Changes

app/src/main/java/org/solovyev/android/calculator/Calculator.java

@@ -28,17 +28,14 @@ import android.text.TextUtils;
 import android.util.Log;
 import com.squareup.otto.Bus;
 import com.squareup.otto.Subscribe;
-import jscl.JsclArithmeticException;
+import jscl.*;
-import jscl.MathEngine;
-import jscl.NumeralBase;
-import jscl.NumeralBaseException;
 import jscl.math.Generic;
+import jscl.math.function.Constants;
 import jscl.math.function.IConstant;
 import jscl.text.ParseInterruptedException;
 import org.solovyev.android.calculator.calculations.CalculationCancelledEvent;
 import org.solovyev.android.calculator.calculations.CalculationFailedEvent;
 import org.solovyev.android.calculator.calculations.CalculationFinishedEvent;
-import org.solovyev.android.calculator.errors.FixableErrorsActivity;
 import org.solovyev.android.calculator.functions.FunctionsRegistry;
 import org.solovyev.android.calculator.jscl.JsclOperation;
 import org.solovyev.android.calculator.units.CalculatorNumeralBase;
@@ -57,6 +54,7 @@ import javax.inject.Inject;
 import javax.inject.Named;
 import javax.inject.Singleton;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.Executor;
 import java.util.concurrent.TimeUnit;
@@ -65,12 +63,13 @@ import java.util.concurrent.atomic.AtomicLong;
 @Singleton
 public class Calculator implements CalculatorEventListener, SharedPreferences.OnSharedPreferenceChangeListener {
 
+    public static final long NO_SEQUENCE = -1;
     private static final long PREFERENCE_CHECK_INTERVAL = TimeUnit.MINUTES.toMillis(15);
 
     @Nonnull
     private final CalculatorEventContainer calculatorEventContainer = new ListCalculatorEventContainer();
     @Nonnull
-    private final AtomicLong counter = new AtomicLong(CalculatorUtils.FIRST_ID);
+    private static final AtomicLong SEQUENCER = new AtomicLong(NO_SEQUENCE);
     @Nonnull
     private final ToJsclTextProcessor preprocessor = ToJsclTextProcessor.getInstance();
     @Nonnull
@@ -90,6 +89,8 @@ public class Calculator implements CalculatorEventListener, SharedPreferences.On
     PreferredPreferences preferredPreferences;
     @Inject
     Editor editor;
+    @Inject
+    JsclMathEngine mathEngine;
 
     @Inject
     public Calculator(@Nonnull SharedPreferences preferences, @Nonnull Bus bus, @Named(AppModule.THREAD_UI) @Nonnull Executor ui, @Named(AppModule.THREAD_BACKGROUND) @Nonnull Executor background) {
@@ -113,7 +114,7 @@ public class Calculator implements CalculatorEventListener, SharedPreferences.On
             String fromString = generic.toString();
             if (!Strings.isEmpty(fromString)) {
                 try {
-                    fromString = ToJsclTextProcessor.getInstance().process(fromString).getExpression();
+                    fromString = ToJsclTextProcessor.getInstance().process(fromString).getValue();
                 } catch (ParseException e) {
                     // ok, problems while processing occurred
                 }
@@ -130,19 +131,19 @@ public class Calculator implements CalculatorEventListener, SharedPreferences.On
 
     @Nonnull
     private CalculatorEventData nextEventData() {
-        long eventId = counter.incrementAndGet();
+        final long eventId = nextSequence();
         return CalculatorEventDataImpl.newInstance(eventId, eventId);
     }
 
     @Nonnull
     private CalculatorEventData nextEventData(@Nonnull Object source) {
-        long eventId = counter.incrementAndGet();
+        long eventId = nextSequence();
         return CalculatorEventDataImpl.newInstance(eventId, eventId, source);
     }
 
 	@Nonnull
     private CalculatorEventData nextEventData(@Nonnull Long sequenceId) {
-        long eventId = counter.incrementAndGet();
+        long eventId = nextSequence();
         return CalculatorEventDataImpl.newInstance(eventId, sequenceId);
     }
 
