Code cleanup and simplification:

Remove un-needed constructs.
Remove over-engineered constructs..
Do things one way and use that everywhere.
Remove inconsistant .editorconfig files.
Remove custom exceptions. Use framework ones instead.
Remove 1 million primes. This is not a prime generating library. I have specialty libraries for that. Why is that here?
Limit the number of new language features to be compatable with older IDE versions.
Restore namespaces.
Remove top-level statements and global usings.

.editorconfig

@@ -1,5 +1,5 @@
-root = true
 # Remove the line below if you want to inherit .editorconfig settings from higher directories
+root = true
 
 ## Roslynator.CSharp.Analyzers
 
@@ -29,13 +29,14 @@ insert_final_newline = false
 
 # Organize usings
 dotnet_separate_import_directive_groups = false
-dotnet_sort_system_directives_first = false
-file_header_template = 
+dotnet_sort_system_directives_first = true
+file_header_template = unset
 
-dotnet_style_qualification_for_event = true
-dotnet_style_qualification_for_field = true
-dotnet_style_qualification_for_method = true
-dotnet_style_qualification_for_property = true
+# this. and Me. preferences
+dotnet_style_qualification_for_event = false
+dotnet_style_qualification_for_field = false
+dotnet_style_qualification_for_method = false
+dotnet_style_qualification_for_property = false
 
 # Language keywords vs BCL types preferences
 dotnet_style_predefined_type_for_locals_parameters_members = true
@@ -54,13 +55,16 @@ dotnet_style_require_accessibility_modifiers = for_non_interface_members
 dotnet_style_coalesce_expression = true
 dotnet_style_collection_initializer = true
 dotnet_style_explicit_tuple_names = true
+dotnet_style_namespace_match_folder = true
 dotnet_style_null_propagation = true
 dotnet_style_object_initializer = true
 dotnet_style_operator_placement_when_wrapping = beginning_of_line
 dotnet_style_prefer_auto_properties = true
+dotnet_style_prefer_collection_expression = true
 dotnet_style_prefer_compound_assignment = true
 dotnet_style_prefer_conditional_expression_over_assignment = true
 dotnet_style_prefer_conditional_expression_over_return = true
+dotnet_style_prefer_foreach_explicit_cast_in_source = when_strongly_typed
 dotnet_style_prefer_inferred_anonymous_type_member_names = true
 dotnet_style_prefer_inferred_tuple_names = true
 dotnet_style_prefer_is_null_check_over_reference_equality_method = true
@@ -106,18 +110,21 @@ csharp_style_prefer_pattern_matching = true
 csharp_style_prefer_switch_expression = true
 
 # Null-checking preferences
-csharp_style_conditional_delegate_call = true:suggestion
-csharp_style_prefer_parameter_null_checking = true
+csharp_style_conditional_delegate_call = true
 
 # Modifier preferences
-csharp_prefer_static_local_function = true:suggestion
-csharp_preferred_modifier_order = public,private,protected,internal,static,extern,new,virtual,abstract,sealed,override,readonly,unsafe,volatile,async
+csharp_prefer_static_local_function = true
+csharp_preferred_modifier_order = public,private,protected,internal,file,static,extern,new,virtual,abstract,sealed,override,readonly,unsafe,required,volatile,async
+csharp_style_prefer_readonly_struct = true
+csharp_style_prefer_readonly_struct_member = true
 
 # Code-block preferences
-csharp_prefer_braces = true:silent
-csharp_prefer_simple_using_statement = true:suggestion
-csharp_style_namespace_declarations = file_scoped:error
-csharp_style_prefer_method_group_conversion = true:silent
+csharp_prefer_braces = true
+csharp_prefer_simple_using_statement = false
+csharp_style_namespace_declarations = block_scoped
+csharp_style_prefer_method_group_conversion = true:suggestion
+csharp_style_prefer_primary_constructors = true
+csharp_style_prefer_top_level_statements = false
 
 # Expression-level preferences
 csharp_prefer_simple_default_expression = true:suggestion
@@ -129,17 +136,20 @@ csharp_style_prefer_local_over_anonymous_function = true:suggestion
 csharp_style_prefer_null_check_over_type_check = true:suggestion
 csharp_style_prefer_range_operator = true:suggestion
 csharp_style_prefer_tuple_swap = true:suggestion
+csharp_style_prefer_utf8_string_literals = true
 csharp_style_throw_expression = true:suggestion
-csharp_style_unused_value_assignment_preference = discard_variable:suggestion
-csharp_style_unused_value_expression_statement_preference = discard_variable:silent
+csharp_style_unused_value_assignment_preference = discard_variable
+csharp_style_unused_value_expression_statement_preference = discard_variable
 
 # 'using' directive preferences
-csharp_using_directive_placement = inside_namespace:error
+csharp_using_directive_placement = outside_namespace
 
