Add Support for Arithmetic Functions

.gitignore

@@ -30,3 +30,6 @@ out/
 `
 
 gradle.properties
+
+*.DS_Store
+**/.DS_Store

build.gradle

@@ -37,6 +37,7 @@ dependencies {
     implementation 'io.vavr:vavr:0.10.4'
     implementation 'com.github.ben-manes.caffeine:caffeine:2.9.3'
     implementation 'org.projectlombok:lombok:1.18.26'
+    implementation 'org.apache.commons:commons-math3:3.6.1'
 
     annotationProcessor 'org.projectlombok:lombok:1.18.26'
     testAnnotationProcessor 'org.openjdk.jmh:jmh-generator-annprocess:1.36'

src/main/java/com/github/sidhant92/boolparser/application/ArithmeticExpressionEvaluator.java

@@ -1,7 +1,11 @@
 package com.github.sidhant92.boolparser.application;
 
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
 import java.util.Map;
 import java.util.Optional;
+import java.util.stream.Collectors;
 import org.apache.commons.lang3.tuple.Pair;
 import com.github.sidhant92.boolparser.constant.ContainerDataType;
 import com.github.sidhant92.boolparser.constant.DataType;
@@ -11,7 +15,9 @@
 import com.github.sidhant92.boolparser.domain.arithmetic.ArithmeticNode;
 import com.github.sidhant92.boolparser.domain.arithmetic.ArithmeticUnaryNode;
 import com.github.sidhant92.boolparser.domain.Node;
+import com.github.sidhant92.boolparser.domain.arithmetic.ArithmeticFunctionNode;
 import com.github.sidhant92.boolparser.exception.UnsupportedToken;
+import com.github.sidhant92.boolparser.function.FunctionEvaluatorService;
 import com.github.sidhant92.boolparser.operator.OperatorService;
 import com.github.sidhant92.boolparser.parser.BoolExpressionParser;
 import com.github.sidhant92.boolparser.util.ValueUtils;
@@ -28,9 +34,12 @@ public class ArithmeticExpressionEvaluator {
 
     private final OperatorService operatorService;
 
+    private final FunctionEvaluatorService functionEvaluatorService;
+
     public ArithmeticExpressionEvaluator(final BoolExpressionParser boolExpressionParser) {
         this.boolExpressionParser = boolExpressionParser;
         operatorService = new OperatorService();
+        functionEvaluatorService = new FunctionEvaluatorService();
     }
 
     public Try<Object> evaluate(final String expression, final Map<String, Object> data) {
@@ -50,6 +59,8 @@ private Object evaluateToken(final Node node, final Map<String, Object> data) {
                 return evaluateArithmeticLeafToken((ArithmeticLeafNode) node, data);
             case ARITHMETIC_UNARY:
                 return evaluateUnaryArithmeticToken((ArithmeticUnaryNode) node, data);
+            case ARITHMETIC_FUNCTION:
+                return evaluateArithmeticFunctionToken((ArithmeticFunctionNode) node, data);
             case STRING:
                 return evaluateStringToken((StringNode) node, data);
             default:
@@ -63,7 +74,8 @@ private Object evaluateStringToken(final StringNode stringNode, final Map<String
     }
 
     private Pair<Object, DataType> evaluateArithmeticLeafToken(final ArithmeticLeafNode arithmeticLeafNode, final Map<String, Object> data) {
-        final Optional<Object> fetchedValue = ValueUtils.getValueFromMap(arithmeticLeafNode.getOperand().toString(), data);
+        final Optional<Object> fetchedValue = arithmeticLeafNode.getDataType() != DataType.STRING ? Optional.of(
+                arithmeticLeafNode.getOperand()) : ValueUtils.getValueFromMap(arithmeticLeafNode.getOperand().toString(), data);
         return fetchedValue
                 .map(o -> Pair.of(o, ValueUtils.getDataType(o)))
                 .orElseGet(() -> Pair.of(arithmeticLeafNode.getOperand(), arithmeticLeafNode.getDataType()));
@@ -80,6 +92,22 @@ private Object evaluateUnaryArithmeticToken(final ArithmeticUnaryNode arithmetic
         return operatorService.evaluateArithmeticOperator(resolvedValue, dataType, null, null, Operator.UNARY, ContainerDataType.PRIMITIVE);
     }
 
