StringUtil.java

package org.drip.numerical.common;

/*
 * -*- mode: java; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 */

/*!
 * Copyright (C) 2020 Lakshmi Krishnamurthy
 * Copyright (C) 2019 Lakshmi Krishnamurthy
 * Copyright (C) 2018 Lakshmi Krishnamurthy
 * Copyright (C) 2017 Lakshmi Krishnamurthy
 * Copyright (C) 2016 Lakshmi Krishnamurthy
 * Copyright (C) 2015 Lakshmi Krishnamurthy
 * Copyright (C) 2014 Lakshmi Krishnamurthy
 * Copyright (C) 2013 Lakshmi Krishnamurthy
 * Copyright (C) 2012 Lakshmi Krishnamurthy
 * 
 *  This file is part of DROP, an open-source library targeting analytics/risk, transaction cost analytics,
 *      asset liability management analytics, capital, exposure, and margin analytics, valuation adjustment
 *      analytics, and portfolio construction analytics within and across fixed income, credit, commodity,
 *      equity, FX, and structured products. It also includes auxiliary libraries for algorithm support,
 *      numerical analysis, numerical optimization, spline builder, model validation, statistical learning,
 *      and computational support.
 *  
 *      https://lakshmidrip.github.io/DROP/
 *  
 *  DROP is composed of three modules:
 *  
 *  - DROP Product Core - https://lakshmidrip.github.io/DROP-Product-Core/
 *  - DROP Portfolio Core - https://lakshmidrip.github.io/DROP-Portfolio-Core/
 *  - DROP Computational Core - https://lakshmidrip.github.io/DROP-Computational-Core/
 * 
 *  DROP Product Core implements libraries for the following:
 *  - Fixed Income Analytics
 *  - Loan Analytics
 *  - Transaction Cost Analytics
 * 
 *  DROP Portfolio Core implements libraries for the following:
 *  - Asset Allocation Analytics
 *  - Asset Liability Management Analytics
 *  - Capital Estimation Analytics
 *  - Exposure Analytics
 *  - Margin Analytics
 *  - XVA Analytics
 * 
 *  DROP Computational Core implements libraries for the following:
 *  - Algorithm Support
 *  - Computation Support
 *  - Function Analysis
 *  - Model Validation
 *  - Numerical Analysis
 *  - Numerical Optimizer
 *  - Spline Builder
 *  - Statistical Learning
 * 
 *  Documentation for DROP is Spread Over:
 * 
 *  - Main                     => https://lakshmidrip.github.io/DROP/
 *  - Wiki                     => https://github.com/lakshmiDRIP/DROP/wiki
 *  - GitHub                   => https://github.com/lakshmiDRIP/DROP
 *  - Repo Layout Taxonomy     => https://github.com/lakshmiDRIP/DROP/blob/master/Taxonomy.md
 *  - Javadoc                  => https://lakshmidrip.github.io/DROP/Javadoc/index.html
 *  - Technical Specifications => https://github.com/lakshmiDRIP/DROP/tree/master/Docs/Internal
 *  - Release Versions         => https://lakshmidrip.github.io/DROP/version.html
 *  - Community Credits        => https://lakshmidrip.github.io/DROP/credits.html
 *  - Issues Catalog           => https://github.com/lakshmiDRIP/DROP/issues
 *  - JUnit                    => https://lakshmidrip.github.io/DROP/junit/index.html
 *  - Jacoco                   => https://lakshmidrip.github.io/DROP/jacoco/index.html
 * 
 *  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.
 */

/**
 * <i>StringUtil</i> implements string utility functions. It exports the following functions:
 *  <ul>
 *      <li>
 *          Decompose + Transform string arrays into appropriate target type set/array/list, and vice versa
 *      </li>
 *      <li>
 *          General-purpose String processor functions, such as GUID generator, splitter, type converter and
 *              input checker
 *      </li>
 *  </ul>
 * 
 * <br><br>
 *  <ul>
 *      <li><b>Module </b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/ComputationalCore.md">Computational Core Module</a></li>
 *      <li><b>Library</b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/NumericalAnalysisLibrary.md">Numerical Analysis Library</a></li>
 *      <li><b>Project</b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/src/main/java/org/drip/numerical">Numerical Quadrature, Differentiation, Eigenization, Linear Algebra, and Utilities</a></li>
 *      <li><b>Package</b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/src/main/java/org/drip/numerical/common">Primitives/Array Manipulate Format Display Utilities</a></li>
 *  </ul>
 * <br><br>
 * 
 * @author Lakshmi Krishnamurthy
 */

public class StringUtil {

    /**
     * Null serialized string
     */

    public static final java.lang.String NULL_SER_STRING = "<<null>>";

