number formatting + fixes

src/main/java/org/solovyev/android/calculator/CalculatorDisplay.java

@@ -35,7 +35,7 @@ public class CalculatorDisplay extends AutoResizeTextView {
 	private JsclOperation jsclOperation = JsclOperation.numeric;
 
 	@NotNull
-	private final static TextProcessor<TextHighlighter.Result, String> textHighlighter = new TextHighlighter(Color.WHITE, true, CalculatorEngine.instance.getEngine());
+	private final static TextProcessor<TextHighlighter.Result, String> textHighlighter = new TextHighlighter(Color.WHITE, false, CalculatorEngine.instance.getEngine());
 
 	@Nullable
 	private Generic genericResult;

src/main/java/org/solovyev/android/calculator/CalculatorEditor.java

@@ -31,7 +31,7 @@ public class CalculatorEditor extends EditText implements SharedPreferences.OnSh
 	private boolean highlightText = true;
 
 	@NotNull
-	private final static TextProcessor<TextHighlighter.Result, String> textHighlighter = new TextHighlighter(Color.WHITE, false, CalculatorEngine.instance.getEngine());
+	private final static TextProcessor<TextHighlighter.Result, String> textHighlighter = new TextHighlighter(Color.WHITE, true, CalculatorEngine.instance.getEngine());
 
 	public CalculatorEditor(Context context) {
 		super(context);

src/main/java/org/solovyev/android/calculator/TextHighlighter.java

@@ -10,8 +10,9 @@ import jscl.MathContext;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.solovyev.android.calculator.math.MathType;
-import org.solovyev.android.calculator.model.NumberBuilder;
+import org.solovyev.android.calculator.model.CalculatorEngine;
 import org.solovyev.android.calculator.model.CalculatorParseException;
+import org.solovyev.android.calculator.model.NumberBuilder;
 import org.solovyev.android.calculator.model.TextProcessor;
 import org.solovyev.common.utils.MutableObject;
 
@@ -74,11 +75,11 @@ public class TextHighlighter implements TextProcessor<TextHighlighter.Result, St
 	private final int colorRed;
 	private final int colorGreen;
 	private final int colorBlue;
-	private final boolean simpleFormat;
+	private final boolean allowScientificFormat;
 
-	public TextHighlighter(int baseColor, boolean simpleFormat, @NotNull MathContext mathContext) {
+	public TextHighlighter(int baseColor, boolean allowScientificFormat, @NotNull MathContext mathContext) {
 		this.color = baseColor;
-		this.simpleFormat = simpleFormat;
+		this.allowScientificFormat = allowScientificFormat;
 		this.mathContext = mathContext;
 		//this.colorRed = Color.red(baseColor);
 		this.colorRed = (baseColor >> 16) & 0xFF;
@@ -100,7 +101,7 @@ public class TextHighlighter implements TextProcessor<TextHighlighter.Result, St
 
 		int numberOffset = 0;
 
-		final NumberBuilder numberBuilder = new NumberBuilder(simpleFormat, mathContext.getNumeralBase());
+		final NumberBuilder numberBuilder = new NumberBuilder(allowScientificFormat, CalculatorEngine.instance.getEngine());
 		for (int i = 0; i < text.length(); i++) {
 			MathType.Result mathType = MathType.getType(text, i, numberBuilder.isHexMode());
 
@@ -144,7 +145,7 @@ public class TextHighlighter implements TextProcessor<TextHighlighter.Result, St
 		}
 
 		final MutableObject<Integer> localNumberOffset  = new MutableObject<Integer>(0);
-		numberBuilder.process(text1, localNumberOffset);
+		numberBuilder.processNumber(text1, localNumberOffset);
 		numberOffset += localNumberOffset.getObject();
 
 		if (maxNumberOfOpenGroupSymbols > 0) {

src/main/java/org/solovyev/android/calculator/math/MathType.java

@@ -21,7 +21,7 @@ import java.util.*;
 
 public enum MathType {
 
-	numeral_base(50, true, false) {
+	numeral_base(50, true, false, MathGroupType.number) {
 
 		private final List<String> tokens = new ArrayList<String>(10);
 		{
@@ -40,23 +40,23 @@ public enum MathType {
 		}
 	},
 
