Remove unnecessary calls to fold()

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/enrich/EnrichPolicyResolver.java

@@ -59,7 +59,7 @@
 import java.util.Set;
 import java.util.stream.Collectors;
 
-import static org.elasticsearch.xpack.esql.core.expression.Foldables.stringLiteralValueOf;
+import static org.elasticsearch.xpack.esql.expression.Foldables.stringLiteralValueOf;
 import static org.elasticsearch.xpack.esql.session.EsqlCCSUtils.markClusterWithFinalStateAndNoShards;
 
 /**

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/FunctionUtils.java → x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/Foldables.java

@@ -4,20 +4,24 @@
  * 2.0; you may not use this file except in compliance with the Elastic License
  * 2.0.
  */
-package org.elasticsearch.xpack.esql.expression.function;
+package org.elasticsearch.xpack.esql.expression;
 
+import org.apache.lucene.util.BytesRef;
 import org.elasticsearch.common.lucene.BytesRefs;
 import org.elasticsearch.core.Nullable;
+import org.elasticsearch.core.Strings;
 import org.elasticsearch.xpack.esql.EsqlIllegalArgumentException;
 import org.elasticsearch.xpack.esql.common.Failure;
 import org.elasticsearch.xpack.esql.common.Failures;
+import org.elasticsearch.xpack.esql.core.QlIllegalArgumentException;
 import org.elasticsearch.xpack.esql.core.expression.Expression;
+import org.elasticsearch.xpack.esql.core.expression.FoldContext;
 import org.elasticsearch.xpack.esql.core.expression.Literal;
 
 import static org.elasticsearch.common.logging.LoggerMessageFormat.format;
 import static org.elasticsearch.xpack.esql.common.Failure.fail;
 
-public class FunctionUtils {
+public abstract class Foldables {
  /**
  * A utility class to validate the type resolution of expressions before and after logical planning.
  * If null is passed for Failures to the constructor, it means we are only type resolution.
@@ -64,6 +68,34 @@ public Expression.TypeResolution getResolvedType() {
  }
  }
 
+ public static Object valueOf(FoldContext ctx, Expression e) {
+ if (e.foldable()) {
+ return e.fold(ctx);
+ }
+ throw new QlIllegalArgumentException("Cannot determine value for {}", e);
+ }
+
+ public static String stringLiteralValueOf(Expression expression, String message) {
+ if (expression instanceof Literal literal && literal.value() instanceof BytesRef bytesRef) {
+ return bytesRef.utf8ToString();
+ }
+ throw new QlIllegalArgumentException(message);
+ }
+
+ public static Object literalValueOf(Expression e) {
+ if (e instanceof Literal literal) {
+ return literal.value();
+ }
+ throw new QlIllegalArgumentException("Expected literal, but got {}", e);
+ }
+
+ public static Object extractLiteralOrReturnSelf(Expression e) {
+ if (e instanceof Literal literal) {
+ return literal.value();
+ }
+ return e;
+ }
+
  public static Integer limitValue(Expression limitField, String sourceText) {
  if (limitField instanceof Literal literal) {
  Object value = literal.value();
@@ -148,4 +180,13 @@ public static String queryAsString(Expression queryField, String sourceText) {
  format(null, "Query value must be a constant string in [{}], found [{}]", sourceText, queryField)
  );
  }
+
+ public static int intValueOf(Expression field, String sourceText, String fieldName) {
+ if (field instanceof Literal literal && literal.value() instanceof Number n) {
+ return n.intValue();
+ }
+ throw new EsqlIllegalArgumentException(
+ Strings.format(null, "[{}] value must be a constant number in [{}], found [{}]", fieldName, sourceText, field)
+ );
+ }
 }