 # New line preferences
-csharp_style_allow_blank_line_after_colon_in_constructor_initializer_experimental = true:silent
-csharp_style_allow_blank_lines_between_consecutive_braces_experimental = true:silent
-csharp_style_allow_embedded_statements_on_same_line_experimental = true:silent
+csharp_style_allow_blank_line_after_colon_in_constructor_initializer_experimental = true
+csharp_style_allow_blank_line_after_token_in_arrow_expression_clause_experimental = true
+csharp_style_allow_blank_line_after_token_in_conditional_expression_experimental = true
+csharp_style_allow_blank_lines_between_consecutive_braces_experimental = true
+csharp_style_allow_embedded_statements_on_same_line_experimental = true
 
 #### C# Formatting Rules ####
 
@@ -192,79 +202,79 @@ csharp_preserve_single_line_statements = true
 
 # Naming rules
 
-dotnet_naming_rule.interface_should_be_begins_with_i.severity = suggestion
-dotnet_naming_rule.interface_should_be_begins_with_i.symbols = interface
-dotnet_naming_rule.interface_should_be_begins_with_i.style = begins_with_i
+dotnet_naming_rule.interface_should_be_iprefix.severity = suggestion
+dotnet_naming_rule.interface_should_be_iprefix.symbols = interface
+dotnet_naming_rule.interface_should_be_iprefix.style = iprefix
+
+dotnet_naming_rule.public_identifiers_should_be_pascalcase.severity = suggestion
+dotnet_naming_rule.public_identifiers_should_be_pascalcase.symbols = public_identifiers
+dotnet_naming_rule.public_identifiers_should_be_pascalcase.style = pascalcase
 
-dotnet_naming_rule.types_should_be_pascal_case.severity = suggestion
-dotnet_naming_rule.types_should_be_pascal_case.symbols = types
-dotnet_naming_rule.types_should_be_pascal_case.style = pascal_case
+dotnet_naming_rule.static_identifiers_should_be_pascalcase.severity = suggestion
+dotnet_naming_rule.static_identifiers_should_be_pascalcase.symbols = static_identifiers
+dotnet_naming_rule.static_identifiers_should_be_pascalcase.style = pascalcase
 
-dotnet_naming_rule.non_field_members_should_be_pascal_case.severity = suggestion
-dotnet_naming_rule.non_field_members_should_be_pascal_case.symbols = non_field_members
-dotnet_naming_rule.non_field_members_should_be_pascal_case.style = pascal_case
+dotnet_naming_rule.const_should_be_uppercase.severity = suggestion
+dotnet_naming_rule.const_should_be_uppercase.symbols = const
+dotnet_naming_rule.const_should_be_uppercase.style = uppercase
+
+dotnet_naming_rule.private_identifiers_should_be__camelcase.severity = suggestion
+dotnet_naming_rule.private_identifiers_should_be__camelcase.symbols = private_identifiers
+dotnet_naming_rule.private_identifiers_should_be__camelcase.style = _camelcase
+
+dotnet_naming_rule.local_identifiers_should_be_camelcase.severity = suggestion
+dotnet_naming_rule.local_identifiers_should_be_camelcase.symbols = local_identifiers
+dotnet_naming_rule.local_identifiers_should_be_camelcase.style = camelcase
 
 # Symbol specifications
 
 dotnet_naming_symbols.interface.applicable_kinds = interface
 dotnet_naming_symbols.interface.applicable_accessibilities = public, internal, private, protected, protected_internal, private_protected
 dotnet_naming_symbols.interface.required_modifiers = 
 
-dotnet_naming_symbols.types.applicable_kinds = class, struct, interface, enum
-dotnet_naming_symbols.types.applicable_accessibilities = public, internal, private, protected, protected_internal, private_protected
-dotnet_naming_symbols.types.required_modifiers = 
+dotnet_naming_symbols.public_identifiers.applicable_kinds = namespace, property, field, event, class, struct, interface, enum, delegate, method, local_function
+dotnet_naming_symbols.public_identifiers.applicable_accessibilities = public
+dotnet_naming_symbols.public_identifiers.required_modifiers = 
+
+dotnet_naming_symbols.private_identifiers.applicable_kinds = property, field
+dotnet_naming_symbols.private_identifiers.applicable_accessibilities = private
+dotnet_naming_symbols.private_identifiers.required_modifiers = 
 
-dotnet_naming_symbols.non_field_members.applicable_kinds = property, event, method
-dotnet_naming_symbols.non_field_members.applicable_accessibilities = public, internal, private, protected, protected_internal, private_protected
-dotnet_naming_symbols.non_field_members.required_modifiers = 
+dotnet_naming_symbols.local_identifiers.applicable_kinds = parameter, local
+dotnet_naming_symbols.local_identifiers.applicable_accessibilities = local
+dotnet_naming_symbols.local_identifiers.required_modifiers = 
+
+dotnet_naming_symbols.static_identifiers.applicable_kinds = field, local, class, struct, interface, delegate, method, local_function
+dotnet_naming_symbols.static_identifiers.applicable_accessibilities = *
+dotnet_naming_symbols.static_identifiers.required_modifiers = static
+
+dotnet_naming_symbols.const.applicable_kinds = field, local
+dotnet_naming_symbols.const.applicable_accessibilities = *
+dotnet_naming_symbols.const.required_modifiers = const
 