-	dot(200, true, true, ".") {
+	dot(200, true, true, MathGroupType.number, ".") {
 		@Override
 		public boolean isNeedMultiplicationSignBefore(@NotNull MathType mathTypeBefore) {
 			return super.isNeedMultiplicationSignBefore(mathTypeBefore) && mathTypeBefore != digit;
 		}
 	},
 
-	grouping_separator(250, false, false, "'", " "){
+	grouping_separator(250, false, false, MathGroupType.number, "'", " "){
 		@Override
 		public int processToJscl(@NotNull StringBuilder result, int i, @NotNull String match) throws CalculatorParseException {
 			return i;
 		}
 	},
 
-	power_10(300, false, false, "E"),
+	power_10(300, false, false, MathGroupType.number, "E"),
 
-	postfix_function(400, false, true) {
+	postfix_function(400, false, true, MathGroupType.function) {
 		@NotNull
 		@Override
 		public List<String> getTokens() {
@@ -64,8 +64,8 @@ public enum MathType {
 		}
 	},
 
-	unary_operation(500, false, false, "-", "="),
+	unary_operation(500, false, false, MathGroupType.operation, "-", "="),
-	binary_operation(600, false, false, "-", "+", "*", "×", "∙", "/", "^") {
+	binary_operation(600, false, false, MathGroupType.operation, "-", "+", "*", "×", "∙", "/", "^") {
 		@Override
 		protected String getSubstituteToJscl(@NotNull String match) {
 			if (match.equals("×") || match.equals("∙")) {
@@ -76,7 +76,7 @@ public enum MathType {
 		}
 	},
 
-	open_group_symbol(800, true, false, "[", "(", "{") {
+	open_group_symbol(800, true, false, MathGroupType.other, "[", "(", "{") {
 		@Override
 		public boolean isNeedMultiplicationSignBefore(@NotNull MathType mathTypeBefore) {
 			return super.isNeedMultiplicationSignBefore(mathTypeBefore) && mathTypeBefore != function && mathTypeBefore != operator;
@@ -88,7 +88,7 @@ public enum MathType {
 		}
 	},
 
-	close_group_symbol(900, false, true, "]", ")", "}") {
+	close_group_symbol(900, false, true, MathGroupType.other, "]", ")", "}") {
 		@Override
 		public boolean isNeedMultiplicationSignBefore(@NotNull MathType mathTypeBefore) {
 			return false;
@@ -100,7 +100,7 @@ public enum MathType {
 		}
 	},
 
-	function(1000, true, true) {
+	function(1000, true, true, MathGroupType.function) {
 		@NotNull
 		@Override
 		public List<String> getTokens() {
@@ -108,7 +108,7 @@ public enum MathType {
 		}
 	},
 
-	operator(1050, true, true) {
+	operator(1050, true, true, MathGroupType.function) {
 		@NotNull
 		@Override
 		public List<String> getTokens() {
@@ -116,7 +116,7 @@ public enum MathType {
 		}
 	},
 
-	constant(1100, true, true) {
+	constant(1100, true, true, MathGroupType.other) {
 		@NotNull
 		@Override
 		public List<String> getTokens() {
@@ -129,7 +129,7 @@ public enum MathType {
 		}
 	},
 
-	digit(1125, true, true) {
+	digit(1125, true, true, MathGroupType.number) {
 
 		private final List<String> tokens = new ArrayList<String>(16);
 		{
@@ -149,9 +149,9 @@ public enum MathType {
 		}
 	},
 
-	comma(1150, false, false, ","),
+	comma(1150, false, false, MathGroupType.other, ","),
 
-	text(1200, false, false) {
+	text(1200, false, false, MathGroupType.other) {
 		@Override
 		public int processToJscl(@NotNull StringBuilder result, int i, @NotNull String match) {
 			if (match.length() > 0) {
@@ -169,6 +169,13 @@ public enum MathType {
 		}
 	};
 
