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

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from SQL::AliasMethods

#as

Constructor Details

#initialize(beg, en, opts = 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 333

def initialize(beg, en, opts=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

#beginObject (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 308

def begin
  @begin
end

#db_typeObject (readonly)

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


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# File 'lib/sequel/extensions/pg_range.rb', line 314

def db_type
  @db_type
end

#endObject (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 311

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 323

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 318

def self.from_range(range, db_type=nil)
  new(range.begin, range.end, :exclude_end=>range.exclude_end?, :db_type=>db_type)
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 394

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

#cover?(value) ⇒ Boolean

Return whether the value is inside the range.


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# File 'lib/sequel/extensions/pg_range.rb', line 352

def cover?(value)
  return false if empty?
  b = self.begin
  return false if b && b.public_send(exclude_begin? ? :>= : :>, value)
  e = self.end
  return false if e && e.public_send(exclude_end? ? :<= : :<, value)
  true
end

#empty?Boolean

Whether this range is empty (has no points). Note that for manually created ranges (ones not retrieved from the database), this will only be true if the range was created using the :empty option.


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# File 'lib/sequel/extensions/pg_range.rb', line 409

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.


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# File 'lib/sequel/extensions/pg_range.rb', line 365

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.


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# File 'lib/sequel/extensions/pg_range.rb', line 414

def exclude_begin?
  @exclude_begin
end

#exclude_end?Boolean

Whether the ending element is excluded from the range.


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# File 'lib/sequel/extensions/pg_range.rb', line 419

def exclude_end?
  @exclude_end
end

#opObject

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 123

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 424

def sql_literal_append(ds, sql)
  if (s = @db_type) && !empty?
    sql << s.to_s << "("
    ds.literal_append(sql, self.begin)
    sql << ','
    ds.literal_append(sql, self.end)
    sql << ','
    ds.literal_append(sql, "#{exclude_begin? ? "(" : "["}#{exclude_end? ? ")" : "]"}")
    sql << ")"
  else
    ds.literal_append(sql, unquoted_literal(ds))
    if s
      sql << '::' << s.to_s
    end
  end
end

#to_rangeObject

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 442

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.


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# File 'lib/sequel/extensions/pg_range.rb', line 459

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

#unbounded_end?Boolean

Whether the end of the range is unbounded.


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# File 'lib/sequel/extensions/pg_range.rb', line 464

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 470

def unquoted_literal(ds)
  if empty?
    'empty'
  else
    "#{exclude_begin? ? "(" : "["}#{escape_value(self.begin, ds)},#{escape_value(self.end, ds)}#{exclude_end? ? ")" : "]"}"
  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.


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# File 'lib/sequel/extensions/pg_range.rb', line 454

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