commit b7fa2ff8cbed33a2843a5bd277a847640a798220
Author: Robert Chatley <rbc@imperial.ac.uk>
Date:   Thu Nov 8 16:13:19 2018 +0000

    Initial files for exercise.

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..c5bf836
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,11 @@
+build
+target
+*.class
+*.iml
+*.ipr
+.idea
+.gradle
+.classpath
+.settings
+.project
+.DS_Store
diff --git a/build.gradle b/build.gradle
new file mode 100644
index 0000000..771b0dd
--- /dev/null
+++ b/build.gradle
@@ -0,0 +1,52 @@
+apply plugin: 'java'
+apply plugin: 'jacoco'
+apply plugin: 'checkstyle'
+
+group = 'uk.ac.ic.doc'
+version = '1.0.0'
+
+description = """Calculator Exercise"""
+
+java {
+  toolchain {
+    languageVersion.set(JavaLanguageVersion.of(21))
+  }
+}
+
+tasks.withType(JavaCompile) {
+    options.encoding = 'UTF-8'
+}
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    testImplementation group: 'junit', name: 'junit', version:'4.12'
+    testImplementation group: 'org.jmock', name: 'jmock-junit4', version: '2.8.3'
+    testImplementation group: 'org.hamcrest', name: 'hamcrest-all', version:'1.3'
+}
+
+test {
+    testLogging {
+        events "PASSED", "FAILED", "SKIPPED"
+    }
+}
+
+checkstyle {
+    toolVersion = '8.45.1'
+    configFile rootProject.file('config/checkstyle/checkstyle.xml')
+    maxErrors = 0
+    maxWarnings = 0
+}
+
+jacoco {
+    toolVersion = '0.8.12'
+}
+
+jacocoTestReport {
+    reports {
+        html.destination file("${buildDir}/reports/coverage")
+    }
+}
+
diff --git a/build.sh b/build.sh
new file mode 100755
index 0000000..5531d79
--- /dev/null
+++ b/build.sh
@@ -0,0 +1 @@
+./gradlew clean test check
diff --git a/config/checkstyle/checkstyle.xml b/config/checkstyle/checkstyle.xml
new file mode 100644
index 0000000..d5eeeab
--- /dev/null
+++ b/config/checkstyle/checkstyle.xml
@@ -0,0 +1,323 @@
+<?xml version="1.0"?>
+<!DOCTYPE module PUBLIC
+          "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
+          "https://checkstyle.org/dtds/configuration_1_3.dtd">
+
+<!--
+    Checkstyle configuration that checks the Google coding conventions from Google Java Style
+    that can be found at https://google.github.io/styleguide/javaguide.html
+
+    Checkstyle is very configurable. Be sure to read the documentation at
+    http://checkstyle.org (or in your downloaded distribution).
+
+    To completely disable a check, just comment it out or delete it from the file.
+    To suppress certain violations please review suppression filters.
+
+    Authors: Max Vetrenko, Ruslan Diachenko, Roman Ivanov.
