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Adds STR_LEFT and STR_RIGHT functions (#503)
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Schnippsche authored Oct 13, 2024
1 parent d5bddfd commit f376e68
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2 changes: 2 additions & 0 deletions docs/references/functions.md
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Expand Up @@ -38,9 +38,11 @@ Available through the _ExpressionConfiguration.StandardFunctionsDictionary_ cons
| STR_CONTAINS(string, substring) | Returns true if the string contains the substring (case-insensitive) |
| STR_ENDS_WITH(string, substring) | Returns true if the string ends with the substring (case-sensitive) |
| STR_FORMAT(format [,argument, ...]) | Returns a formatted string using the specified format string and arguments, using the configured locale |
| STR_LEFT(value, n) | Returns the first n characters from the left of the given string |
| STR_LENGTH(string) | Returns the length of the string |
| STR_LOWER(value) | Converts the given value to lower case |
| STR_MATCHES(string, pattern) | Returns true if the string matches the RegEx pattern |
| STR_RIGHT(value, n) | Returns the last n characters from the left of the given string |
| STR_STARTS_WITH(string, substring) | Returns true if the string starts with the substring (case-sensitive) |
| STR_SUBSTRING(string, start[, end]) | Returns a substring of the given string, starting at the _start_ index and ending at the _end_ index (the end of the string if not specified) |
| STR_TRIM(string) | Returns the given string with all leading and trailing space removed. |
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180 changes: 135 additions & 45 deletions src/main/java/com/ezylang/evalex/config/ExpressionConfiguration.java
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Expand Up @@ -21,19 +21,109 @@
import com.ezylang.evalex.data.conversion.DefaultEvaluationValueConverter;
import com.ezylang.evalex.data.conversion.EvaluationValueConverterIfc;
import com.ezylang.evalex.functions.FunctionIfc;
import com.ezylang.evalex.functions.basic.*;
import com.ezylang.evalex.functions.datetime.*;
import com.ezylang.evalex.functions.string.*;
import com.ezylang.evalex.functions.trigonometric.*;
import com.ezylang.evalex.functions.basic.AbsFunction;
import com.ezylang.evalex.functions.basic.AverageFunction;
import com.ezylang.evalex.functions.basic.CeilingFunction;
import com.ezylang.evalex.functions.basic.CoalesceFunction;
import com.ezylang.evalex.functions.basic.FactFunction;
import com.ezylang.evalex.functions.basic.FloorFunction;
import com.ezylang.evalex.functions.basic.IfFunction;
import com.ezylang.evalex.functions.basic.Log10Function;
import com.ezylang.evalex.functions.basic.LogFunction;
import com.ezylang.evalex.functions.basic.MaxFunction;
import com.ezylang.evalex.functions.basic.MinFunction;
import com.ezylang.evalex.functions.basic.NotFunction;
import com.ezylang.evalex.functions.basic.RandomFunction;
import com.ezylang.evalex.functions.basic.RoundFunction;
import com.ezylang.evalex.functions.basic.SqrtFunction;
import com.ezylang.evalex.functions.basic.SumFunction;
import com.ezylang.evalex.functions.basic.SwitchFunction;
import com.ezylang.evalex.functions.datetime.DateTimeFormatFunction;
import com.ezylang.evalex.functions.datetime.DateTimeNewFunction;
import com.ezylang.evalex.functions.datetime.DateTimeNowFunction;
import com.ezylang.evalex.functions.datetime.DateTimeParseFunction;
import com.ezylang.evalex.functions.datetime.DateTimeToEpochFunction;
import com.ezylang.evalex.functions.datetime.DateTimeTodayFunction;
import com.ezylang.evalex.functions.datetime.DurationFromMillisFunction;
import com.ezylang.evalex.functions.datetime.DurationNewFunction;
import com.ezylang.evalex.functions.datetime.DurationParseFunction;
import com.ezylang.evalex.functions.datetime.DurationToMillisFunction;
import com.ezylang.evalex.functions.string.StringContains;
import com.ezylang.evalex.functions.string.StringEndsWithFunction;
import com.ezylang.evalex.functions.string.StringFormatFunction;
import com.ezylang.evalex.functions.string.StringLeftFunction;
import com.ezylang.evalex.functions.string.StringLengthFunction;
import com.ezylang.evalex.functions.string.StringLowerFunction;
import com.ezylang.evalex.functions.string.StringMatchesFunction;
import com.ezylang.evalex.functions.string.StringRightFunction;
import com.ezylang.evalex.functions.string.StringStartsWithFunction;
import com.ezylang.evalex.functions.string.StringSubstringFunction;
import com.ezylang.evalex.functions.string.StringTrimFunction;
