[uast] Add UAST API for pattern matching

#IDEA-310333

GitOrigin-RevId: a469ebb49dc0c49a96a492192524709ef4a400f7

uast/uast-common/src/org/jetbrains/uast/expressions/UBinaryExpressionWithPattern.kt

@@ -0,0 +1,35 @@
+// Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package org.jetbrains.uast
+
+import org.jetbrains.annotations.ApiStatus.Experimental
+import org.jetbrains.uast.internal.acceptList
+import org.jetbrains.uast.internal.log
+import org.jetbrains.uast.visitor.UastTypedVisitor
+import org.jetbrains.uast.visitor.UastVisitor
+
+@Experimental
+interface UBinaryExpressionWithPattern : UExpression {
+  /**
+   * Returns the operand expression.
+   */
+  val operand: UExpression
+
+  /**
+   * Returns the pattern of this expression.
+   */
+  val patternExpression: UPatternExpression?
+
+  override fun asLogString(): String = log()
+
+  override fun asRenderString(): String = "${operand.asRenderString()} is ${patternExpression?.asRenderString()}"
+
+  override fun accept(visitor: UastVisitor) {
+    if (visitor.visitBinaryExpressionWithPattern(this)) return
+    uAnnotations.acceptList(visitor)
+    operand.accept(visitor)
+    patternExpression?.accept(visitor)
+    visitor.afterVisitBinaryExpressionWithPattern(this)
+  }
+
+  override fun <D, R> accept(visitor: UastTypedVisitor<D, R>, data: D): R = visitor.visitBinaryExpressionWithPattern(this, data)
+}

uast/uast-common/src/org/jetbrains/uast/expressions/UPatternExpression.kt

@@ -0,0 +1,52 @@
+// Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package org.jetbrains.uast
+
+import org.jetbrains.annotations.ApiStatus.Experimental
+import org.jetbrains.uast.internal.acceptList
+import org.jetbrains.uast.internal.log
+import org.jetbrains.uast.visitor.UastTypedVisitor
+import org.jetbrains.uast.visitor.UastVisitor
+
+/**
+ * A pattern matching expression.
+ * Examples (Java):
+ * * Type pattern: `Point p`
+ * * Deconstruction pattern: `Point(int x, int y)` or `Point(int _, int _)` (variables are unnamed)
+ * * Unnamed pattern: `Point(_, _)`
+ */
+@Experimental
+interface UPatternExpression : UExpression {
+  /**
+   * Name of the pattern, can be null if the pattern is unnamed or no name is specified.
+   */
+  val name: String?
+
+  /**
+   * The primary type reference that is checked when evaluating this pattern or null when there is none.
+   * * For deconstruction patterns like `Point(int x, int y)` this will be then main type `Point`.
+   */
+  val typeReference: UTypeReferenceExpression?
+
+  /**
+   * The deconstructed patterns or empty if this pattern is not a deconstruction pattern.
+   */
+  val deconstructedPatterns: List<UPatternExpression>
+
+  override fun asLogString(): String = log()
+
+  override fun asRenderString(): String {
+    val renderPatternList = if (deconstructedPatterns.isNotEmpty()) "(${deconstructedPatterns.joinToString { it.asRenderString() }})" else ""
+    val renderName = "${if (typeReference != null) " " else ""}${name ?: "_"}"
+    return "${typeReference?.type?.name ?: ""}$renderPatternList$renderName"
+  }
+
+  override fun accept(visitor: UastVisitor) {
+    if (visitor.visitPatternExpression(this)) return
+    uAnnotations.acceptList(visitor)
+    typeReference?.accept(visitor)
+    deconstructedPatterns.acceptList(visitor)
+    visitor.afterVisitPatternExpression(this)
+  }
+
+  override fun <D, R> accept(visitor: UastTypedVisitor<D, R>, data: D): R = visitor.visitPatternExpression(this, data)
+}

uast/uast-common/src/org/jetbrains/uast/visitor/UastTypedVisitor.kt

@@ -47,6 +47,8 @@ interface UastTypedVisitor<in D, out R> {
   fun visitBinaryExpression(node: UBinaryExpression, data: D): R = visitPolyadicExpression(node, data)
 
   fun visitBinaryExpressionWithType(node: UBinaryExpressionWithType, data: D): R = visitExpression(node, data)
+  fun visitBinaryExpressionWithPattern(node: UBinaryExpressionWithPattern, data: D): R = visitExpression(node, data)
+  fun visitPatternExpression(node: UPatternExpression, data: D): R = visitExpression(node, data)
   fun visitParenthesizedExpression(node: UParenthesizedExpression, data: D): R = visitExpression(node, data)
   // Unary operations
   fun visitUnaryExpression(node: UUnaryExpression, data: D): R = visitExpression(node, data)

uast/uast-common/src/org/jetbrains/uast/visitor/UastVisitor.kt

@@ -30,6 +30,8 @@ interface UastVisitor {
   fun visitCallExpression(node: UCallExpression): Boolean = visitExpression(node)
   fun visitBinaryExpression(node: UBinaryExpression): Boolean = visitExpression(node)
   fun visitBinaryExpressionWithType(node: UBinaryExpressionWithType): Boolean = visitExpression(node)
+  fun visitBinaryExpressionWithPattern(node: UBinaryExpressionWithPattern): Boolean = visitExpression(node)
+  fun visitPatternExpression(node: UPatternExpression) = visitExpression(node)
   fun visitPolyadicExpression(node: UPolyadicExpression): Boolean = visitExpression(node)
   fun visitParenthesizedExpression(node: UParenthesizedExpression): Boolean = visitExpression(node)
   fun visitUnaryExpression(node: UUnaryExpression): Boolean = visitExpression(node)
@@ -88,6 +90,8 @@ interface UastVisitor {
   fun afterVisitCallExpression(node: UCallExpression) = afterVisitExpression(node)
   fun afterVisitBinaryExpression(node: UBinaryExpression) = afterVisitExpression(node)
   fun afterVisitBinaryExpressionWithType(node: UBinaryExpressionWithType) = afterVisitExpression(node)
+  fun afterVisitBinaryExpressionWithPattern(node: UBinaryExpressionWithPattern) = afterVisitExpression(node)
+  fun afterVisitPatternExpression(node: UPatternExpression) = afterVisitExpression(node)
   fun afterVisitParenthesizedExpression(node: UParenthesizedExpression) = afterVisitExpression(node)
   fun afterVisitUnaryExpression(node: UUnaryExpression) = afterVisitExpression(node)
   fun afterVisitPrefixExpression(node: UPrefixExpression) = afterVisitExpression(node)