+ -->
+
+<module name = "Checker">
+  <property name="charset" value="UTF-8"/>
+
+  <property name="severity" value="warning"/>
+
+  <property name="fileExtensions" value="java, properties, xml"/>
+  <!-- Excludes all 'module-info.java' files              -->
+  <!-- See https://checkstyle.org/config_filefilters.html -->
+  <module name="BeforeExecutionExclusionFileFilter">
+    <property name="fileNamePattern" value="module\-info\.java$"/>
+  </module>
+  <!-- https://checkstyle.org/config_filters.html#SuppressionFilter -->
+  <module name="SuppressionFilter">
+    <property name="file" value="${org.checkstyle.google.suppressionfilter.config}"
+           default="checkstyle-suppressions.xml" />
+    <property name="optional" value="true"/>
+  </module>
+
+  <!-- Checks for whitespace                               -->
+  <!-- See http://checkstyle.org/config_whitespace.html -->
+  <module name="FileTabCharacter">
+    <property name="eachLine" value="true"/>
+  </module>
+
+  <module name="LineLength">
+    <property name="fileExtensions" value="java"/>
+    <property name="max" value="100"/>
+    <property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://|ftp://"/>
+  </module>
+
+  <module name="TreeWalker">
+    <module name="OuterTypeFilename"/>
+    <module name="IllegalTokenText">
+      <property name="tokens" value="STRING_LITERAL, CHAR_LITERAL"/>
+      <property name="format"
+               value="\\u00(09|0(a|A)|0(c|C)|0(d|D)|22|27|5(C|c))|\\(0(10|11|12|14|15|42|47)|134)"/>
+      <property name="message"
+               value="Consider using special escape sequence instead of octal value or Unicode escaped value."/>
+    </module>
+    <module name="AvoidEscapedUnicodeCharacters">
+      <property name="allowEscapesForControlCharacters" value="true"/>
+      <property name="allowByTailComment" value="true"/>
+      <property name="allowNonPrintableEscapes" value="true"/>
+    </module>
+    <module name="AvoidStarImport"/>
+    <module name="OneTopLevelClass"/>
+    <module name="NoLineWrap">
+      <property name="tokens" value="PACKAGE_DEF, IMPORT, STATIC_IMPORT"/>
+    </module>
+    <module name="EmptyBlock">
+      <property name="option" value="TEXT"/>
+      <property name="tokens"
+               value="LITERAL_TRY, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE, LITERAL_SWITCH"/>
+    </module>
+    <module name="NeedBraces">
+      <property name="tokens"
+               value="LITERAL_DO, LITERAL_ELSE, LITERAL_FOR, LITERAL_IF, LITERAL_WHILE"/>
+    </module>
+    <module name="LeftCurly">
+      <property name="tokens"
+               value="ANNOTATION_DEF, CLASS_DEF, CTOR_DEF, ENUM_CONSTANT_DEF, ENUM_DEF,
+                    INTERFACE_DEF, LAMBDA, LITERAL_CASE, LITERAL_CATCH, LITERAL_DEFAULT,
+                    LITERAL_DO, LITERAL_ELSE, LITERAL_FINALLY, LITERAL_FOR, LITERAL_IF,
+                    LITERAL_SWITCH, LITERAL_SYNCHRONIZED, LITERAL_TRY, LITERAL_WHILE, METHOD_DEF,
+                    OBJBLOCK, STATIC_INIT, RECORD_DEF, COMPACT_CTOR_DEF"/>
+    </module>
+    <module name="RightCurly">
+      <property name="id" value="RightCurlySame"/>
+      <property name="tokens"
+               value="LITERAL_TRY, LITERAL_CATCH, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE,
+                    LITERAL_DO"/>
+    </module>
+    <module name="RightCurly">
+      <property name="id" value="RightCurlyAlone"/>
+      <property name="option" value="alone"/>
+      <property name="tokens"
+               value="CLASS_DEF, METHOD_DEF, CTOR_DEF, LITERAL_FOR, LITERAL_WHILE, STATIC_INIT,
+                    ANNOTATION_DEF, ENUM_DEF, INTERFACE_DEF, RECORD_DEF,
+                    COMPACT_CTOR_DEF"/>
+    </module>
+    <module name="SuppressionXpathSingleFilter">
+      <!-- suppresion is required till https://github.com/checkstyle/checkstyle/issues/7541 -->
+      <property name="id" value="RightCurlyAlone"/>
+      <property name="query" value="//RCURLY[parent::SLIST[count(./*)=1]
+                                     or preceding-sibling::*[last()][self::LCURLY]]"/>
+    </module>
+    <module name="WhitespaceAfter">
+      <property name="tokens"