import com.ezylang.evalex.functions.string.StringUpperFunction;
import com.ezylang.evalex.functions.trigonometric.AcosFunction;
import com.ezylang.evalex.functions.trigonometric.AcosHFunction;
import com.ezylang.evalex.functions.trigonometric.AcosRFunction;
import com.ezylang.evalex.functions.trigonometric.AcotFunction;
import com.ezylang.evalex.functions.trigonometric.AcotHFunction;
import com.ezylang.evalex.functions.trigonometric.AcotRFunction;
import com.ezylang.evalex.functions.trigonometric.AsinFunction;
import com.ezylang.evalex.functions.trigonometric.AsinHFunction;
import com.ezylang.evalex.functions.trigonometric.AsinRFunction;
import com.ezylang.evalex.functions.trigonometric.Atan2Function;
import com.ezylang.evalex.functions.trigonometric.Atan2RFunction;
import com.ezylang.evalex.functions.trigonometric.AtanFunction;
import com.ezylang.evalex.functions.trigonometric.AtanHFunction;
import com.ezylang.evalex.functions.trigonometric.AtanRFunction;
import com.ezylang.evalex.functions.trigonometric.CosFunction;
import com.ezylang.evalex.functions.trigonometric.CosHFunction;
import com.ezylang.evalex.functions.trigonometric.CosRFunction;
import com.ezylang.evalex.functions.trigonometric.CotFunction;
import com.ezylang.evalex.functions.trigonometric.CotHFunction;
import com.ezylang.evalex.functions.trigonometric.CotRFunction;
import com.ezylang.evalex.functions.trigonometric.CscFunction;
import com.ezylang.evalex.functions.trigonometric.CscHFunction;
import com.ezylang.evalex.functions.trigonometric.CscRFunction;
import com.ezylang.evalex.functions.trigonometric.DegFunction;
import com.ezylang.evalex.functions.trigonometric.RadFunction;
import com.ezylang.evalex.functions.trigonometric.SecFunction;
import com.ezylang.evalex.functions.trigonometric.SecHFunction;
import com.ezylang.evalex.functions.trigonometric.SecRFunction;
import com.ezylang.evalex.functions.trigonometric.SinFunction;
import com.ezylang.evalex.functions.trigonometric.SinHFunction;
import com.ezylang.evalex.functions.trigonometric.SinRFunction;
import com.ezylang.evalex.functions.trigonometric.TanFunction;
import com.ezylang.evalex.functions.trigonometric.TanHFunction;
import com.ezylang.evalex.functions.trigonometric.TanRFunction;
import com.ezylang.evalex.operators.OperatorIfc;
import com.ezylang.evalex.operators.arithmetic.*;
import com.ezylang.evalex.operators.booleans.*;
import com.ezylang.evalex.operators.arithmetic.InfixDivisionOperator;
import com.ezylang.evalex.operators.arithmetic.InfixMinusOperator;
import com.ezylang.evalex.operators.arithmetic.InfixModuloOperator;
import com.ezylang.evalex.operators.arithmetic.InfixMultiplicationOperator;
import com.ezylang.evalex.operators.arithmetic.InfixPlusOperator;
import com.ezylang.evalex.operators.arithmetic.InfixPowerOfOperator;
import com.ezylang.evalex.operators.arithmetic.PrefixMinusOperator;
import com.ezylang.evalex.operators.arithmetic.PrefixPlusOperator;
import com.ezylang.evalex.operators.booleans.InfixAndOperator;
import com.ezylang.evalex.operators.booleans.InfixEqualsOperator;
import com.ezylang.evalex.operators.booleans.InfixGreaterEqualsOperator;
import com.ezylang.evalex.operators.booleans.InfixGreaterOperator;
import com.ezylang.evalex.operators.booleans.InfixLessEqualsOperator;
import com.ezylang.evalex.operators.booleans.InfixLessOperator;
import com.ezylang.evalex.operators.booleans.InfixNotEqualsOperator;
import com.ezylang.evalex.operators.booleans.InfixOrOperator;
import com.ezylang.evalex.operators.booleans.PrefixNotOperator;
import java.math.BigDecimal;
import java.math.MathContext;
import java.math.RoundingMode;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.util.*;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.TreeMap;
import java.util.function.Supplier;
import lombok.Builder;
import lombok.Getter;
Expand Down Expand Up @@ -183,9 +273,11 @@ public class ExpressionConfiguration {
Map.entry("STR_CONTAINS", new StringContains()),
Map.entry("STR_ENDS_WITH", new StringEndsWithFunction()),
Map.entry("STR_FORMAT", new StringFormatFunction()),
Map.entry("STR_LEFT", new StringLeftFunction()),
Map.entry("STR_LENGTH", new StringLengthFunction()),
Map.entry("STR_LOWER", new StringLowerFunction()),
Map.entry("STR_MATCHES", new StringMatchesFunction()),
Map.entry("STR_RIGHT", new StringRightFunction()),
Map.entry("STR_STARTS_WITH", new StringStartsWithFunction()),
Map.entry("STR_SUBSTRING", new StringSubstringFunction()),
Map.entry("STR_TRIM", new StringTrimFunction()),
Expand Down Expand Up @@ -305,17 +397,44 @@ public static ExpressionConfiguration defaultConfiguration() {
return ExpressionConfiguration.builder().build();
}

