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$ ./bin/crystal --version
Using compiled compiler at .build/crystal
Crystal 1.8.0-dev [58fb584cb87] (2023-01-21)

LLVM: 14.0.1
Default target: aarch64-apple-darwin21.6.0

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These configuration will let you use CodeLLDB extension to debug Crystal programs.

Store them as .vscode/tasks.json and .vscode/launch.json in your project.

When starting the debugging the current file will be built in the bin/ folder (as in shards build).

Note: You will need to set the crystal binary path in tasks.json "command" field and the whole path in launch.json "initCommands". Read more at #8538

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FROM ruby:2.2

RUN \
  # node
  curl -sL https://deb.nodesource.com/setup_5.x | bash - && \
  apt-get install -y nodejs && \
  # cleanup
  apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*

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# The lock is at the end of the unions
#
# CHECK: %"(Bool | Int32)" = type { i32, [1 x i64], i32 }

local_var = uninitialized Int32 | Bool

# After the alloca the lock is initialized as free (1)
#
# CHECK: %local_var = alloca %"(Bool | Int32)"
# CHECK: %0 = getelementptr inbounds %"(Bool | Int32)", %"(Bool | Int32)"* %local_var, i32 0, i32 2

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# The lock is at the end of the unions
#
# CHECK: %"(Bool | Int32)" = type { i32, [1 x i64], i32 }

local_var = uninitialized Int32 | Bool

# After the alloca the lock is initialized as free (1)
#
# CHECK: %local_var = alloca %"(Bool | Int32)"
# CHECK: %0 = getelementptr inbounds %"(Bool | Int32)", %"(Bool | Int32)"* %local_var, i32 0, i32 2

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Blocking and non-blocking channel actions

Channel#receive vs Channel#receive? differs on their behavior for closed channels. Using them directly is always blocking.

Performing an operation over a closed and closing the channel during the operation must behave in the same way.

Channel#receive

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# $ crystal run -Dpreview_mt synchronized.cr

struct Synchronized(T)
  @lock = Mutex.new

  getter inner : T

  def initialize(@inner : T)
  end

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Try it on https://www.jsonschemavalidator.net/

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# A Logger allow sending logging information to a stream.
# Each logger instance is built and binded to a specific
# context that is sent on each entry.
#
# When requesting a logger via `Logger#get` a context needs to be
# specified. Context are meant to be dot seperated path as:
# `"http.client"`. Class names and modules are translated into that format.
#
# ```
# class HTTP::Client

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# A Logger allow sending logging information to a stream.
# Each logger instance is built and binded to a specific
# context that is sent on each entry.
#
# When requesting a logger via `Logger#get` a context needs to be
# specified. Context are meant to be dot seperated path as:
# `"http.client"`. Class names and modules are translated into that format.
#
# ```
# class HTTP::Client