Which string identifiers for field types do exist? There are several enum classes containing constants such as the SectionType class which I can use to create sections:

//  …
$section = new SectionModel();
$section-&gt;type = SectionType::Single;
//  …


But what about creating fields? Currently I create fields like so:

//  …
$field = new FieldModel();
$field-&gt;type = 'PlainText';
//  …


Is there any enum class containing valid identifiers I could use to create a field? Like in the following way?

//  …
$field = new FieldModel();
$field-&gt;type = FieldType::PlainText;     // Does something like this exist?
//  …


I can't find such a class or any other listing of existing field types, where do I?

Unfortunately, a list of string identifiers is missing on the guide for plugin development and field types. The list of field types only tells me which field types exist but not what identifiers they have.
I don't know if any enum exists (couldn't find it in source), but you could have a look at the contents of the craft/app/fieldtypes folder (and ignore BaseFieldtypes, DataModels and interfaces) to find the identifiers:


UsersFieldType.php
TagsFieldType.php
TableFieldType.php
RichTextFieldType.php
RadioButtonsFieldType.php
PositionSelectFieldType.php
PlainTextFieldType.php
NumberFieldType.php
MultiSelectFieldType.php
MatrixFieldType.php
LightswitchFieldType.php
EntriesFieldType.php
DropdownFieldType.php
DateFieldType.php
ColorFieldType.php
CheckboxesFieldType.php
CategoriesFieldType.php
AssetsFieldType.php


String identifiers correspond to the file names (without "FieldType.php", obviously).