private static Map<String, EvaluationValue> getStandardConstants() {

Map<String, EvaluationValue> constants = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);

constants.put("TRUE", EvaluationValue.TRUE);
constants.put("FALSE", EvaluationValue.FALSE);
constants.put(
"PI",
EvaluationValue.numberValue(
new BigDecimal(
"3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679")));
constants.put(
"E",
EvaluationValue.numberValue(
new BigDecimal(
"2.71828182845904523536028747135266249775724709369995957496696762772407663")));
constants.put("NULL", EvaluationValue.NULL_VALUE);

constants.put(
"DT_FORMAT_ISO_DATE_TIME",
EvaluationValue.stringValue("yyyy-MM-dd'T'HH:mm:ss[.SSS][XXX]['['VV']']"));
constants.put(
"DT_FORMAT_LOCAL_DATE_TIME", EvaluationValue.stringValue("yyyy-MM-dd'T'HH:mm:ss[.SSS]"));
constants.put("DT_FORMAT_LOCAL_DATE", EvaluationValue.stringValue("yyyy-MM-dd"));

return constants;
}

/**
* Adds additional operators to this configuration.
*
* @param operators variable number of arguments with a map entry holding the operator name and
* implementation. <br>
* Example: <code>
* ExpressionConfiguration.defaultConfiguration()
* .withAdditionalOperators(
* Map.entry("++", new PrefixPlusPlusOperator()),
* Map.entry("++", new PostfixPlusPlusOperator()));
* </code>
* ExpressionConfiguration.defaultConfiguration() .withAdditionalOperators(
* Map.entry("++", new PrefixPlusPlusOperator()), Map.entry("++", new
* PostfixPlusPlusOperator()));
* </code>
* @return The modified configuration, to allow chaining of methods.
*/
@SafeVarargs
Expand All @@ -332,11 +451,10 @@ public final ExpressionConfiguration withAdditionalOperators(
* @param functions variable number of arguments with a map entry holding the functions name and
* implementation. <br>
* Example: <code>
* ExpressionConfiguration.defaultConfiguration()
* .withAdditionalFunctions(
* Map.entry("save", new SaveFunction()),
* Map.entry("update", new UpdateFunction()));
* </code>
* ExpressionConfiguration.defaultConfiguration() .withAdditionalFunctions(
* Map.entry("save", new SaveFunction()), Map.entry("update", new
* UpdateFunction()));
* </code>
* @return The modified configuration, to allow chaining of methods.
*/
@SafeVarargs
Expand All @@ -346,32 +464,4 @@ public final ExpressionConfiguration withAdditionalFunctions(
.forEach(entry -> functionDictionary.addFunction(entry.getKey(), entry.getValue()));
return this;
}

private static Map<String, EvaluationValue> getStandardConstants() {

Map<String, EvaluationValue> constants = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);

constants.put("TRUE", EvaluationValue.TRUE);
constants.put("FALSE", EvaluationValue.FALSE);
constants.put(
"PI",
EvaluationValue.numberValue(
new BigDecimal(
"3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679")));
constants.put(
"E",
EvaluationValue.numberValue(
new BigDecimal(
"2.71828182845904523536028747135266249775724709369995957496696762772407663")));
constants.put("NULL", EvaluationValue.NULL_VALUE);

