Results for: "partition"

Individual switch class. Not important to the user.

Defined within Switch are several Switch-derived classes: NoArgument, RequiredArgument, etc.

Raises when there is an argument for a switch which takes no argument.

Raises when a switch with mandatory argument has no argument.

Raises when the given argument does not match required format.

Raises when the given argument word can’t be completed uniquely.

DesugarCompiler is a compiler that desugars Ruby code into a more primitive form. This is useful for consumers that want to deal with fewer node types.

A pattern is an object that wraps a Ruby pattern matching expression. The expression would normally be passed to an ‘in` clause within a `case` expression or a rightward assignment expression. For example, in the following snippet:

case node
in ConstantPathNode[ConstantReadNode[name: :Prism], ConstantReadNode[name: :Pattern]]
end

the pattern is the ConstantPathNode[...] expression.

The pattern gets compiled into an object that responds to call by running the compile method. This method itself will run back through Prism to parse the expression into a tree, then walk the tree to generate the necessary callable objects. For example, if you wanted to compile the expression above into a callable, you would:

callable = Prism::Pattern.new("ConstantPathNode[ConstantReadNode[name: :Prism], ConstantReadNode[name: :Pattern]]").compile
callable.call(node)

The callable object returned by compile is guaranteed to respond to call with a single argument, which is the node to match against. It also is guaranteed to respond to ===, which means it itself can be used in a ‘case` expression, as in:

case node
when callable
end

If the query given to the initializer cannot be compiled into a valid matcher (either because of a syntax error or because it is using syntax we do not yet support) then a Prism::Pattern::CompilationError will be raised.

Gem::ConfigFile RubyGems options and gem command options from gemrc.

gemrc is a YAML file that uses strings to match gem command arguments and symbols to match RubyGems options.

Gem command arguments use a String key that matches the command name and allow you to specify default arguments:

install: --no-rdoc --no-ri
update: --no-rdoc --no-ri

You can use gem: to set default arguments for all commands.

RubyGems options use symbol keys. Valid options are:

:backtrace

See backtrace

:sources

Sets Gem::sources

:verbose

See verbose

:concurrent_downloads

See concurrent_downloads

gemrc files may exist in various locations and are read and merged in the following order:

• system wide (/etc/gemrc)

• per user (~/.gemrc)

• per environment (gemrc files listed in the GEMRC environment variable)

Raised when there are conflicting gem specs loaded

Example using a Gem::Package

Builds a .gem file given a Gem::Specification. A .gem file is a tarball which contains a data.tar.gz, metadata.gz, checksums.yaml.gz and possibly signatures.

require 'rubygems'
require 'rubygems/package'

spec = Gem::Specification.new do |s|
  s.summary = "Ruby based make-like utility."
  s.name = 'rake'
  s.version = PKG_VERSION
  s.requirements << 'none'
  s.files = PKG_FILES
  s.description = <<-EOF
Rake is a Make-like program implemented in Ruby. Tasks
and dependencies are specified in standard Ruby syntax.
  EOF
end

Gem::Package.build spec

Reads a .gem file.

require 'rubygems'
require 'rubygems/package'

the_gem = Gem::Package.new(path_to_dot_gem)
the_gem.contents # get the files in the gem
the_gem.extract_files destination_directory # extract the gem into a directory
the_gem.spec # get the spec out of the gem
the_gem.verify # check the gem is OK (contains valid gem specification, contains a not corrupt contents archive)

files are the files in the .gem tar file, not the Ruby files in the gem extract_files and contents automatically call verify

Create a package based upon a Gem::Specification. Gem packages, as well as zip files and tar/gzipped packages can be produced by this task.

In addition to the Rake targets generated by Rake::PackageTask, a Gem::PackageTask will also generate the following tasks:

“package_dir/name-version.gem”

Create a RubyGems package with the given name and version.

Example using a Gem::Specification:

require 'rubygems'
require 'rubygems/package_task'

spec = Gem::Specification.new do |s|
  s.summary = "Ruby based make-like utility."
  s.name = 'rake'
  s.version = PKG_VERSION
  s.requirements << 'none'
  s.files = PKG_FILES
  s.description = <<-EOF
Rake is a Make-like program implemented in Ruby. Tasks
and dependencies are specified in standard Ruby syntax.
  EOF
end

Gem::PackageTask.new(spec) do |pkg|
  pkg.need_zip = true
  pkg.need_tar = true
end

Subclass of StreamUI that instantiates the user interaction using $stdin, $stdout, and $stderr.

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

This class is responsible for taking a code block that exists at a far indentaion and then iteratively increasing the block so that it captures everything within the same indentation block.

def dog
  puts "bow"
  puts "wow"
end

block = BlockExpand.new(code_lines: code_lines)

.call(CodeBlock.new(lines: code_lines[1]))

puts block.to_s # => puts “bow”

puts "wow"

Once a code block has captured everything at a given indentation level then it will expand to capture surrounding indentation.

block = BlockExpand.new(code_lines: code_lines)

.call(block)

block.to_s # => def dog

  puts "bow"
  puts "wow"
end

Turns a “invalid block(s)” into useful context

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 third part.

The algorithm is very good at capturing all of a syntax error in a single block in number 2, however the results can contain ambiguities. Humans are good at pattern matching and filtering and can mentally remove extraneous data, but they can’t add extra data that’s not present.

In the case of known ambiguious cases, this class adds context back to the ambiguity so the programmer has full information.

Beyond handling these ambiguities, it also captures surrounding code context information:

puts block.to_s # => "def bark"

context = CaptureCodeContext.new(
  blocks: block,
  code_lines: code_lines
)

lines = context.call.map(&:original)
puts lines.join
# =>
  class Dog
    def bark
  end

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"]