+	public static enum MathGroupType {
+		function,
+		number,
+		operation,
+		other
+	}
+
 	@NotNull
 	private final List<String> tokens;
 
@@ -179,24 +186,35 @@ public enum MathType {
 
 	private final boolean needMultiplicationSignAfter;
 
+	@NotNull
+	private final MathGroupType groupType;
+
 	MathType(@NotNull Integer priority,
 			 boolean needMultiplicationSignBefore,
 			 boolean needMultiplicationSignAfter,
+			 @NotNull MathGroupType groupType,
 			 @NotNull String... tokens) {
-		this(priority, needMultiplicationSignBefore, needMultiplicationSignAfter, CollectionsUtils.asList(tokens));
+		this(priority, needMultiplicationSignBefore, needMultiplicationSignAfter, groupType, CollectionsUtils.asList(tokens));
 	}
 
 	MathType(@NotNull Integer priority,
 			 boolean needMultiplicationSignBefore,
 			 boolean needMultiplicationSignAfter,
+			 @NotNull MathGroupType groupType,
 			 @NotNull List<String> tokens) {
 		this.priority = priority;
 		this.needMultiplicationSignBefore = needMultiplicationSignBefore;
 		this.needMultiplicationSignAfter = needMultiplicationSignAfter;
+		this.groupType = groupType;
 		this.tokens = Collections.unmodifiableList(tokens);
 	}
 
-/*	public static int getPostfixFunctionStart(@NotNull CharSequence s, int position) throws ParseException {
+	@NotNull
+	public MathGroupType getGroupType() {
+		return groupType;
+	}
+
+	/*	public static int getPostfixFunctionStart(@NotNull CharSequence s, int position) throws ParseException {
 		assert s.length() > position;
 
 		int numberOfOpenGroups = 0;

src/main/java/org/solovyev/android/calculator/model/CalculatorEngine.java

@@ -169,7 +169,7 @@ public enum CalculatorEngine {
 
 						calculationResult.setObject(genericResult);
 					} catch (AbstractJsclArithmeticException e) {
-						evalException.setObject(new CalculatorEvalException(e, jsclExpression));
+						evalException.setObject(new CalculatorEvalException(e, e, jsclExpression));
 					} catch (ArithmeticException e) {
 						//System.out.println(e.getMessage());
 						parseException.setObject(new CalculatorParseException(Messages.msg_1, jsclExpression, e.getMessage()));
@@ -207,7 +207,8 @@ public enum CalculatorEngine {
 				}
 
 				if (parseExceptionObject != null || evalExceptionObject != null) {
-					if (finalOperation == JsclOperation.numeric && preparedExpression.isExistsUndefinedVar()) {
+					if (finalOperation == JsclOperation.numeric &&
+							( preparedExpression.isExistsUndefinedVar() || ( evalExceptionObject != null && evalExceptionObject.getCause() instanceof NumeralBaseException)) ) {
 						return evaluate(JsclOperation.simplify, expression, mr);
 					}
 

src/main/java/org/solovyev/android/calculator/model/CalculatorEvalException.java

@@ -6,6 +6,7 @@
 
 package org.solovyev.android.calculator.model;
 
+import jscl.AbstractJsclArithmeticException;
 import org.jetbrains.annotations.NotNull;
 import org.solovyev.common.exceptions.SersoException;
 import org.solovyev.common.msg.Message;
@@ -27,7 +28,8 @@ public class CalculatorEvalException extends SersoException implements Message {
 	@NotNull
 	private final String expression;
 
-	public CalculatorEvalException(@NotNull Message message, String expression) {
+	public CalculatorEvalException(@NotNull Message message, @NotNull Throwable cause, String expression) {
+		super(cause);
 		this.message = message;
 		this.expression = expression;
 	}

src/main/java/org/solovyev/android/calculator/model/FromJsclSimplifyTextProcessor.java

