var activity

res/layout/var_edit.xml

@@ -37,7 +37,7 @@
 		<EditText a:id="@+id/var_edit_value"
 				  a:layout_width="match_parent"
 				  a:layout_height="wrap_content"
-				  a:inputType="number"
+				  a:inputType="numberDecimal"
 				  a:textSize="20dp">
 		</EditText>
 

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

@@ -26,7 +26,10 @@ import org.solovyev.util.math.Complex;
 public class CalculatorModel {
 
 	@NotNull
-	private final Interpreter interpreter;
+	private Interpreter interpreter;
+
+	@NotNull
+	private final Object interpreterMonitor = new Object();
 
 	private int numberOfFractionDigits = 5;
 
@@ -38,30 +41,41 @@ public class CalculatorModel {
 
 	private static CalculatorModel instance;
 
-	private CalculatorModel(@Nullable Context context) throws EvalError {
+	private CalculatorModel(@Nullable Context context) {
 		load(context);
 
-		interpreter = new Interpreter();
+		reset();
-		interpreter.eval(ToJsclPreprocessor.wrap(JsclOperation.importCommands, "/jscl/editorengine/commands"));
+	}
+
+	public void reset() {
+		synchronized (interpreterMonitor) {
+			try {
+				interpreter = new Interpreter();
+				interpreter.eval(ToJsclPreprocessor.wrap(JsclOperation.importCommands, "/jscl/editorengine/commands"));
+
+				/*for (Var var : varsRegister.getVars()) {
+					if (!var.isSystem()) {
+						exec(var.getName() + "=" + var.getValue() + ";");
+					}
+				}*/
+			} catch (EvalError evalError) {
+				throw new RuntimeException(evalError);
+			}
+		}
 	}
 
 	public String evaluate(@NotNull JsclOperation operation, @NotNull String expression) throws EvalError, ParseException {
 
 		final StringBuilder sb = new StringBuilder();
 
-/*
-		for (Var var : varsRegister.getVars()) {
-			if (!var.isSystem()) {
-				sb.append(var.getName()).append("=").append(var.getValue()).append(";");
-			}
-		}
-*/
-
 		sb.append(preprocessor.process(expression));
 
 		//Log.d(CalculatorModel.class.getName(), "Preprocessed expression: " + preprocessedExpression);
 
-		Object evaluationObject = interpreter.eval(ToJsclPreprocessor.wrap(operation, sb.toString()));
+		final Object evaluationObject;
+		synchronized (interpreterMonitor) {
+			evaluationObject = interpreter.eval(ToJsclPreprocessor.wrap(operation, sb.toString()));
+		}
 		String result = String.valueOf(evaluationObject).trim();
 
 		try {
@@ -120,7 +134,7 @@ public class CalculatorModel {
 		return MathUtils.round(dResult, numberOfFractionDigits);
 	}
 
-	public synchronized  void load(@Nullable Context context) {
+	public synchronized void load(@Nullable Context context) {
 		if (context != null) {
 			final SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
 
@@ -154,7 +168,7 @@ public class CalculatorModel {
 	}
 
 	public static CalculatorModel getInstance() {
-		if (!isLoaded())	{
+		if (!isLoaded()) {
 			throw new RuntimeException("CalculatorModel must be instantiated!");
 		}
 
@@ -165,8 +179,34 @@ public class CalculatorModel {
 		return instance != null;
 	}
 
+
+	private void exec(String str) throws EvalError {
+		interpreter.eval(str);
+	}
+
+	private String eval(String str) throws EvalError {
+		return interpreter.eval(commands(str)).toString();
+	}
+
+
 	@NotNull
 	public VarsRegister getVarsRegister() {
 		return varsRegister;
 	}
+
+	String commands(String str) {
+		return commands(str, false);
+	}
+
+	String commands(String str, boolean found) {
+		for (int i = 0; i < cmds.length; i++) {
+			int n = str.length() - cmds[i].length() - 1;
+			if (n >= 0 && (" " + cmds[i].toLowerCase()).equals(str.substring(n)))
+				return commands(str.substring(0, n), true) + "." + cmds[i] + "()";
+		}
+		str = str.replaceAll("\n", "");
+		return found ? "jscl.math.Expression.valueOf(\"" + str + "\")" : str;
+	}
+
+	static final String cmds[] = new String[]{"expand", "factorize", "elementary", "simplify", "numeric", "toMathML", "toJava"};
 }

