Code Cleanup

README.md

@@ -4,15 +4,15 @@ A Boolean Expression Parser for Java
 The library can help parse complex and nested boolean expressions.
 The expressions are in SQL-like syntax, where you can use boolean operators and parentheses to combine individual expressions.
 
-An expression can be as simple as `name = Sidhant`.
+An expression can be as simple as `name = 'Sidhant'`.
 A Complex expression is formed by combining these small expressions by logical operators and giving precedence using parenthesis
 
 ### Examples
 #### Textual Equality
 
 Format: `${attributeName} = ${value}`
 
-Example: `name = john`
+Example: `name = 'john'`
 
 #### Numeric Comparisons
 
@@ -34,7 +34,7 @@ Example: `price 5.99 TO 100`
 
 Example:
 
-`price < 10 AND (category:Book OR NOT category:Ebook)`
+`price < 10 AND (category:'Book' OR NOT category:'Ebook')`
 
 Individual filters can be combined via boolean operators. The following operators are supported:
 
@@ -45,6 +45,8 @@ Individual filters can be combined via boolean operators. The following operator
 Parentheses, `(` and `)`, can be used for grouping.
 
 #### Usage Notes
+* String must be enclosed either in single or double quotes.
+* Variables substitution is supported by passing the name of the variable without the quotes.
 * Phrases that includes quotes, like `content = "It's a wonderful day"`
 * Phrases that includes quotes, like `attribute = 'She said "Hello World"'`
 * For nested keys in data map you can use the dot notation, like `person.age`
@@ -72,7 +74,7 @@ dependencies {
 Code
 ```
 final BoolParser boolParser = new BoolParser();
-final Try<Node> nodeOptional = boolParser.parseExpression("name = test");
+final Try<Node> nodeOptional = boolParser.parseExpression("name = 'test'");
 ```
 
 ### Node Types Post Parsing
@@ -120,12 +122,18 @@ private final DataType dataType;
 private final Object value;
 ```
 
+####
+FieldNode
+```
+private final String field;
+```
+
 ####
 InNode
 ```
 private final String field;
 
-private final List<Pair<DataType, Object>> items;
+private final List<Node> items;
 ```
 
 
@@ -160,7 +168,7 @@ final BooleanExpressionEvaluator booleanExpressionEvaluator = new BooleanExpress
 final Map<String, Object> data = new HashMap<>();
 data.put("age", 25);
 data.put("name", "sid");
-final Try<Boolean> resultOptional = booleanExpressionEvaluator.evaluate("name = sid AND age = 25", data);
+final Try<Boolean> resultOptional = booleanExpressionEvaluator.evaluate("name = 'sid' AND age = 25", data);
 assertTrue(resultOptional.isPresent());
 assertTrue(resultOptional.get());
 ```
@@ -171,7 +179,7 @@ final Map<String, Object> data = new HashMap<>();
 data.put("age", 25);
 data.put("name", "sid");
 data.put("num", 45);
-final Try<Boolean> resultOptional = booleanExpressionEvaluator.evaluate("name:sid AND (age = 25 OR num = 44)", data);
+final Try<Boolean> resultOptional = booleanExpressionEvaluator.evaluate("name = sid AND (age = 25 OR num = 44)", data);
 assertTrue(resultOptional.isPresent());
 assertTrue(resultOptional.get());
 ```
@@ -211,6 +219,22 @@ The following Operators are supported:
 5. Modulus (%)
 6. Exponent (^)
 
+The following functions are supported:
+1. Minimum (min)
+2. Maximum (max)
+3. Average (avg)
+4. Sum (sum)
+5. Mean (mean)
+6. Mode (mode)
+7. Median (median)
+8. Integer (int) - converts the input to integer
+9. Length (len) - Returns length of the give array
+
+Syntax For using functions
+Format: `${FunctionIdentifier} (item1, item2...)`
+
+Example: `min (1,2,3)` or with variable substitution `min (a,b,c)`
+
 Usage examples:
 
 Simple Addition Operation
@@ -232,5 +256,14 @@ final Try<Object> resultOptional = evaluator.evaluate("((5 * 2) + a) * 2 + (1 +
 assertTrue(resultOptional.isPresent());
 assertTrue(resultOptional.get(), 56);
 ```
+Function Usage
+```
+final ArithmeticExpressionEvaluator evaluator = new ArithmeticExpressionEvaluator(new Boolparser());
+final Map<String, Object> data = new HashMap<>();
+data.put("a", 10);
+final Try<Object> resultOptional = arithmeticExpressionEvaluator.evaluate("min (1,2,3)", data);
+assertTrue(resultOptional.isSuccess());
+assertEquals(resultOptional.get(), 1);
+```
 