    /**
     * Serialization Version - ALWAYS prepend this on all derived classes
     */

    public static final double VERSION = 2.4;

    /**
     * Look for a match of the field in the input array
     * 
     * @param strFieldToMatch Field To Match
     * @param astrMatchSet Array of fields to compare with
     * @param bCaseMatch TRUE - Match case
     * 
     * @return TRUE - Match found according to the criteria specified
     */

    public static final boolean MatchInStringArray (
        final java.lang.String strFieldToMatch,
        final java.lang.String[] astrMatchSet,
        final boolean bCaseMatch)
    {
        if (null == strFieldToMatch || strFieldToMatch.isEmpty() || null == astrMatchSet || 0 ==
            astrMatchSet.length)
            return false;

        for (java.lang.String strMatchSetEntry : astrMatchSet) {
            if (null == strMatchSetEntry || strMatchSetEntry.isEmpty()) continue;

            if (strMatchSetEntry.equals (strFieldToMatch)) return true;

            if (!bCaseMatch && strMatchSetEntry.equalsIgnoreCase (strFieldToMatch)) return true;
        }

        return false;
    }

    /**
     * Look for a match of the field in the field set to an entry in the input array
     * 
     * @param astrFieldToMatch Field Array To Match
     * @param astrMatchSet Array of fields to compare with
     * @param bCaseMatch TRUE - Match case
     * 
     * @return TRUE - Match found according to the criteria specified
     */

    public static final boolean MatchInStringArray (
        final java.lang.String[] astrFieldToMatch,
        final java.lang.String[] astrMatchSet,
        final boolean bCaseMatch)
    {
        if (null == astrFieldToMatch || 0 == astrFieldToMatch.length || null == astrMatchSet || 0 ==
            astrMatchSet.length)
            return false;

        for (java.lang.String strFieldToMatch : astrFieldToMatch) {
            if (MatchInStringArray (strFieldToMatch, astrMatchSet, bCaseMatch)) return true;
        }

        return false;
    }

    /**
     * Format the given string parameter into an argument
     * 
     * @param strArg String Argument
     * 
     * @return Parameter from the Argument
     */

    public static final java.lang.String MakeStringArg (
        final java.lang.String strArg)
    {
        if (null == strArg) return "null";

        if (strArg.isEmpty()) return "\"\"";

        return "\"" + strArg.trim() + "\"";
    }

    /**
     * Check the Input String to Check for NULL - and return it
     * 
     * @param strIn Input String
     * @param bEmptyToNULL TRUE if Empty String needs to be converted to NULL
     * 
     * @return The Processed String
     */

    public static final java.lang.String ProcessInputForNULL (
        final java.lang.String strIn,
        final boolean bEmptyToNULL)
    {
        if (null == strIn) return null;

        if (strIn.isEmpty()) return bEmptyToNULL ? null : "";

        if ("null".equalsIgnoreCase (strIn.trim())) return null;

        if (strIn.trim().toUpperCase().startsWith ("NO")) return null;

        return strIn;
    }

    /**
     * Parse and Split the Input Phrase into a String Array using the specified Delimiter
     * 
     * @param strPhrase Input Phrase
     * @param strDelim Delimiter
     * 
     * @return Array of Sub-Strings
     */

    public static final java.lang.String[] Split (
        final java.lang.String strPhrase,
        final java.lang.String strDelim)
    {
        if (null == strPhrase || strPhrase.isEmpty() || null == strDelim || strDelim.isEmpty()) return null;

        java.util.List<java.lang.Integer> lsDelimIndex = new java.util.ArrayList<java.lang.Integer>();