@@ -33,16 +33,16 @@ public class FromJsclSimplifyTextProcessor implements TextProcessor<String, Gene
 	public String process(@NotNull String s) {
 		final StringBuilder sb = new StringBuilder();
 
-		final NumberBuilder numberBuilder = new NumberBuilder(true, mathContext.getNumeralBase());
+		final NumberBuilder nb = new NumberBuilder(false, CalculatorEngine.instance.getEngine());
 		for (int i = 0; i < s.length(); i++) {
-			final MathType.Result mathTypeResult = MathType.getType(s, i, numberBuilder.isHexMode());
+			final MathType.Result mathTypeResult = MathType.getType(s, i, nb.isHexMode());
 
-			numberBuilder.process(sb, mathTypeResult, null);
+			nb.process(sb, mathTypeResult, null);
 
 			i = mathTypeResult.processFromJscl(sb, i);
 		}
 
-		numberBuilder.process(sb, null);
+		nb.processNumber(sb, null);
 
 		return removeMultiplicationSigns(sb.toString());
 	}

src/main/java/org/solovyev/android/calculator/model/NumberBuilder.java

@@ -6,9 +6,10 @@
 
 package org.solovyev.android.calculator.model;
 
+import jscl.MathContext;
 import jscl.MathEngine;
 import jscl.NumeralBase;
-import jscl.math.numeric.Numeric;
+import jscl.math.function.IConstant;
 import jscl.math.numeric.Real;
 import jscl.text.*;
 import org.jetbrains.annotations.NotNull;
@@ -28,59 +29,79 @@ import java.util.List;
  */
 public class NumberBuilder {
 
+	@NotNull
+	private final MathEngine engine;
+
 	@Nullable
 	private StringBuilder numberBuilder = null;
-	@Nullable
-	private String number = null;
 
-	private final boolean simpleFormat;
+	private final boolean allowScientificFormat;
-
-	@NotNull
-	private final NumeralBase defaultNumeralBase;
 
 	@Nullable
 	private NumeralBase nb;
 
-	public NumberBuilder(boolean simpleFormat, @NotNull NumeralBase defaultNumeralBase) {
+	public NumberBuilder(boolean allowScientificFormat, @NotNull MathEngine engine) {
-		this.simpleFormat = simpleFormat;
+		this.allowScientificFormat = allowScientificFormat;
-		this.defaultNumeralBase = defaultNumeralBase;
+		this.nb = engine.getNumeralBase();
-		this.nb = defaultNumeralBase;
+		this.engine = engine;
 	}
 
+	/**
+	 * Method replaces number in text according to some rules (e.g. formatting)
+	 *
+	 * @param text text where number can be replaced
+	 * @param mathTypeResult math type result of current token
+	 * @param offset offset between new number length and old number length (newNumberLength - oldNumberLength)
+	 *
+	 *
+	 * @return new math type result (as one can be changed due to substituting of number with constant)
+	 */
 	@NotNull
-	public MathType.Result process(@NotNull StringBuilder sb, @NotNull MathType.Result mathTypeResult, @Nullable MutableObject<Integer> numberOffset) {
+	public MathType.Result process(@NotNull StringBuilder text, @NotNull MathType.Result mathTypeResult, @Nullable MutableObject<Integer> offset) {
-		number = null;
-
 		final MathType.Result possibleResult;
-		if ((CollectionsUtils.contains(mathTypeResult.getMathType(), MathType.digit, MathType.numeral_base, MathType.dot, MathType.grouping_separator, MathType.power_10) ||
+		if (canContinue(mathTypeResult)) {
-				isSignAfterE(mathTypeResult)) && numeralBaseCheck(mathTypeResult) && numeralBaseInTheStart(mathTypeResult.getMathType())) {
+			// let's continue building number
 			if (numberBuilder == null) {
+				// if new number => create new builder
 				numberBuilder = new StringBuilder();
 			}
 
 			if (mathTypeResult.getMathType() != MathType.numeral_base) {
+				// just add matching string
 				numberBuilder.append(mathTypeResult.getMatch());
 			} else {
+				// set explicitly numeral base (do not include it into number)
 				nb = NumeralBase.getByPrefix(mathTypeResult.getMatch());
 			}
 