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/AggregateFunction.java

@@ -12,7 +12,6 @@
 import org.elasticsearch.xpack.esql.capabilities.PostAnalysisPlanVerificationAware;
 import org.elasticsearch.xpack.esql.common.Failures;
 import org.elasticsearch.xpack.esql.core.expression.Expression;
-import org.elasticsearch.xpack.esql.core.expression.FoldContext;
 import org.elasticsearch.xpack.esql.core.expression.Literal;
 import org.elasticsearch.xpack.esql.core.expression.TypeResolutions;
 import org.elasticsearch.xpack.esql.core.expression.function.Function;
@@ -130,7 +129,7 @@ public List<? extends Expression> parameters() {
 
  public boolean hasFilter() {
  return filter != null
- && (filter.foldable() == false || Boolean.TRUE.equals(filter.fold(FoldContext.small() /* TODO remove me */)) == false);
+ && (filter.foldable() == false || (filter instanceof Literal literal && Boolean.TRUE.equals(literal.value()) == false));
  }
 
  public Expression filter() {

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/CountDistinct.java

@@ -19,7 +19,6 @@
 import org.elasticsearch.compute.aggregation.CountDistinctLongAggregatorFunctionSupplier;
 import org.elasticsearch.xpack.esql.EsqlIllegalArgumentException;
 import org.elasticsearch.xpack.esql.core.expression.Expression;
-import org.elasticsearch.xpack.esql.core.expression.FoldContext;
 import org.elasticsearch.xpack.esql.core.expression.Literal;
 import org.elasticsearch.xpack.esql.core.tree.NodeInfo;
 import org.elasticsearch.xpack.esql.core.tree.Source;
@@ -49,6 +48,7 @@
 import static org.elasticsearch.xpack.esql.core.expression.TypeResolutions.isType;
 import static org.elasticsearch.xpack.esql.core.expression.TypeResolutions.isWholeNumber;
 import static org.elasticsearch.xpack.esql.core.util.CollectionUtils.nullSafeList;
+import static org.elasticsearch.xpack.esql.expression.Foldables.intValueOf;
 
 public class CountDistinct extends AggregateFunction implements OptionalArgument, ToAggregator, SurrogateExpression {
  public static final NamedWriteableRegistry.Entry ENTRY = new NamedWriteableRegistry.Entry(
@@ -210,16 +210,18 @@ protected TypeResolution resolveType() {
  @Override
  public AggregatorFunctionSupplier supplier() {
  DataType type = field().dataType();
- int precision = this.precision == null
- ? DEFAULT_PRECISION
- : ((Number) this.precision.fold(FoldContext.small() /* TODO remove me */)).intValue();
+ int precision = this.precision == null ? DEFAULT_PRECISION : precisionValue();
  if (SUPPLIERS.containsKey(type) == false) {
  // If the type checking did its job, this should never happen
  throw EsqlIllegalArgumentException.illegalDataType(type);
  }
  return SUPPLIERS.get(type).apply(precision);
  }
 
+ private int precisionValue() {
+ return intValueOf(precision, source().text(), "Precision");
+ }
+
  @Override
  public Expression surrogate() {
  var s = source();

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/Percentile.java

@@ -16,7 +16,6 @@
 import org.elasticsearch.compute.aggregation.PercentileIntAggregatorFunctionSupplier;
 import org.elasticsearch.compute.aggregation.PercentileLongAggregatorFunctionSupplier;
 import org.elasticsearch.xpack.esql.core.expression.Expression;
-import org.elasticsearch.xpack.esql.core.expression.FoldContext;
 import org.elasticsearch.xpack.esql.core.expression.Literal;
 import org.elasticsearch.xpack.esql.core.tree.NodeInfo;
 import org.elasticsearch.xpack.esql.core.tree.Source;
@@ -38,6 +37,7 @@
 import static org.elasticsearch.xpack.esql.core.expression.TypeResolutions.ParamOrdinal.SECOND;
 import static org.elasticsearch.xpack.esql.core.expression.TypeResolutions.isFoldable;
 import static org.elasticsearch.xpack.esql.core.expression.TypeResolutions.isType;
+import static org.elasticsearch.xpack.esql.expression.Foldables.intValueOf;
 
 public class Percentile extends NumericAggregate implements SurrogateExpression {
  public static final NamedWriteableRegistry.Entry ENTRY = new NamedWriteableRegistry.Entry(
@@ -169,7 +169,7 @@ protected AggregatorFunctionSupplier doubleSupplier() {
  }
 
  private int percentileValue() {
- return ((Number) percentile.fold(FoldContext.small() /* TODO remove me */)).intValue();
+ return intValueOf(percentile(), source().text(), "Percentile");
  }
 