@@ -167,7 +168,7 @@ public class Calculator implements CalculatorEventListener, SharedPreferences.On
         background.execute(new Runnable() {
             @Override
             public void run() {
-                Calculator.this.evaluateAsync(eventDataId.getSequenceId(), operation, expression, null);
+                evaluateAsync(eventDataId.getSequenceId(), operation, expression);
             }
         });
 
@@ -181,7 +182,7 @@ public class Calculator implements CalculatorEventListener, SharedPreferences.On
         background.execute(new Runnable() {
             @Override
             public void run() {
-                evaluateAsync(eventDataId.getSequenceId(), operation, expression, null);
+                evaluateAsync(eventDataId.getSequenceId(), operation, expression);
             }
         });
 
@@ -215,72 +216,75 @@ public class Calculator implements CalculatorEventListener, SharedPreferences.On
         return CalculatorConversionEventDataImpl.newInstance(nextEventData(sequenceId), value, from, to, displayViewState);
     }
 
+    private void evaluateAsync(long sequence, @Nonnull JsclOperation o, @Nonnull String e) {
+        evaluateAsync(sequence, o, e, new ListMessageRegistry());
+    }
+
     private void evaluateAsync(long sequence,
-                               @Nonnull JsclOperation operation,
+                               @Nonnull JsclOperation o,
-                               @Nonnull String expression,
+                               @Nonnull String e,
-                               @Nullable MessageRegistry mr) {
+                               @Nonnull MessageRegistry mr) {
+        e = e.trim();
+        if (Strings.isEmpty(e)) {
+            bus.post(new CalculationFinishedEvent(o, e, sequence));
+            return;
+        }
+
         checkPreferredPreferences();
-        expression = expression.trim();
+        PreparedExpression pe = null;
-
-        PreparedExpression preparedExpression = null;
         try {
-            if (Strings.isEmpty(expression)) {
+            pe = prepare(e);
-                bus.post(new CalculationFinishedEvent(operation, expression, sequence));
-                return;
-            }
-            preparedExpression = prepareExpression(expression);
-
-            final String jsclExpression = preparedExpression.toString();
 
             try {
-                final MathEngine mathEngine = Locator.getInstance().getEngine().getMathEngine();
+                Locator.getInstance().getEngine().getMathEngine().setMessageRegistry(mr);
 
-                final MessageRegistry messageRegistry = new ListMessageRegistry();
+                final Generic result = o.evaluateGeneric(pe.value, mathEngine);
-                Locator.getInstance().getEngine().getMathEngine().setMessageRegistry(messageRegistry);
-
-                final Generic result = operation.evaluateGeneric(jsclExpression, mathEngine);
 
                 // NOTE: toString() method must be called here as ArithmeticOperationException may occur in it (just to avoid later check!)
+                //noinspection ResultOfMethodCallIgnored
                 result.toString();
 
-                if (messageRegistry.hasMessage()) {
+                final String stringResult = o.getFromProcessor().process(result);
-                    try {
+                bus.post(new CalculationFinishedEvent(o, e, sequence, result, stringResult, collectMessages(mr)));
-                        final List<Message> messages = new ArrayList<>();
-                        while (messageRegistry.hasMessage()) {
-                            messages.add(messageRegistry.getMessage());
-                        }
-                        if (!messages.isEmpty()) {
-                            fireCalculatorEvent(newCalculationEventData(operation, expression, sequence), CalculatorEventType.calculation_messages, messages);
-                        }
-                    } catch (Throwable e) {
-                        // todo serso: not good but we need proper synchronization
-                        Log.e("Calculator", e.getMessage(), e);
-                    }
-                }
 