 			possibleResult = null;
 		} else {
-			possibleResult = process(sb, numberOffset);
+			// process current number (and go to the next one)
+			possibleResult = processNumber(text, offset);
 		}
 
 		return possibleResult == null ? mathTypeResult : possibleResult;
 	}
 
+	/**
+	 * Method determines if we can continue to process current number
+	 * @param mathTypeResult current math type result
+	 *
+	 * @return true if we can continue of processing of current number, if false - new number should be constructed
+	 */
+	private boolean canContinue(@NotNull MathType.Result mathTypeResult) {
+		return ((mathTypeResult.getMathType().getGroupType() == MathType.MathGroupType.number && numeralBaseCheck(mathTypeResult) && numeralBaseInTheStart(mathTypeResult.getMathType()) || isSignAfterE(mathTypeResult)));
+	}
+
 	private boolean numeralBaseInTheStart(@NotNull MathType mathType) {
 		return mathType != MathType.numeral_base || numberBuilder == null;
 	}
 
-	private boolean numeralBaseCheck( @NotNull MathType.Result mathType ) {
+	private boolean numeralBaseCheck(@NotNull MathType.Result mathType) {
-		if ( mathType.getMathType() == MathType.digit ) {
+		if (mathType.getMathType() == MathType.digit) {
 			final Character ch = mathType.getMatch().charAt(0);
-			if ( NumeralBase.hex.getAcceptableCharacters().contains(ch) && !NumeralBase.dec.getAcceptableCharacters().contains(ch) ) {
+			if (NumeralBase.hex.getAcceptableCharacters().contains(ch) && !NumeralBase.dec.getAcceptableCharacters().contains(ch)) {
-				if ( nb == NumeralBase.hex ) {
+				if (nb == NumeralBase.hex) {
 					return true;
 				} else {
 					return false;
@@ -104,101 +125,92 @@ public class NumberBuilder {
 		return false;
 	}
 
-
+	/**
+	 * Method replaces number in text according to some rules (e.g. formatting)
+	 *
+	 * @param text text where number can be replaced
+	 * @param offset offset between new number length and old number length (newNumberLength - oldNumberLength)
+	 *
+	 * @return new math type result (as one can be changed due to substituting of number with constant)
+	 */
 	@Nullable
-	public MathType.Result process(@NotNull StringBuilder sb, @Nullable MutableObject<Integer> numberOffset) {
+	public MathType.Result processNumber(@NotNull StringBuilder text, @Nullable MutableObject<Integer> offset) {
-		int numberOfTokens = 0;
+		// total number of trimmed chars
+		int trimmedChars = 0;
+
+		String number = null;
+
+		// save numeral base (as later it might be replaced)
+		final NumeralBase localNb = getNumeralBase();
 
-		final NumeralBase localNb;
 		if (numberBuilder != null) {
 			try {
 				number = numberBuilder.toString();
-				List<String> tokens = new ArrayList<String>();
+
+				// let's get rid of unnecessary characters (grouping separators, + after E)
+				final List<String> tokens = new ArrayList<String>();
 				tokens.addAll(MathType.grouping_separator.getTokens());
+				// + after E can be omitted: 10+E = 10E (NOTE: - cannot be omitted )
 				tokens.add("+");
 				for (String groupingSeparator : tokens) {
-					String newNumber = number.replace(groupingSeparator, "");
+					final String trimmedNumber = number.replace(groupingSeparator, "");
-					numberOfTokens += number.length() - newNumber.length();
+					trimmedChars += number.length() - trimmedNumber.length();
-					number = newNumber;
+					number = trimmedNumber;
 				}
 
-				toDouble(number, getNumeralBase());
+				// check if number still valid
+				toDouble(number, getNumeralBase(), engine);
 
