Make Enso "conversion and equality oriented" language (#14133)

Enso, at it roots, is a **conversion oriented language**. Enso supports flexible definitions of conversions of values of a type to another. To stress the importance of conversions in usage of the Enso language, there is `Any.to target_type` method available on any value in the Enso system that allows to _morph and view any object as a different type_ easily when such a conversion is available.

In addition to that Enso is **structured equality oriented language**. There is `Any.==` operator that allows any two values to be compared for equality. The comparison is based on structure - e.g. two instances of the same atom with equal fields are the same. Enso provides such a _structured equality_ implementation to every user defined type automatically, yet it also offers more complex equality handling when needed (via `Comparable` type).

Enso is **conversion and** (structured) **equality oriented language**. That fact is stressed by the shape of its root type `Any`. It exposes just `.to`, `==` and `!=` operations.

# Important Notes
- To fulfill the promise of Enso being  **conversion and equality oriented language**
- this PR proposes to turn `Nothing` related methods into _extension methods_
- e.g. to move them out of `Any` type into `Nothing` type
- the change is supposed to be compatible for everyone using `from Standard.Base import all`
- this PR is the final step finishing the work previously started by
- #14004
- #14003
- #13978
- #14017
- #14050
- in the tradition of those PRs let's argue:
- it is better to be somebody, or at least anybody - nobody wants to feel like `Nothing`
- hence we don't want Enso to feel like "nothing oriented language"
- as such `Nothing` related methods should be provided only as extension methods!
- on a more technical note: `obj.is_nothing.not` can actually be written as `obj!=Nothing`, not sure why we prefer the former (and longer) variant? Maybe some FP bias!?

Author: JaroslavTulach

CHANGELOG.md

@@ -44,6 +44,7 @@
 
 #### Enso Language & Runtime
 
+- [Enso is "conversion and equality oriented" language][14133]
 - [Moving >, >=, <, <= to types where such operators make sense][14017]
 - [Moving warning releated methods outside of `Any`][13978]
 - [Moving error relelated methods outside of `Any`][14003]
@@ -55,6 +56,7 @@
   expressions][13914]
 - [Autocompletion for table expression operators and operands][13917]
 
+[14133]: https://github.com/enso-org/enso/pull/14133
 [14017]: https://github.com/enso-org/enso/pull/14017
 [14003]: https://github.com/enso-org/enso/pull/14003
 [13978]: https://github.com/enso-org/enso/pull/13978

distribution/lib/Standard/Base/0.0.0-dev/docs/api/Any.md

@@ -3,8 +3,4 @@
 - type Any
     - != self that:Standard.Base.Any.Any -> Standard.Base.Any.Any
     - == self that:Standard.Base.Any.Any -> Standard.Base.Any.Any
-    - if_not_nothing self ~action:Standard.Base.Any.Any -> Standard.Base.Any.Any
-    - if_nothing self ~other:Standard.Base.Any.Any -> Standard.Base.Any.Any
-    - is_nothing self -> Standard.Base.Any.Any
-    - map_nothing self f:Standard.Base.Any.Any -> Standard.Base.Any.Any
     - to self target_type:Standard.Base.Any.Any -> Standard.Base.Any.Any

distribution/lib/Standard/Base/0.0.0-dev/docs/api/Nothing.md

@@ -5,3 +5,7 @@
     - if_not_nothing self ~action:Standard.Base.Any.Any -> Standard.Base.Any.Any
     - if_nothing self ~function:Standard.Base.Any.Any -> Standard.Base.Any.Any
     - is_nothing self -> Standard.Base.Any.Any
+- Standard.Base.Any.Any.if_not_nothing self ~action:Standard.Base.Any.Any -> Standard.Base.Any.Any
+- Standard.Base.Any.Any.if_nothing self ~other:Standard.Base.Any.Any -> Standard.Base.Any.Any
+- Standard.Base.Any.Any.is_nothing self -> Standard.Base.Data.Boolean.Boolean
+- Standard.Base.Any.Any.map_nothing self f:Standard.Base.Any.Any -> Standard.Base.Any.Any

distribution/lib/Standard/Base/0.0.0-dev/src/Any.enso

@@ -1,9 +1,4 @@
-import project.Meta
-import project.Nothing.Nothing
-from project.Data.Boolean import Boolean, False, True
-from project.Data.Ordering import all
-from project.Data.Range.Extensions import all
-from project.Function import const
+from project.Data.Boolean import Boolean
 import project.Errors.Common.No_Such_Conversion
 from project.Metadata import Widget
 
