（元组数组）的散列导致 compile/runtime 错误 "index out of bounds for tuple {(String, String -> Void)}"

Question

我正在尝试创建一个包含元组的数组哈希。这导致了一个奇怪的问题，我怀疑是编译器错误，但我不是 100% 确定。

我使用的语法：

class SomeClass
  @@weird_object = Hash(String, Array(Tuple(String, String -> ))).new {|h, k| h[k] = [] of Tuple(String, String -> ) }

  #...
  def self.some_method
    @@weird_object.each do |tuple|
      pp tuple[0]
      pp tuple[1] #=> This causes compile error "index out of bounds for tuple {(String, String -> Void)}"
    end

    @@weird_object.each do |the_sting, callback|
      #this causes a "Nil trace:" for the callback parameter
    end
#...
end

看起来这已成为 (String, String -> void) 对象的元组，而不是 String, String -> void。当我运行 crystal spec 但当我运行 crystal build ./src/main.cr.

时不会出现此错误

这是 compiler/runtime 错误，还是我搞错了语法？

Crystal 0.8.0 [e363b63]（9 月 19 日星期六 12:00:17 UTC 2015）

Answer 1

您的实际代码有：

Hash(String, Array({String, String -> })).new

这个元组与

相同

{(String, String ->)}

所以你需要parens来消除歧义

Hash(String, Array({String, (String -> )})).new

您的实际代码也存在到处都出现 Void 的问题，我不确定为什么，但是一些转换可以解决它。这是让它工作的完整差异

diff --git a/src/untangle/aggregator.cr b/src/untangle/aggregator.cr
index 8c49681..7553eb2 100644
--- a/src/untangle/aggregator.cr
+++ b/src/untangle/aggregator.cr
@@ -3,7 +3,7 @@ class Aggregator
    @@subscribers_all = Array(String, String ->).new
    @@responders = Hash(String, (String ->)).new
    #@@reroutes = {} of String => Proc(String)
-   @@reroutes = Hash(String, Array({String, String -> })).new {|h, k| h[k] = Array({String, String -> }).new }
+   @@reroutes = Hash(String, Array({String, (String -> )})).new {|h, k| h[k] = Array({String, (String -> )}).new }

    def self.subscribe (message_type, &callback : String ->)
        @@subscribers[message_type] << callback
@@ -35,11 +35,11 @@ class Aggregator
            spawn do
                message_type = ch.receive
                data = ch.receive
-               callback.call(message_type, data)
+               callback.call(message_type, data as String)
            end

            ch.send(message_type)
-           ch.send(data)
+           ch.send(data as String)
        end

        @@subscribers[message_type].each do |callback|
@@ -48,14 +48,14 @@ class Aggregator
            spawn do
                callback.call(ch.receive)
            end
-           ch.send(data)
+           ch.send(data as String)
        end

        @@reroutes[message_type].each do |tuple| #|to_type, callback|
            # puts "!!!!!!!!!!!!!!!!!!!"
            # pp tuple
            # puts "!!!!!!!!!!!!!!!!!!!"
-           Aggregator.publish(tuple[0], tuple[1].call(data))
+           Aggregator.publish(tuple[0], tuple[1].call(data as String))
        end
    end
    def self.request(message_type, arguments)

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（元组数组）的散列导致 compile/runtime 错误 "index out of bounds for tuple {(String, String -> Void)}"

Hash of (Array of Tuples) causing compile/runtime error "index out of bounds for tuple {(String, String -> Void)}"

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