为什么在这个Elixir程序中需要:错误模式匹配?
我只是试图从编程Elixir 1.0中运行一个示例Elixir程序,并得到以下错误,尽管这样做似乎不应该: 我做错了什么 我执行iex-S混合并查看错误报告: Erlang/OTP18[erts-7.2][source][64位][smp:8:8][async threads:10][hipe][kernel poll:false]为什么在这个Elixir程序中需要:错误模式匹配?,elixir,Elixir,我只是试图从编程Elixir 1.0中运行一个示例Elixir程序,并得到以下错误,尽管这样做似乎不应该: 我做错了什么 我执行iex-S混合并查看错误报告: Erlang/OTP18[erts-7.2][source][64位][smp:8:8][async threads:10][hipe][kernel poll:false] =INFO REPORT==== 2-Apr-2016::20:11:46 === application: logger exited: stop
=INFO REPORT==== 2-Apr-2016::20:11:46 ===
application: logger
exited: stopped
type: temporary
** (Mix) Could not start application sequence_supervisor: exited in: SequenceSupervisor.start(:normal, [])
** (EXIT) an exception was raised:
** (MatchError) no match of right hand side value: {:error, {:shutdown, {:failed_to_start_child, Sequence.Server, {:EXIT, {:undef, [{Sequence.Server, :start_link, '{', []}, {:supervisor, :do_start_child, 2, [file: 'supervisor.erl', line: 343]}, {:supervisor, :start_children, 3, [file: 'supervisor.erl', line: 326]}, {:supervisor, :init_children, 2, [file: 'supervisor.erl', line: 292]}, {:gen_server, :init_it, 6, [file: 'gen_server.erl', line: 328]}, {:proc_lib, :init_p_do_apply, 3, [file: 'proc_lib.erl', line: 240]}]}}}}}
(sequence_supervisor) lib/sequence_supervisor.ex:18: SequenceSupervisor.start/2
(kernel) application_master.erl:273: :application_master.start_it_old/4
defmodule SequenceSupervisor do
use Application
# See http://elixir-lang.org/docs/stable/elixir/Application.html
# for more information on OTP Applications
def start(_type, _args) do
import Supervisor.Spec, warn: false
children = [
# Define workers and child supervisors to be supervised
# worker(SequenceSupervisor.Worker, [arg1, arg2, arg3]),
worker(SequenceSupervisor.Server, [123])
]
# See http://elixir-lang.org/docs/stable/elixir/Supervisor.html
# for other strategies and supported options
opts = [strategy: :one_for_one, name: SequenceSupervisor.Supervisor]
{:ok, _pid} = Supervisor.start_link(children, opts)
end
end
目录树
sequence_supervisor.ex
mix文件mix.exs
如果查看提供的堆栈跟踪,则有一个段:
{:undef, [{Sequence.Server, :start_link, '{', []
这意味着有东西试图调用Sequence.Server模块上的start_link函数,但它是一个未定义的函数
根据目录树判断,不仅Sequence.Server的start_link函数未定义,而且Sequence.Server模块本身似乎也未定义。这可能是因为您还没有为它编写代码
它的代码可以在上找到。如果您查看提供的堆栈跟踪,则有一段:
{:undef, [{Sequence.Server, :start_link, '{', []
这意味着有东西试图调用Sequence.Server模块上的start_link函数,但它是一个未定义的函数
根据目录树判断,不仅Sequence.Server的start_link函数未定义,而且Sequence.Server模块本身似乎也未定义。这可能是因为您还没有为它编写代码
其代码可在上找到
defmodule SequenceSupervisor.Mixfile do
use Mix.Project
def project do
[app: :sequence_supervisor,
version: "0.0.1",
elixir: "~> 1.1",
build_embedded: Mix.env == :prod,
start_permanent: Mix.env == :prod,
deps: deps]
end
# Configuration for the OTP application
#
# Type "mix help compile.app" for more information
def application do
[applications: [:logger],
mod: {SequenceSupervisor, []}]
end
# Dependencies can be Hex packages:
#
# {:mydep, "~> 0.3.0"}
#
# Or git/path repositories:
#
# {:mydep, git: "https://github.com/elixir-lang/mydep.git", tag: "0.1.0"}
#
# Type "mix help deps" for more examples and options
defp deps do
[]
end
end
{:undef, [{Sequence.Server, :start_link, '{', []