module Bmg

Constants

Leaf: Deprecated
VERSION

Public Class Methods

csv(path, options = {}, type = Type::ANY) click to toggle source

# File lib/bmg.rb, line 17
def csv(path, options = {}, type = Type::ANY)
  Reader::Csv.new(type, path, options).spied(main_spy)
end

excel(path, options = {}, type = Type::ANY) click to toggle source

# File lib/bmg.rb, line 22
def excel(path, options = {}, type = Type::ANY)
  Reader::Excel.new(type, path, options).spied(main_spy)
end

in_memory(enumerable, type = Type::ANY) click to toggle source

# File lib/bmg.rb, line 7
def in_memory(enumerable, type = Type::ANY)
  Relation::InMemory.new(type, enumerable).spied(main_spy)
end

main_spy() click to toggle source

# File lib/bmg.rb, line 27
def main_spy
  @main_spy
end

main_spy=(spy) click to toggle source

# File lib/bmg.rb, line 32
def main_spy=(spy)
  @main_spy = spy
end

sequel(source, sequel_db = nil, type = nil) click to toggle source

Builds a Relation that uses Sequel for managing real data accesses.

Supported signatures:

# Table name, providing the Sequel's Database object
Bmg.sequel(:suppliers, DB)

# Sequel dataset object, embedding the Database object
# `from_self` will be used at compilation time, you don't
# need to call it yourself.
Bmg.sequel(DB[:suppliers])

# Similar, but with with a pure SQL query
Bmg.sequel(DB[%Q{SELECT ... FROM ...}])

# All signatures above with an explicit type object, e.g.:
Bmg.sequel(:suppliers, DB, Type::ANY)
Bmg.sequel(DB[:suppliers], Type::ANY)

# File lib/bmg/sequel.rb, line 57
def sequel(source, sequel_db = nil, type = nil)
  Sequel.sequel(source, sequel_db, type)
end

sql(table, type = Type::ANY) click to toggle source

# File lib/bmg/sql.rb, line 10
def sql(table, type = Type::ANY)
  builder = Sql::Builder.new
  sexpr = builder.select_star_from(table)
  Sql::Relation.new(type, builder, sexpr).spied(main_spy)
end

text_file(path, options = {}, type = Type::ANY) click to toggle source

# File lib/bmg.rb, line 12
def text_file(path, options = {}, type = Type::ANY)
  Reader::TextFile.new(type, path, options).spied(main_spy)
end

Public Instance Methods

_join(type, right, on) click to toggle source

Calls superclass method

# File lib/bmg/operator/autowrap.rb, line 72
def _join(type, right, on)
  if _join_optimizable?(type, right, on)
    operand.join(right, on).autowrap(options)
  else
    super
  end
end

_join_optimizable?(type, right, on) click to toggle source

# File lib/bmg/operator/autowrap.rb, line 88
def _join_optimizable?(type, right, on)
  # 1. Can't optimize if wrapped roots are used in join clause
  # 2. Can't optimize if other attributes would be autowrapped
  (wrapped_roots! & on).empty? && wrapped_roots_of!(right, options).empty?
rescue UnknownAttributesError
  false
end

_joined_with(type, right, on) click to toggle source

Calls superclass method

# File lib/bmg/operator/autowrap.rb, line 80
def _joined_with(type, right, on)
  if _join_optimizable?(type, right, on)
    right.join(operand, on).autowrap(options)
  else
    super
  end
end

_matching(type, right, on) click to toggle source

Calls superclass method

# File lib/bmg/operator/autowrap.rb, line 96
def _matching(type, right, on)
  if (wrapped_roots! & on).empty?
    operand.matching(right, on).autowrap(options)
  else
    super
  end
rescue UnknownAttributesError
  super
end

_not_matching(type, right, on = []) click to toggle source

Calls superclass method

# File lib/bmg/operator/extend.rb, line 97
def _not_matching(type, right, on = [])
  ext_keys = extension.keys
  if (ext_keys & on).empty?
    operand.not_matching(right, on).extend(extension)
  else
    super
  end
end

_page(type, ordering, page_index, opts) click to toggle source

Calls superclass method

# File lib/bmg/operator/autowrap.rb, line 106
def _page(type, ordering, page_index, opts)
  attrs = ordering.map{|(a,d)| a }
  if (wrapped_roots! & attrs).empty?
    operand.page(ordering, page_index, opts).autowrap(options)
  else
    super
  end
rescue UnknownAttributesError
  super
end

_project(type, attrlist) click to toggle source

Calls superclass method

# File lib/bmg/operator/autowrap.rb, line 117
def _project(type, attrlist)
  if (wrapped_roots! & attrlist).empty?
    operand.project(attrlist).autowrap(options)
  else
    super
  end
rescue UnknownAttributesError
  super
end

_rename(type, renaming) click to toggle source

Calls superclass method

# File lib/bmg/operator/autowrap.rb, line 127
def _rename(type, renaming)
  # 1. Can't optimize if renaming applies to a wrapped one
  return super unless (wrapped_roots! & renaming.keys).empty?

