Rework pattern matching fundamentals

.openpublishing.redirection.csharp.json

@@ -38,7 +38,7 @@
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@@ -76,6 +76,14 @@
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+      "redirect_url": "/dotnet/csharp/fundamentals/patterns/discards"
+    },
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@@ -3370,7 +3378,7 @@
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docs/csharp/advanced-topics/expression-trees/index.md

@@ -64,6 +64,6 @@ Expression trees don't support new expression node types. It would be a breaking
 - Expressions using <xref:System.Index?displayProperty=nameWithType> or <xref:System.Range?displayProperty=nameWithType>, [index "from end" (`^`) operator](../../language-reference/operators/member-access-operators.md#index-from-end-operator-) or [range expressions (`..`)](../../language-reference/operators/member-access-operators.md#range-operator-)
 - [`async` lambda expressions or `await` expressions](../../language-reference/operators/lambda-expressions.md#async-lambdas), including [`await foreach` and `await using`](../../language-reference/operators/await.md#asynchronous-streams-and-disposables)
 - [Tuple literals, tuple conversions, tuple `==` or `!=`, or `with` expressions](../../language-reference/builtin-types/value-tuples.md)
-- [Discards (`_`)](../../fundamentals/functional/discards.md), [deconstructing assignment](../../fundamentals/functional/deconstruct.md), [pattern matching `is` operator, or the pattern matching `switch` expression](../../language-reference/operators/patterns.md)
+- [Discards (`_`)](../../fundamentals/patterns/discards.md), [deconstructing assignment](../../fundamentals/functional/deconstruct.md), [pattern matching `is` operator, or the pattern matching `switch` expression](../../language-reference/operators/patterns.md)
 - COM call with `ref` omitted on the arguments
 - [`ref`](../../language-reference/keywords/ref.md), [`in`](../../language-reference/keywords/method-parameters.md#in-parameter-modifier) or [`out`](../../language-reference/keywords/method-parameters.md#out-parameter-modifier) parameters, `ref` return values, `out` arguments, or any values of [`ref struct` type](../../language-reference/builtin-types/ref-struct.md)

docs/csharp/advanced-topics/interface-implementation/mixins-with-default-interface-methods.md

@@ -96,7 +96,7 @@ The `HalogenLight` you created earlier doesn't support blinking. So, don't add t
 
 ## Detect the light types using pattern matching
 
-Next, let's write some test code. You can make use of C#'s [pattern matching](../../fundamentals/functional/pattern-matching.md) feature to determine a light's capabilities by examining which interfaces it supports. The following method exercises the supported capabilities of each light:
+Next, let's write some test code. You can make use of C#'s [pattern matching](../../fundamentals/patterns/pattern-matching.md) feature to determine a light's capabilities by examining which interfaces it supports. The following method exercises the supported capabilities of each light:
 
 :::code language="csharp" source="./snippets/mixins-with-default-interface-methods/Program.cs" id="SnippetTestLightFunctions":::
 

docs/csharp/fundamentals/expressions/index.md

@@ -105,4 +105,5 @@ For a broader look at null-safe operators, see [C# null operators](../null-safet
 - [Arithmetic, comparison, logical, and assignment operators](operators.md) — the everyday operators in depth
 - [Equality comparisons](equality.md) — how `==`, `!=`, and `Equals` work
 - [C# null operators](../null-safety/null-operators.md) — `?.`, `??`, and `??=`
+- [Pattern matching](../patterns/pattern-matching.md) — use a `switch` expression to select a value by matching the type, value, or shape of data
 - [Boolean logical operators](../../language-reference/operators/boolean-logical-operators.md)

docs/csharp/fundamentals/functional/deconstruct.md

@@ -107,5 +107,5 @@ When you declare a [record](../../language-reference/builtin-types/record.md) ty
 ## See also
 
 - [Deconstruct variable declaration (style rule IDE0042)](../../../fundamentals/code-analysis/style-rules/ide0042.md)
-- [Discards](discards.md)
+- [Discards](../patterns/discards.md)
 - [Tuple types](../../language-reference/builtin-types/value-tuples.md)