constants.put(
"DT_FORMAT_ISO_DATE_TIME",
EvaluationValue.stringValue("yyyy-MM-dd'T'HH:mm:ss[.SSS][XXX]['['VV']']"));
constants.put(
"DT_FORMAT_LOCAL_DATE_TIME", EvaluationValue.stringValue("yyyy-MM-dd'T'HH:mm:ss[.SSS]"));
constants.put("DT_FORMAT_LOCAL_DATE", EvaluationValue.stringValue("yyyy-MM-dd"));

return constants;
}
}
Original file line number Diff line number Diff line change
@@ -0,0 +1,64 @@
/*
Copyright 2012-2024 Udo Klimaschewski
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package com.ezylang.evalex.functions.string;

import com.ezylang.evalex.Expression;
import com.ezylang.evalex.data.EvaluationValue;
import com.ezylang.evalex.functions.AbstractFunction;
import com.ezylang.evalex.functions.FunctionParameter;
import com.ezylang.evalex.parser.Token;

/**
* Represents a function that extracts a substring from the left side of a given string. This class
* extends the {@link AbstractFunction} and implements the logic for the `LEFT` string function,
* which returns a specified number of characters from the beginning (left) of the input string.
*
* <p>Two parameters are required for this function:
*
* <ul>
* <li><b>string</b> - The input string from which the substring will be extracted.
* <li><b>length</b> - The number of characters to extract from the left side of the string. If
* the specified length is greater than the string's length, the entire string is returned. If
* the length is negative or zero, an empty string is returned.
* </ul>
*
* <p>Example usage: If the input string is "hello" and the length is 2, the result will be "he".
*/
@FunctionParameter(name = "string")
@FunctionParameter(name = "length")
public class StringLeftFunction extends AbstractFunction {

/**
* Evaluates the `LEFT` string function by extracting a substring from the left side of the given
* string.
*
* @param expression the current expression being evaluated
* @param functionToken the token representing the function being called
* @param parameterValues the parameters passed to the function; expects exactly two parameters: a
* string and a numeric value for length
* @return the substring extracted from the left side of the input string as an {@link
* EvaluationValue}
*/
@Override
public EvaluationValue evaluate(
Expression expression, Token functionToken, EvaluationValue... parameterValues) {
String string = parameterValues[0].getStringValue();
int length =
Math.max(0, Math.min(parameterValues[1].getNumberValue().intValue(), string.length()));
String substr = string.substring(0, length);
return expression.convertValue(substr);
}
}
Original file line number Diff line number Diff line change
@@ -0,0 +1,64 @@
/*
Copyright 2012-2024 Udo Klimaschewski
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package com.ezylang.evalex.functions.string;

import com.ezylang.evalex.Expression;
import com.ezylang.evalex.data.EvaluationValue;
import com.ezylang.evalex.functions.AbstractFunction;
import com.ezylang.evalex.functions.FunctionParameter;
import com.ezylang.evalex.parser.Token;

/**
* Represents a function that extracts a substring from the right side of a given string. This class
* extends the {@link AbstractFunction} and implements the logic for the `RIGHT` string function,
* which returns a specified number of characters from the end (right) of the input string.
*
* <p>Two parameters are required for this function:
*
* <ul>
* <li><b>string</b> - The input string from which the substring will be extracted.
* <li><b>length</b> - The number of characters to extract from the right side of the string. If
* the specified length is greater than the string's length, the entire string is returned. If
* the length is negative or zero, an empty string is returned.
* </ul>
*
* <p>Example usage: If the input string is "hello" and the length is 2, the result will be "lo".
*/
@FunctionParameter(name = "string")
@FunctionParameter(name = "length")
public class StringRightFunction extends AbstractFunction {

/**
* Evaluates the `RIGHT` string function by extracting a substring from the right side of the
* given string.
*
* @param expression the current expression being evaluated
* @param functionToken the token representing the function being called
* @param parameterValues the parameters passed to the function; expects exactly two parameters: a
* string and a numeric value for length
* @return the substring extracted from the right side of the input string as an {@link
* EvaluationValue}
*/
@Override
public EvaluationValue evaluate(
Expression expression, Token functionToken, EvaluationValue... parameterValues) {
String string = parameterValues[0].getStringValue();
int length =
Math.max(0, Math.min(parameterValues[1].getNumberValue().intValue(), string.length()));
String substr = string.substring(string.length() - length);
return expression.convertValue(substr);
}
}
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