+               value="COMMA, SEMI, TYPECAST, LITERAL_IF, LITERAL_ELSE,
+                    LITERAL_WHILE, LITERAL_DO, LITERAL_FOR, DO_WHILE"/>
+    </module>
+    <module name="WhitespaceAround">
+      <property name="allowEmptyConstructors" value="true"/>
+      <property name="allowEmptyLambdas" value="true"/>
+      <property name="allowEmptyMethods" value="true"/>
+      <property name="allowEmptyTypes" value="true"/>
+      <property name="allowEmptyLoops" value="true"/>
+      <property name="ignoreEnhancedForColon" value="false"/>
+      <property name="tokens"
+               value="ASSIGN, BAND, BAND_ASSIGN, BOR, BOR_ASSIGN, BSR, BSR_ASSIGN, BXOR,
+                    BXOR_ASSIGN, COLON, DIV, DIV_ASSIGN, DO_WHILE, EQUAL, GE, GT, LAMBDA, LAND,
+                    LCURLY, LE, LITERAL_CATCH, LITERAL_DO, LITERAL_ELSE, LITERAL_FINALLY,
+                    LITERAL_FOR, LITERAL_IF, LITERAL_RETURN, LITERAL_SWITCH, LITERAL_SYNCHRONIZED,
+                    LITERAL_TRY, LITERAL_WHILE, LOR, LT, MINUS, MINUS_ASSIGN, MOD, MOD_ASSIGN,
+                    NOT_EQUAL, PLUS, PLUS_ASSIGN, QUESTION, RCURLY, SL, SLIST, SL_ASSIGN, SR,
+                    SR_ASSIGN, STAR, STAR_ASSIGN, LITERAL_ASSERT, TYPE_EXTENSION_AND"/>
+      <message key="ws.notFollowed"
+              value="WhitespaceAround: ''{0}'' is not followed by whitespace. Empty blocks may only be represented as '{}' when not part of a multi-block statement (4.1.3)"/>
+      <message key="ws.notPreceded"
+              value="WhitespaceAround: ''{0}'' is not preceded with whitespace."/>
+    </module>
+    <module name="OneStatementPerLine"/>
+    <module name="MultipleVariableDeclarations"/>
+    <module name="ArrayTypeStyle"/>
+    <module name="MissingSwitchDefault"/>
+    <module name="FallThrough"/>
+    <module name="UpperEll"/>
+    <module name="ModifierOrder"/>
+    <module name="EmptyLineSeparator">
+      <property name="tokens"
+               value="PACKAGE_DEF, IMPORT, STATIC_IMPORT, CLASS_DEF, INTERFACE_DEF, ENUM_DEF,
+                    STATIC_INIT, INSTANCE_INIT, METHOD_DEF, CTOR_DEF, VARIABLE_DEF, RECORD_DEF,
+                    COMPACT_CTOR_DEF"/>
+      <property name="allowNoEmptyLineBetweenFields" value="true"/>
+    </module>
+    <module name="SeparatorWrap">
+      <property name="id" value="SeparatorWrapDot"/>
+      <property name="tokens" value="DOT"/>
+      <property name="option" value="nl"/>
+    </module>
+    <module name="SeparatorWrap">
+      <property name="id" value="SeparatorWrapComma"/>
+      <property name="tokens" value="COMMA"/>
+      <property name="option" value="EOL"/>
+    </module>
+    <module name="SeparatorWrap">
+      <!-- ELLIPSIS is EOL until https://github.com/google/styleguide/issues/258 -->
+      <property name="id" value="SeparatorWrapEllipsis"/>
+      <property name="tokens" value="ELLIPSIS"/>
+      <property name="option" value="EOL"/>
+    </module>
+    <module name="SeparatorWrap">
+      <!-- ARRAY_DECLARATOR is EOL until https://github.com/google/styleguide/issues/259 -->
+      <property name="id" value="SeparatorWrapArrayDeclarator"/>
+      <property name="tokens" value="ARRAY_DECLARATOR"/>
+      <property name="option" value="EOL"/>
+    </module>
+    <module name="SeparatorWrap">
+      <property name="id" value="SeparatorWrapMethodRef"/>
+      <property name="tokens" value="METHOD_REF"/>
+      <property name="option" value="nl"/>
+    </module>
+    <module name="PackageName">
+      <property name="format" value="^[a-z]+(\.[a-z][a-z0-9]*)*$"/>
+      <message key="name.invalidPattern"
+             value="Package name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="TypeName">
+      <property name="tokens" value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF,
+                    ANNOTATION_DEF, RECORD_DEF"/>
+      <message key="name.invalidPattern"
+             value="Type name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="MemberName">
+      <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9]*$"/>
+      <message key="name.invalidPattern"
+             value="Member name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="ParameterName">