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

@@ -177,10 +177,10 @@ public class CalculatorVarsActivity extends ListActivity {
 					Toast.makeText(CalculatorVarsActivity.this, error, Toast.LENGTH_LONG).show();
 					createEditVariableDialog(editedInstance, name, value, description);
 				} else {
-					if (editedInstance != null && !editedInstance.getName().equals(name)) {
+					if ( editedInstance == null ) {
-						varsRegister.addVar(editedInstance.getName(), varBuilder);
-					} else {
 						CalculatorVarsActivity.this.adapter.add(varsRegister.addVar(null, varBuilder));
+					} else {
+						varsRegister.addVar(editedInstance.getName(), varBuilder);
 					}
 
 					varsRegister.save(CalculatorVarsActivity.this);

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

@@ -192,7 +192,7 @@ public class CalculatorView implements CursorControl, HistoryControl<CalculatorH
 				@Override
 				public void doOperation(@NotNull EditText editor) {
 
-					final MathEntityType type = MathEntityType.getType(text);
+					final MathEntityType type = MathEntityType.getType(text, 0);
 
 					int cursorPositionOffset = 0;
 					final StringBuilder textToBeInserted = new StringBuilder(text);

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

@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+ * For more information, please, contact se.solovyev@gmail.com
+ * or visit http://se.solovyev.org
+ */
+
+package org.solovyev.android.calculator;
+
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import org.solovyev.common.utils.Finder;
+
+/**
+ * User: serso
+ * Date: 10/3/11
+ * Time: 12:54 AM
+ */
+public class CharacterAtPositionFinder implements Finder<Character> {
+
+	private int i;
+
+	@NotNull
+	private final String targetString;
+
+	public CharacterAtPositionFinder(@NotNull String targetString, int i) {
+		this.targetString = targetString;
+		this.i = i;
+	}
+
+	@Override
+	public boolean isFound(@Nullable Character s) {
+		return s != null && s.equals(targetString.charAt(i));
+	}
+
+	public void setI(int i) {
+		this.i = i;
+	}
+}

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

@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+ * For more information, please, contact se.solovyev@gmail.com
+ * or visit http://se.solovyev.org
+ */
+
+package org.solovyev.android.calculator;
+
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import org.solovyev.common.utils.Finder;
+
+/**
+* User: serso
+* Date: 10/3/11
+* Time: 12:49 AM
+*/
+public class StartsWithFinder implements Finder<String> {
+
+	private int i;
+
+	@NotNull
+	private final String targetString;
+
+	public StartsWithFinder(@NotNull String targetString, int i) {
+		this.targetString = targetString;
+		this.i = i;
+	}
+
+	@Override
+	public boolean isFound(@Nullable String s) {
+		return targetString.startsWith(s, i);
+	}
+
+	public void setI(int i) {
+		this.i = i;
+	}
+}

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

@@ -19,46 +19,88 @@ public class ToJsclPreprocessor implements Preprocessor {
 	@Override
 	@NotNull
 	public String process(@NotNull String s) {
+
+		final StartsWithFinder startsWithFinder = new StartsWithFinder(s, 0);
 		final StringBuilder sb = new StringBuilder();
 
+		boolean constantBefore = false;
 		for (int i = 0; i < s.length(); i++) {
 			char ch = s.charAt(i);
-			if ( MathEntityType.getType(ch) == MathEntityType.postfix_function ) {
+			startsWithFinder.setI(i);
-		   		int start = getPostfixFunctionStart(s, i - 1);
-			}
-		}
 