@@ -149,73 +144,3 @@ type Any
        `Any.==`.
     != : Any -> Boolean
     != self that = (self == that).not
-
-    ## ---
-       group: Logical
-       icon: metadata
-       ---
-       Checks if the type is an instance of `Nothing`.
-       Nothing in Enso is used as a universal value to indicate the lack of
-       presence of a value. This function is primarily useful in the IDE.
-
-       ## Examples
-       ### Checking if the value 1 is nothing.
-
-       ```
-             1.is_nothing
-       ```
-    is_nothing : Boolean
-    is_nothing self = False
-
-    ## ---
-       group: Logical
-       icon: operators
-       ---
-       If `self` is Nothing then returns `other`.
-
-       ## Examples
-       ### If the value "Hello" is nothing return "".
-
-       ```
-             "Hello".if_nothing ""
-       ```
-    if_nothing : Any -> Any
-    if_nothing self ~other =
-        const self other
-
-    ## ---
-       group: Logical
-       icon: operators
-       ---
-       If `self` is Nothing then returns Nothing, otherwise returns the result of
-       running the provided `action`.
-
-       ## Examples
-       ### Transform a value only if it is not nothing.
-
-       ```
-             my_result.if_not_nothing <| my_result + 1
-       ```
-    if_not_nothing : Any -> Any
-    if_not_nothing self ~action = action
-
-    ## ---
-       icon: column_add
-       ---
-       Applies the provided function to `self` unless `self` is `Nothing`, which
-       is returned unchanged.
-
-       ## Arguments
-        - `f`: The function to apply to `self` if `self` is not `Nothing`.
-
-       ## Examples
-       ### Applying a function over a value 10.
-
-       ```
-             10.map_nothing *2
-       ```
-    map_nothing : (Any -> Any) -> Any | Nothing
-    map_nothing self f = case self of
-        Nothing -> Nothing
-        a -> f a
-

distribution/lib/Standard/Base/0.0.0-dev/src/Data/Filter_Condition.enso

@@ -9,7 +9,7 @@ import project.Data.Vector.Vector
 import project.Errors.Common.Missing_Argument
 import project.Internal.Predicate_Helpers
 import project.Meta
-import project.Nothing.Nothing
+from project.Nothing import all
 from project.Data.Boolean import Boolean, False, True
 from project.Data.Filter_Condition.Filter_Condition import all
 from project.Data.Text.Extensions import all

distribution/lib/Standard/Base/0.0.0-dev/src/Data/List.enso

@@ -21,8 +21,8 @@ import project.Errors.Common.Index_Out_Of_Bounds
 import project.Errors.Common.Not_Found
 import project.Errors.Empty_Error.Empty_Error
 import project.Meta
-import project.Nothing.Nothing
 import project.Panic.Panic
+from project.Nothing import all
 from project.Data.Boolean import Boolean, False, True
 from project.Data.List.List import Cons, Nil
 from project.Internal.Predicate_Helpers import unify_condition_or_predicate, unify_condition_predicate_or_element

distribution/lib/Standard/Base/0.0.0-dev/src/Data/Locale.enso

@@ -6,8 +6,8 @@ import project.Data.Vector.Vector
 import project.Meta
 import project.Metadata.Display
 import project.Metadata.Widget
-import project.Nothing.Nothing
 import project.Panic.Panic
+from project.Nothing import all
 from project.Data.Text.Extensions import all
 from project.Metadata.Choice import Option
 

distribution/lib/Standard/Base/0.0.0-dev/src/Data/Numbers.enso

@@ -10,8 +10,8 @@ import project.Errors.Common.Incomparable_Values
 import project.Errors.Common.Unsupported_Argument_Types
 import project.Errors.Illegal_Argument.Illegal_Argument
 import project.Internal.Rounding_Helpers
-import project.Nothing.Nothing
 import project.Panic.Panic
+from project.Nothing import all
 from project.Data.Boolean import Boolean, False, True
 from project.Internal.Number_Builtins import all
 from project.Internal.Ordering_Helpers import Positive_Integer_Comparator

distribution/lib/Standard/Base/0.0.0-dev/src/Data/Range.enso

@@ -11,8 +11,8 @@ import project.Errors.Empty_Error.Empty_Error
 import project.Errors.Illegal_Argument.Illegal_Argument
 import project.Errors.Illegal_State.Illegal_State
 import project.Function.Function
-import project.Nothing.Nothing
 import project.Panic.Panic
+from project.Nothing import all
 from project.Data.Boolean import Boolean, False, True
 from project.Error import all
 from project.Internal.Predicate_Helpers import unify_condition_or_predicate

distribution/lib/Standard/Base/0.0.0-dev/src/Data/Read/Return_As.enso

@@ -11,8 +11,8 @@ import project.Function.Function
 import project.Meta
 import project.Metadata.Display
 import project.Metadata.Widget
-import project.Nothing.Nothing
 import project.Panic.Panic
+from project.Nothing import all
 from project.Data.Boolean import False, True
 from project.Metadata.Choice import Option
 from project.Metadata.Widget import Single_Choice