+      <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+      <message key="name.invalidPattern"
+             value="Parameter name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="LambdaParameterName">
+      <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+      <message key="name.invalidPattern"
+             value="Lambda parameter name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="CatchParameterName">
+      <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+      <message key="name.invalidPattern"
+             value="Catch parameter name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="LocalVariableName">
+      <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+      <message key="name.invalidPattern"
+             value="Local variable name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="PatternVariableName">
+      <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+      <message key="name.invalidPattern"
+             value="Pattern variable name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="ClassTypeParameterName">
+      <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+      <message key="name.invalidPattern"
+             value="Class type name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="RecordTypeParameterName">
+      <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+      <message key="name.invalidPattern"
+               value="Record type name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="MethodTypeParameterName">
+      <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+      <message key="name.invalidPattern"
+             value="Method type name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="InterfaceTypeParameterName">
+      <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+      <message key="name.invalidPattern"
+             value="Interface type name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="NoFinalizer"/>
+    <module name="GenericWhitespace">
+      <message key="ws.followed"
+             value="GenericWhitespace ''{0}'' is followed by whitespace."/>
+      <message key="ws.preceded"
+             value="GenericWhitespace ''{0}'' is preceded with whitespace."/>
+      <message key="ws.illegalFollow"
+             value="GenericWhitespace ''{0}'' should followed by whitespace."/>
+      <message key="ws.notPreceded"
+             value="GenericWhitespace ''{0}'' is not preceded with whitespace."/>
+    </module>
+    <module name="AbbreviationAsWordInName">
+      <property name="ignoreFinal" value="false"/>
+      <property name="allowedAbbreviationLength" value="0"/>
+      <property name="tokens"
+               value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, ANNOTATION_DEF, ANNOTATION_FIELD_DEF,
+                    PARAMETER_DEF, VARIABLE_DEF, METHOD_DEF, PATTERN_VARIABLE_DEF, RECORD_DEF,
+                    RECORD_COMPONENT_DEF"/>
+    </module>
+    <module name="OverloadMethodsDeclarationOrder"/>
+    <module name="VariableDeclarationUsageDistance"/>
+    <module name="MethodParamPad">
+      <property name="tokens"
+               value="CTOR_DEF, LITERAL_NEW, METHOD_CALL, METHOD_DEF,
+                    SUPER_CTOR_CALL, ENUM_CONSTANT_DEF, RECORD_DEF"/>
+    </module>
+    <module name="NoWhitespaceBefore">
+      <property name="tokens"
+               value="COMMA, SEMI, POST_INC, POST_DEC, DOT,
+                    LABELED_STAT, METHOD_REF"/>
+      <property name="allowLineBreaks" value="true"/>
+    </module>
+    <module name="ParenPad">
+      <property name="tokens"
+               value="ANNOTATION, ANNOTATION_FIELD_DEF, CTOR_CALL, CTOR_DEF, DOT, ENUM_CONSTANT_DEF,
+                    EXPR, LITERAL_CATCH, LITERAL_DO, LITERAL_FOR, LITERAL_IF, LITERAL_NEW,
+                    LITERAL_SWITCH, LITERAL_SYNCHRONIZED, LITERAL_WHILE, METHOD_CALL,
+                    METHOD_DEF, QUESTION, RESOURCE_SPECIFICATION, SUPER_CTOR_CALL, LAMBDA,
+                    RECORD_DEF"/>
+    </module>
+    <module name="OperatorWrap">
+      <property name="option" value="NL"/>
+      <property name="tokens"
