Class: Sequel::SQL::DelayedEvaluation

Inherits:

GenericExpression

• Object
• Expression
• GenericExpression
• Sequel::SQL::DelayedEvaluation

Defined in:

lib/sequel/sql.rb

Overview

Represents a delayed evaluation, encapsulating a callable object which returns the value to use when called.

Instance Attribute Summary

• #callable ⇒ Object readonly

  A callable object that returns the value of the evaluation when called.

Instance Method Summary

• #call(ds) ⇒ Object

  Call the underlying callable and return the result.

• #initialize(callable) ⇒ DelayedEvaluation constructor

  Set the callable object.

Methods included from IsDistinctFrom::Methods

#is_distinct_from

Methods included from Sequel::SQLite::JSONOpMethods

#sqlite_json_op, #sqlite_jsonb_op

Methods included from Postgres::HStoreOpMethods

#hstore

Methods included from Postgres::RangeOpMethods

#pg_range

Methods included from Postgres::ArrayOpMethods

#pg_array

Methods included from Postgres::JSONOpMethods

#pg_json, #pg_jsonb

Methods included from Postgres::InetOpMethods

#pg_inet

Methods included from Postgres::PGRowOp::ExpressionMethods

#pg_row

Methods included from SubscriptMethods

#sql_subscript

Methods included from StringMethods

#escaped_ilike, #escaped_like, #ilike, #like

Methods included from PatternMatchMethods

#!~, #=~

Methods included from OrderMethods

#asc, #desc

Methods included from NumericMethods

#+, #coerce

Methods included from ComplexExpressionMethods

#extract, #sql_boolean, #sql_number, #sql_string

Methods included from CastMethods

#cast, #cast_numeric, #cast_string

Methods included from BooleanMethods

#~

Methods included from AliasMethods

#as

Methods inherited from Expression

#==, attr_reader, #clone, #eql?, #hash, inherited, #inspect

Constructor Details

#initialize(callable) ⇒ DelayedEvaluation

Set the callable object

# File 'lib/sequel/sql.rb', line 1344

def initialize(callable)
  @callable = callable
  freeze
end

Instance Attribute Details

#callable ⇒ Object (readonly)

A callable object that returns the value of the evaluation when called.

# File 'lib/sequel/sql.rb', line 1341

def callable
  @callable
end

Instance Method Details

#call(ds) ⇒ Object

Call the underlying callable and return the result. If the underlying callable only accepts a single argument, call it with the given dataset.

# File 'lib/sequel/sql.rb', line 1352

def call(ds)
  if @callable.respond_to?(:arity) && @callable.arity == 1
    @callable.call(ds)
  else
    @callable.call
  end
end