 			} catch (NumberFormatException e) {
+				// number is not valid => stop
 				number = null;
 			}
 
 			numberBuilder = null;
-			localNb = getNumeralBase();
+
-			nb = defaultNumeralBase;
+			// must set default numeral base (exit numeral base mode)
-		} else {
+			nb = engine.getNumeralBase();
-			number = null;
-			localNb = getNumeralBase();
 		}
 
-		return replaceSystemVars(sb, number, numberOfTokens, numberOffset, localNb, simpleFormat);
+		return replaceNumberInText(text, number, trimmedChars, offset, localNb, allowScientificFormat, engine);
 	}
 
 	@Nullable
-	private static MathType.Result replaceSystemVars(StringBuilder sb, String number, int numberOfTokens, @Nullable MutableObject<Integer> numberOffset, @NotNull NumeralBase nb, boolean simpleFormat) {
+	private static MathType.Result replaceNumberInText(@NotNull StringBuilder text,
+													   @Nullable String number,
+													   int trimmedChars,
+													   @Nullable MutableObject<Integer> offset,
+													   @NotNull NumeralBase nb,
+													   boolean allowScientificFormat,
+													   @NotNull final MathEngine engine) {
 		MathType.Result result = null;
 
 		if (number != null) {
 			final String finalNumber = number;
-			final Var var = CollectionsUtils.find(CalculatorEngine.instance.getVarsRegister().getSystemEntities(), new Finder<Var>() {
+
+			// detect if current number is precisely equals to constant in constants' registry  (NOTE: ONLY FOR SYSTEM CONSTANTS)
+			final IConstant constant = CollectionsUtils.find(engine.getConstantsRegistry().getSystemEntities(), new Finder<IConstant>() {
 				@Override
-				public boolean isFound(@Nullable Var var) {
+				public boolean isFound(@Nullable IConstant constant) {
-					return var != null && finalNumber.equals(var.getValue());
+					return constant != null && finalNumber.equals(constant.getValue());
 				}
 			});
 
-			if (var != null) {
+			// in any case remove old number from text
-				sb.delete(sb.length() - number.length() - numberOfTokens, sb.length());
+			final int oldNumberLength = number.length() + trimmedChars;
-				sb.append(var.getName());
+			text.delete(text.length() - oldNumberLength, text.length());
-				result = new MathType.Result(MathType.constant, var.getName());
+
+			if (constant != null) {
+				// let's change number with constant from registry
+				text.append(constant.getName());
+				result = new MathType.Result(MathType.constant, constant.getName());
 			} else {
-				sb.delete(sb.length() - number.length() - numberOfTokens, sb.length());
+				final String newNumber = formatNumber(number, nb, allowScientificFormat, engine);
-
+				if (offset != null) {
-				final String formattedNumber;
+					// register offset between old number and new number
-
+					offset.setObject(newNumber.length() - oldNumberLength);
-				if (!simpleFormat) {
-					int indexOfDot = number.indexOf('.');
-
-					if (indexOfDot < 0) {
-						int indexOfE;
-						if (nb == NumeralBase.hex) {
-							indexOfE = -1;
-						} else {
-							indexOfE = number.indexOf('E');
-						}
-						if (indexOfE < 0) {
-							formattedNumber = toString(toDouble(number, nb), nb);
-						} else {
-							final String part;
-							if (indexOfDot != 0) {
-								part = toString(toDouble(number.substring(0, indexOfE), nb), nb);
-							} else {
-								part = "";
-							}
-							formattedNumber = part + number.substring(indexOfE);
-						}
-					} else {
-						final String integerPart;
-						if (indexOfDot != 0) {
-							integerPart = toString(toDouble(number.substring(0, indexOfDot), nb), nb);
-						} else {
-							integerPart = "";
-						}
-						formattedNumber = integerPart + number.substring(indexOfDot);
-					}
-				} else {
-					formattedNumber = toString(toDouble(number, nb), nb);
 				}
-
+				text.append(newNumber);
-				if (numberOffset != null) {
-					numberOffset.setObject(formattedNumber.length() - number.length() - numberOfTokens);
-				}
-				sb.append(formattedNumber);
 			}
 		}
 