+               value="BAND, BOR, BSR, BXOR, DIV, EQUAL, GE, GT, LAND, LE, LITERAL_INSTANCEOF, LOR,
+                    LT, MINUS, MOD, NOT_EQUAL, PLUS, QUESTION, SL, SR, STAR, METHOD_REF "/>
+    </module>
+    <module name="AnnotationLocation">
+      <property name="id" value="AnnotationLocationMostCases"/>
+      <property name="tokens"
+               value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF,
+                      RECORD_DEF, COMPACT_CTOR_DEF"/>
+    </module>
+    <module name="AnnotationLocation">
+      <property name="id" value="AnnotationLocationVariables"/>
+      <property name="tokens" value="VARIABLE_DEF"/>
+      <property name="allowSamelineMultipleAnnotations" value="true"/>
+    </module>
+    <module name="NonEmptyAtclauseDescription"/>
+    <module name="InvalidJavadocPosition"/>
+    <module name="JavadocTagContinuationIndentation"/>
+    <module name="SummaryJavadoc">
+      <property name="forbiddenSummaryFragments"
+               value="^@return the *|^This method returns |^A [{]@code [a-zA-Z0-9]+[}]( is a )"/>
+    </module>
+    <module name="RequireEmptyLineBeforeBlockTagGroup"/>
+    <module name="AtclauseOrder">
+      <property name="tagOrder" value="@param, @return, @throws, @deprecated"/>
+      <property name="target"
+               value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF, VARIABLE_DEF"/>
+    </module>
+    <module name="MethodName">
+      <property name="format" value="^[a-z][a-zA-Z0-9_]*$"/>
+      <message key="name.invalidPattern"
+             value="Method name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="SingleLineJavadoc">
+      <property name="ignoreInlineTags" value="false"/>
+    </module>
+    <module name="EmptyCatchBlock">
+      <property name="exceptionVariableName" value="expected"/>
+    </module>
+    <module name="CommentsIndentation">
+      <property name="tokens" value="SINGLE_LINE_COMMENT, BLOCK_COMMENT_BEGIN"/>
+    </module>
+    <!-- https://checkstyle.org/config_filters.html#SuppressionXpathFilter -->
+    <module name="SuppressionXpathFilter">
+      <property name="file" value="${org.checkstyle.google.suppressionxpathfilter.config}"
+             default="checkstyle-xpath-suppressions.xml" />
+      <property name="optional" value="true"/>
+    </module>
+  </module>
+</module>
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..7a3265e
Binary files /dev/null and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..e1adfb4
--- /dev/null
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.10-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
diff --git a/gradlew b/gradlew
new file mode 100755
index 0000000..cccdd3d
--- /dev/null
+++ b/gradlew
@@ -0,0 +1,172 @@
+#!/usr/bin/env sh
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=$((i+1))
+    done
+    case $i in
+        (0) set -- ;;
+        (1) set -- "$args0" ;;
+        (2) set -- "$args0" "$args1" ;;
+        (3) set -- "$args0" "$args1" "$args2" ;;
+        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=$(save "$@")
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
+if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
+  cd "$(dirname "$0")"
+fi
+
+exec "$JAVACMD" "$@"
diff --git a/gradlew.bat b/gradlew.bat
new file mode 100644
index 0000000..e95643d
--- /dev/null
+++ b/gradlew.bat
@@ -0,0 +1,84 @@
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS=
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/settings.gradle b/settings.gradle
new file mode 100644
index 0000000..8b5f3fd
--- /dev/null
+++ b/settings.gradle
@@ -0,0 +1 @@
+rootProject.name = 'Calculator'
diff --git a/src/main/java/ic/doc/README.txt b/src/main/java/ic/doc/README.txt
new file mode 100644
index 0000000..f2127d4
--- /dev/null
+++ b/src/main/java/ic/doc/README.txt
@@ -0,0 +1,2 @@
+Put your implementation code in this directory. 
+Delete this file before submission.
diff --git a/src/test/java/ic/doc/README.txt b/src/test/java/ic/doc/README.txt
new file mode 100644
index 0000000..6719ce3
--- /dev/null
+++ b/src/test/java/ic/doc/README.txt
@@ -0,0 +1,2 @@
+Put your test code in this directory. 
+Delete this file before submission.