-                final String stringResult = operation.getFromProcessor().process(result);
+            } catch (JsclArithmeticException exception) {
-                bus.post(new CalculationFinishedEvent(operation, expression, sequence, result, stringResult));
+                if (o == JsclOperation.numeric && exception.getCause() instanceof NumeralBaseException) {
-
+                    evaluateAsync(sequence, JsclOperation.simplify, e, mr);
-            } catch (JsclArithmeticException e) {
-                if (operation == JsclOperation.numeric && e.getCause() instanceof NumeralBaseException) {
-                    evaluateAsync(sequence, JsclOperation.simplify, expression, mr);
                 } else {
-                    bus.post(new CalculationFailedEvent(operation, expression, sequence, e));
+                    bus.post(new CalculationFailedEvent(o, e, sequence, exception));
                 }
             }
-        } catch (ArithmeticException e) {
+        } catch (ArithmeticException exception) {
-            handleException(sequence, operation, expression, mr, preparedExpression, new ParseException(expression, new CalculatorMessage(CalculatorMessages.msg_001, MessageType.error, e.getMessage())));
+            onException(sequence, o, e, mr, pe, new ParseException(e, new CalculatorMessage(CalculatorMessages.msg_001, MessageType.error, exception.getMessage())));
-        } catch (StackOverflowError e) {
+        } catch (StackOverflowError exception) {
-            handleException(sequence, operation, expression, mr, preparedExpression, new ParseException(expression, new CalculatorMessage(CalculatorMessages.msg_002, MessageType.error)));
+            onException(sequence, o, e, mr, pe, new ParseException(e, new CalculatorMessage(CalculatorMessages.msg_002, MessageType.error)));
-        } catch (jscl.text.ParseException e) {
+        } catch (jscl.text.ParseException exception) {
-            handleException(sequence, operation, expression, mr, preparedExpression, new ParseException(e));
+            onException(sequence, o, e, mr, pe, new ParseException(exception));
-        } catch (ParseInterruptedException e) {
+        } catch (ParseInterruptedException exception) {
-            bus.post(new CalculationCancelledEvent(operation, expression, sequence));
+            bus.post(new CalculationCancelledEvent(o, e, sequence));
-        } catch (ParseException e) {
+        } catch (ParseException exception) {
-            handleException(sequence, operation, expression, mr, preparedExpression, e);
+            onException(sequence, o, e, mr, pe, exception);
         }
     }
 
+    @Nonnull
+    private List<Message> collectMessages(@Nonnull MessageRegistry mr) {
+        if (mr.hasMessage()) {
+            try {
+                final List<Message> messages = new ArrayList<>();
+                while (mr.hasMessage()) {
+                    messages.add(mr.getMessage());
+                }
+                return messages;
+            } catch (Throwable exception) {
+                // several threads might use the same instance of MessageRegistry, as no proper synchronization is done
+                // catch Throwable here
+                Log.e("Calculator", exception.getMessage(), exception);
+            }
+        }
+        return Collections.emptyList();
+    }
+
     private void checkPreferredPreferences() {
         if (shouldCheckPreferredPreferences()) {
             preferredPreferences.check(false);
@@ -298,30 +302,23 @@ public class Calculator implements CalculatorEventListener, SharedPreferences.On
     }
 
     @Nonnull
-    public PreparedExpression prepareExpression(@Nonnull String expression) throws ParseException {
+    public PreparedExpression prepare(@Nonnull String expression) throws ParseException {
         return preprocessor.process(expression);
     }
 
-    @Nonnull
+    private void onException(long sequence,
-    private CalculatorEventData newCalculationEventData(@Nonnull JsclOperation operation,
+                             @Nonnull JsclOperation operation,
-                                                        @Nonnull String expression,
+                             @Nonnull String e,
-                                                        @Nonnull Long calculationId) {
+                             @Nonnull MessageRegistry mr,
-        return new CalculatorEvaluationEventDataImpl(nextEventData(calculationId), operation, expression);
+                             @Nullable PreparedExpression pe,
-    }
+                             @Nonnull ParseException parseException) {
-
-    private void handleException(long sequence,
-                                 @Nonnull JsclOperation operation,
-                                 @Nonnull String expression,
-                                 @Nullable MessageRegistry mr,
-                                 @Nullable PreparedExpression preparedExpression,
-                                 @Nonnull ParseException parseException) {
         if (operation == JsclOperation.numeric
-                && preparedExpression != null
+                && pe != null
-                && preparedExpression.isExistsUndefinedVar()) {
+                && pe.hasUndefinedVariables()) {
-            evaluateAsync(sequence, JsclOperation.simplify, expression, mr);
+            evaluateAsync(sequence, JsclOperation.simplify, e, mr);
-        } else {
+            return;
-            bus.post(new CalculationFailedEvent(operation, expression, sequence, parseException));
         }
+        bus.post(new CalculationFailedEvent(operation, e, sequence, parseException));
     }
 