@@ -206,40 +218,78 @@ public class NumberBuilder {
 	}
 
 	@NotNull
-	private static String toString(@NotNull Double value, @NotNull NumeralBase nb) {
+	private static String formatNumber(@NotNull String number, @NotNull NumeralBase nb, boolean allowScientificFormat, @NotNull MathEngine engine) {
-		return CalculatorEngine.instance.getEngine().format(value, nb);
+		String result;
+
+		if (allowScientificFormat) {
+			int indexOfDot = number.indexOf('.');
+
+			if (indexOfDot < 0) {
+				int indexOfE;
+				if (nb == NumeralBase.hex) {
+					indexOfE = -1;
+				} else {
+					indexOfE = number.indexOf(MathType.POWER_10);
+				}
+				if (indexOfE < 0) {
+					result = toString(number, nb, engine);
+				} else {
+					final String part;
+					if (indexOfDot != 0) {
+						part = toString(number.substring(0, indexOfE), nb, engine);
+					} else {
+						part = "";
+					}
+					result = part + number.substring(indexOfE);
+				}
+			} else {
+				final String integerPart;
+				if (indexOfDot != 0) {
+					integerPart = toString(number.substring(0, indexOfDot), nb, engine);
+				} else {
+					integerPart = "";
+				}
+				result = integerPart + number.substring(indexOfDot);
+			}
+		} else {
+			result = toString(number, nb, engine);
+		}
+
+		return result;
+	}
+
+	@NotNull
+	private static String toString(@NotNull String value, @NotNull NumeralBase nb, @NotNull MathContext mathContext) {
+		return mathContext.format(toDouble(value, nb, mathContext), nb);
 	}
 
 	public boolean isHexMode() {
-		return nb == NumeralBase.hex || ( nb == null && defaultNumeralBase == NumeralBase.hex);
+		return nb == NumeralBase.hex || (nb == null && engine.getNumeralBase() == NumeralBase.hex);
 	}
 
 	@NotNull
-	private NumeralBase getNumeralBase(){
+	private NumeralBase getNumeralBase() {
-		return nb == null ? defaultNumeralBase : nb;
+		return nb == null ? engine.getNumeralBase() : nb;
 	}
 
 	@NotNull
-	private static Double toDouble(@NotNull String s, @NotNull NumeralBase nb) throws NumberFormatException{
+	private static Double toDouble(@NotNull String s, @NotNull NumeralBase nb, @NotNull final MathContext mc) throws NumberFormatException {
-
+		final NumeralBase defaultNb = mc.getNumeralBase();
-		final MathEngine me = CalculatorEngine.instance.getEngine();
-
-		final NumeralBase defaultNb = me.getNumeralBase();
 		try {
-			me.setNumeralBase(nb);
+			mc.setNumeralBase(nb);
 
 			try {
-				return JsclIntegerParser.parser.parse(Parser.Parameters.newInstance(s, new MutableInt(0), me), null).content().doubleValue();
+				return JsclIntegerParser.parser.parse(Parser.Parameters.newInstance(s, new MutableInt(0), mc), null).content().doubleValue();
 			} catch (ParseException e) {
 				try {
-					return ((Real) DoubleParser.parser.parse(Parser.Parameters.newInstance(s, new MutableInt(0), me), null).content()).doubleValue();
+					return ((Real) DoubleParser.parser.parse(Parser.Parameters.newInstance(s, new MutableInt(0), mc), null).content()).doubleValue();
 				} catch (ParseException e1) {
 					throw new NumberFormatException();
 				}
 			}
 
 		} finally {
-			me.setNumeralBase(defaultNb);
+			mc.setNumeralBase(defaultNb);
 		}
 	}
 }

src/main/java/org/solovyev/android/calculator/model/ToJsclTextProcessor.java

@@ -6,7 +6,6 @@
 
 package org.solovyev.android.calculator.model;
 
-import jscl.JsclMathEngine;
 import org.jetbrains.annotations.NotNull;
 import org.solovyev.android.calculator.StartsWithFinder;
 import org.solovyev.android.calculator.jscl.JsclOperation;
@@ -41,7 +40,7 @@ class ToJsclTextProcessor implements TextProcessor<PreparedExpression, String> {
 
 		final StringBuilder sb = new StringBuilder(s);
 