+    private Object evaluateArithmeticFunctionToken(final ArithmeticFunctionNode arithmeticFunctionNode, final Map<String, Object> data) {
+        final List<Pair<Object, DataType>> resolvedValues = arithmeticFunctionNode.getItems()
+                .stream()
+                .map(item -> evaluateArithmeticLeafToken(item, data))
+                .collect(Collectors.toList());
+        final List<Pair<Object, DataType>> flattenedValues = new ArrayList<>();
+        resolvedValues.forEach(value -> {
+            if (value.getKey() instanceof Collection) {
+                ((Collection<?>) value.getKey()).forEach(v -> flattenedValues.add(Pair.of(v, ValueUtils.getDataType(v))));
+            } else {
+                flattenedValues.add(value);
+            }
+        });
+        return functionEvaluatorService.evaluateArithmeticFunction(arithmeticFunctionNode.getFunctionType(), flattenedValues);
+    }
+
     private Object evaluateArithmeticToken(final ArithmeticNode arithmeticNode, final Map<String, Object> data) {
         final Object leftValue = evaluateToken(arithmeticNode.getLeft(), data);
         final Object rightValue = evaluateToken(arithmeticNode.getRight(), data);

src/main/java/com/github/sidhant92/boolparser/constant/FunctionType.java

@@ -0,0 +1,28 @@
+package com.github.sidhant92.boolparser.constant;
+
+import java.util.Arrays;
+import java.util.Optional;
+
+/**
+ * @author sidhant.aggarwal
+ * @since 21/05/2024
+ */
+public enum FunctionType {
+    MIN,
+    MAX,
+    AVG,
+    SUM,
+    MEAN,
+    MODE,
+    MEDIAN,
+    INT,
+    LEN;
+
+    public static Optional<FunctionType> getArrayFunctionFromSymbol(final String symbol) {
+        final String symbolUpperCase = symbol.toUpperCase();
+        return Arrays
+                .stream(FunctionType.values())
+                .filter(function -> function.name().equals(symbolUpperCase))
+                .findFirst();
+    }
+}

src/main/java/com/github/sidhant92/boolparser/constant/NodeType.java

@@ -14,5 +14,6 @@ public enum NodeType {
     ARITHMETIC,
     ARITHMETIC_LEAF,
     ARITHMETIC_UNARY,
+    ARITHMETIC_FUNCTION,
     STRING
 }

src/main/java/com/github/sidhant92/boolparser/domain/arithmetic/ArithmeticFunctionNode.java

@@ -0,0 +1,30 @@
+package com.github.sidhant92.boolparser.domain.arithmetic;
+
+import java.util.List;
+import com.github.sidhant92.boolparser.constant.FunctionType;
+import com.github.sidhant92.boolparser.constant.NodeType;
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.Setter;
+
+/**
+ * @author sidhant.aggarwal
+ * @since 21/05/2024
+ */
+@AllArgsConstructor
+@Getter
+@Setter
+@Builder
+public class ArithmeticFunctionNode extends ArithmeticBaseNode {
+    private FunctionType functionType;
+
+
+    private final List<ArithmeticLeafNode> items;
+
+
+    @Override
+    public NodeType getTokenType() {
+        return NodeType.ARITHMETIC_FUNCTION;
+    }
+}

src/main/java/com/github/sidhant92/boolparser/function/FunctionEvaluatorService.java