     @Nonnull
@@ -423,9 +420,9 @@ public class Calculator implements CalculatorEventListener, SharedPreferences.On
 
     private void updateAnsVariable(@NonNull String value) {
         final VariablesRegistry variablesRegistry = Locator.getInstance().getEngine().getVariablesRegistry();
-        final IConstant variable = variablesRegistry.get(VariablesRegistry.ANS);
+        final IConstant variable = variablesRegistry.get(Constants.ANS);
 
-        final CppVariable.Builder b = variable != null ? CppVariable.builder(variable) : CppVariable.builder(VariablesRegistry.ANS);
+        final CppVariable.Builder b = variable != null ? CppVariable.builder(variable) : CppVariable.builder(Constants.ANS);
         b.withValue(value);
         b.withSystem(true);
         b.withDescription(CalculatorMessages.getBundle().getString(CalculatorMessages.ans_description));
@@ -460,7 +457,7 @@ public class Calculator implements CalculatorEventListener, SharedPreferences.On
 
     @Subscribe
     public void onVariableChanged(@NonNull VariablesRegistry.ChangedEvent e) {
-        if (!e.newVariable.getName().equals(VariablesRegistry.ANS)) {
+        if (!e.newVariable.getName().equals(Constants.ANS)) {
             evaluate();
         }
     }
@@ -468,9 +465,6 @@ public class Calculator implements CalculatorEventListener, SharedPreferences.On
     @Override
     public void onCalculatorEvent(@Nonnull CalculatorEventData calculatorEventData, @Nonnull CalculatorEventType calculatorEventType, @Nullable Object data) {
         switch (calculatorEventType) {
-            case calculation_messages:
-                FixableErrorsActivity.show(App.getApplication(), (List<Message>) data);
-                break;
             case show_history:
                 ActivityLauncher.showHistory(App.getApplication());
                 break;
@@ -520,4 +514,7 @@ public class Calculator implements CalculatorEventListener, SharedPreferences.On
         }
     }
 
+    public static long nextSequence() {
+        return SEQUENCER.incrementAndGet();
+    }
 }

app/src/main/java/org/solovyev/android/calculator/CalculatorUtils.java

@@ -22,15 +22,14 @@
 
 package org.solovyev.android.calculator;
 
-import java.util.HashSet;
-import java.util.Set;
-
-import javax.annotation.Nonnull;
-
 import jscl.math.Generic;
 import jscl.math.function.Constant;
 import jscl.math.function.IConstant;
 
+import javax.annotation.Nonnull;
+import java.util.HashSet;
+import java.util.Set;
+
 /**
  * User: serso
  * Date: 9/22/12
@@ -38,15 +37,13 @@ import jscl.math.function.IConstant;
  */
 public final class CalculatorUtils {
 
-    static final long FIRST_ID = 0;
-
     private CalculatorUtils() {
         throw new AssertionError();
     }
 
     @Nonnull
     public static CalculatorEventData createFirstEventDataId() {
-        return CalculatorEventDataImpl.newInstance(FIRST_ID, FIRST_ID);
+        return CalculatorEventDataImpl.newInstance(Calculator.NO_SEQUENCE, Calculator.NO_SEQUENCE);
     }
 
     @Nonnull

app/src/main/java/org/solovyev/android/calculator/Display.java

@@ -22,6 +22,8 @@
 
 package org.solovyev.android.calculator;
 
