class Gem::Requirement

A Requirement is a set of one or more version restrictions. It supports a few (=, !=, >, <, >=, <=, ~>) different restriction operators.

See Gem::Version for a description on how versions and requirements work together in RubyGems.

Constants

DefaultPrereleaseRequirement: The default requirement matches any version
DefaultRequirement: The default requirement matches any non-prerelease version
PATTERN: A regular expression that matches a requirement

Public Class Methods

create (*inputs)

Factory method to create a Gem::Requirement object. Input may be a Version, a String, or nil. Intended to simplify client code.

If the input is “weird”, the default version requirement is returned.

# File lib/rubygems/requirement.rb, line 55
def self.create(*inputs)
  return new inputs if inputs.length > 1

  input = inputs.shift

  case input
  when Gem::Requirement then
    input
  when Gem::Version, Array then
    new input
  when "!" then
    source_set
  else
    if input.respond_to? :to_str
      new [input.to_str]
    else
      default
    end
  end
end

default ()

# File lib/rubygems/requirement.rb, line 76
def self.default
  new ">= 0"
end

default_prerelease ()

# File lib/rubygems/requirement.rb, line 80
def self.default_prerelease
  new ">= 0.a"
end

new (*requirements)

Constructs a requirement from requirements. Requirements can be Strings, Gem::Versions, or Arrays of those. nil and duplicate requirements are ignored. An empty set of requirements is the same as ">= 0".

# File lib/rubygems/requirement.rb, line 131
def initialize(*requirements)
  requirements = requirements.flatten
  requirements.compact!
  requirements.uniq!

  if requirements.empty?
    @requirements = [DefaultRequirement]
  else
    @requirements = requirements.map! {|r| self.class.parse r }
  end
end

parse (obj)

Parse obj, returning an [op, version] pair. obj can be a String or a Gem::Version.

If obj is a String, it can be either a full requirement specification, like ">= 1.2", or a simple version number, like "1.2".

parse("> 1.0")                 # => [">", Gem::Version.new("1.0")]
parse("1.0")                   # => ["=", Gem::Version.new("1.0")]
parse(Gem::Version.new("1.0")) # => ["=,  Gem::Version.new("1.0")]

# File lib/rubygems/requirement.rb, line 103
def self.parse(obj)
  return ["=", obj] if Gem::Version === obj

  unless PATTERN =~ obj.to_s
    raise BadRequirementError, "Illformed requirement [#{obj.inspect}]"
  end

  if $1 == ">=" && $2 == "0"
    DefaultRequirement
  elsif $1 == ">=" && $2 == "0.a"
    DefaultPrereleaseRequirement
  else
    [-($1 || "="), Gem::Version.new($2)]
  end
end

Public Instance Methods

=== (version)

Alias for: satisfied_by?

=~ (version)

Alias for: satisfied_by?

concat (new)

Concatenates the new requirements onto this requirement.

# File lib/rubygems/requirement.rb, line 146
def concat(new)
  new = new.flatten
  new.compact!
  new.uniq!
  new = new.map {|r| self.class.parse r }

  @requirements.concat new
end

exact? ()

true if the requirement is for only an exact version

# File lib/rubygems/requirement.rb, line 184
def exact?
  return false unless @requirements.size == 1
  @requirements[0][0] == "="
end

none? ()

true if this gem has no requirements.

# File lib/rubygems/requirement.rb, line 173
def none?
  if @requirements.size == 1
    @requirements[0] == DefaultRequirement
  else
    false
  end
end

prerelease? ()

A requirement is a prerelease if any of the versions inside of it are prereleases

# File lib/rubygems/requirement.rb, line 225
def prerelease?
  requirements.any? {|r| r.last.prerelease? }
end

satisfied_by? (version)

True if version satisfies this Requirement.

# File lib/rubygems/requirement.rb, line 238
def satisfied_by?(version)
  raise ArgumentError, "Need a Gem::Version: #{version.inspect}" unless
    Gem::Version === version
  requirements.all? {|op, rv| OPS[op].call version, rv }
end

Also aliased as: ===, =~

specific? ()

True if the requirement will not always match the latest version.

# File lib/rubygems/requirement.rb, line 250
def specific?
  return true if @requirements.length > 1 # GIGO, > 1, > 2 is silly

  !%w[> >=].include? @requirements.first.first # grab the operator
end

Protected Instance Methods

_sorted_requirements ()

# File lib/rubygems/requirement.rb, line 276
def _sorted_requirements
  @_sorted_requirements ||= requirements.sort_by(&:to_s)
end

_tilde_requirements ()

# File lib/rubygems/requirement.rb, line 280
def _tilde_requirements
  @_tilde_requirements ||= _sorted_requirements.select {|r| r.first == "~>" }
end