@@ -0,0 +1,50 @@
+package com.github.sidhant92.boolparser.function;
+
+import java.util.List;
+import org.apache.commons.lang3.tuple.Pair;
+import com.github.sidhant92.boolparser.constant.ContainerDataType;
+import com.github.sidhant92.boolparser.constant.DataType;
+import com.github.sidhant92.boolparser.constant.FunctionType;
+import com.github.sidhant92.boolparser.exception.InvalidContainerTypeException;
+import com.github.sidhant92.boolparser.exception.InvalidDataType;
+import com.github.sidhant92.boolparser.exception.InvalidExpressionException;
+import com.github.sidhant92.boolparser.function.arithmetic.AbstractFunction;
+import lombok.extern.slf4j.Slf4j;
+
+/**
+ * @author sidhant.aggarwal
+ * @since 21/05/2024
+ */
+@Slf4j
+public class FunctionEvaluatorService {
+    public FunctionEvaluatorService() {
+        FunctionFactory.initialize();
+    }
+
+    public Object evaluateArithmeticFunction(final FunctionType functionType, final List<Pair<Object, DataType>> items) {
+        final AbstractFunction abstractFunction = FunctionFactory.getArithmeticFunction(functionType);
+        if (items.isEmpty()) {
+            log.error("Empty items not allowed");
+            throw new InvalidExpressionException();
+        }
+        final ContainerDataType containerDataType = items.size() > 1 ? ContainerDataType.LIST : ContainerDataType.PRIMITIVE;
+        if (!abstractFunction.getAllowedContainerTypes().contains(containerDataType)) {
+            log.error("Invalid container type {} for function {}", containerDataType, functionType.name());
+            throw new InvalidContainerTypeException();
+        }
+        final boolean validDataType = items
+                .stream().allMatch(item -> abstractFunction.getAllowedDataTypes().contains(item.getValue()));
+        if (!validDataType) {
+            log.error("Invalid data type {} for function {}", items, functionType.name());
+            throw new InvalidDataType();
+        }
+
+        items.forEach(item -> {
+            if (!ContainerDataType.PRIMITIVE.isValid(item.getValue(), item.getKey())) {
+                log.error("Validation failed for the function {} for the operand {}", functionType.name(), item.getKey());
+                throw new InvalidDataType();
+            }
+        });
+        return abstractFunction.evaluate(items);
+    }
+}

src/main/java/com/github/sidhant92/boolparser/function/FunctionFactory.java

@@ -0,0 +1,43 @@
+package com.github.sidhant92.boolparser.function;
+
+import java.util.EnumMap;
+import java.util.Map;
+import com.github.sidhant92.boolparser.constant.FunctionType;
+import com.github.sidhant92.boolparser.function.arithmetic.AbstractFunction;
+import com.github.sidhant92.boolparser.function.arithmetic.AvgFunction;
+import com.github.sidhant92.boolparser.function.arithmetic.IntFunction;
+import com.github.sidhant92.boolparser.function.arithmetic.LenFunction;
+import com.github.sidhant92.boolparser.function.arithmetic.MaxFunction;
+import com.github.sidhant92.boolparser.function.arithmetic.MeanFunction;
+import com.github.sidhant92.boolparser.function.arithmetic.MedianFunction;
+import com.github.sidhant92.boolparser.function.arithmetic.MinFunction;
+import com.github.sidhant92.boolparser.function.arithmetic.ModeFunction;
+import com.github.sidhant92.boolparser.function.arithmetic.SumFunction;
+
+/**
+ * @author sidhant.aggarwal
+ * @since 21/05/2024
+ */
+public class FunctionFactory {
+    private static final Map<FunctionType, AbstractFunction> arithmeticFunctionrMap = new EnumMap<>(FunctionType.class);
+
+    private FunctionFactory() {
+        super();
+    }
+
+    public static void initialize() {
+        arithmeticFunctionrMap.put(FunctionType.MIN, new MinFunction());
+        arithmeticFunctionrMap.put(FunctionType.MAX, new MaxFunction());
+        arithmeticFunctionrMap.put(FunctionType.AVG, new AvgFunction());
+        arithmeticFunctionrMap.put(FunctionType.SUM, new SumFunction());
+        arithmeticFunctionrMap.put(FunctionType.MEAN, new MeanFunction());
+        arithmeticFunctionrMap.put(FunctionType.MEDIAN, new MedianFunction());
+        arithmeticFunctionrMap.put(FunctionType.MODE, new ModeFunction());
+        arithmeticFunctionrMap.put(FunctionType.INT, new IntFunction());
+        arithmeticFunctionrMap.put(FunctionType.LEN, new LenFunction());
+    }
+
+    public static AbstractFunction getArithmeticFunction(final FunctionType functionType) {
+        return arithmeticFunctionrMap.get(functionType);
+    }
+}

src/main/java/com/github/sidhant92/boolparser/function/arithmetic/AbstractFunction.java