+import android.app.Application;
+import android.content.Context;
 import android.view.ContextMenu;
 import android.view.MenuItem;
 import android.view.View;
@@ -33,6 +35,7 @@ import org.solovyev.android.Check;
 import org.solovyev.android.calculator.calculations.CalculationCancelledEvent;
 import org.solovyev.android.calculator.calculations.CalculationFailedEvent;
 import org.solovyev.android.calculator.calculations.CalculationFinishedEvent;
+import org.solovyev.android.calculator.errors.FixableErrorsActivity;
 import org.solovyev.android.calculator.jscl.JsclOperation;
 import org.solovyev.android.calculator.view.NumeralBaseConverterDialog;
 
@@ -53,6 +56,8 @@ public class Display implements CalculatorEventListener, View.OnClickListener, V
     @Nonnull
     private final Bus bus;
     @Inject
+    Application application;
+    @Inject
     Lazy<Keyboard> keyboard;
     @Inject
     Lazy<Clipboard> clipboard;
@@ -84,6 +89,10 @@ public class Display implements CalculatorEventListener, View.OnClickListener, V
     public void onCalculationFinished(@Nonnull CalculationFinishedEvent e) {
         if (e.sequence < state.sequence) return;
         setState(DisplayState.createValid(e.operation, e.result, e.stringResult, e.sequence));
+        if (!e.messages.isEmpty()) {
+            final Context context = view != null ? view.getContext() : application;
+            FixableErrorsActivity.show(context, e.messages);
+        }
     }
 
     @Subscribe

app/src/main/java/org/solovyev/android/calculator/DisplayState.java

@@ -64,18 +64,18 @@ public class DisplayState implements Parcelable, ContextMenu.ContextMenuInfo {
     }
 
     DisplayState(@Nonnull JSONObject json) {
-        this(json.optString(JSON_TEXT), true, EditorState.NO_SEQUENCE);
+        this(json.optString(JSON_TEXT), true, Calculator.NO_SEQUENCE);
     }
 
     private DisplayState(Parcel in) {
         text = in.readString();
         valid = in.readByte() != 0;
-        sequence = EditorState.NO_SEQUENCE;
+        sequence = Calculator.NO_SEQUENCE;
     }
 
     @Nonnull
     public static DisplayState empty() {
-        return new DisplayState("", true, EditorState.NO_SEQUENCE);
+        return new DisplayState("", true, Calculator.NO_SEQUENCE);
     }
 
     @Nonnull

app/src/main/java/org/solovyev/android/calculator/EditorState.java

@@ -25,18 +25,14 @@ package org.solovyev.android.calculator;
 import android.os.Parcel;
 import android.os.Parcelable;
 import android.text.TextUtils;
-
 import org.json.JSONException;
 import org.json.JSONObject;
 
-import java.util.concurrent.atomic.AtomicLong;
-
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
 public class EditorState implements Parcelable {
 
-    public static final long NO_SEQUENCE = -1;
     public static final Creator<EditorState> CREATOR = new Creator<EditorState>() {
         @Override
         public EditorState createFromParcel(Parcel in) {
@@ -50,7 +46,6 @@ public class EditorState implements Parcelable {
     };
     private static final String JSON_TEXT = "t";
     private static final String JSON_SELECTION = "s";
-    private static AtomicLong counter = new AtomicLong(NO_SEQUENCE + 1);
     public final long sequence;
     @Nonnull
     public final CharSequence text;
@@ -63,7 +58,7 @@ public class EditorState implements Parcelable {
     }
 
     private EditorState(@Nonnull CharSequence text, int selection) {
-        this.sequence = counter.getAndIncrement();
+        this.sequence = Calculator.nextSequence();
         this.text = text;
         this.selection = selection;
     }
@@ -73,7 +68,7 @@ public class EditorState implements Parcelable {
     }
 
     private EditorState(Parcel in) {
-        sequence = NO_SEQUENCE;
+        sequence = Calculator.NO_SEQUENCE;
         selection = in.readInt();
         textString = in.readString();
         text = textString;

app/src/main/java/org/solovyev/android/calculator/PreparedExpression.java

@@ -31,48 +31,43 @@ import java.util.List;
 public class PreparedExpression implements CharSequence {
 