  # 2. Can't optimize if new attributes would be autowrapped
  new_roots = Support.wrapped_roots(renaming.values, options[:split])
  return super unless new_roots.empty?

  operand.rename(renaming).autowrap(options)
rescue UnknownAttributesError
  super
end

_restrict(type, predicate) click to toggle source

Calls superclass method

# File lib/bmg/operator/autowrap.rb, line 140
def _restrict(type, predicate)
  vars = predicate.free_variables
  if (wrapped_roots! & vars).empty?
    operand.restrict(predicate).autowrap(options)
  else
    super
  end
rescue UnknownAttributesError
  super
end

args() click to toggle source

# File lib/bmg/operator/allbut.rb, line 99
def args
  [ butlist ]
end

Private Instance Methods

csv(path, options = {}, type = Type::ANY) click to toggle source

# File lib/bmg.rb, line 17
def csv(path, options = {}, type = Type::ANY)
  Reader::Csv.new(type, path, options).spied(main_spy)
end

empty_group() click to toggle source

# File lib/bmg/operator/group.rb, line 79
def empty_group
  Relation::InMemory.new(group_type, Set.new)
end

excel(path, options = {}, type = Type::ANY) click to toggle source

# File lib/bmg.rb, line 22
def excel(path, options = {}, type = Type::ANY)
  Reader::Excel.new(type, path, options).spied(main_spy)
end

group_type() click to toggle source

# File lib/bmg/operator/group.rb, line 83
def group_type
  operand.type.project(attrs)
end

in_memory(enumerable, type = Type::ANY) click to toggle source

# File lib/bmg.rb, line 7
def in_memory(enumerable, type = Type::ANY)
  Relation::InMemory.new(type, enumerable).spied(main_spy)
end

init(key, tuple) click to toggle source

Returns the initial tuple to use for a given determinant.

# File lib/bmg/operator/autosummarize.rb, line 96
def init(key, tuple)
  tuple.each_with_object({}){|(k,v),h|
    h.merge!(k => summarizer(k).init(v))
  }
end

key(tuple) click to toggle source

Returns the tuple determinant.

# File lib/bmg/operator/autosummarize.rb, line 91
def key(tuple)
  @by.map{|by| tuple[by] }
end

main_spy() click to toggle source

# File lib/bmg.rb, line 27
def main_spy
  @main_spy
end

main_spy=(spy) click to toggle source

# File lib/bmg.rb, line 32
def main_spy=(spy)
  @main_spy = spy
end

sequel(source, sequel_db = nil, type = nil) click to toggle source

Builds a Relation that uses Sequel for managing real data accesses.

Supported signatures:

# Table name, providing the Sequel's Database object
Bmg.sequel(:suppliers, DB)

# Sequel dataset object, embedding the Database object
# `from_self` will be used at compilation time, you don't
# need to call it yourself.
Bmg.sequel(DB[:suppliers])

# Similar, but with with a pure SQL query
Bmg.sequel(DB[%Q{SELECT ... FROM ...}])

# All signatures above with an explicit type object, e.g.:
Bmg.sequel(:suppliers, DB, Type::ANY)
Bmg.sequel(DB[:suppliers], Type::ANY)

# File lib/bmg/sequel.rb, line 57
def sequel(source, sequel_db = nil, type = nil)
  Sequel.sequel(source, sequel_db, type)
end

sql(table, type = Type::ANY) click to toggle source

# File lib/bmg/sql.rb, line 10
def sql(table, type = Type::ANY)
  builder = Sql::Builder.new
  sexpr = builder.select_star_from(table)
  Sql::Relation.new(type, builder, sexpr).spied(main_spy)
end

sum(memo, tuple) click to toggle source

Sums `tuple` on `memo`, returning the new tuple to use as memo.

# File lib/bmg/operator/autosummarize.rb, line 108
def sum(memo, tuple)
  tuple.each_with_object(memo.dup){|(k,v),h|
    h.merge!(k => summarizer(k).sum(h[k], v))
  }
end

summarizer(k) click to toggle source

Returns the summarizer to use for a given key.

# File lib/bmg/operator/autosummarize.rb, line 103
def summarizer(k)
  @sums[k] || Same.new
end

term(tuple) click to toggle source

Terminates the summarization of a given tuple.

# File lib/bmg/operator/autosummarize.rb, line 115
def term(tuple)
  tuple.each_with_object({}){|(k,v),h|
    h.merge!(k => summarizer(k).term(v))
  }
end

text_file(path, options = {}, type = Type::ANY) click to toggle source

# File lib/bmg.rb, line 12
def text_file(path, options = {}, type = Type::ANY)
  Reader::TextFile.new(type, path, options).spied(main_spy)
end

to_summarizer(x) click to toggle source

# File lib/bmg/operator/autosummarize.rb, line 121
def to_summarizer(x)
  case x
  when :same  then Same.new
  when :group then DistinctList.new
  else
    x
  end
end

transformer() click to toggle source

# File lib/bmg/operator/transform.rb, line 89
def transformer
  @transformer ||= TupleTransformer.new(transformation)
end

tuple_allbut(tuple) click to toggle source

# File lib/bmg/operator/allbut.rb, line 105
def tuple_allbut(tuple)
  TupleAlgebra.allbut(tuple, @butlist)
end

tuple_project(tuple, on) click to toggle source

# File lib/bmg/operator/join.rb, line 93
def tuple_project(tuple, on)
  TupleAlgebra.project(tuple, on)
end

valid_tuple!(tuple) click to toggle source

# File lib/bmg/operator/allbut.rb, line 109
def valid_tuple!(tuple)
  offending = tuple.keys & butlist
  raise InvalidUpdateError, "#{offending.inspect} cannot be updated" unless offending.empty?
  tuple
end