@@ -0,0 +1,22 @@
+package com.github.sidhant92.boolparser.function.arithmetic;
+
+import java.util.List;
+import org.apache.commons.lang3.tuple.Pair;
+import com.github.sidhant92.boolparser.constant.ContainerDataType;
+import com.github.sidhant92.boolparser.constant.DataType;
+import com.github.sidhant92.boolparser.constant.FunctionType;
+import com.github.sidhant92.boolparser.domain.arithmetic.ArithmeticFunctionNode;
+
+/**
+ * @author sidhant.aggarwal
+ * @since 21/05/2024
+ */
+public abstract class AbstractFunction {
+    public abstract Object evaluate(final List<Pair<Object, DataType>> items);
+
+    public abstract FunctionType getFunctionType();
+
+    public abstract List<ContainerDataType> getAllowedContainerTypes();
+
+    public abstract List<DataType> getAllowedDataTypes();
+}

src/main/java/com/github/sidhant92/boolparser/function/arithmetic/AvgFunction.java

@@ -0,0 +1,47 @@
+package com.github.sidhant92.boolparser.function.arithmetic;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import org.apache.commons.lang3.tuple.Pair;
+import com.github.sidhant92.boolparser.constant.ContainerDataType;
+import com.github.sidhant92.boolparser.constant.DataType;
+import com.github.sidhant92.boolparser.constant.FunctionType;
+import com.github.sidhant92.boolparser.util.ValueUtils;
+
+/**
+ * @author sidhant.aggarwal
+ * @since 21/05/2024
+ */
+public class AvgFunction extends AbstractFunction {
+    @Override
+    public Object evaluate(final List<Pair<Object, DataType>> items) {
+        if (items
+                .stream().anyMatch(a -> a.getValue().equals(DataType.DECIMAL))) {
+            return ValueUtils.caseDouble(items
+                                                 .stream().mapToDouble(a -> Double.parseDouble(a.getKey().toString())).average().getAsDouble());
+        }
+        if (items
+                .stream().anyMatch(a -> a.getValue().equals(DataType.LONG))) {
+            return ValueUtils.caseDouble(items
+                                                 .stream().mapToLong(a -> Long.parseLong(a.getKey().toString())).average().getAsDouble());
+        }
+        return ValueUtils.caseDouble(items
+                                             .stream().mapToInt(a -> Integer.parseInt(a.getKey().toString())).average().getAsDouble());
+    }
+
+    @Override
+    public FunctionType getFunctionType() {
+        return FunctionType.AVG;
+    }
+
+    @Override
+    public List<ContainerDataType> getAllowedContainerTypes() {
+        return Collections.singletonList(ContainerDataType.LIST);
+    }
+
+    @Override
+    public List<DataType> getAllowedDataTypes() {
+        return Arrays.asList(DataType.INTEGER, DataType.LONG, DataType.DECIMAL);
+    }
+}

src/main/java/com/github/sidhant92/boolparser/function/arithmetic/IntFunction.java

@@ -0,0 +1,42 @@
+package com.github.sidhant92.boolparser.function.arithmetic;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import org.apache.commons.lang3.tuple.Pair;
+import com.github.sidhant92.boolparser.constant.ContainerDataType;
+import com.github.sidhant92.boolparser.constant.DataType;
+import com.github.sidhant92.boolparser.constant.FunctionType;
+
+/**
+ * @author sidhant.aggarwal
+ * @since 21/05/2024
+ */
+public class IntFunction extends AbstractFunction {
+    @Override
+    public Object evaluate(final List<Pair<Object, DataType>> items) {
+        final Pair<Object, DataType> item = items.get(0);
+        if (item.getValue() == DataType.DECIMAL) {
+            return ((Double) item.getKey()).intValue();
+        }
+        if (item.getValue() == DataType.LONG) {
+            return ((Long) item.getKey()).intValue();
+        }
+        return item.getKey();
+    }
+
+    @Override
+    public FunctionType getFunctionType() {
+        return FunctionType.INT;
+    }
+
+    @Override
+    public List<ContainerDataType> getAllowedContainerTypes() {
+        return Collections.singletonList(ContainerDataType.PRIMITIVE);
+    }
+
+    @Override
+    public List<DataType> getAllowedDataTypes() {
+        return Arrays.asList(DataType.INTEGER, DataType.LONG, DataType.DECIMAL);
+    }
+}