  @Override

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/Sample.java

@@ -24,12 +24,12 @@
 import org.elasticsearch.xpack.esql.core.tree.NodeInfo;
 import org.elasticsearch.xpack.esql.core.tree.Source;
 import org.elasticsearch.xpack.esql.core.type.DataType;
+import org.elasticsearch.xpack.esql.expression.Foldables;
 import org.elasticsearch.xpack.esql.expression.function.Example;
 import org.elasticsearch.xpack.esql.expression.function.FunctionAppliesTo;
 import org.elasticsearch.xpack.esql.expression.function.FunctionAppliesToLifecycle;
 import org.elasticsearch.xpack.esql.expression.function.FunctionInfo;
 import org.elasticsearch.xpack.esql.expression.function.FunctionType;
-import org.elasticsearch.xpack.esql.expression.function.FunctionUtils;
 import org.elasticsearch.xpack.esql.expression.function.Param;
 import org.elasticsearch.xpack.esql.planner.PlannerUtils;
 import org.elasticsearch.xpack.esql.planner.ToAggregator;
@@ -42,9 +42,9 @@
 import static org.elasticsearch.xpack.esql.core.expression.TypeResolutions.isNotNull;
 import static org.elasticsearch.xpack.esql.core.expression.TypeResolutions.isRepresentableExceptCounters;
 import static org.elasticsearch.xpack.esql.core.expression.TypeResolutions.isType;
-import static org.elasticsearch.xpack.esql.expression.function.FunctionUtils.TypeResolutionValidator.forPostOptimizationValidation;
-import static org.elasticsearch.xpack.esql.expression.function.FunctionUtils.TypeResolutionValidator.forPreOptimizationValidation;
-import static org.elasticsearch.xpack.esql.expression.function.FunctionUtils.resolveTypeLimit;
+import static org.elasticsearch.xpack.esql.expression.Foldables.TypeResolutionValidator.forPostOptimizationValidation;
+import static org.elasticsearch.xpack.esql.expression.Foldables.TypeResolutionValidator.forPreOptimizationValidation;
+import static org.elasticsearch.xpack.esql.expression.Foldables.resolveTypeLimit;
 
 public class Sample extends AggregateFunction implements ToAggregator, PostOptimizationVerificationAware {
  public static final NamedWriteableRegistry.Entry ENTRY = new NamedWriteableRegistry.Entry(Expression.class, "Sample", Sample::new);
@@ -174,7 +174,7 @@ Expression limitField() {
  }
 
  private int limitValue() {
- return FunctionUtils.limitValue(limitField(), sourceText());
+ return Foldables.limitValue(limitField(), sourceText());
  }
 
  Expression uuid() {
@@ -183,6 +183,6 @@ Expression uuid() {
 
  @Override
  public void postOptimizationVerification(Failures failures) {
- FunctionUtils.resolveTypeLimit(limitField(), sourceText(), forPostOptimizationValidation(limitField(), failures));
+ Foldables.resolveTypeLimit(limitField(), sourceText(), forPostOptimizationValidation(limitField(), failures));
  }
 }