     @Nonnull
-    private String expression;
+    public final String value;
 
     @Nonnull
-    private List<IConstant> undefinedVars;
+    public final List<IConstant> undefinedVariables;
 
-    public PreparedExpression(@Nonnull String expression, @Nonnull List<IConstant> undefinedVars) {
+    public PreparedExpression(@Nonnull String value, @Nonnull List<IConstant> undefinedVariables) {
-        this.expression = expression;
+        this.value = value;
-        this.undefinedVars = undefinedVars;
+        this.undefinedVariables = undefinedVariables;
     }
 
     @Nonnull
-    public String getExpression() {
+    public String getValue() {
-        return expression;
+        return value;
     }
 
-    public boolean isExistsUndefinedVar() {
+    public boolean hasUndefinedVariables() {
-        return !this.undefinedVars.isEmpty();
+        return !undefinedVariables.isEmpty();
-    }
-
-    @Nonnull
-    public List<IConstant> getUndefinedVars() {
-        return undefinedVars;
     }
 
     @Override
     public int length() {
-        return expression.length();
+        return value.length();
     }
 
     @Override
     public char charAt(int i) {
-        return expression.charAt(i);
+        return value.charAt(i);
     }
 
     @Override
     public CharSequence subSequence(int i, int i1) {
-        return expression.subSequence(i, i1);
+        return value.subSequence(i, i1);
     }
 
     @NonNull
     @Override
     public String toString() {
-        return this.expression;
+        return this.value;
     }
 }

app/src/main/java/org/solovyev/android/calculator/VariablesRegistry.java

@@ -52,9 +52,6 @@ import java.util.Map;
 @Singleton
 public class VariablesRegistry extends BaseEntitiesRegistry<IConstant> {
 
-    @Nonnull
-    public static final String ANS = "ans";
-
     @Nonnull
     private static final Map<String, String> substitutes = new HashMap<>();
 

app/src/main/java/org/solovyev/android/calculator/calculations/CalculationFinishedEvent.java

@@ -2,25 +2,32 @@ package org.solovyev.android.calculator.calculations;
 
 import jscl.math.Generic;
 import org.solovyev.android.calculator.jscl.JsclOperation;
+import org.solovyev.common.msg.Message;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
+import java.util.Collections;
+import java.util.List;
 
 public final class CalculationFinishedEvent extends BaseCalculationEvent {
     @Nullable
     public final Generic result;
     @Nonnull
     public final String stringResult;
+    @Nonnull
+    public final List<Message> messages;
 
     public CalculationFinishedEvent(@Nonnull JsclOperation operation, @Nonnull String expression, long sequence) {
         super(operation, expression, sequence);
         result = null;
         stringResult = "";
+        messages = Collections.emptyList();
     }
 
-    public CalculationFinishedEvent(@Nonnull JsclOperation operation, @Nonnull String expression, long sequence, @Nullable Generic result, @Nonnull String stringResult) {
+    public CalculationFinishedEvent(@Nonnull JsclOperation operation, @Nonnull String expression, long sequence, @Nullable Generic result, @Nonnull String stringResult, @Nonnull List<Message> messages) {
         super(operation, expression, sequence);
         this.result = result;
         this.stringResult = stringResult;
+        this.messages = messages;
     }
 }

app/src/main/java/org/solovyev/android/calculator/functions/EditFunctionFragment.java

@@ -271,7 +271,7 @@ public class EditFunctionFragment extends BaseDialogFragment implements View.OnC
 
     private boolean applyData() {
         try {
-            final String body = calculator.prepareExpression(bodyView.getText().toString()).getExpression();
+            final String body = calculator.prepare(bodyView.getText().toString()).getValue();
 
             final CppFunction newFunction = CppFunction.builder(nameView.getText().toString(), body)
                     .withId(isNewFunction() ? NO_ID : function.id)
@@ -326,7 +326,7 @@ public class EditFunctionFragment extends BaseDialogFragment implements View.OnC
             return false;
         }
         try {
-            calculator.prepareExpression(body);
+            calculator.prepare(body);
             clearError(bodyLabel);
             return true;
         } catch (ParseException e) {

