Class: Sequel::Postgres::PGRange

Inherits:
Object
  • Object
show all
Includes:
Enumerable, SQL::AliasMethods
Defined in:
lib/sequel/extensions/pg_range.rb,
lib/sequel/extensions/pg_range_ops.rb

Defined Under Namespace

Modules: DatabaseMethods, DatasetMethods Classes: Parser

Constant Summary collapse

RANGE_TYPES =

Map of string database type names to type symbols (e.g. ‘int4range’ => :int4range), used in the schema parsing.

{}
EMPTY = 
'empty'.freeze
EMPTY_STRING = 
''.freeze
QUOTED_EMPTY_STRING = 
'""'.freeze
OPEN_PAREN = 
"(".freeze
CLOSE_PAREN = 
")".freeze
OPEN_BRACKET = 
"[".freeze
CLOSE_BRACKET = 
"]".freeze
ESCAPE_RE = 
/("|,|\\|\[|\]|\(|\))/.freeze
ESCAPE_REPLACE = 
'\\\\\1'.freeze
CAST = 
'::'.freeze

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from SQL::AliasMethods

#as

Constructor Details

#initialize(beg, en, opts = {}) ⇒ PGRange

Initialize a new PGRange instance. Accepts the following options:

:db_type

The PostgreSQL database type for the range.

:empty

Whether the range is empty (has no points)

:exclude_begin

Whether the beginning element is excluded from the range.

:exclude_end

Whether the ending element is excluded from the range.



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# File 'lib/sequel/extensions/pg_range.rb', line 316

def initialize(beg, en, opts={})
  @begin = beg
  @end = en
  @empty = !!opts[:empty]
  @exclude_begin = !!opts[:exclude_begin]
  @exclude_end = !!opts[:exclude_end]
  @db_type = opts[:db_type]
  if @empty
    raise(Error, 'cannot have an empty range with either a beginning or ending') unless @begin.nil? && @end.nil? && opts[:exclude_begin].nil? && opts[:exclude_end].nil?
  end
end

Instance Attribute Details

#begin ⇒ Object (readonly)

The beginning of the range. If nil, the range has an unbounded beginning.



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# File 'lib/sequel/extensions/pg_range.rb', line 291

def begin
  @begin
end

#db_type ⇒ Object (readonly)

The PostgreSQL database type for the range (e.g. ‘int4range’).



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# File 'lib/sequel/extensions/pg_range.rb', line 297

def db_type
  @db_type
end

#end ⇒ Object (readonly)

The end of the range. If nil, the range has an unbounded ending.



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# File 'lib/sequel/extensions/pg_range.rb', line 294

def end
  @end
end

Class Method Details

.empty(db_type = nil) ⇒ Object

Create an empty PGRange with the given database type.



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# File 'lib/sequel/extensions/pg_range.rb', line 306

def self.empty(db_type=nil)
  new(nil, nil, :empty=>true, :db_type=>db_type)
end

.from_range(range, db_type = nil) ⇒ Object

Create a new PGRange instance using the beginning and ending of the ruby Range, with the given db_type.



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# File 'lib/sequel/extensions/pg_range.rb', line 301

def self.from_range(range, db_type=nil)
  new(range.begin, range.end, :exclude_end=>range.exclude_end?, :db_type=>db_type)
end

.register(db_type, opts = {}, &block) ⇒ Object

Registers a range type that the extension should handle. Makes a Database instance that has been extended with DatabaseMethods recognize the range type given and set up the appropriate typecasting. Also sets up automatic typecasting for the native postgres adapter, so that on retrieval, the values are automatically converted to PGRange instances. The db_type argument should be the name of the range type. Accepts the following options:

:converter

A callable object (e.g. Proc), that is called with the start or end of the range (usually a string), and should return the appropriate typecasted object.

:oid

The PostgreSQL OID for the range type. This is used by the Sequel postgres adapter to set up automatic type conversion on retrieval from the database.

:subtype_oid

Should be the PostgreSQL OID for the range’s subtype. If given,

automatically sets the :converter option by looking for scalar conversion
proc.

If a block is given, it is treated as the :converter option.



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# File 'lib/sequel/extensions/pg_range.rb', line 95

def self.register(db_type, opts={}, &block)
  db_type = db_type.to_s.dup.freeze

  if converter = opts[:converter]
    raise Error, "can't provide both a block and :converter option to register" if block
  else
    converter = block
  end

  if soid = opts[:subtype_oid]
    raise Error, "can't provide both a converter and :scalar_oid option to register" if converter 
    raise Error, "no conversion proc for :scalar_oid=>#{soid.inspect} in PG_TYPES" unless converter = PG_TYPES[soid]
  end

  parser = Parser.new(db_type, converter)

  RANGE_TYPES[db_type] = db_type.to_sym

  DatabaseMethods.define_range_typecast_method(db_type, parser)

  if oid = opts[:oid]
    Sequel::Postgres::PG_TYPES[oid] = parser
  end

  nil
end

Instance Method Details

#===(other) ⇒ Object

Allow PGRange values in case statements, where they return true if they are equal to each other using eql?, or if this PGRange can be converted to a Range, delegating to that range.