-		final StartsWithFinder startsWithFinder = new StartsWithFinder(s);
+			checkMultiplicationSignBeforeFunction(sb, s, i, constantBefore);
-		for (int i = 0; i < s.length(); i++) {
+			constantBefore = false;
-			char ch = s.charAt(i);
-
-			checkMultiplicationSignBeforeFunction(sb, s, i);
 
 			if (MathEntityType.openGroupSymbols.contains(ch)) {
 				sb.append('(');
 			} else if (MathEntityType.closeGroupSymbols.contains(ch)) {
 				sb.append(')');
-			} else if (ch == 'π') {
-				sb.append("pi");
 			} else if (ch == '×' || ch == '∙') {
 				sb.append("*");
 			} else {
-				startsWithFinder.setI(i);
+				String entity = CollectionsUtils.get(MathEntityType.prefixFunctions, startsWithFinder);
-				final String function = CollectionsUtils.get(MathEntityType.prefixFunctions, startsWithFinder);
+				if (entity == null) {
-				if (function != null) {
+					entity = CollectionsUtils.get(CalculatorModel.getInstance().getVarsRegister().getVarNames(), startsWithFinder);
-					sb.append(toJsclFunction(function));
+					if (entity == null) {
-					i += function.length() - 1;
+						sb.append(ch);
-				} else if (ch == 'e') {
+					} else {
-					sb.append("exp(1)");
+						sb.append(entity);
-				} else if (ch == 'i') {
+						i += entity.length() - 1;
-					sb.append("sqrt(-1)");
+						constantBefore = true;
+					}
 				} else {
-					sb.append(ch);
+					sb.append(toJsclFunction(entity));
+					i += entity.length() - 1;
 				}
 			}
 		}
 
-		return sb.toString();
+		return replaceVariables(sb.toString());
+	}
+
+	private String replaceVariables(@NotNull final String s) {
+		final StartsWithFinder startsWithFinder = new StartsWithFinder(s, 0);
+
+		final StringBuilder result = new StringBuilder();
+		for (int i = 0; i < s.length(); i++) {
+			startsWithFinder.setI(i);
+
+			int offset = 0;
+			String functionName = CollectionsUtils.get(MathEntityType.prefixFunctions, startsWithFinder);
+			if (functionName == null) {
+				String varName = CollectionsUtils.get(CalculatorModel.getInstance().getVarsRegister().getVarNames(), startsWithFinder);
+				if (varName != null) {
+					final Var var = CalculatorModel.getInstance().getVarsRegister().getVar(varName);
+					if (var != null) {
+						result.append(var.getValue());
+						offset = varName.length();
+					}
+				}
+			} else {
+				result.append(functionName);
+				offset = functionName.length();
+			}
+
+
+			if (offset == 0) {
+				result.append(s.charAt(i));
+			} else {
+				i += offset - 1;
+			}
+		}
+
+		return result.toString();
+	}
+
+	private void replaceVariables(StringBuilder sb, String s, int i, @NotNull StartsWithFinder startsWithFinder) {
+		for (Var var : CalculatorModel.getInstance().getVarsRegister().getVars()) {
+			if (!var.isSystem()) {
+				if (s.startsWith(var.getName(), i)) {
+					if (CollectionsUtils.get(MathEntityType.prefixFunctions, startsWithFinder) == null) {
+					}
+				}
+			}
+		}
 	}
 
 	public int getPostfixFunctionStart(@NotNull String s, int position) {
@@ -66,17 +108,16 @@ public class ToJsclPreprocessor implements Preprocessor {
 
 		int numberOfOpenGroups = 0;
 		int result = position;
-		for ( ; result >= 0; result-- ) {
+		for (; result >= 0; result--) {
-			char ch = s.charAt(result);
 
-			final MathEntityType mathEntityType = MathEntityType.getType(ch);
+			final MathEntityType mathEntityType = MathEntityType.getType(s, result);
 
-			if ( mathEntityType != null  ) {
+			if (mathEntityType != null) {
-				if ( CollectionsUtils.contains(mathEntityType, MathEntityType.digit, MathEntityType.dot) ) {
+				if (CollectionsUtils.contains(mathEntityType, MathEntityType.digit, MathEntityType.dot)) {
 					// continue
-				} else if (MathEntityType.closeGroupSymbols.contains(ch)) {
+				} else if (MathEntityType.closeGroupSymbols.contains(s.charAt(result))) {
 					numberOfOpenGroups++;
-				} else if (MathEntityType.openGroupSymbols.contains(ch)) {
+				} else if (MathEntityType.openGroupSymbols.contains(s.charAt(result))) {
 					numberOfOpenGroups--;
 				} else {
 					if (stop(s, numberOfOpenGroups, result)) break;
@@ -90,12 +131,12 @@ public class ToJsclPreprocessor implements Preprocessor {
 	}
 
