docs(core): fix javadoc in TypeExpressionVisitor

core/src/main/java/io/substrait/function/TypeExpressionVisitor.java

@@ -1,47 +1,192 @@
 package io.substrait.function;
 
+/**
+ * Visitor over the concrete {@link TypeExpression} kinds, extending {@link
+ * ParameterizedTypeVisitor} with the derivation-expression variants.
+ *
+ * @param <R> the result type produced by the visitor
+ * @param <E> the exception type that may be thrown
+ */
 public interface TypeExpressionVisitor<R, E extends Throwable>
     extends ParameterizedTypeVisitor<R, E> {
+  /**
+   * Visits a fixed-length character type expression.
+   *
+   * @param expr the expression being visited
+   * @return the visit result
+   * @throws E if the visit fails
+   */
   R visit(TypeExpression.FixedChar expr) throws E;
 
+  /**
+   * Visits a variable-length character type expression.
+   *
+   * @param expr the expression being visited
+   * @return the visit result
+   * @throws E if the visit fails
+   */
   R visit(TypeExpression.VarChar expr) throws E;
 
+  /**
+   * Visits a fixed-length binary type expression.
+   *
+   * @param expr the expression being visited
+   * @return the visit result
+   * @throws E if the visit fails
+   */
   R visit(TypeExpression.FixedBinary expr) throws E;
 
+  /**
+   * Visits a decimal type expression.
+   *
+   * @param expr the expression being visited
+   * @return the visit result
+   * @throws E if the visit fails
+   */
   R visit(TypeExpression.Decimal expr) throws E;
 
+  /**
+   * Visits a day-time interval type expression.
+   *
+   * @param expr the expression being visited
+   * @return the visit result
+   * @throws E if the visit fails
+   */
   R visit(TypeExpression.IntervalDay expr) throws E;
 
+  /**
+   * Visits a compound interval type expression.
+   *
+   * @param expr the expression being visited
+   * @return the visit result
+   * @throws E if the visit fails
+   */
   R visit(TypeExpression.IntervalCompound expr) throws E;
 
+  /**
+   * Visits a precision-time type expression.
+   *
+   * @param expr the expression being visited
+   * @return the visit result
+   * @throws E if the visit fails
+   */
   R visit(TypeExpression.PrecisionTime expr) throws E;
 
+  /**
+   * Visits a precision-timestamp (without timezone) type expression.
+   *
+   * @param expr the expression being visited
+   * @return the visit result
+   * @throws E if the visit fails
+   */
   R visit(TypeExpression.PrecisionTimestamp expr) throws E;
 
+  /**
+   * Visits a precision-timestamp with timezone type expression.
+   *
+   * @param expr the expression being visited
+   * @return the visit result
+   * @throws E if the visit fails
+   */
   R visit(TypeExpression.PrecisionTimestampTZ expr) throws E;
 
+  /**
+   * Visits a struct type expression.
+   *
+   * @param expr the expression being visited
+   * @return the visit result
+   * @throws E if the visit fails
+   */
   R visit(TypeExpression.Struct expr) throws E;
 
+  /**
+   * Visits a list type expression.
+   *
+   * @param expr the expression being visited
+   * @return the visit result
+   * @throws E if the visit fails
+   */
   R visit(TypeExpression.ListType expr) throws E;
 
+  /**
+   * Visits a map type expression.
+   *
+   * @param expr the expression being visited
+   * @return the visit result
+   * @throws E if the visit fails
+   */
   R visit(TypeExpression.Map expr) throws E;
 
+  /**
+   * Visits a function type expression.
+   *
+   * @param expr the expression being visited
+   * @return the visit result
+   * @throws E if the visit fails
+   */
   R visit(TypeExpression.Func expr) throws E;
 
+  /**
+   * Visits a binary operation type expression.
+   *
+   * @param expr the expression being visited
+   * @return the visit result
+   * @throws E if the visit fails
+   */
   R visit(TypeExpression.BinaryOperation expr) throws E;
 
+  /**
+   * Visits a logical-not operation type expression.
+   *
+   * @param expr the expression being visited
+   * @return the visit result
+   * @throws E if the visit fails
+   */
   R visit(TypeExpression.NotOperation expr) throws E;
 
+  /**
+   * Visits an if/then operation type expression.
+   *
+   * @param expr the expression being visited
+   * @return the visit result
+   * @throws E if the visit fails
+   */
   R visit(TypeExpression.IfOperation expr) throws E;
 
+  /**
+   * Visits an integer-literal type expression.
+   *
+   * @param expr the expression being visited
+   * @return the visit result
+   * @throws E if the visit fails
+   */
   R visit(TypeExpression.IntegerLiteral expr) throws E;
 
+  /**
+   * Visits a return-program type expression.
+   *
+   * @param expr the expression being visited
+   * @return the visit result
+   * @throws E if the visit fails
+   */
   R visit(TypeExpression.ReturnProgram expr) throws E;
 
+  /**
+   * Base {@link TypeExpressionVisitor} that throws {@link UnsupportedOperationException} for every
+   * expression, allowing subclasses to override only the visit methods they support.
+   *
+   * @param <R> the result type produced by the visitor
+   * @param <E> the exception type that may be thrown
+   */
   abstract class TypeExpressionThrowsVisitor<R, E extends Throwable>
       extends ParameterizedTypeVisitor.ParameterizedTypeThrowsVisitor<R, E>
       implements TypeExpressionVisitor<R, E> {
 
+    /**
+     * Creates a visitor that throws with the given message for unsupported expressions.
+     *
+     * @param unsupportedMessage the message used for unsupported expressions
+     */
     protected TypeExpressionThrowsVisitor(String unsupportedMessage) {
       super(unsupportedMessage);
     }