Class: Gamefic::Query::Base

Inherits:
Object
  • Object
show all
Defined in:
lib/gamefic/query/base.rb

Overview

A base class for entity-based queries that can be applied to responses. Each query matches a command token to an object that can be passed into a response callback.

Most queries return entities, but there are also queries for plain text and integers.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*arguments, name: self.class.to_s) ⇒ Base

Returns a new instance of Base.

Raises:

  • (ArgumentError) —

    if any of the arguments are nil



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# File 'lib/gamefic/query/base.rb', line 20

def initialize *arguments, name: self.class.to_s
  raise ArgumentError, "nil argument in query" if arguments.any?(&:nil?)

  @arguments = arguments
  @name = name
end

Instance Attribute Details

#arguments ⇒ Array<Object> (readonly) 



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# File 'lib/gamefic/query/base.rb', line 14

def arguments
  @arguments
end

Class Method Details

.plain ⇒ Object 



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# File 'lib/gamefic/query/base.rb', line 101

def self.plain
  @plain ||= new
end

.span(subject) ⇒ Object 



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# File 'lib/gamefic/query/base.rb', line 105

def self.span(subject)
  plain.span(subject)
end

Instance Method Details

#accept?(subject, object) ⇒ Boolean

True if the object is selectable by the subject.



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# File 'lib/gamefic/query/base.rb', line 65

def accept?(subject, object)
  select(subject).include?(object)
end

#bind(narrative) ⇒ Object 



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# File 'lib/gamefic/query/base.rb', line 93

def bind(narrative)
  clone.tap do |query|
    query.instance_exec do
      @arguments = narrative.unproxy(@arguments)
    end
  end
end

#filter(subject, token) ⇒ Result

Get a query result for a given subject and token.



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# File 'lib/gamefic/query/base.rb', line 32

def filter(subject, token)
  scan = Scanner.scan(select(subject), token)
  return Result.new(nil, scan.token) unless scan.matched.one?

  Result.new(scan.matched.first, scan.remainder, scan.strictness)
end

#inspect ⇒ Object 



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# File 'lib/gamefic/query/base.rb', line 89

def inspect
  "#{name}(#{arguments.map(&:inspect).join(', ')})"
end

#name ⇒ Object 



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# File 'lib/gamefic/query/base.rb', line 85

def name
  @name || self.class.to_s
end

#precision ⇒ Integer

The query’s precision. The higher the number, the more specific the query is.

In general terms, a query’s precision is highest if its arguments select for a specific instance of an entity instead of a class of entity.

When a command gets parsed, the resulting list of available actions gets sorted in descending order of their responses’ overall precision, so the action with the highest precision gets attempted first.



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# File 'lib/gamefic/query/base.rb', line 81

def precision
  @precision ||= calculate_precision
end

#select(subject) ⇒ Array<Entity>

Get an array of entities that match the arguments from the context of the subject.



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# File 'lib/gamefic/query/base.rb', line 44

def select(subject)
  span(subject).that_are(*arguments)
end

#span(_subject) ⇒ Array<Entity>

Get an array of entities that are candidates for selection from the context of the subject. These are the entities that #select will filter through query’s arguments.

Subclasses should override this method.



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# File 'lib/gamefic/query/base.rb', line 56

def span(_subject)
  []
end