 [For a complete list of examples please check out the test file](src/test/java/com/github/sidhant92/boolparser/application/ArithmeticExpressionEvaluatorTest.java)

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

@@ -1,21 +1,18 @@
 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;
 import com.github.sidhant92.boolparser.constant.Operator;
-import com.github.sidhant92.boolparser.domain.StringNode;
-import com.github.sidhant92.boolparser.domain.arithmetic.ArithmeticLeafNode;
+import com.github.sidhant92.boolparser.domain.EvaluatedNode;
+import com.github.sidhant92.boolparser.domain.FieldNode;
+import com.github.sidhant92.boolparser.domain.arithmetic.UnaryNode;
 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.logical.Node;
 import com.github.sidhant92.boolparser.domain.arithmetic.ArithmeticFunctionNode;
+import com.github.sidhant92.boolparser.exception.DataNotFoundException;
 import com.github.sidhant92.boolparser.exception.UnsupportedToken;
 import com.github.sidhant92.boolparser.function.FunctionEvaluatorService;
 import com.github.sidhant92.boolparser.operator.OperatorService;
@@ -55,76 +52,66 @@ private Object evaluateToken(final Node node, final Map<String, Object> data) {
         switch (node.getTokenType()) {
             case ARITHMETIC:
                 return evaluateArithmeticToken((ArithmeticNode) node, data);
-            case ARITHMETIC_LEAF:
-                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);
+            case UNARY:
+                return evaluateUnaryToken((UnaryNode) node, data);
+            case FIELD:
+                return evaluateFieldToken((FieldNode) node, data);
             default:
                 log.error("unsupported token {}", node.getTokenType());
                 throw new UnsupportedToken();
         }
     }
 
-    private Object evaluateStringToken(final StringNode stringNode, final Map<String, Object> data) {
-        return ValueUtils.getValueFromMap(stringNode.getField(), data).orElse(stringNode.getField());
-    }
-
-    private Pair<Object, DataType> evaluateArithmeticLeafToken(final ArithmeticLeafNode arithmeticLeafNode, final Map<String, Object> 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()));
+    private Object evaluateFieldToken(final FieldNode fieldNode, final Map<String, Object> data) {
+        if (!data.containsKey(fieldNode.getField())) {
+            throw new DataNotFoundException();
+        }
+        return data.get(fieldNode.getField());
     }
 
-    private Object evaluateUnaryArithmeticToken(final ArithmeticUnaryNode arithmeticUnaryNode, final Map<String, Object> data) {
-        final Object resolvedValue = evaluateToken(arithmeticUnaryNode.getOperand(), data);
-        if (resolvedValue instanceof Pair) {
-            final Pair<Object, DataType> pair = (Pair<Object, DataType>) resolvedValue;
-            return operatorService.evaluateArithmeticOperator(pair.getLeft(), pair.getRight(), null, null, Operator.UNARY,
-                                                              ContainerDataType.PRIMITIVE);
-        }
-        final DataType dataType = ValueUtils.getDataType(resolvedValue);
-        return operatorService.evaluateArithmeticOperator(resolvedValue, dataType, null, null, Operator.UNARY, ContainerDataType.PRIMITIVE);
+    private Object evaluateUnaryToken(final UnaryNode unaryNode, final Map<String, Object> data) {
+        return unaryNode.getValue();
     }
 
     private Object evaluateArithmeticFunctionToken(final ArithmeticFunctionNode arithmeticFunctionNode, final Map<String, Object> data) {
-        final List<Pair<Object, DataType>> resolvedValues = arithmeticFunctionNode.getItems()
+        final List<Object> resolvedValues = arithmeticFunctionNode.getItems()
                 .stream()
-                .map(item -> evaluateArithmeticLeafToken(item, data))
+                .map(item -> evaluate(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);
-            }
-        });
+        final List<EvaluatedNode> flattenedValues = ValueUtils.mapToEvaluatedNodes(resolvedValues);
         return functionEvaluatorService.evaluateArithmeticFunction(arithmeticFunctionNode.getFunctionType(), flattenedValues);
     }
 
