Remove type translation

This has been deprecated for a while, time to remove it.  If users want
to keep the type translation feature, they can upgrade their
applications by implementing a delegate class.

CHANGELOG.md

@@ -28,6 +28,46 @@ This release drops support for Ruby 2.7. [#453] @flavorjones
 ### Removed
 
 - Remove `SQLite3::VersionProxy` which has been deprecated since v1.3.2. [#453] @flavorjones
+- Remove `SQLite3::Translator` and all related type translation methods.
+ If you need to do type translation on values returned from the statement object,
+ please wrap it with a delegate object. Here is an example of using a delegate
+ class to implement type translation:
+
+```ruby
+require "sqlite3"
+require "delegate"
+
+db = SQLite3::Database.new(":memory:")
+
+return_value = db.execute_batch2 <<-EOSQL
+ CREATE TABLE items (id integer PRIMARY KEY AUTOINCREMENT, name string);
+ INSERT INTO items (name) VALUES ("foo");
+ INSERT INTO items (name) VALUES ("bar");
+EOSQL
+
+class MyTranslator < DelegateClass(SQLite3::Statement)
+ def step
+ row = super
+ return if done?
+
+ row.map.with_index do |item, i|
+ case types[i]
+ when "integer" # turn all integers to floats
+ item.to_f
+ when "string" # add "hello" to all strings
+ item + "hello"
+ end
+ end
+ end
+end
+
+db.prepare("SELECT * FROM items") do |stmt|
+ stmt = MyTranslator.new(stmt)
+ while row = stmt.step
+ p row
+ end
+end
+```
 
 
 ## 1.7.0 / 2023-12-27

lib/sqlite3/database.rb

@@ -82,7 +82,6 @@ def quote(string)
  # Other supported +options+:
  # - +:strict+: boolean (default false), disallow the use of double-quoted string literals (see https://www.sqlite.org/quirks.html#double_quoted_string_literals_are_accepted)
  # - +:results_as_hash+: boolean (default false), return rows as hashes instead of arrays
- # - +:type_translation+: boolean (default false), enable type translation
  # - +:default_transaction_mode+: one of +:deferred+ (default), +:immediate+, or +:exclusive+. If a mode is not specified in a call to #transaction, this will be the default transaction mode.
  #
  def initialize file, options = {}, zvfs = nil
@@ -124,8 +123,6 @@ def initialize file, options = {}, zvfs = nil
  @collations = {}
  @functions = {}
  @results_as_hash = options[:results_as_hash]
- @type_translation = options[:type_translation]
- @type_translator = make_type_translator @type_translation
  @readonly = mode & Constants::Open::READONLY != 0
  @default_transaction_mode = options[:default_transaction_mode] || :deferred
 
@@ -145,25 +142,6 @@ def encoding
  @encoding ||= Encoding.find(execute("PRAGMA encoding").first.first)
  end
 
- def type_translation= value # :nodoc:
- warn(<<~EOWARN) if $VERBOSE
- #{caller(1..1).first} is calling `SQLite3::Database#type_translation=` which is deprecated and will be removed in version 2.0.0.
- EOWARN
- @type_translator = make_type_translator value
- @type_translation = value
- end
- attr_reader :type_translation # :nodoc:
-
- # Return the type translator employed by this database instance. Each
- # database instance has its own type translator; this allows for different
- # type handlers to be installed in each instance without affecting other
- # instances. Furthermore, the translators are instantiated lazily, so that
- # if a database does not use type translation, it will not be burdened by
- # the overhead of a useless type translator. (See the Translator class.)
- def translator
- @translator ||= Translator.new
- end
-
  # Installs (or removes) a block that will be invoked for every access
  # to the database. If the block returns 0 (or +nil+), the statement
  # is allowed to proceed. Returning 1 causes an authorization error to
@@ -741,11 +719,6 @@ def []=(key, value)
  end
  end
 
- # Translates a +row+ of data from the database with the given +types+
- def translate_from_db types, row
- @type_translator.call types, row
- end
-
  # Given a statement, return a result set.
  # This is not intended for general consumption
  # :nodoc:
@@ -756,21 +729,5 @@ def build_result_set stmt
  ResultSet.new(self, stmt)
  end
  end
-
- private
-
- NULL_TRANSLATOR = lambda { |_, row| row }
-
- def make_type_translator should_translate
- if should_translate
- lambda { |types, row|
- types.zip(row).map do |type, value|
- translator.translate(type, value)
- end
- }
- else
- NULL_TRANSLATOR
- end
- end
  end
 end

lib/sqlite3/resultset.rb

@@ -9,10 +9,6 @@ module SQLite3
  class ResultSet
  include Enumerable
 
- class ArrayWithTypes < Array # :nodoc:
- attr_accessor :types
- end
-
  class ArrayWithTypesAndFields < Array # :nodoc:
  attr_writer :types
  attr_writer :fields
@@ -94,19 +90,10 @@ def next
  row = @stmt.step
  return nil if @stmt.done?
 
- row = @db.translate_from_db @stmt.types, row
-
- row = if row.respond_to?(:fields)
- # FIXME: this can only happen if the translator returns something
- # that responds to `fields`. Since we're removing the translator
- # in 2.0, we can remove this branch in 2.0.
- ArrayWithTypes.new(row)
- else
- # FIXME: the `fields` and `types` methods are deprecated on this
- # object for version 2.0, so we can safely remove this branch
- # as well.
- ArrayWithTypesAndFields.new(row)
- end
+ # FIXME: the `fields` and `types` methods are deprecated on this
+ # object for version 2.0, so we can safely remove this branch
+ # as well.
+ row = ArrayWithTypesAndFields.new(row)
 
  row.fields = @stmt.columns
  row.types = @stmt.types
@@ -156,10 +143,6 @@ def next_hash
  row = @stmt.step
  return nil if @stmt.done?
 
- # FIXME: type translation is deprecated, so this can be removed
- # in 2.0
- row = @db.translate_from_db @stmt.types, row
-
  # FIXME: this can be switched to a regular hash in 2.0
  row = HashWithTypesAndFields[*@stmt.columns.zip(row).flatten]
 
@@ -172,6 +155,6 @@ def next_hash
  end
 
  class HashResultSet < ResultSet # :nodoc:
- alias :next :next_hash
+ alias_method :next, :next_hash
  end
 end

sqlite3.gemspec

@@ -68,7 +68,6 @@ Gem::Specification.new do |s|
  "lib/sqlite3/pragmas.rb",
  "lib/sqlite3/resultset.rb",
  "lib/sqlite3/statement.rb",
- "lib/sqlite3/translator.rb",
  "lib/sqlite3/value.rb",
  "lib/sqlite3/version.rb",
  "test/helper.rb",

test/test_database.rb

@@ -97,26 +97,6 @@ def test_get_first_row
  assert_equal [1], @db.get_first_row("SELECT 1")
  end
 
- def test_get_first_row_with_type_translation_and_hash_results
- @db.results_as_hash = true
- capture_io do # hush translation deprecation warnings
- @db.type_translation = true
- assert_equal({"1" => 1}, @db.get_first_row("SELECT 1"))
- end
- end
-
- def test_execute_with_type_translation_and_hash
- rows = []
- @db.results_as_hash = true
-
- capture_io do # hush translation deprecation warnings
- @db.type_translation = true
- @db.execute("SELECT 1") { |row| rows << row }
- end
-
- assert_equal({"1" => 1}, rows.first)
- end
-
  def test_encoding
  assert @db.encoding, "database has encoding"
  end