Results for: "Array"

This class is useful for exploring contents before and after a block

It searches above and below the passed in block to match for whatever criteria you give it:

Example:

def dog         # 1
  puts "bark"   # 2
  puts "bark"   # 3
end             # 4

scan = AroundBlockScan.new(
  code_lines: code_lines
  block: CodeBlock.new(lines: code_lines[1])
)

scan.scan_while { true }

puts scan.before_index # => 0
puts scan.after_index  # => 3

Searches code for a syntax error

There are three main phases in the algorithm:

1. Sanitize/format input source

2. Search for invalid blocks

3. Format invalid blocks into something meaninful

This class handles the part.

The bulk of the heavy lifting is done in:

- CodeFrontier (Holds information for generating blocks and determining if we can stop searching)
- ParseBlocksFromLine (Creates blocks into the frontier)
- BlockExpand (Expands existing blocks to search more code)

## Syntax error detection

When the frontier holds the syntax error, we can stop searching

search = CodeSearch.new(<<~EOM)
  def dog
    def lol
  end
EOM

search.call

search.invalid_blocks.map(&:to_s) # =>
# => ["def lol\n"]

Outputs code with highlighted lines

Whatever is passed to this class will be rendered even if it is “marked invisible” any filtering of output should be done before calling this class.

DisplayCodeWithLineNumbers.new(
  lines: lines,
  highlight_lines: [lines[2], lines[3]]
).call
# =>
    1
    2  def cat
  > 3    Dir.chdir
  > 4    end
    5  end
    6

Used for formatting invalid blocks

This class is responsible for generating initial code blocks that will then later be expanded.

The biggest concern when guessing code blocks, is accidentally grabbing one that contains only an “end”. In this example:

def dog
  begonn # misspelled `begin`
  puts "bark"
  end
end

The following lines would be matched (from bottom to top):

1) end

2) puts "bark"
   end

3) begonn
   puts "bark"
   end

At this point it has no where else to expand, and it will yield this inner code as a block

Capture parse errors from Ripper

Prism returns the errors with their messages, but Ripper does not. To get them we must make a custom subclass.

Example:

puts RipperErrors.new(" def foo").call.errors
# => ["syntax error, unexpected end-of-input, expecting ';' or '\\n'"]

Raised by Timeout.timeout when the block times out.

Base class for all URI exceptions.

Not a URI.

Not a URI component.

URI is valid, bad usage is not.

RefError is raised when a referenced object has been recycled by the garbage collector

Raised when a mathematical function is evaluated outside of its domain of definition.

For example, since cos returns values in the range -1..1, its inverse function acos is only defined on that interval:

Math.acos(42)

produces:

Math::DomainError: Numerical argument is out of domain - "acos"

Raised on attempt to Ractor#take if there was an uncaught exception in the Ractor. Its cause will contain the original exception, and ractor is the original ractor it was raised in.

r = Ractor.new { raise "Something weird happened" }

begin
  r.take
rescue => e
  p e             # => #<Ractor::RemoteError: thrown by remote Ractor.>
  p e.ractor == r # => true
  p e.cause       # => #<RuntimeError: Something weird happened>
end

Raised on an attempt to access an object which was moved in Ractor#send or Ractor.yield.

r = Ractor.new { sleep }

ary = [1, 2, 3]
r.send(ary, move: true)
ary.inspect
# Ractor::MovedError (can not send any methods to a moved object)

Raised when an attempt is made to send a message to a closed port, or to retrieve a message from a closed and empty port. Ports may be closed explicitly with Ractor#close_outgoing/close_incoming and are closed implicitly when a Ractor terminates.

r = Ractor.new { sleep(500) }
r.close_outgoing
r.take # Ractor::ClosedError

ClosedError is a descendant of StopIteration, so the closing of the ractor will break the loops without propagating the error:

r = Ractor.new do
  loop do
    msg = receive # raises ClosedError and loop traps it
    puts "Received: #{msg}"
  end
  puts "loop exited"
end

3.times{|i| r << i}
r.close_incoming
r.take
puts "Continue successfully"

This will print:

Received: 0
Received: 1
Received: 2
loop exited
Continue successfully

ConditionVariable objects augment class Mutex. Using condition variables, it is possible to suspend while in the middle of a critical section until a resource becomes available.

Example:

mutex = Thread::Mutex.new
resource = Thread::ConditionVariable.new

a = Thread.new {
   mutex.synchronize {
     # Thread 'a' now needs the resource
     resource.wait(mutex)
     # 'a' can now have the resource
   }
}

b = Thread.new {
   mutex.synchronize {
     # Thread 'b' has finished using the resource
     resource.signal
   }
}

Raised by Encoding and String methods when a transcoding operation fails.

Raised by Encoding and String methods when the string being transcoded contains a byte invalid for the either the source or target encoding.

Raised by transcoding methods when a named encoding does not correspond with a known converter.

An internal representation of the backtrace. The user will never interact with objects of this class directly, but class methods can be used to get backtrace settings of the current session.