todo 10

src/Spreadsheet.java

@@ -1,18 +1,146 @@
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Set;
 
 public class Spreadsheet {
+
+	private static final String CIRCULAR_TAG = "#Circular";
+	private static final String ERROR_TAG = "#Error";
+	HashMap<String, List<SubEntry>> cell_entries = new HashMap<>();
+	Set<Integer> references;
+	boolean circularDetected = false;
 
 	public String get(String cell) {
-		// to be implemented
-		return null;
+		return concatSubEntries(cell_entries.get(cell));
 	}
 
 	public void set(String cell, String value) {
-		// to be implemented
+		cell_entries.put(cell, createSubEntries(value));
 	}
 
 	public String evaluate(String cell) {
-		// to be implemented
-		return null;
+		references = new HashSet<>();
+		List<String> evaluatedSubEntries = new LinkedList<>();
+		for (SubEntry se : cell_entries.get(cell)) {
+			String evaluatedSubEntry = evaluateSubEntry(se);
+			if (evaluatedSubEntry.equals(ERROR_TAG))
+				return ERROR_TAG;
+			else
+				evaluatedSubEntries.add(evaluatedSubEntry);
+
+			if (circularDetected) {
+				return CIRCULAR_TAG;
+			}
+		}
+		String cell_entry = concatStrings(evaluatedSubEntries);
+
+		return cell_entry;
+	}
+
+	public String evaluateSubEntry(SubEntry se) {
+		if (se.getType() == SubEntryType.NUMBER && ! isNum(se.getValue())) {
+			return ERROR_TAG;
+		} else if (se.getType() == SubEntryType.REFERENCE) {
+			if (references.contains(Integer.valueOf(se.getValue()))) {
+				circularDetected = true;
+				return CIRCULAR_TAG;
+			} else {
+				references.add(Integer.valueOf(se.getValue()));
+				return evaluate("A" + se.getValue());
+			}
+		} else {
+			return se.getValue();
+		}
+	}
+
+	public String concatSubEntries(List<SubEntry> subEntries) {
+		String res = "";
+		for (SubEntry se : subEntries) {
+			res += se.getValue();
+		}
+		return res;
+	}
+
+	public String concatStrings(List<String> strings) {
+		String res = "";
+		for (String s : strings) {
+			res += s;
+		}
+		return res;
+	}
+
+	public List<SubEntry> createSubEntries(String cell) {
+		List<SubEntry> subEntries = new LinkedList<>();
+		String intSubEntry = "";
+		String strSubEntry = "";
+		String refValue = "";
+		boolean quotesOpen = false;
+		boolean refToCell = false;
+
+		for (int i = 0; i < cell.toCharArray().length; i++) {
+			char c = cell.toCharArray()[i];
+
+			// Check for "=" at the beginning of the cell value
+			if (i == 0 && c == '=')
+				continue;
+
+			if (refToCell) {
+				if (c != ' ') {
+					refValue += c;
+				} else {
+					refToCell = false;
+					subEntries.add(new SubEntry(refValue, SubEntryType.REFERENCE));
+					refValue = "";
+				}
+			} else if (quotesOpen == false) {
+				if (c == 'A') {
+					refToCell = true;
+					if (intSubEntry != "" || strSubEntry != "") {
+						subEntries.add(new SubEntry(ERROR_TAG, SubEntryType.ERROR));
+						intSubEntry = "";
+						strSubEntry = "";
+					}
+				} else if (c != '\'') {
+					intSubEntry += c;
+				} else {
+					if (intSubEntry != "")
+						subEntries.add(new SubEntry(intSubEntry, SubEntryType.NUMBER));
+					intSubEntry = "";
+					quotesOpen = true;
+				}
+			} else {
+				if (c != '\'') {
+					strSubEntry += c;
+				} else {
+					subEntries.add(new SubEntry(strSubEntry, SubEntryType.STRING));
+					strSubEntry = "";
+					quotesOpen = false;
+				}
+			}
+		}
+		if (intSubEntry != "")
+			subEntries.add(new SubEntry(intSubEntry, SubEntryType.NUMBER));
+		if (strSubEntry != "")
+			subEntries.add(new SubEntry(ERROR_TAG, SubEntryType.ERROR));
+		if (refToCell == true) {
+			if (refValue != "")
+				subEntries.add(new SubEntry(refValue, SubEntryType.REFERENCE));
+			else 
+				subEntries.add(new SubEntry(ERROR_TAG, SubEntryType.ERROR));
+		}
+
+		return subEntries;
+	}
+
+	public boolean isNum(String s) {
+		try {
+			Integer.valueOf(s);
+		} catch (NumberFormatException ex) {
+			return false;
+		}
+		return true;
 	}
 