 	private boolean stop(String s, int numberOfOpenGroups, int i) {
-		if ( numberOfOpenGroups == 0 ) {
+		if (numberOfOpenGroups == 0) {
 			if (i > 0) {
 				final EndsWithFinder endsWithFinder = new EndsWithFinder(s);
-				endsWithFinder.setI(i+1);
+				endsWithFinder.setI(i + 1);
-				if ( !CollectionsUtils.contains(MathEntityType.prefixFunctions, FilterType.included, endsWithFinder) ) {
+				if (!CollectionsUtils.contains(MathEntityType.prefixFunctions, FilterType.included, endsWithFinder)) {
-					MathEntityType type = MathEntityType.getType(s.charAt(i));
+					MathEntityType type = MathEntityType.getType(s, i);
 					if (type != null && type != MathEntityType.constant) {
 						return true;
 					}
@@ -123,27 +164,6 @@ public class ToJsclPreprocessor implements Preprocessor {
 		return result;
 	}
 
-	private static class StartsWithFinder implements Finder<String> {
-
-		private int i;
-
-		@NotNull
-		private final String targetString;
-
-		private StartsWithFinder(@NotNull String targetString) {
-			this.targetString = targetString;
-		}
-
-		@Override
-		public boolean isFound(@Nullable String s) {
-			return targetString.startsWith(s, i);
-		}
-
-		public void setI(int i) {
-			this.i = i;
-		}
-	}
-
 	private static class EndsWithFinder implements Finder<String> {
 
 		private int i;
@@ -165,25 +185,25 @@ public class ToJsclPreprocessor implements Preprocessor {
 		}
 	}
 
-	private static void checkMultiplicationSignBeforeFunction(@NotNull StringBuilder sb, @NotNull String s, int i) {
+	private static void checkMultiplicationSignBeforeFunction(@NotNull StringBuilder sb, @NotNull String s, int i, boolean constantBefore) {
 		if (i > 0) {
 			// get character before function
 			char chBefore = s.charAt(i - 1);
 			char ch = s.charAt(i);
 
 			final MathEntityType mathTypeBefore = MathEntityType.getType(String.valueOf(chBefore));
-			final MathEntityType mathType = MathEntityType.getType(String.valueOf(ch));
+			final MathEntityType mathType = MathEntityType.getType(s, i);
 
-			if (mathTypeBefore != MathEntityType.binary_operation &&
+			if (constantBefore || (mathTypeBefore != MathEntityType.binary_operation &&
 					mathTypeBefore != MathEntityType.unary_operation &&
-						mathTypeBefore != MathEntityType.function &&
+					mathTypeBefore != MathEntityType.function &&
-							!MathEntityType.openGroupSymbols.contains(chBefore)) {
+					!MathEntityType.openGroupSymbols.contains(chBefore))) {
 
 				if (mathType == MathEntityType.constant) {
 					sb.append("*");
 				} else if (MathEntityType.openGroupSymbols.contains(ch) && mathTypeBefore != null) {
 					sb.append("*");
-				} else if (mathType == MathEntityType.digit && mathTypeBefore != MathEntityType.digit && mathTypeBefore != MathEntityType.dot) {
+				} else if (mathType == MathEntityType.digit && ((mathTypeBefore != MathEntityType.digit && mathTypeBefore != MathEntityType.dot) || constantBefore) ) {
 					sb.append("*");
 				} else {
 					for (String function : MathEntityType.prefixFunctions) {

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

@@ -13,6 +13,7 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.simpleframework.xml.Serializer;
 import org.simpleframework.xml.core.Persister;
+import org.solovyev.android.calculator.math.MathEntityComparator;
 import org.solovyev.android.calculator.math.MathEntityType;
 import org.solovyev.common.utils.CollectionsUtils;
 import org.solovyev.common.utils.Finder;
@@ -46,20 +47,34 @@ public class VarsRegister {
 	public Var addVar(@Nullable String name, @NotNull Var.Builder builder) {
 		final Var var = builder.create();
 