app/src/main/java/org/solovyev/android/calculator/history/History.java

@@ -100,7 +100,7 @@ public class History {
             final OldDisplayHistoryState oldDisplay = state.getDisplayState();
             final String editorText = oldEditor.getText();
             final EditorState editor = EditorState.create(Strings.nullToEmpty(editorText), oldEditor.getCursorPosition());
-            final DisplayState display = DisplayState.createValid(oldDisplay.getJsclOperation(), null, Strings.nullToEmpty(oldDisplay.getEditorState().getText()), EditorState.NO_SEQUENCE);
+            final DisplayState display = DisplayState.createValid(oldDisplay.getJsclOperation(), null, Strings.nullToEmpty(oldDisplay.getEditorState().getText()), Calculator.NO_SEQUENCE);
             states.add(HistoryState.builder(editor, display).withTime(state.getTime()).withComment(state.getComment()).build());
         }
         return states;

app/src/main/java/org/solovyev/android/calculator/variables/VariablesFragment.java

@@ -61,9 +61,8 @@ public class VariablesFragment extends BaseEntitiesFragment<IConstant> {
 
     public static boolean isValidValue(@Nonnull String value) {
         try {
-            final PreparedExpression expression = ToJsclTextProcessor.getInstance().process(value);
+            final PreparedExpression pe = ToJsclTextProcessor.getInstance().process(value);
-            final List<IConstant> variables = expression.getUndefinedVars();
+            return !pe.hasUndefinedVariables();
-            return variables.isEmpty();
         } catch (RuntimeException e) {
             return false;
         }

app/src/main/java/org/solovyev/android/calculator/view/NumeralBaseConverterDialog.java

@@ -57,7 +57,7 @@ public class NumeralBaseConverterDialog {
         if (!Strings.isEmpty(initialFromValue)) {
             String value = initialFromValue;
             try {
-                value = ToJsclTextProcessor.getInstance().process(value).getExpression();
+                value = ToJsclTextProcessor.getInstance().process(value).getValue();
                 b.setFromValue(UnitImpl.newInstance(value, CalculatorNumeralBase.valueOf(Locator.getInstance().getEngine().getMathEngine().getNumeralBase())));
             } catch (ParseException e) {
                 b.setFromValue(UnitImpl.newInstance(value, CalculatorNumeralBase.valueOf(Locator.getInstance().getEngine().getMathEngine().getNumeralBase())));

app/src/test/java/org/solovyev/android/calculator/model/AndroidEngineTest.java

@@ -90,7 +90,7 @@ public class AndroidEngineTest extends AbstractCalculatorTest {
     }
 
     @Test
-    public void testI() throws ParseException, EvalException {
+    public void testI() throws ParseException {
         final MathEngine cm = Locator.getInstance().getEngine().getMathEngine();
 
         CalculatorTestUtils.assertEval("-i", cm.evaluate("i^3"));

app/src/test/java/org/solovyev/android/calculator/model/NumeralBaseTest.java

@@ -22,26 +22,24 @@
 
 package org.solovyev.android.calculator.model;
 
-import org.junit.Assert;
-import org.junit.BeforeClass;
-import org.junit.Test;
-import org.solovyev.android.calculator.AbstractCalculatorTest;
-import org.solovyev.android.calculator.ParseException;
-import org.solovyev.android.calculator.CalculatorTestUtils;
-import org.solovyev.android.calculator.Locator;
-import org.solovyev.common.Converter;
-
-import java.io.InputStreamReader;
-import java.util.ArrayList;
-import java.util.List;
-
-import javax.annotation.Nonnull;
-
 import au.com.bytecode.opencsv.CSVReader;
 import jscl.JsclMathEngine;
 import jscl.MathEngine;
 import jscl.math.Expression;
 import jscl.util.ExpressionGeneratorWithInput;
+import org.junit.Assert;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.solovyev.android.calculator.AbstractCalculatorTest;
+import org.solovyev.android.calculator.CalculatorTestUtils;
+import org.solovyev.android.calculator.Locator;
+import org.solovyev.android.calculator.ParseException;
+import org.solovyev.common.Converter;
+
+import javax.annotation.Nonnull;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+import java.util.List;
 