-		final NumberBuilder nb = new NumberBuilder(true, CalculatorEngine.instance.getEngine().getNumeralBase());
+		final NumberBuilder nb = new NumberBuilder(false, CalculatorEngine.instance.getEngine());
 		for (int i = 0; i < s.length(); i++) {
 			if (s.charAt(i) == ' ') continue;
 			startsWithFinder.setI(i);

src/test/java/org/solovyev/android/calculator/TextHighlighterTest.java

@@ -26,7 +26,7 @@ public class TextHighlighterTest {
 
 	@Test
 	public void testProcess() throws Exception {
-		TextProcessor<?, String> textHighlighter = new TextHighlighter(0, true, JsclMathEngine.instance);
+		TextProcessor<?, String> textHighlighter = new TextHighlighter(0, false, JsclMathEngine.instance);
 
 		final Random random = new Random(new Date().getTime());
 		for (int i = 0; i < 1000; i++) {
@@ -48,7 +48,7 @@ public class TextHighlighterTest {
 		Assert.assertEquals("1 000 000", textHighlighter.process("1000000").toString());
 		Assert.assertEquals("1 000 000", textHighlighter.process("1000000").toString());
 
-		textHighlighter = new TextHighlighter(0, false, JsclMathEngine.instance);
+		textHighlighter = new TextHighlighter(0, true, JsclMathEngine.instance);
 		Assert.assertEquals("0.1E3", textHighlighter.process("0.1E3").toString());
 		Assert.assertEquals("1E3", textHighlighter.process("1E3").toString());
 		Assert.assertEquals("2<b>0x:</b>", textHighlighter.process("20x:").toString());
@@ -60,7 +60,7 @@ public class TextHighlighterTest {
 		Assert.assertEquals("-1 000 000E3", textHighlighter.process("-1000000E3").toString());
 		Assert.assertEquals("-1 000 000E-3", textHighlighter.process("-1000000E-3").toString());
 		Assert.assertEquals("-1 000 000E-30000", textHighlighter.process("-1000000E-30000").toString());
-		textHighlighter = new TextHighlighter(0, true, JsclMathEngine.instance);
+		textHighlighter = new TextHighlighter(0, false, JsclMathEngine.instance);
 
 		textHighlighter.process("cannot calculate 3^10^10 !!!\n" +
 				"        unable to enter 0. FIXED\n" +

src/test/java/org/solovyev/android/calculator/model/CalculatorEngineTest.java

@@ -183,6 +183,18 @@ public class CalculatorEngineTest {
 		Assert.assertEquals("100", cm.evaluate(JsclOperation.numeric, "0.1E3").getResult());
 		Assert.assertEquals("3.957", cm.evaluate(JsclOperation.numeric, "ln(8)lg(8)+ln(8)").getResult());
 
+		Assert.assertEquals("0.933", cm.evaluate(JsclOperation.numeric, "0x:E/0x:F").getResult());
+
+		try {
+		 	cm.getEngine().setNumeralBase(NumeralBase.hex);
+			Assert.assertEquals("E/F", cm.evaluate(JsclOperation.numeric, "0x:E/0x:F").getResult());
+			Assert.assertEquals("E/F", cm.evaluate(JsclOperation.simplify, "0x:E/0x:F").getResult());
+			Assert.assertEquals("E/F", cm.evaluate(JsclOperation.numeric, "E/F").getResult());
+			Assert.assertEquals("E/F", cm.evaluate(JsclOperation.simplify, "E/F").getResult());
+		} finally {
+			cm.getEngine().setNumeralBase(NumeralBase.dec);
+		}
+
 		Assert.assertEquals("0", cm.evaluate(JsclOperation.numeric, "((((((0))))))").getResult());
 		Assert.assertEquals("0", cm.evaluate(JsclOperation.numeric, "((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((0))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))").getResult());