-		final Var varFromRegister = getVar(name == null ? var.getName() : name);
+		Var varFromRegister = getVar(name == null ? var.getName() : name);
 		if (varFromRegister == null) {
+			varFromRegister = var;
 			vars.add(var);
 		} else {
 			varFromRegister.copy(var);
 		}
 
-		return var;
+		return varFromRegister;
 	}
 
 	public void remove (@NotNull Var var) {
 		this.vars.remove(var);
 	}
 
+	@NotNull
+	public List<String> getVarNames () {
+		final List<String> result = new ArrayList<String>();
+
+		for (Var var : vars) {
+			result.add(var.getName());
+		}
+
+		Collections.sort(result, new MathEntityComparator());
+
+		return result;
+	}
+
 	@Nullable
 	public Var getVar(@NotNull final String name) {
 		return CollectionsUtils.get(vars, new Finder<Var>() {
@@ -121,7 +136,7 @@ public class VarsRegister {
 			} else if (systemVarName.equals("π")) {
 				systemVar = new Var.Builder(systemVarName, Math.PI).setSystem(true).create();
 			} else if (systemVarName.equals("i")) {
-				systemVar = new Var.Builder(systemVarName, "√(-1)").setSystem(true).create();
+				systemVar = new Var.Builder(systemVarName, "sqrt(-1)").setSystem(true).create();
 			} else {
 				throw new IllegalArgumentException(systemVarName + " is not supported yet!");
 			}
@@ -157,7 +172,7 @@ public class VarsRegister {
 			throw new RuntimeException(e);
 		}
 
-		editor.putString(context.getString(R.string.p_calc_vars),sw.toString());
+		editor.putString(context.getString(R.string.p_calc_vars), sw.toString());
 
 		editor.commit();
 	}

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

@@ -5,41 +5,48 @@
 
 package org.solovyev.android.calculator.math;
 
-import org.jetbrains.annotations.NonNls;
+import java.util.*;
-
-import java.util.Arrays;
-import java.util.List;
 
 /**
  * User: serso
  * Date: 9/17/11
  * Time: 10:01 PM
  */
-public interface Functions {
+public class Functions {
 
-	String SIN = "sin";
+	public final static String SIN = "sin";
-	String SINH = "sinh";
+	public final static String SINH = "sinh";
-	String ASIN = "asin";
+	public final static String ASIN = "asin";
-	String ASINH = "asinh";
+	public final static String ASINH = "asinh";
-	String COS = "cos";
+	public final static String COS = "cos";
-	String COSH = "cosh";
+	public final static String COSH = "cosh";
-	String ACOS = "acos";
+	public final static String ACOS = "acos";
-	String ACOSH = "acosh";
+	public final static String ACOSH = "acosh";
-	String TAN = "tan";
+	public final static String TAN = "tan";
-	String TANH = "tanh";
+	public final static String TANH = "tanh";
-	String ATAN = "atan";
+	public final static String ATAN = "atan";
-	String ATANH = "atanh";
+	public final static String ATANH = "atanh";
-	String LOG = "log";
+	public final static String LOG = "log";
-	String LN = "ln";
+	public final static String LN = "ln";
-	String MOD = "mod";
+	public final static String MOD = "mod";
-	String EXP = "exp";
+	public final static String EXP = "exp";
-	String SQRT_SIGN = "√";
+	public final static String SQRT_SIGN = "√";
-	String SQRT = "sqrt";
+	public final static String SQRT = "sqrt";
 
-	public static final List<String> allPrefix = Arrays.asList(SIN, SINH, ASIN, ASINH, COS, COSH, ACOS, ACOSH, TAN, TANH, ATAN, ATANH, LOG, LN, MOD, SQRT, SQRT_SIGN, EXP);
+	public static final List<String> allPrefix;
 
-	Character FACT = '!';
+	static {
-	Character DEGREE = '°';
+		final List<String> functions = new ArrayList<String>(Arrays.asList(SIN, SINH, ASIN, ASINH, COS, COSH, ACOS, ACOSH, TAN, TANH, ATAN, ATANH, LOG, LN, MOD, SQRT, SQRT_SIGN, EXP));
+		Collections.sort(functions, new MathEntityComparator());
+		allPrefix = functions;
+	}
+
+	public final static Character FACT = '!';
+	public final static Character DEGREE = '°';
 
 	public static final List<Character> allPostfix = Arrays.asList(FACT, DEGREE);
+
+	private Functions() {
+		throw new AssertionError("Not allowed!");
+	}
 }

