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separate evaluator

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rhysd 9 年之前
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7073b1728f
共有 2 個檔案被更改,包括 237 行新增222 行删除
  1. +233
    -0
      src/crisp/evaluator.cr
  2. +4
    -222
      src/crisp/interpreter.cr

+ 233
- 0
src/crisp/evaluator.cr 查看文件

@ -0,0 +1,233 @@
require "colorize"
require "readline"
require "./reader"
require "./printer"
require "./types"
require "./env"
require "./core"
require "./error"
module Crisp
class Evaluator
def func_of(env, binds, body)
-> (args : Array(Crisp::Type)) {
new_env = Crisp::Env.new(env, binds, args)
eval(body, new_env)
} as Crisp::Func
end
def eval_ast(ast, env)
return ast.map{|n| eval(n, env) as Crisp::Type} if ast.is_a? Array
val = ast.unwrap
Crisp::Type.new case val
when Crisp::Symbol
if e = env.get(val.str)
e
else
Crisp.eval_error "'#{val.str}' not found"
end
when Crisp::List
val.each_with_object(Crisp::List.new){|n, l| l << eval(n, env)}
when Crisp::Vector
val.each_with_object(Crisp::Vector.new){|n, l| l << eval(n, env)}
when Crisp::HashMap
new_map = Crisp::HashMap.new
val.each{|k, v| new_map[k] = eval(v, env)}
new_map
else
val
end
end
macro pair?(list)
{{list}}.is_a?(Array) && !{{list}}.empty?
end
def quasiquote(ast)
list = ast.unwrap
unless pair?(list)
return Crisp::Type.new(
Crisp::List.new << gen_type(Crisp::Symbol, "quote") << ast
)
end
head = list.first.unwrap
case
# ("unquote" ...)
when head.is_a?(Crisp::Symbol) && head.str == "unquote"
list[1]
# (("splice-unquote" ...) ...)
when pair?(head) && (arg0 = head.first.unwrap).is_a?(Crisp::Symbol) && arg0.str == "splice-unquote"
tail = Crisp::Type.new list[1..-1].to_crisp_value
Crisp::Type.new(
Crisp::List.new << gen_type(Crisp::Symbol, "concat") << head[1] << quasiquote(tail)
)
else
tail = Crisp::Type.new list[1..-1].to_crisp_value
Crisp::Type.new(
Crisp::List.new << gen_type(Crisp::Symbol, "cons") << quasiquote(list.first) << quasiquote(tail)
)
end
end
def macro_call?(ast, env)
list = ast.unwrap
return false unless list.is_a? Crisp::List
return false if list.empty?
sym = list.first.unwrap
return false unless sym.is_a? Crisp::Symbol
func = env.find(sym.str).try(&.data[sym.str])
return false unless func && func.macro?
true
end
def macroexpand(ast, env)
while macro_call?(ast, env)
# Already checked in macro_call?
list = ast.unwrap as Crisp::List
func_sym = list[0].unwrap as Crisp::Symbol
func = env.get(func_sym.str).unwrap
case func
when Crisp::Func
ast = func.call(list[1..-1])
when Crisp::Closure
ast = func.fn.call(list[1..-1])
else
Crisp.eval_error "macro '#{func_sym.str}' must be function: #{ast}"
end
end
ast
end
macro invoke_list(l, env)
f = eval({{l}}.first, {{env}}).unwrap
args = eval_ast({{l}}[1..-1], {{env}}) as Array
case f
when Crisp::Closure
ast = f.ast
{{env}} = Crisp::Env.new(f.env, f.params, args)
next # TCO
when Crisp::Func
return f.call args
else
Crisp.eval_error "expected function as the first argument: #{f}"
end
end
def debug(ast)
puts print(ast).colorize.red
end
def eval(ast, env)
# 'next' in 'do...end' has a bug in crystal 0.7.1
# https://github.com/manastech/crystal/issues/659
while true
return eval_ast(ast, env) unless ast.unwrap.is_a? Crisp::List
ast = macroexpand(ast, env)
list = ast.unwrap
return ast unless list.is_a? Crisp::List
return ast if list.empty?
head = list.first.unwrap
return invoke_list(list, env) unless head.is_a? Crisp::Symbol
return Crisp::Type.new case head.str
when "def!"
Crisp.eval_error "wrong number of argument for 'def!'" unless list.size == 3
a1 = list[1].unwrap
Crisp.eval_error "1st argument of 'def!' must be symbol: #{a1}" unless a1.is_a? Crisp::Symbol
env.set(a1.str, eval(list[2], env))
when "let*"
Crisp.eval_error "wrong number of argument for 'def!'" unless list.size == 3
bindings = list[1].unwrap
Crisp.eval_error "1st argument of 'let*' must be list or vector" unless bindings.is_a? Array
Crisp.eval_error "size of binding list must be even" unless bindings.size.even?
new_env = Crisp::Env.new env
bindings.each_slice(2) do |binding|
key, value = binding
name = key.unwrap
Crisp.eval_error "name of binding must be specified as symbol #{name}" unless name.is_a? Crisp::Symbol
new_env.set(name.str, eval(value, new_env))
end
ast, env = list[2], new_env
next # TCO
when "do"
if list.empty?
ast = Crisp::Type.new nil
next
end
eval_ast(list[1..-2].to_crisp_value, env)
ast = list.last
next # TCO
when "if"
ast = unless eval(list[1], env).unwrap
list.size >= 4 ? list[3] : Crisp::Type.new(nil)
else
list[2]
end
next # TCO
when "fn*"
params = list[1].unwrap
unless params.is_a? Array
Crisp.eval_error "'fn*' parameters must be list or vector: #{params}"
end
Crisp::Closure.new(list[2], params, env, func_of(env, params, list[2]))
when "quote"
list[1]
when "quasiquote"
ast = quasiquote list[1]
next # TCO
when "defmacro!"
Crisp.eval_error "wrong number of argument for 'defmacro!'" unless list.size == 3
a1 = list[1].unwrap
Crisp.eval_error "1st argument of 'defmacro!' must be symbol: #{a1}" unless a1.is_a? Crisp::Symbol
env.set(a1.str, eval(list[2], env).tap{|n| n.is_macro = true})
when "macroexpand"
macroexpand(list[1], env)
when "try*"
catch_list = list[2].unwrap
return eval(list[1], env) unless catch_list.is_a? Crisp::List
catch_head = catch_list.first.unwrap
return eval(list[1], env) unless catch_head.is_a? Crisp::Symbol
return eval(list[1], env) unless catch_head.str == "catch*"
begin
eval(list[1], env)
rescue e : Crisp::RuntimeException
new_env = Crisp::Env.new(env, [catch_list[1]], [e.thrown])
eval(catch_list[2], new_env)
rescue e
new_env = Crisp::Env.new(env, [catch_list[1]], [Crisp::Type.new e.message])
eval(catch_list[2], new_env)
end
else
invoke_list(list, env)
end
end
end
end
end

