) unless head.is_a? Mal::Symbol | |
151 | ||
152 | return Mal::Type.new case head.str | |
5185c56e OR |
153 | when "def!" |
154 | eval_error "wrong number of argument for 'def!'" unless list.size == 3 | |
155 | a1 = list[1].unwrap | |
156 | eval_error "1st argument of 'def!' must be symbol: #{a1}" unless a1.is_a? Mal::Symbol | |
157 | env.set(a1.str, eval(list[2], env)) | |
158 | when "let*" | |
159 | eval_error "wrong number of argument for 'def!'" unless list.size == 3 | |
160 | ||
161 | bindings = list[1].unwrap | |
162 | eval_error "1st argument of 'let*' must be list or vector" unless bindings.is_a? Array | |
163 | eval_error "size of binding list must be even" unless bindings.size.even? | |
164 | ||
165 | new_env = Mal::Env.new env | |
166 | bindings.each_slice(2) do |binding| | |
167 | key, value = binding | |
168 | name = key.unwrap | |
169 | eval_error "name of binding must be specified as symbol #{name}" unless name.is_a? Mal::Symbol | |
170 | new_env.set(name.str, eval(value, new_env)) | |
171 | end | |
172 | ||
173 | ast, env = list[2], new_env | |
174 | next # TCO | |
175 | when "do" | |
176 | if list.empty? | |
177 | ast = Mal::Type.new nil | |
178 | next | |
179 | end | |
180 | ||
181 | eval_ast(list[1..-2].each_with_object(Mal::List.new) { |i, l| l << i }, env) | |
182 | ast = list.last | |
183 | next # TCO | |
184 | when "if" | |
185 | ast = unless eval(list[1], env).unwrap | |
186 | list.size >= 4 ? list[3] : Mal::Type.new(nil) | |
9bbb8ccc | 187 | else |
5185c56e OR |
188 | list[2] |
189 | end | |
190 | next # TCO | |
191 | when "fn*" | |
192 | params = list[1].unwrap | |
193 | unless params.is_a? Array | |
194 | eval_error "'fn*' parameters must be list or vector: #{params}" | |
9bbb8ccc | 195 | end |
5185c56e OR |
196 | Mal::Closure.new(list[2], params, env, func_of(env, params, list[2])) |
197 | when "quote" | |
198 | list[1] | |
199 | when "quasiquote" | |
200 | ast = quasiquote list[1] | |
201 | next # TCO | |
202 | when "defmacro!" | |
203 | eval_error "wrong number of argument for 'defmacro!'" unless list.size == 3 | |
204 | a1 = list[1].unwrap | |
205 | eval_error "1st argument of 'defmacro!' must be symbol: #{a1}" unless a1.is_a? Mal::Symbol | |
206 | env.set(a1.str, eval(list[2], env).tap { |n| n.is_macro = true }) | |
207 | when "macroexpand" | |
208 | macroexpand(list[1], env) | |
209 | else | |
210 | invoke_list(list, env) | |
211 | end | |
97d0deb1 | 212 | end |
9bbb8ccc | 213 | end |
9bbb8ccc | 214 | |
97d0deb1 | 215 | def print(result) |
216 | pr_str(result, true) | |
217 | end | |
9bbb8ccc | 218 | |
97d0deb1 | 219 | def rep(str) |
5185c56e | 220 | print(eval(read(str), REPL_ENV)) |
97d0deb1 | 221 | end |
9bbb8ccc | 222 | end |
223 | ||
5185c56e OR |
224 | REPL_ENV = Mal::Env.new nil |
225 | Mal::NS.each { |k, v| REPL_ENV.set(k, Mal::Type.new(v)) } | |
226 | REPL_ENV.set("eval", Mal::Type.new ->(args : Array(Mal::Type)) { Mal.eval(args[0], REPL_ENV) }) | |
97d0deb1 | 227 | Mal.rep "(def! not (fn* (a) (if a false true)))" |
228 | Mal.rep "(def! load-file (fn* (f) (eval (read-string (str \"(do \" (slurp f) \")\")))))" | |
229 | 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)))))))" | |
230 | Mal.rep "(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))))))))" | |
9bbb8ccc | 231 | |
5185c56e OR |
232 | argv = Mal::List.new |
233 | REPL_ENV.set("*ARGV*", Mal::Type.new argv) | |
9bbb8ccc | 234 | |
235 | unless ARGV.empty? | |
236 | if ARGV.size > 1 | |
237 | ARGV[1..-1].each do |a| | |
5185c56e | 238 | argv << Mal::Type.new(a) |
9bbb8ccc | 239 | end |
240 | end | |
241 | ||
242 | begin | |
97d0deb1 | 243 | Mal.rep "(load-file \"#{ARGV[0]}\")" |
9bbb8ccc | 244 | rescue e |
245 | STDERR.puts e | |
246 | end | |
247 | exit | |
248 | end | |
249 | ||
5185c56e | 250 | while line = Readline.readline("user> ", true) |
9bbb8ccc | 251 | begin |
97d0deb1 | 252 | puts Mal.rep(line) |
9bbb8ccc | 253 | rescue e |
254 | STDERR.puts e | |
255 | end | |
256 | end |