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

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+ * For more information, please, contact se.solovyev@gmail.com
+ * or visit http://se.solovyev.org
+ */
+
+package org.solovyev.android.calculator.math;
+
+import java.util.Comparator;
+
+/**
+ * User: serso
+ * Date: 10/3/11
+ * Time: 12:30 AM
+ */
+public class MathEntityComparator implements Comparator<String> {
+
+	@Override
+	public int compare(String s, String s1) {
+		return s1.length() - s.length();
+	}
+}

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

@@ -8,6 +8,8 @@ package org.solovyev.android.calculator.math;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.solovyev.android.calculator.CalculatorModel;
+import org.solovyev.android.calculator.CharacterAtPositionFinder;
+import org.solovyev.android.calculator.StartsWithFinder;
 import org.solovyev.android.calculator.Var;
 import org.solovyev.common.utils.CollectionsUtils;
 import org.solovyev.common.utils.Finder;
@@ -31,11 +33,12 @@ public enum MathEntityType {
 
 	public static final List<String> constants = Arrays.asList("e", "π", "i");
 
+	public static final List<String> digits = Arrays.asList("0", "1", "2", "3", "4", "5", "6", "7", "8", "9");
 	public static final List<Character> dots = Arrays.asList('.');
 
 	public static final List<Character> unaryOperations = Arrays.asList('-', '=', '!');
 
-	public static final List<Character> binaryOperations = Arrays.asList('-', '+', '*', '×', '∙', '/', '^' );
+	public static final List<Character> binaryOperations = Arrays.asList('-', '+', '*', '×', '∙', '/', '^');
 
 	public static final List<String> prefixFunctions = Functions.allPrefix;
 
@@ -48,6 +51,7 @@ public enum MathEntityType {
 	public static final List<Character> closeGroupSymbols = Arrays.asList(']', ')', '}');
 
 	public static final List<Character> singleGroupSymbols;
+
 	static {
 		final List<Character> list = new ArrayList<Character>();
 		list.addAll(openGroupSymbols);
@@ -56,19 +60,19 @@ public enum MathEntityType {
 	}
 
 	@Nullable
-	public static MathEntityType getType( @NotNull String s ) {
+	public static MathEntityType getType(@NotNull String s) {
 		MathEntityType result = null;
 
-		if ( s.length() == 1 ) {
+		if (s.length() == 1) {
 			result = getType(s.charAt(0));
 		}
 
-		if ( result == null ) {
+		if (result == null) {
-			if ( isConstant(s) ) {
+			if (prefixFunctions.contains(s)) {
-				result = MathEntityType.constant;
-			} else if ( prefixFunctions.contains(s) ) {
 				result = MathEntityType.function;
-			} else if ( groupSymbols.contains(s) ) {
+			} else if (isConstant(s)) {
+				result = MathEntityType.constant;
+			} else if (groupSymbols.contains(s)) {
 				result = MathEntityType.group_symbols;
 			}
 		}
@@ -81,19 +85,19 @@ public enum MathEntityType {
 	public static MathEntityType getType(final char ch) {
 		MathEntityType result = null;
 