        int iDelimIndex = -1;

        while (-1 != (iDelimIndex = strPhrase.indexOf (strDelim, iDelimIndex + 1)))
            lsDelimIndex.add (iDelimIndex);

        int iNumField = lsDelimIndex.size();

        if (0 == iNumField) return null;

        int iBeginIndex = 0;
        java.lang.String[] astr = new java.lang.String[iNumField + 1];

        for (int i = 0; i < iNumField; ++i) {
            int iFinishIndex = lsDelimIndex.get (i);

            astr[i] = iBeginIndex >= iFinishIndex ? "" : strPhrase.substring (iBeginIndex, iFinishIndex);

            iBeginIndex = lsDelimIndex.get (i) + 1;
        }

        astr[iNumField] = strPhrase.substring (iBeginIndex);

        return astr;
    }

    /**
     * Check if the string represents an unitary boolean
     * 
     * @param strUnitaryBoolean String input
     * 
     * @return TRUE - Unitary Boolean
     */

    public static final boolean ParseFromUnitaryString (
        final java.lang.String strUnitaryBoolean)
    {
        if (null == strUnitaryBoolean || strUnitaryBoolean.isEmpty() || !"1".equalsIgnoreCase
            (strUnitaryBoolean.trim()))
            return false;

        return true;
    }

    /**
     * Make an array of Integers from a string tokenizer
     * 
     * @param st Tokenizer containing delimited doubles
     *  
     * @return Double array
     */

    public static final int[] MakeIntegerArrayFromStringTokenizer (
        final java.util.StringTokenizer st)
    {
        if (null == st) return null;

        java.util.List<java.lang.Integer> li = new java.util.ArrayList<java.lang.Integer>();

        while (st.hasMoreTokens())
            li.add (java.lang.Integer.parseInt (st.nextToken()));

        if (0 == li.size()) return null;

        int[] ai = new int[li.size()];

        int i = 0;

        for (int iValue : li)
            ai[i++] = iValue;

        return ai;
    }

    /**
     * Make an array of double from a string tokenizer
     * 
     * @param stdbl Tokenizer containing delimited doubles
     *  
     * @return Double array
     */

    public static final double[] MakeDoubleArrayFromStringTokenizer (
        final java.util.StringTokenizer stdbl)
    {
        if (null == stdbl) return null;

        java.util.List<java.lang.Double> lsdbl = new java.util.ArrayList<java.lang.Double>();

        while (stdbl.hasMoreTokens())
            lsdbl.add (java.lang.Double.parseDouble (stdbl.nextToken()));

        if (0 == lsdbl.size()) return null;

        double[] adbl = new double[lsdbl.size()];

        int i = 0;

        for (double dbl : lsdbl)
            adbl[i++] = dbl;

        return adbl;
    }

    /**
     * Generate a GUID string
     * 
     * @return String representing the GUID
     */

    public static final java.lang.String GUID()
    {
        return java.util.UUID.randomUUID().toString();
    }

    /**
     * Split the string array into pairs of key-value doubles and returns them
     * 
     * @param lsdblKey [out] List of Keys
     * @param lsdblValue [out] List of Values
     * @param strArray [in] String containing KV records
     * @param strRecordDelim [in] Record Delimiter
     * @param strKVDelim [in] Key-Value Delimiter
     * 
     * @return True if parsing is successful
     */

    public static final boolean KeyValueListFromStringArray (
        final java.util.List<java.lang.Double> lsdblKey,
        final java.util.List<java.lang.Double> lsdblValue,
        final java.lang.String strArray,
        final java.lang.String strRecordDelim,
        final java.lang.String strKVDelim)
    {
        if (null == strArray || strArray.isEmpty() || null == strRecordDelim || strRecordDelim.isEmpty() ||
            null == strKVDelim || strKVDelim.isEmpty() || null == lsdblKey || null == lsdblValue)
            return false;

        java.lang.String[] astr = Split (strArray, strRecordDelim);

        if (null == astr || 0 == astr.length) return false;

        for (int i = 0; i < astr.length; ++i) {
            if (null == astr[i] || astr[i].isEmpty()) return false;