+ 4
- 222
src/crisp/interpreter.cr 查看文件

@ -7,19 +7,18 @@ require "./types"
require "./env"
require "./core"
require "./error"
# Note:
# Employed downcase names because Crystal prohibits uppercase names for methods
require "./evaluator"
module Crisp
class Interpreter
def initialize(args = nil)
@printer = Printer.new
@evaluator = Evaluator.new
@env = Crisp::Env.new
Crisp::NameSpace.each{|k,v| @env.set(k, Crisp::Type.new(v))}
@env.set("eval", Crisp::Type.new -> (args: Array(Crisp::Type)){ eval(args[0], @env) })
@env.set("eval", Crisp::Type.new -> (args: Array(Crisp::Type)){ vi">@evaluator.eval(args[0], @env) })
eval_string "(def! not (fn* (a) (if a false true)))"
eval_string "(def! load-file (fn* (f) (eval (read-string (str \"(do \" (slurp f) \")\")))))"
@ -38,233 +37,16 @@ module Crisp
@env.set("*ARGV*", Crisp::Type.new argv)
end
def func_of(env, binds, body)
-> (args : Array(Crisp::Type)) {
new_env = Crisp::Env.new(env, binds, args)
eval(body, new_env)
} as Crisp::Func
end
def eval_ast(ast, env)
return ast.map{|n| eval(n, env) as Crisp::Type} if ast.is_a? Array
val = ast.unwrap
Crisp::Type.new case val
when Crisp::Symbol
if e = env.get(val.str)
e
else
Crisp.eval_error "'#{val.str}' not found"
end
when Crisp::List
val.each_with_object(Crisp::List.new){|n, l| l << eval(n, env)}
when Crisp::Vector
val.each_with_object(Crisp::Vector.new){|n, l| l << eval(n, env)}
when Crisp::HashMap
new_map = Crisp::HashMap.new
val.each{|k, v| new_map[k] = eval(v, env)}
new_map
else
val
end
end
def read(str)
Crisp.read_str str
end
macro pair?(list)
{{list}}.is_a?(Array) && !{{list}}.empty?
end
def quasiquote(ast)
list = ast.unwrap
unless pair?(list)
return Crisp::Type.new(
Crisp::List.new << gen_type(Crisp::Symbol, "quote") << ast
)
end
head = list.first.unwrap
case
# ("unquote" ...)
when head.is_a?(Crisp::Symbol) && head.str == "unquote"
list[1]
# (("splice-unquote" ...) ...)
when pair?(head) && (arg0 = head.first.unwrap).is_a?(Crisp::Symbol) && arg0.str == "splice-unquote"
tail = Crisp::Type.new list[1..-1].to_crisp_value
Crisp::Type.new(
Crisp::List.new << gen_type(Crisp::Symbol, "concat") << head[1] << quasiquote(tail)
)
else
tail = Crisp::Type.new list[1..-1].to_crisp_value
Crisp::Type.new(
Crisp::List.new << gen_type(Crisp::Symbol, "cons") << quasiquote(list.first) << quasiquote(tail)
)
end
end
def macro_call?(ast, env)
list = ast.unwrap
return false unless list.is_a? Crisp::List
return false if list.empty?
sym = list.first.unwrap
return false unless sym.is_a? Crisp::Symbol
func = env.find(sym.str).try(&.data[sym.str])
return false unless func && func.macro?
true
end
def macroexpand(ast, env)
while macro_call?(ast, env)
# Already checked in macro_call?
list = ast.unwrap as Crisp::List
func_sym = list[0].unwrap as Crisp::Symbol
func = env.get(func_sym.str).unwrap
case func
when Crisp::Func
ast = func.call(list[1..-1])
when Crisp::Closure
ast = func.fn.call(list[1..-1])
else
Crisp.eval_error "macro '#{func_sym.str}' must be function: #{ast}"
end
end
ast
end
macro invoke_list(l, env)
f = eval({{l}}.first, {{env}}).unwrap
args = eval_ast({{l}}[1..-1], {{env}}) as Array
case f
when Crisp::Closure