-		if ( Character.isDigit(ch) ) {
+		if (Character.isDigit(ch)) {
 			result = MathEntityType.digit;
-		} else if ( postfixFunctions.contains(ch) ) {
+		} else if (postfixFunctions.contains(ch)) {
 			result = MathEntityType.postfix_function;
-		} else if ( unaryOperations.contains(ch) ) {
+		} else if (unaryOperations.contains(ch)) {
 			result = MathEntityType.unary_operation;
-		} else if ( binaryOperations.contains(ch) ) {
+		} else if (binaryOperations.contains(ch)) {
 			result = MathEntityType.binary_operation;
-		} else if ( singleGroupSymbols.contains(ch) ) {
+		} else if (singleGroupSymbols.contains(ch)) {
 			result = MathEntityType.group_symbol;
 		} else if (isConstant(ch)) {
 			result = MathEntityType.constant;
-		} else if ( dots.contains(ch) ) {
+		} else if (dots.contains(ch)) {
 			result = MathEntityType.dot;
 		}
 		return result;
@@ -113,4 +117,46 @@ public enum MathEntityType {
 			}
 		}) != null;
 	}
+
+	public static MathEntityType getType(String s, int i) {
+		final StartsWithFinder startsWithFinder = new StartsWithFinder(s, i);
+		final CharacterAtPositionFinder characterStartWithFinder = new CharacterAtPositionFinder(s, i);
+
+		return getType(startsWithFinder, characterStartWithFinder);
+	}
+
+	@Nullable
+	private static MathEntityType getType(@NotNull Finder<String> finder, @NotNull CharacterAtPositionFinder characterStartWithFinder) {
+		MathEntityType result = null;
+
+		if (contains(digits, finder)) {
+			result = MathEntityType.digit;
+		} else if (contains(postfixFunctions, characterStartWithFinder)) {
+			result = MathEntityType.postfix_function;
+		} else if (contains(unaryOperations, characterStartWithFinder)) {
+			result = MathEntityType.unary_operation;
+		} else if (contains(binaryOperations, characterStartWithFinder)) {
+			result = MathEntityType.binary_operation;
+		} else if (contains(groupSymbols, finder)) {
+			result = MathEntityType.group_symbols;
+		} else if (contains(singleGroupSymbols, characterStartWithFinder)) {
+			result = MathEntityType.group_symbol;
+		} else if (contains(prefixFunctions, finder)) {
+			result = MathEntityType.function;
+		} else if (contains(CalculatorModel.getInstance().getVarsRegister().getVarNames(), finder)) {
+			result = MathEntityType.constant;
+		} else if (contains(dots, characterStartWithFinder)) {
+			result = MathEntityType.dot;
+		}
+
+		return result;
+	}
+
+	private static boolean contains(@NotNull List<String> list, @NotNull final Finder<String> startsWithFinder) {
+		return CollectionsUtils.get(list, startsWithFinder) != null;
+	}
+
+	private static boolean contains(@NotNull List<Character> list, @NotNull final CharacterAtPositionFinder atPositionFinder) {
+		return CollectionsUtils.get(list, atPositionFinder) != null;
+	}
 }

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

@@ -5,8 +5,8 @@
 
 package org.solovyev.android.calculator;
 
+import bsh.EvalError;
 import org.junit.Assert;
-import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.Test;
 
@@ -47,6 +47,25 @@ public class CalculatorModelTest {
 		Assert.assertEquals("-3.41007+3.41007i", cm.evaluate(JsclOperation.numeric, "(5tan(2i)+2i)/(1-i)"));
 		Assert.assertEquals("-0.1-0.2i", cm.evaluate(JsclOperation.numeric, "(1-i)/(2+6i)"));
 
+		CalculatorModel.getInstance().getVarsRegister().addVar(null, new Var.Builder("si", 5d));
+		Assert.assertEquals("5.0", cm.evaluate(JsclOperation.numeric, "si"));
+		try {
+			cm.evaluate(JsclOperation.numeric, "sin");
+			Assert.fail();
+		} catch (EvalError e) {
+		}
+		Assert.assertEquals("-0.95892", cm.evaluate(JsclOperation.numeric, "sin(5)"));
+		Assert.assertEquals("-4.79462", cm.evaluate(JsclOperation.numeric, "sin(5)si"));
+		Assert.assertEquals("-23.97311", cm.evaluate(JsclOperation.numeric, "sisin(5)si"));
+		Assert.assertEquals("-23.97311", cm.evaluate(JsclOperation.numeric, "si*sin(5)si"));
+		Assert.assertEquals("-3.30879", cm.evaluate(JsclOperation.numeric, "sisin(5si)si"));
+
+		CalculatorModel.getInstance().getVarsRegister().addVar(null, new Var.Builder("s", 1d));
+		Assert.assertEquals("5.0", cm.evaluate(JsclOperation.numeric, "si"));
+
+		CalculatorModel.getInstance().getVarsRegister().addVar(null, new Var.Builder("k", 3.5d));
+		CalculatorModel.getInstance().getVarsRegister().addVar(null, new Var.Builder("k1", 4d));
+		Assert.assertEquals("4.0", cm.evaluate(JsclOperation.numeric, "k11"));
 	}
 
 	@Test