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# File 'lib/sequel/extensions/pg_range.rb', line 368

def ===(other)
  if eql?(other)
    true
  else
    if valid_ruby_range?
      to_range === other 
    else
      false
    end
  end
end

#empty? ⇒ Boolean

Whether this range is empty (has no points).

Returns:

  • (Boolean) 


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# File 'lib/sequel/extensions/pg_range.rb', line 381

def empty?
  @empty
end

#eql?(other) ⇒ Boolean Also known as: ==

Consider the receiver equal to other PGRange instances with the same beginning, ending, exclusions, and database type. Also consider it equal to Range instances if this PGRange can be converted to a a Range and those ranges are equal.

Returns:

  • (Boolean) 


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# File 'lib/sequel/extensions/pg_range.rb', line 339

def eql?(other)
  case other
  when PGRange
    if db_type == other.db_type
      if empty?
        other.empty?
      elsif other.empty?
        false
      else
        [:@begin, :@end, :@exclude_begin, :@exclude_end].all?{|v| instance_variable_get(v) == other.instance_variable_get(v)}
      end
    else
      false
    end
  when Range
    if valid_ruby_range?
      to_range.eql?(other)
    else
      false
    end
  else
    false
  end
end

#exclude_begin? ⇒ Boolean

Whether the beginning element is excluded from the range.

Returns:

  • (Boolean) 


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# File 'lib/sequel/extensions/pg_range.rb', line 386

def exclude_begin?
  @exclude_begin
end

#exclude_end? ⇒ Boolean

Whether the ending element is excluded from the range.

Returns:

  • (Boolean) 


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# File 'lib/sequel/extensions/pg_range.rb', line 391

def exclude_end?
  @exclude_end
end

#op ⇒ Object

Wrap the PGRange instance in an RangeOp, allowing you to easily use the PostgreSQL range functions and operators with literal ranges.



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# File 'lib/sequel/extensions/pg_range_ops.rb', line 119

def op
  RangeOp.new(self)
end

#sql_literal_append(ds, sql) ⇒ Object

Append a literalize version of the receiver to the sql.



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# File 'lib/sequel/extensions/pg_range.rb', line 396

def sql_literal_append(ds, sql)
  ds.literal_append(sql, unquoted_literal(ds))
  if s = @db_type
    sql << CAST << s.to_s
  end
end

#to_range ⇒ Object

Return a ruby Range object for this instance, if one can be created.

Raises:



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# File 'lib/sequel/extensions/pg_range.rb', line 404

def to_range
  return @range if @range
  raise(Error, "cannot create ruby range for an empty PostgreSQL range") if empty?
  raise(Error, "cannot create ruby range when PostgreSQL range excludes beginning element") if exclude_begin?
  raise(Error, "cannot create ruby range when PostgreSQL range has unbounded beginning") unless self.begin
  raise(Error, "cannot create ruby range when PostgreSQL range has unbounded ending") unless self.end
  @range = Range.new(self.begin, self.end, exclude_end?)
end

#unbounded_begin? ⇒ Boolean

Whether the beginning of the range is unbounded.

Returns:

  • (Boolean) 


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# File 'lib/sequel/extensions/pg_range.rb', line 421

def unbounded_begin?
  self.begin.nil? && !empty?
end

#unbounded_end? ⇒ Boolean

Whether the end of the range is unbounded.

Returns:

  • (Boolean) 


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# File 'lib/sequel/extensions/pg_range.rb', line 426

def unbounded_end?
  self.end.nil? && !empty?
end

#unquoted_literal(ds) ⇒ Object

Return a string containing the unescaped version of the range. Separated out for use by the bound argument code.



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# File 'lib/sequel/extensions/pg_range.rb', line 432

def unquoted_literal(ds)
  if empty?
    EMPTY
  else
    "#{exclude_begin? ? OPEN_PAREN : OPEN_BRACKET}#{escape_value(self.begin, ds)},#{escape_value(self.end, ds)}#{exclude_end? ? CLOSE_PAREN : CLOSE_BRACKET}"
  end
end

#valid_ruby_range? ⇒ Boolean

Whether or not this PGRange is a valid ruby range. In order to be a valid ruby range, it must have a beginning and an ending (no unbounded ranges), and it cannot exclude the beginning element.

Returns:

  • (Boolean) 


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# File 'lib/sequel/extensions/pg_range.rb', line 416

def valid_ruby_range?
  !(empty? || exclude_begin? || !self.begin || !self.end)
end