     private Object evaluateArithmeticToken(final ArithmeticNode arithmeticNode, final Map<String, Object> data) {
         final Object leftValue = evaluateToken(arithmeticNode.getLeft(), data);
+        if (arithmeticNode.getOperator().equals(Operator.UNARY)) {
+            if (leftValue instanceof EvaluatedNode) {
+                final EvaluatedNode left = (EvaluatedNode) leftValue;
+                return operatorService.evaluateArithmeticOperator(left.getValue(), left.getDataType(), null, null, arithmeticNode.getOperator(),
+                                                                  ContainerDataType.PRIMITIVE);
+            } else {
+                final DataType leftDataType = ValueUtils.getDataType(leftValue);
+                return operatorService.evaluateArithmeticOperator(leftValue, leftDataType, null, null, arithmeticNode.getOperator(),
+                                                                  ContainerDataType.PRIMITIVE);
+            }
+        }
         final Object rightValue = evaluateToken(arithmeticNode.getRight(), data);
-        if (leftValue instanceof Pair && rightValue instanceof Pair) {
-            final Pair<Object, DataType> leftPair = (Pair<Object, DataType>) leftValue;
-            final Pair<Object, DataType> rightPair = (Pair<Object, DataType>) rightValue;
-            return operatorService.evaluateArithmeticOperator(leftPair.getLeft(), leftPair.getRight(), rightPair.getLeft(), rightPair.getRight(),
+        if (leftValue instanceof EvaluatedNode && rightValue instanceof EvaluatedNode) {
+            final EvaluatedNode left = (EvaluatedNode) leftValue;
+            final EvaluatedNode right = (EvaluatedNode) rightValue;
+            return operatorService.evaluateArithmeticOperator(left.getValue(), left.getDataType(), right.getValue(), right.getDataType(),
                                                               arithmeticNode.getOperator(), ContainerDataType.PRIMITIVE);
-        } else if (leftValue instanceof Pair) {
-            final Pair<Object, DataType> leftPair = (Pair<Object, DataType>) leftValue;
+        } else if (leftValue instanceof EvaluatedNode) {
+            final EvaluatedNode left = (EvaluatedNode) leftValue;
             final DataType rightDataType = ValueUtils.getDataType(rightValue);
-            return operatorService.evaluateArithmeticOperator(leftPair.getLeft(), leftPair.getRight(), rightValue, rightDataType,
+            return operatorService.evaluateArithmeticOperator(left.getValue(), left.getDataType(), rightValue, rightDataType,
                                                               arithmeticNode.getOperator(), ContainerDataType.PRIMITIVE);
-        } else if (rightValue instanceof Pair) {
-            final Pair<Object, DataType> rightPair = (Pair<Object, DataType>) rightValue;
+        } else if (rightValue instanceof EvaluatedNode) {
+            final EvaluatedNode right = (EvaluatedNode) rightValue;
             final DataType leftDataType = ValueUtils.getDataType(leftValue);
-            return operatorService.evaluateArithmeticOperator(leftValue, leftDataType, rightPair.getLeft(), rightPair.getRight(),
+            return operatorService.evaluateArithmeticOperator(leftValue, leftDataType, right.getValue(), right.getDataType(),
                                                               arithmeticNode.getOperator(), ContainerDataType.PRIMITIVE);
         } else {
             final DataType leftDataType = ValueUtils.getDataType(leftValue);

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

@@ -1,17 +1,19 @@
 package com.github.sidhant92.boolparser.application;
 