 /**
  * User: serso
@@ -56,7 +54,7 @@ public class NumeralBaseTest extends AbstractCalculatorTest {
         Locator.getInstance().getEngine().getMathEngine().setPrecision(3);
     }
 
-    public static void testExpression(@Nonnull String[] line, @Nonnull Converter<String, String> converter) throws jscl.text.ParseException, EvalException, ParseException {
+    public static void testExpression(@Nonnull String[] line, @Nonnull Converter<String, String> converter) throws jscl.text.ParseException, ParseException {
         final String dec = line[0].toUpperCase();
         final String hex = "0x:" + line[1].toUpperCase();
         final String bin = "0b:" + line[2].toUpperCase();

app/src/test/java/org/solovyev/android/calculator/model/ToJsclTextProcessorTest.java

@@ -149,7 +149,7 @@ public class ToJsclTextProcessorTest extends AbstractCalculatorTest {
             Assert.assertEquals("101", JsclMathEngine.getInstance().evaluate("10+11"));
 
             JsclMathEngine.getInstance().setNumeralBase(NumeralBase.hex);
-            Assert.assertEquals("56CE+CAD", processor.process("56CE+CAD").getExpression());
+            Assert.assertEquals("56CE+CAD", processor.process("56CE+CAD").getValue());
         } finally {
             JsclMathEngine.getInstance().setNumeralBase(defaultNumeralBase);
         }

jscl/src/main/java/jscl/JsclMathEngine.java

@@ -16,7 +16,6 @@ import org.solovyev.common.msg.MessageRegistry;
 import org.solovyev.common.msg.Messages;
 
 import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
 import java.math.BigDecimal;
 import java.text.DecimalFormat;
 import java.text.DecimalFormatSymbols;
@@ -168,19 +167,16 @@ public class JsclMathEngine implements MathEngine {
 
                     // detect if current number is precisely equals to constant in constants' registry  (NOTE: ONLY FOR SYSTEM CONSTANTS)
                     final Double localValue = value;
-                    IConstant constant = Collections.find(this.getConstantsRegistry().getSystemEntities(), new JPredicate<IConstant>() {
+                    IConstant constant = Collections.find(getConstantsRegistry().getSystemEntities(), new JPredicate<IConstant>() {
-                        public boolean apply(@Nullable IConstant constant) {
+                        public boolean apply(@Nonnull IConstant constant) {
-                            if (constant != null) {
+                            if (!localValue.equals(constant.getDoubleValue())) {
-                                if (localValue.equals(constant.getDoubleValue())) {
+                                return false;
-                                    if (!constant.getName().equals(Constants.PI_INV.getName())) {
-                                        if (!constant.getName().equals(Constants.PI.getName()) || JsclMathEngine.getInstance().getAngleUnits() == AngleUnit.rad) {
-                                            return true;
-                                        }
-                                    }
-                                }
                             }
-
+                            final String name = constant.getName();
-                            return false;
+                            if (name.equals(Constants.PI_INV.getName()) || name.equals(Constants.ANS)) {
+                                return false;
+                            }
+                            return !name.equals(Constants.PI.getName()) || JsclMathEngine.getInstance().getAngleUnits() == AngleUnit.rad;
                         }
                     });
 

jscl/src/main/java/jscl/math/function/Constants.java

@@ -2,6 +2,8 @@ package jscl.math.function;
 
 import jscl.math.JsclInteger;
 
+import javax.annotation.Nonnull;
+
 /**
  * User: serso
  * Date: 1/7/12
@@ -14,6 +16,8 @@ public final class Constants {
     public static final Constant I = new Constant("i");
     public static final Constant INF = new Constant("∞");
     public static final Constant INF_2 = new Constant("Infinity");
+    @Nonnull
+    public static final String ANS = "ans";
 
     // not intended for instantiation
     private Constants() {