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/Top.java

@@ -27,12 +27,12 @@
 import org.elasticsearch.xpack.esql.core.tree.NodeInfo;
 import org.elasticsearch.xpack.esql.core.tree.Source;
 import org.elasticsearch.xpack.esql.core.type.DataType;
+import org.elasticsearch.xpack.esql.expression.Foldables;
+import org.elasticsearch.xpack.esql.expression.Foldables.TypeResolutionValidator;
 import org.elasticsearch.xpack.esql.expression.SurrogateExpression;
 import org.elasticsearch.xpack.esql.expression.function.Example;
 import org.elasticsearch.xpack.esql.expression.function.FunctionInfo;
 import org.elasticsearch.xpack.esql.expression.function.FunctionType;
-import org.elasticsearch.xpack.esql.expression.function.FunctionUtils;
-import org.elasticsearch.xpack.esql.expression.function.FunctionUtils.TypeResolutionValidator;
 import org.elasticsearch.xpack.esql.expression.function.Param;
 import org.elasticsearch.xpack.esql.io.stream.PlanStreamInput;
 import org.elasticsearch.xpack.esql.planner.ToAggregator;
@@ -49,8 +49,8 @@
 import static org.elasticsearch.xpack.esql.core.expression.TypeResolutions.isNotNull;
 import static org.elasticsearch.xpack.esql.core.expression.TypeResolutions.isString;
 import static org.elasticsearch.xpack.esql.core.expression.TypeResolutions.isType;
-import static org.elasticsearch.xpack.esql.expression.function.FunctionUtils.TypeResolutionValidator.forPostOptimizationValidation;
-import static org.elasticsearch.xpack.esql.expression.function.FunctionUtils.TypeResolutionValidator.forPreOptimizationValidation;
+import static org.elasticsearch.xpack.esql.expression.Foldables.TypeResolutionValidator.forPostOptimizationValidation;
+import static org.elasticsearch.xpack.esql.expression.Foldables.TypeResolutionValidator.forPreOptimizationValidation;
 
 public class Top extends AggregateFunction implements ToAggregator, SurrogateExpression, PostOptimizationVerificationAware {
  public static final NamedWriteableRegistry.Entry ENTRY = new NamedWriteableRegistry.Entry(Expression.class, "Top", Top::new);
@@ -123,7 +123,7 @@ Expression orderField() {
  }
 
  private Integer limitValue() {
- return FunctionUtils.limitValue(limitField(), sourceText());
+ return Foldables.limitValue(limitField(), sourceText());
  }
 
  private boolean orderValue() {
@@ -181,7 +181,7 @@ protected TypeResolution resolveType() {
  * During postOptimizationVerification folding is already done, so we also verify that it is definitively a literal
  */
  private TypeResolution resolveTypeLimit() {
- return FunctionUtils.resolveTypeLimit(limitField(), sourceText(), forPreOptimizationValidation(limitField()));
+ return Foldables.resolveTypeLimit(limitField(), sourceText(), forPreOptimizationValidation(limitField()));
  }
 
  /**
@@ -238,7 +238,7 @@ public void postOptimizationVerification(Failures failures) {
  }
 
  private void postOptimizationVerificationLimit(Failures failures) {
- FunctionUtils.resolveTypeLimit(limitField(), sourceText(), forPostOptimizationValidation(limitField(), failures));
+ Foldables.resolveTypeLimit(limitField(), sourceText(), forPostOptimizationValidation(limitField(), failures));
  }
 
  private void postOptimizationVerificationOrder(Failures failures) {

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/fulltext/FullTextFunction.java

@@ -56,9 +56,9 @@
 import static org.elasticsearch.xpack.esql.core.expression.TypeResolutions.ParamOrdinal.DEFAULT;
 import static org.elasticsearch.xpack.esql.core.expression.TypeResolutions.isNotNull;
 import static org.elasticsearch.xpack.esql.core.expression.TypeResolutions.isString;
-import static org.elasticsearch.xpack.esql.expression.function.FunctionUtils.TypeResolutionValidator.forPostOptimizationValidation;
-import static org.elasticsearch.xpack.esql.expression.function.FunctionUtils.TypeResolutionValidator.forPreOptimizationValidation;
-import static org.elasticsearch.xpack.esql.expression.function.FunctionUtils.resolveTypeQuery;
+import static org.elasticsearch.xpack.esql.expression.Foldables.TypeResolutionValidator.forPostOptimizationValidation;
+import static org.elasticsearch.xpack.esql.expression.Foldables.TypeResolutionValidator.forPreOptimizationValidation;
+import static org.elasticsearch.xpack.esql.expression.Foldables.resolveTypeQuery;
 
 /**
  * Base class for full-text functions that use ES queries to match documents.