+import java.util.List;
 import java.util.Map;
-import org.apache.commons.lang3.tuple.Pair;
+import java.util.stream.Collectors;
 import com.github.sidhant92.boolparser.constant.ContainerDataType;
 import com.github.sidhant92.boolparser.constant.DataType;
 import com.github.sidhant92.boolparser.constant.Operator;
-import com.github.sidhant92.boolparser.domain.ArrayNode;
-import com.github.sidhant92.boolparser.domain.BooleanNode;
-import com.github.sidhant92.boolparser.domain.InNode;
-import com.github.sidhant92.boolparser.domain.NumericRangeNode;
-import com.github.sidhant92.boolparser.domain.ComparisonNode;
-import com.github.sidhant92.boolparser.domain.Node;
-import com.github.sidhant92.boolparser.domain.UnaryNode;
+import com.github.sidhant92.boolparser.domain.logical.ArrayNode;
+import com.github.sidhant92.boolparser.domain.logical.BooleanNode;
+import com.github.sidhant92.boolparser.domain.EvaluatedNode;
+import com.github.sidhant92.boolparser.domain.logical.InNode;
+import com.github.sidhant92.boolparser.domain.logical.NumericRangeNode;
+import com.github.sidhant92.boolparser.domain.logical.ComparisonNode;
+import com.github.sidhant92.boolparser.domain.logical.Node;
+import com.github.sidhant92.boolparser.domain.arithmetic.UnaryNode;
 import com.github.sidhant92.boolparser.domain.arithmetic.ArithmeticBaseNode;
 import com.github.sidhant92.boolparser.exception.DataNotFoundException;
 import com.github.sidhant92.boolparser.exception.HeterogeneousArrayException;
@@ -71,7 +73,7 @@ private boolean evaluateToken(final Node node, final Map<String, Object> data) {
     private boolean evaluateComparisonToken(final ComparisonNode comparisonToken, final Map<String, Object> data) {
         final Object fieldData = ValueUtils.getValueFromMap(comparisonToken.getField(), data).orElseThrow(DataNotFoundException::new);
         final Object value = comparisonToken.getValue() instanceof ArithmeticBaseNode ? arithmeticExpressionEvaluator.evaluate(
-                (Node) comparisonToken.getValue(), data) : comparisonToken.getValue();
+                comparisonToken.getValue(), data) : comparisonToken.getValue();
         return operatorService.evaluateLogicalOperator(comparisonToken.getOperator(), ContainerDataType.PRIMITIVE, comparisonToken.getDataType(),
                                                        fieldData, value);
     }
@@ -85,24 +87,39 @@ private boolean evaluateNumericRangeToken(final NumericRangeNode numericRangeTok
 
     private boolean evaluateInToken(final InNode inToken, final Map<String, Object> data) {
         final Object fieldData = ValueUtils.getValueFromMap(inToken.getField(), data).orElseThrow(DataNotFoundException::new);
+        final List<EvaluatedNode> items = resolveArrayElements(inToken.getItems(), data);
         final DataType dataType = ValueUtils.getDataType(fieldData);
-        final Object[] values = inToken.getItems()
+        final Object[] values = items
                 .stream()
-                .map(Pair::getRight).toArray();
+                .map(EvaluatedNode::getValue).toArray();
         return operatorService.evaluateLogicalOperator(Operator.IN, ContainerDataType.PRIMITIVE, dataType, fieldData, values);
     }
 
+    private List<EvaluatedNode> resolveArrayElements(final List<Node> items, final Map<String, Object> data) {
+        final List<Object> resolvedValues = items
+                .stream()
+                .map(item -> {
+                    if (item instanceof ArithmeticBaseNode) {
+                        return arithmeticExpressionEvaluator.evaluate(item, data);
+                    }
+                    return evaluateToken(item, data);
+                })
+                .collect(Collectors.toList());
+        return ValueUtils.mapToEvaluatedNodes(resolvedValues);
+    }
+
     private boolean evaluateArrayToken(final ArrayNode arrayNode, final Map<String, Object> data) {
         final Object fieldData = ValueUtils.getValueFromMap(arrayNode.getField(), data).orElseThrow(DataNotFoundException::new);
-        if (arrayNode.getItems()
+        final List<EvaluatedNode> items = resolveArrayElements(arrayNode.getItems(), data);
+        if (items
                 .stream()
-                .map(Pair::getLeft).distinct().count() > 1) {
+                .map(EvaluatedNode::getDataType).distinct().count() > 1) {
             throw new HeterogeneousArrayException();
         }
-        final DataType dataType = arrayNode.getItems().get(0).getLeft();
-        final Object[] values = arrayNode.getItems()
+        final DataType dataType = items.get(0).getDataType();
+        final Object[] values = items
                 .stream()
-                .map(Pair::getRight).toArray();
+                .map(EvaluatedNode::getValue).toArray();
         return operatorService.evaluateLogicalOperator(arrayNode.getOperator(), ContainerDataType.LIST, dataType, fieldData, values);
     }
 

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

@@ -11,9 +11,7 @@ public enum NodeType {
     IN,
     ARRAY,
     UNARY,
+    FIELD,
     ARITHMETIC,
-    ARITHMETIC_LEAF,
-    ARITHMETIC_UNARY,
-    ARITHMETIC_FUNCTION,
-    STRING
+    ARITHMETIC_FUNCTION
 }

src/main/java/com/github/sidhant92/boolparser/domain/EvaluatedNode.java

@@ -0,0 +1,17 @@
+package com.github.sidhant92.boolparser.domain;
+
+import com.github.sidhant92.boolparser.constant.DataType;
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.Setter;
+
+@AllArgsConstructor
+@Getter
+@Setter
+@Builder
+public class EvaluatedNode {
+    private final DataType dataType;
+
+    private final Object value;
+}