ast = f.ast
{{env}} = Crisp::Env.new(f.env, f.params, args)
next # TCO
when Crisp::Func
return f.call args
else
Crisp.eval_error "expected function as the first argument: #{f}"
end
end
def debug(ast)
puts print(ast).colorize.red
end
def eval(ast, env)
# 'next' in 'do...end' has a bug in crystal 0.7.1
# https://github.com/manastech/crystal/issues/659
while true
return eval_ast(ast, env) unless ast.unwrap.is_a? Crisp::List
ast = macroexpand(ast, env)
list = ast.unwrap
return ast unless list.is_a? Crisp::List
return ast if list.empty?
head = list.first.unwrap
return invoke_list(list, env) unless head.is_a? Crisp::Symbol
return Crisp::Type.new case head.str
when "def!"
Crisp.eval_error "wrong number of argument for 'def!'" unless list.size == 3
a1 = list[1].unwrap
Crisp.eval_error "1st argument of 'def!' must be symbol: #{a1}" unless a1.is_a? Crisp::Symbol
env.set(a1.str, eval(list[2], env))
when "let*"
Crisp.eval_error "wrong number of argument for 'def!'" unless list.size == 3
bindings = list[1].unwrap
Crisp.eval_error "1st argument of 'let*' must be list or vector" unless bindings.is_a? Array
Crisp.eval_error "size of binding list must be even" unless bindings.size.even?
new_env = Crisp::Env.new env
bindings.each_slice(2) do |binding|
key, value = binding
name = key.unwrap
Crisp.eval_error "name of binding must be specified as symbol #{name}" unless name.is_a? Crisp::Symbol
new_env.set(name.str, eval(value, new_env))
end
ast, env = list[2], new_env
next # TCO
when "do"
if list.empty?
ast = Crisp::Type.new nil
next
end
eval_ast(list[1..-2].to_crisp_value, env)
ast = list.last
next # TCO
when "if"
ast = unless eval(list[1], env).unwrap
list.size >= 4 ? list[3] : Crisp::Type.new(nil)
else
list[2]
end
next # TCO
when "fn*"
params = list[1].unwrap
unless params.is_a? Array
Crisp.eval_error "'fn*' parameters must be list or vector: #{params}"
end
Crisp::Closure.new(list[2], params, env, func_of(env, params, list[2]))
when "quote"
list[1]
when "quasiquote"
ast = quasiquote list[1]
next # TCO
when "defmacro!"
Crisp.eval_error "wrong number of argument for 'defmacro!'" unless list.size == 3
a1 = list[1].unwrap
Crisp.eval_error "1st argument of 'defmacro!' must be symbol: #{a1}" unless a1.is_a? Crisp::Symbol
env.set(a1.str, eval(list[2], env).tap{|n| n.is_macro = true})
when "macroexpand"
macroexpand(list[1], env)
when "try*"
catch_list = list[2].unwrap
return eval(list[1], env) unless catch_list.is_a? Crisp::List
catch_head = catch_list.first.unwrap
return eval(list[1], env) unless catch_head.is_a? Crisp::Symbol
return eval(list[1], env) unless catch_head.str == "catch*"
begin
eval(list[1], env)
rescue e : Crisp::RuntimeException
new_env = Crisp::Env.new(env, [catch_list[1]], [e.thrown])
eval(catch_list[2], new_env)
rescue e
new_env = Crisp::Env.new(env, [catch_list[1]], [Crisp::Type.new e.message])
eval(catch_list[2], new_env)
end
else
invoke_list(list, env)
end
end
end
def print(result)
@printer.print(result)
end
def eval_string(str)
print(eval(read(str), @env))
print(@evaluator.eval(read(str), @env))
end
def run(filename = nil)

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