Class: BibTeX::Value

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Includes:
Comparable
Defined in:
lib/bibtex/value.rb

Overview

A BibTeX Value is something very much like a string. In BibTeX files it can appear on the right hand side of @string or @entry field assignments or as @preamble contents. In the example below [VALUE] indicates possible occurences of values in BibTeX:

@preamble{ "foo" [VALUE] }
@string{ foo = "foo" [VALUE] }
@book{id,
  author = {John Doe} [VALUE],
  title = foo # "bar" [VALUE]
}

All Values have in common that they can be simple strings in curly braces or double quotes or complex BibTeX string-concatenations (using the ‘#’ symbol).

Generally, Values try to behave as much as normal Ruby strings as possible; If you do not require any of the advanced BibTeX functionality (string replacement or concatentaion) you can simply convert them to strings using to_s. Note that BibTeX Names are special instances of Values which currently do not support string concatenation or replacement.

Direct Known Subclasses

Names

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*arguments) ⇒ Value

Returns a new instance of Value.



69
70
71
72
73
74
 
# File 'lib/bibtex/value.rb', line 69

def initialize(*arguments)
  @tokens = []
  arguments.flatten.compact.each do |argument|
    add(argument)
  end
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(name, *args) ⇒ Object 



279
280
281
282
283
284
285
 
# File 'lib/bibtex/value.rb', line 279

def method_missing(name, *args)
  if name.to_s =~ /^(?:convert|from)_([a-z]+)(!)?$/
    Regexp.last_match(2) ? convert!(Regexp.last_match(1)) : convert(Regexp.last_match(1))
  else
    super
  end
end

Instance Attribute Details

#tokens ⇒ Object (readonly) Also known as: to_a

Returns the value of attribute tokens.



48
49
50
 
# File 'lib/bibtex/value.rb', line 48

def tokens
  @tokens
end

Class Method Details

.create(*args) ⇒ Object

call-seq:

create(other) => other.dup
create(*args) => Value.new(args)

Duplicates a Value object (or an object of any subclass of Value), or initializes a new one.



65
66
67
 
# File 'lib/bibtex/value.rb', line 65

def self.create(*args)
  args[0].class < Value && args.size == 1 ? args[0].dup : Value.new(args)
end

Instance Method Details

#<=>(other) ⇒ Object 



291
292
293
294
295
296
297
 
# File 'lib/bibtex/value.rb', line 291

def <=>(other)
  if numeric? && other.respond_to?(:numeric?) && other.numeric?
    to_i <=> other.to_i
  else
    to_s <=> other.to_s
  end
end

#add(argument) ⇒ Object Also known as: <<, push 



101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
 
# File 'lib/bibtex/value.rb', line 101

def add(argument)
  case argument
  when Value
    @tokens += argument.tokens.dup
  when ::String
    @tokens << argument
  when Symbol
    @tokens << argument
  else
    if argument.respond_to?(:to_s)
      @tokens << argument.to_s
    else
      raise(ArgumentError, "Failed to create Value from argument #{argument.inspect}; expected String, Symbol or Value instance.")
    end
  end
  self
end

#atomic? ⇒ Boolean

Returns true if the Value is empty or consists of a single token.

Returns:

  • (Boolean) 


209
210
211
 
# File 'lib/bibtex/value.rb', line 209

def atomic?
  @tokens.length < 2
end

#convert(*filters) ⇒ Object

Returns a new Value with all string values converted according to the given filter(s).



265
266
267
 
# File 'lib/bibtex/value.rb', line 265

def convert(*filters)
  dup.convert!(*filters)
end

#convert!(*filters) ⇒ Object

Converts all string values according to the given filter(s).



270
271
272
273
274
275
276
277
 
# File 'lib/bibtex/value.rb', line 270

def convert!(*filters)
  filters.flatten.each do |filter|
    f = Filters.resolve!(filter)
    @tokens.map! { |t| f.apply(t) }
  end

  self
end

#date? ⇒ Boolean

Returns true if the Value’s content is a date.

Returns:

  • (Boolean) 


227
228
229
 
# File 'lib/bibtex/value.rb', line 227

def date?
  !to_date.nil?
end

#include_token?(token) ⇒ Boolean

Returns:

  • (Boolean) 


97
98
99
 
# File 'lib/bibtex/value.rb', line 97

def include_token?(token)
  @tokens.include?(token)
end

#initialize_copy(other) ⇒ Object 



76
77
78
79
80
81
82
83
 
# File 'lib/bibtex/value.rb', line 76

def initialize_copy(other)
  @tokens = other.tokens.map do |token|
    if token.nil? then nil
    elsif token.is_a?(Symbol) then token
    else token.dup
    end
  end
end

#inspect ⇒ Object 



204
205
206
 
# File 'lib/bibtex/value.rb', line 204

def inspect
  "#<#{self.class} #{@tokens.map(&:inspect).join(', ')}>"
end

#join(separator = '') ⇒ Value

call-seq:

Value.new('foo', 'bar').join #=> <'foobar'>
Value.new(:foo, 'bar').join  #=> <:foo, 'bar'>

Parameters:

  • separator (String) (defaults to: '')

Returns:

  • (Value) —

    the instance with all consecutive String tokens joined



154
155
156
157
158
159
160
161
162
163
 
# File 'lib/bibtex/value.rb', line 154

def join(separator = '')
  @tokens = @tokens.each_with_object([]) do |b, a|
    if a[-1].is_a?(::String) && b.is_a?(::String)
      a[-1] = [a[-1], b].join(separator)
    else
      a << b
    end
  end
  self
end

#merge(other) ⇒ Object 



85
86
87
 
# File 'lib/bibtex/value.rb', line 85

def merge(other)
  dup.merge!(other)
end

#merge!(other) ⇒ Object 



89
90
91
92
93
94
95
 
# File 'lib/bibtex/value.rb', line 89

def merge!(other)
  other.tokens.each do |token|
    add token unless include_token?(token)
  end

  self
end

#name? ⇒ Boolean Also known as: names?

Returns true if the value is a BibTeX name value.

Returns:

  • (Boolean) 


214
215
216
 
# File 'lib/bibtex/value.rb', line 214

def name?
  false
end

#numeric? ⇒ Boolean

Returns true if the Value’s content is numeric.

Returns:

  • (Boolean) 


240
241
242
 
# File 'lib/bibtex/value.rb', line 240

def numeric?
  atomic? && @tokens[0] =~ /^\s*[+-]?\d+\s*$/
end

#replace(*arguments) ⇒ Object 



131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
 
# File 'lib/bibtex/value.rb', line 131

def replace(*arguments)
  return self unless has_symbol?

  arguments.flatten.each do |argument|
    case argument
    when ::String # simulates Ruby's String#replace
      @tokens = [argument]
    when String
      @tokens = @tokens.map { |v| argument.key == v ? argument.value.tokens : v }.flatten
    when Hash
      @tokens = @tokens.map { |v| argument[v] || v }
    end
  end
  self
end

#respond_to?(method, include_all = false) ⇒ Boolean

Returns:

  • (Boolean) 


287
288
289
 
# File 'lib/bibtex/value.rb', line 287

def respond_to?(method, include_all = false)
  method =~ /^(?:convert|from)_([a-z]+)(!)?$/ || super
end

#symbol? ⇒ Boolean Also known as: has_symbol?

Returns true if the Value contains at least one symbol.

Returns:

  • (Boolean) 


253
254
255
 
# File 'lib/bibtex/value.rb', line 253

def symbol?
  @tokens.detect { |v| v.is_a?(Symbol) }
end

#symbols ⇒ Object

Returns all symbols contained in the Value.



260
261
262
 
# File 'lib/bibtex/value.rb', line 260

def symbols
  @tokens.select { |v| v.is_a?(Symbol) }
end

#to_citeproc(options = {}) ⇒ Object 



248
249
250
 
# File 'lib/bibtex/value.rb', line 248

def to_citeproc(options = {})
  to_s(options)
end

#to_date ⇒ Object

Returns the string as a date.



232
233
234
235
236
237
 
# File 'lib/bibtex/value.rb', line 232

def to_date
  require 'date'
  Date.parse(to_s)
rescue StandardError
  nil
end

#to_i ⇒ Object 



244
245
246
 
# File 'lib/bibtex/value.rb', line 244

def to_i
  @tokens[0].to_i
end

#to_name ⇒ Object Also known as: to_names 



220
221
222
 
# File 'lib/bibtex/value.rb', line 220

def to_name
  Names.parse(to_s)
end

#to_s(options = {}) ⇒ Object

call-seq:

Value.new('foo').to_s                       #=> "foo"
Value.new(:foo).to_s                        #=> "foo"
Value.new('foo').to_s(:quotes => '"')       #=> "\"foo\""
Value.new(:foo).to_s(:quotes => '"')       #=> "foo"
Value.new('foo').to_s(:quotes => ['"','"']) #=> "\"foo\""
Value.new('foo').to_s(:quotes => ['{','}']) #=> "{foo}"
Value.new(:foo, 'bar').to_s                 #=> "foo # \"bar\""
Value.new('foo', 'bar').to_s                #=> "\"foo\" # \"bar\""
Value.new('\"u').to_s(:filter => :latex)    #=> "ü"

Returns a the Value as a string. @see #value; If the Value is atomic and the option :quotes is given, the string will be quoted using the quote symbols specified.

If the option :filter is given, the Value will be converted using the filter(s) specified.



182
183
184
185
186
187
188
 
# File 'lib/bibtex/value.rb', line 182

def to_s(options = {})
  return convert(options.delete(:filter)).to_s(options) if options.key?(:filter)
  return value.to_s unless options.key?(:quotes) && atomic? && !symbol?

  q = Array(options[:quotes])
  [q[0], value, q[-1]].compact.join
end

#value ⇒ Object Also known as: v

Returns the Value as a string or, if it consists of a single symbol, as a Symbol instance. If the Value contains multiple tokens, they will be joined by a ‘#’, additionally, all string tokens will be turned into string literals (i.e., delimitted by quotes).



194
195
196
197
198
199
200
 
# File 'lib/bibtex/value.rb', line 194

def value
  if atomic?
    @tokens[0]
  else
    @tokens.map { |v| v.is_a?(::String) ? v.inspect : v }.join(' # ')
  end
end