 }

src/SubEntry.java

@@ -0,0 +1,27 @@
+
+public class SubEntry {
+	private String value;
+	private SubEntryType type;
+
+	public SubEntry(String value, SubEntryType type) {
+		this.value = value;
+		this.type = type;
+	}
+
+	public String getValue() {
+		return value;
+	}
+
+	public void setValue(String value) {
+		this.value = value;
+	}
+
+	public SubEntryType getType() {
+		return type;
+	}
+
+	public void setType(SubEntryType type) {
+		this.type = type;
+	}
+
+}

src/SubEntryType.java

@@ -0,0 +1,4 @@
+
+public enum SubEntryType {
+	NUMBER, STRING, REFERENCE, ERROR
+}

tests/SpreadsheetTest.java

@@ -1,15 +1,121 @@
 import static org.junit.Assert.*;
 
+import java.util.List;
 
 import org.junit.Test;
 
 
 public class SpreadsheetTest {
+	private static final String CIRCULAR_TAG = "#Circular";
+	private static final String ERROR_TAG = "#Error";
+	Spreadsheet spreadSheet = new Spreadsheet();
 
-	@Test
-	public void test() {
-		fail("Not yet implemented");
-
+
+	/*
+	 * 1
+	 */
+
+	@Test public void testSpreadsheet_SetA1_1_GetA1_String_1() {
+		spreadSheet.set("A1", "1");
+		assertEquals("1", spreadSheet.get("A1"));
+	}
+
+
+	/*
+	 * 2
+	 */
+
+	@Test public void testSpreadsheet_SetA1_1_EvalA1_String_1() {
+		spreadSheet.set("A1", "1");
+		assertEquals("1", spreadSheet.evaluate("A1"));
+	}
+
+
+	/*
+	 * 3
+	 */
+
+	@Test public void testSpreadsheet_SetA1_A5_EvalA1_ErrorString() {
+		spreadSheet.set("A1", "5A");
+		assertEquals(ERROR_TAG, spreadSheet.evaluate("A1"));
+	}
+
+
+	/*
+	 * 4
+	 */
+
+	@Test public void testSpreadsheet_SetA1_String_EvalA1_StringWithoutQuotes() {
+		spreadSheet.set("A1", "'a string'");
+		assertEquals("a string", spreadSheet.evaluate("A1"));
+	}
+
+
+	/*
+	 * 5
+	 */
+
+	@Test public void testSpreadsheet_SetA1WrongQuotedString_EvalA1_Error() {
+		spreadSheet.set("A1", "'a string");
+		assertEquals(ERROR_TAG, spreadSheet.evaluate("A1"));
+	}
+
+
+	/*
+	 * 6
+	 */
+
+	@Test public void testSpreadSheet_SetA1_EqualSignBeforeString_EvalA1_OnlyString() {
+		spreadSheet.set("A1", "='a string'");
+		assertEquals("a string", spreadSheet.evaluate("A1"));
+	}
+
+
+	/*
+	 * 7
+	 */
+
+	@Test public void testSpreadsheet_SetA1_EqualSignAndWrongQuotedString_EvalA1_Error() {
+		spreadSheet.set("A1", "='a string");
+		assertEquals(ERROR_TAG, spreadSheet.evaluate("A1"));
+	}
+
+
+	/*
+	 * 8
+	 */
+
+	@Test public void testSpreadSheet_createOneSubEntryWithReference_TypeOfSubEntry_REFERENCE() {
+		List<SubEntry> subEntries = spreadSheet.createSubEntries("=A5");
+		assertEquals(SubEntryType.REFERENCE, subEntries.get(0).getType());
+	}
+
+	@Test public void testSpreadSheet_Set_A5_5_And_A1_EqualA5_EvalA1_5() {
+		spreadSheet.set("A5", "5");
+		spreadSheet.set("A1", "=A5");
+		assertEquals("5", spreadSheet.evaluate("A1"));
+	}
+
+
+	/*
+	 * 9
+	 */
+
+	@Test public void testSpreadSheet_Set_A5_5A_And_A1_EqualA5_EvalA1_Error() {
+		spreadSheet.set("A5", "5A");
+		spreadSheet.set("A1", "=A5");
+		assertEquals(ERROR_TAG, spreadSheet.evaluate("A1"));
+	}
+
+
+	/*
+	 * 10
+	 */
+
+	@Test public void testSpreadSheet_Set_A5_EqualA1_And_A1_EqualA5_EvalA1_CircularTag() {
+		spreadSheet.set("A5", "=A1");
+		spreadSheet.set("A1", "=A5");
+		assertEquals(CIRCULAR_TAG, spreadSheet.evaluate("A1"));
 	}
 
 }