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/fulltext/Kql.java

@@ -16,11 +16,11 @@
 import org.elasticsearch.xpack.esql.core.querydsl.query.Query;
 import org.elasticsearch.xpack.esql.core.tree.NodeInfo;
 import org.elasticsearch.xpack.esql.core.tree.Source;
+import org.elasticsearch.xpack.esql.expression.Foldables;
 import org.elasticsearch.xpack.esql.expression.function.Example;
 import org.elasticsearch.xpack.esql.expression.function.FunctionAppliesTo;
 import org.elasticsearch.xpack.esql.expression.function.FunctionAppliesToLifecycle;
 import org.elasticsearch.xpack.esql.expression.function.FunctionInfo;
-import org.elasticsearch.xpack.esql.expression.function.FunctionUtils;
 import org.elasticsearch.xpack.esql.expression.function.Param;
 import org.elasticsearch.xpack.esql.io.stream.PlanStreamInput;
 import org.elasticsearch.xpack.esql.optimizer.rules.physical.local.LucenePushdownPredicates;
@@ -95,7 +95,7 @@ protected NodeInfo<? extends Expression> info() {
 
  @Override
  protected Query translate(LucenePushdownPredicates pushdownPredicates, TranslatorHandler handler) {
- return new KqlQuery(source(), FunctionUtils.queryAsString(query(), sourceText()));
+ return new KqlQuery(source(), Foldables.queryAsString(query(), sourceText()));
  }
 
  @Override

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/fulltext/Match.java

@@ -26,11 +26,11 @@
 import org.elasticsearch.xpack.esql.core.type.DataType;
 import org.elasticsearch.xpack.esql.core.util.Check;
 import org.elasticsearch.xpack.esql.core.util.NumericUtils;
+import org.elasticsearch.xpack.esql.expression.Foldables;
 import org.elasticsearch.xpack.esql.expression.function.Example;
 import org.elasticsearch.xpack.esql.expression.function.FunctionAppliesTo;
 import org.elasticsearch.xpack.esql.expression.function.FunctionAppliesToLifecycle;
 import org.elasticsearch.xpack.esql.expression.function.FunctionInfo;
-import org.elasticsearch.xpack.esql.expression.function.FunctionUtils;
 import org.elasticsearch.xpack.esql.expression.function.MapParam;
 import org.elasticsearch.xpack.esql.expression.function.OptionalArgument;
 import org.elasticsearch.xpack.esql.expression.function.Options;
@@ -79,8 +79,8 @@
 import static org.elasticsearch.xpack.esql.core.type.DataType.TEXT;
 import static org.elasticsearch.xpack.esql.core.type.DataType.UNSIGNED_LONG;
 import static org.elasticsearch.xpack.esql.core.type.DataType.VERSION;
-import static org.elasticsearch.xpack.esql.expression.function.FunctionUtils.TypeResolutionValidator.forPreOptimizationValidation;
-import static org.elasticsearch.xpack.esql.expression.function.FunctionUtils.resolveTypeQuery;
+import static org.elasticsearch.xpack.esql.expression.Foldables.TypeResolutionValidator.forPreOptimizationValidation;
+import static org.elasticsearch.xpack.esql.expression.Foldables.resolveTypeQuery;
 import static org.elasticsearch.xpack.esql.expression.predicate.operator.comparison.EsqlBinaryComparison.formatIncompatibleTypesMessage;
 
 /**
@@ -405,7 +405,7 @@ public BiConsumer<LogicalPlan, Failures> postAnalysisPlanVerification() {
  }
 
  public Object queryAsObject() {
- Object queryAsObject = FunctionUtils.queryAsObject(query(), sourceText());
+ Object queryAsObject = Foldables.queryAsObject(query(), sourceText());
 
  // Convert BytesRef to string for string-based values
  if (queryAsObject instanceof BytesRef bytesRef) {