            java.lang.String[] astrRecord = Split (astr[i], strKVDelim);

            if (null == astrRecord || 2 != astrRecord.length || null == astrRecord[0] ||
                astrRecord[0].isEmpty() || null == astrRecord[1] || astrRecord[1].isEmpty())
                return false;

            lsdblKey.add (java.lang.Double.parseDouble (astrRecord[0]));

            lsdblValue.add (java.lang.Double.parseDouble (astrRecord[1]));
        }

        return true;
    }

    /**
     * Create a list of integers from a delimited string
     * 
     * @param lsi [Output] List of Integers
     * @param strList Delimited String input
     * @param strDelim Delimiter
     * 
     * @return True if successful
     */

    public static final boolean IntegerListFromString (
        final java.util.List<java.lang.Integer> lsi,
        final java.lang.String strList,
        final java.lang.String strDelim)
    {
        if (null == lsi || null == strList || strList.isEmpty() || null == strDelim || strDelim.isEmpty())
            return false;

        java.lang.String[] astr = Split (strList, strDelim);

        if (null == astr || 0 == astr.length) return false;

        for (int i = 0; i < astr.length; ++i) {
            if (null == astr[i] || astr[i].isEmpty()) continue;

            lsi.add (java.lang.Integer.parseInt (astr[i]));
        }

        return true;
    }

    /**
     * Create a list of booleans from a delimited string
     * 
     * @param lsb [Output] List of Booleans
     * @param strList Delimited String input
     * @param strDelim Delimiter
     * 
     * @return True if successful
     */

    public static final boolean BooleanListFromString (
        final java.util.List<java.lang.Boolean> lsb,
        final java.lang.String strList,
        final java.lang.String strDelim)
    {
        if (null == lsb || null == strList || strList.isEmpty() || null == strDelim || strDelim.isEmpty())
            return false;

        java.lang.String[] astr = Split (strList, strDelim);

        if (null == astr || 0 == astr.length) return false;

        for (int i = 0; i < astr.length; ++i) {
            if (null == astr[i] || astr[i].isEmpty()) continue;

            lsb.add (java.lang.Boolean.parseBoolean (astr[i]));
        }

        return true;
    }

    /**
     * Convert the String Array to a Record Delimited String
     * 
     * @param astr Input String Array
     * @param strRecordDelimiter The String Record Delimiter
     * @param strNULL NULL String Indicator
     * 
     * @return The Record Delimited String Array
     */

    public static final java.lang.String StringArrayToString (
        final java.lang.String[] astr,
        final java.lang.String strRecordDelimiter,
        final java.lang.String strNULL)
    {
        if (null == astr || null == strRecordDelimiter || strRecordDelimiter.isEmpty() || null == strNULL ||
            strNULL.isEmpty())
            return null;

        int iNumStr = astr.length;

        if (0 == iNumStr) return null;

        java.lang.StringBuffer sb = new java.lang.StringBuffer();

        for (int i = 0; i < iNumStr; ++i) {
            java.lang.String str = astr[i];

            if (0 != i) sb.append (strRecordDelimiter);

            sb.append (null == str || str.isEmpty() ? strNULL : str);
        }

        return sb.toString();
    }

    /**
     * Indicate if the Input String is Empty
     * 
     * @param str The Input String
     * 
     * @return TRUE - The Input String is Empty
     */

    public static final boolean IsEmpty (
        final java.lang.String str)
    {
        return null == str || str.isEmpty();
    }

    /**
     * Indicate it the pair of Strings Match each other in Value
     * 
     * @param strLeft The Left String
     * @param strRight The Right String
     * 
     * @return TRUE - The Strings Match
     */

    public static final boolean StringMatch (
        final java.lang.String strLeft,
        final java.lang.String strRight)
    {
        boolean bIsLeftEmpty = IsEmpty (strLeft);

        boolean bIsRightEmpty = IsEmpty (strRight);

        if (bIsLeftEmpty && bIsRightEmpty) return true;

        if ((bIsLeftEmpty && !bIsRightEmpty) || (!bIsLeftEmpty && bIsRightEmpty)) return false;

        return strLeft.equalsIgnoreCase (strRight);
    }
}