Vous ne pouvez pas sélectionner plus de 25 sujets
Les noms de sujets doivent commencer par une lettre ou un nombre, peuvent contenir des tirets ('-') et peuvent comporter jusqu'à 35 caractères.
130 lignes
3.2 KiB
130 lignes
3.2 KiB
#! /usr/bin/env crystal run
|
|
|
|
require "./readline"
|
|
require "./reader"
|
|
require "./printer"
|
|
require "./types"
|
|
require "./env"
|
|
require "./core"
|
|
require "./error"
|
|
|
|
# Note:
|
|
# Employed downcase names because Crystal prohibits uppercase names for methods
|
|
|
|
def func_of(env, binds, body)
|
|
-> (args : Array(Mal::Type)) {
|
|
new_env = Mal::Env.new(env, binds, args)
|
|
eval(body, new_env)
|
|
} as Mal::Func
|
|
end
|
|
|
|
def eval_ast(ast, env)
|
|
return ast.map{|n| eval(n, env) as Mal::Type} if ast.is_a? Mal::List
|
|
|
|
val = ast.unwrap
|
|
|
|
Mal::Type.new case val
|
|
when Mal::Symbol
|
|
if e = env.get(val.str)
|
|
e
|
|
else
|
|
eval_error "'#{val.str}' not found"
|
|
end
|
|
when Mal::List
|
|
val.each_with_object(Mal::List.new){|n, l| l << eval(n, env)}
|
|
when Mal::Vector
|
|
val.each_with_object(Mal::Vector.new){|n, l| l << eval(n, env)}
|
|
when Mal::HashMap
|
|
val.each{|k, v| val[k] = eval(v, env)}
|
|
val
|
|
else
|
|
val
|
|
end
|
|
end
|
|
|
|
def eval_invocation(list, env)
|
|
f = eval(list.first, env).unwrap
|
|
eval_error "expected function symbol as the first symbol of list" unless f.is_a? Mal::Func
|
|
f.call eval_ast(list[1..-1].each_with_object(Mal::List.new){|i, l| l << i}, env)
|
|
end
|
|
|
|
def read(str)
|
|
read_str str
|
|
end
|
|
|
|
def eval(ast, env)
|
|
list = ast.unwrap
|
|
|
|
return eval_ast(ast, env) unless list.is_a? Mal::List
|
|
return gen_type Mal::List if list.empty?
|
|
|
|
head = list.first.unwrap
|
|
|
|
Mal::Type.new case head
|
|
when Mal::Symbol
|
|
case head.str
|
|
when "def!"
|
|
eval_error "wrong number of argument for 'def!'" unless list.size == 3
|
|
a1 = list[1].unwrap
|
|
eval_error "1st argument of 'def!' must be symbol" unless a1.is_a? Mal::Symbol
|
|
env.set(a1.str, eval(list[2], env))
|
|
when "let*"
|
|
eval_error "wrong number of argument for 'def!'" unless list.size == 3
|
|
|
|
bindings = list[1].unwrap
|
|
eval_error "1st argument of 'let*' must be list or vector" unless bindings.is_a? Array
|
|
eval_error "size of binding list must be even" unless bindings.size.even?
|
|
|
|
new_env = Mal::Env.new env
|
|
bindings.each_slice(2) do |binding|
|
|
key, value = binding
|
|
name = key.unwrap
|
|
eval_error "name of binding must be specified as symbol" unless name.is_a? Mal::Symbol
|
|
new_env.set(name.str, eval(value, new_env))
|
|
end
|
|
|
|
eval(list[2], new_env)
|
|
when "do"
|
|
list.shift 1
|
|
eval_ast(list, env).last
|
|
when "if"
|
|
cond = eval(list[1], env).unwrap
|
|
case cond
|
|
when Nil
|
|
list.size >= 4 ? eval(list[3], env) : nil
|
|
when false
|
|
list.size >= 4 ? eval(list[3], env) : nil
|
|
else
|
|
eval(list[2], env)
|
|
end
|
|
when "fn*"
|
|
# Note:
|
|
# If writing lambda expression here directly, compiler will fail to infer type of 'list'. (Error 'Nil for empty?')
|
|
func_of(env, list[1].unwrap, list[2])
|
|
else
|
|
eval_invocation(list, env)
|
|
end
|
|
else
|
|
eval_invocation(list, env)
|
|
end
|
|
end
|
|
|
|
def print(result)
|
|
pr_str(result, true)
|
|
end
|
|
|
|
def rep(str)
|
|
print(eval(read(str), $repl_env))
|
|
end
|
|
|
|
$repl_env = Mal::Env.new nil
|
|
Mal::NS.each{|k,v| $repl_env.set(k, Mal::Type.new(v))}
|
|
rep "(def! not (fn* (a) (if a false true)))"
|
|
|
|
while line = my_readline("user> ")
|
|
begin
|
|
puts rep(line)
|
|
rescue e
|
|
STDERR.puts e
|
|
end
|
|
end
|