 # Naming styles
 
-dotnet_naming_style.pascal_case.required_prefix = 
-dotnet_naming_style.pascal_case.required_suffix = 
-dotnet_naming_style.pascal_case.word_separator = 
-dotnet_naming_style.pascal_case.capitalization = pascal_case
-
-dotnet_naming_style.begins_with_i.required_prefix = I
-dotnet_naming_style.begins_with_i.required_suffix = 
-dotnet_naming_style.begins_with_i.word_separator = 
-dotnet_naming_style.begins_with_i.capitalization = pascal_case
-csharp_style_prefer_top_level_statements = true:silent
-csharp_style_prefer_utf8_string_literals = true:suggestion
-csharp_style_prefer_readonly_struct = true:suggestion
-csharp_style_prefer_readonly_struct_member = true:suggestion
-csharp_style_allow_blank_line_after_token_in_conditional_expression_experimental = true:silent
-csharp_style_allow_blank_line_after_token_in_arrow_expression_clause_experimental = true:silent
-
-[*.{cs,vb}]
-dotnet_style_operator_placement_when_wrapping = beginning_of_line
-tab_width = 4
-indent_size = 4
-end_of_line = crlf
-dotnet_style_coalesce_expression = true:suggestion
-dotnet_style_null_propagation = true:suggestion
-dotnet_style_prefer_is_null_check_over_reference_equality_method = true:suggestion
-dotnet_style_prefer_auto_properties = true:silent
-dotnet_style_object_initializer = true:suggestion
-dotnet_style_collection_initializer = true:suggestion
-dotnet_style_prefer_simplified_boolean_expressions = true:suggestion
-dotnet_style_prefer_conditional_expression_over_assignment = true:silent
-dotnet_style_prefer_conditional_expression_over_return = true:silent
-dotnet_style_explicit_tuple_names = true:suggestion
-dotnet_style_prefer_inferred_tuple_names = true:suggestion
-dotnet_style_prefer_inferred_anonymous_type_member_names = true:suggestion
-dotnet_style_prefer_compound_assignment = true:suggestion
-dotnet_style_prefer_simplified_interpolation = true:suggestion
-
-dotnet_style_namespace_match_folder = true:error
-
-dotnet_style_readonly_field = true:suggestion
-dotnet_style_predefined_type_for_locals_parameters_members = true:silent
-dotnet_style_predefined_type_for_member_access = true:silent
-dotnet_style_require_accessibility_modifiers = for_non_interface_members:silent
-dotnet_style_allow_multiple_blank_lines_experimental = true:silent
-dotnet_style_allow_statement_immediately_after_block_experimental = true:silent
-dotnet_code_quality_unused_parameters = all:suggestion
-
-dotnet_analyzer_diagnostic.category-roslynator.severity = suggestion
-dotnet_analyzer_diagnostic.category-style.severity = suggestion
+dotnet_naming_style.pascalcase.required_prefix = 
+dotnet_naming_style.pascalcase.required_suffix = 
+dotnet_naming_style.pascalcase.word_separator = 
+dotnet_naming_style.pascalcase.capitalization = pascal_case
+
+dotnet_naming_style.iprefix.required_prefix = I
+dotnet_naming_style.iprefix.required_suffix = 
+dotnet_naming_style.iprefix.word_separator = 
+dotnet_naming_style.iprefix.capitalization = pascal_case
+
+dotnet_naming_style._camelcase.required_prefix = _
+dotnet_naming_style._camelcase.required_suffix = 
+dotnet_naming_style._camelcase.word_separator = 
+dotnet_naming_style._camelcase.capitalization = camel_case
+
+dotnet_naming_style.camelcase.required_prefix = 
+dotnet_naming_style.camelcase.required_suffix = 
+dotnet_naming_style.camelcase.word_separator = 
+dotnet_naming_style.camelcase.capitalization = camel_case
+
+dotnet_naming_style.uppercase.required_prefix = 
+dotnet_naming_style.uppercase.required_suffix = 
+dotnet_naming_style.uppercase.word_separator = 
+dotnet_naming_style.uppercase.capitalization = all_upper

BigDecimal.sln

@@ -9,7 +9,6 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "TestBigDecimal", "TestBigDe
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution Items", "{14B967DD-43D9-4797-A0B2-CD989241D463}"
 	ProjectSection(SolutionItems) = preProject
-		.editorconfig = .editorconfig
 		LICENSE.txt = LICENSE.txt
 		README.md = README.md
 	EndProjectSection