Exercise finished

src/Spreadsheet.java

@@ -1,18 +1,105 @@
+import java.util.HashMap;
 
 public class Spreadsheet {
-
+	private String error = "#Error";
+	HashMap<String, Object> sheet = new HashMap<String, Object>();
+
+	public static boolean isNumeric(String str)
+	{
+	  return str.matches("-?\\d+");  //match a number with optional '-' and decimal.
+	}
+
+	public static boolean isAlphaNumeric(String str) {
+		return str.matches("-?[a-zA-Z0-9]+");
+	}
+
+	public static boolean containsNumeric(String str) { 
+		return str.matches(".*\\d.*");
+	}
+
+	public static boolean isString(String str) {
+		return str.matches("'.*'");
+	}
+
+	public static boolean isBroken(String str) {
+		if(str.matches("'.*[^\\']")) {
+			return true;
+		}
+		if(str.matches("[^\\'=].*'")) {
+			return true;
+		}
+		if(str.matches("='.*[^\\']")) {
+			return true;
+		}
+		if(str.matches("=[^\\'].*'")) {
+			return true;
+		}
+		return false;
+	}
+
+	public static boolean isFormula(String str) {
+		return str.matches("=.*");
+	}
+
+	public static boolean isStringFormula(String str) {
+		return str.matches("=\\'.*\\'");
+	}
+
+	public static boolean isIntegerFormula(String str) {
+		return str.matches("=\\d+");
+	}
+
+	public static boolean isReference(String str) {
+		return str.matches("=[A-Za-z][0-9]+");
+	}
+
 	public String get(String cell) {
 		// to be implemented
-		return null;
+		return sheet.get(cell).toString();
 	}
 
 	public void set(String cell, String value) {
 		// to be implemented
+		sheet.put(cell, value);
+	}
+
+	private Object evaluateFormula(String formula) {
+		if(Spreadsheet.isIntegerFormula(formula)) {
+			return Integer.parseInt(formula.substring(1, formula.length()));
+		} else {
+			if(Spreadsheet.isReference(formula)) {
+				String reffed = get(formula.substring(1, formula.length()));
+				return reffed.substring(1, reffed.length() - 1);
+			} else {
+				return formula.substring(2, formula.length() - 1);
+			}
+		}
 	}
 
-	public String evaluate(String cell) {
+	public Object evaluate(String cell) {
 		// to be implemented
-		return null;
+		Object v = sheet.get(cell);
+		String sv = v.toString();
+		if(Spreadsheet.isAlphaNumeric(sv)) {
+			if(Spreadsheet.isNumeric(sv)) {
+				return Integer.parseInt(sv);
+			} else {
+				if(Spreadsheet.containsNumeric(sv)) {
+					return error;
+				} 
+			}
+		} else {
+			if(Spreadsheet.isBroken(sv)) {
+				return error;
+			}
+			if(Spreadsheet.isFormula(sv)) {
+				return evaluateFormula(sv);
+			}
+			if(Spreadsheet.isString(sv)) {
+				return sv.substring(1,  sv.length()- 1);
+			}
+		}
+		return v;
 	}
 
 }

tests/SpreadsheetTest.java

@@ -1,15 +1,81 @@
 import static org.junit.Assert.*;
 
-
+import org.junit.Before;
 import org.junit.Test;
 
 
 public class SpreadsheetTest {
+	Spreadsheet shiaat;
+	@Before
+	public void initialization() {
+		shiaat = new Spreadsheet();
+	}
 
+
+	@Test
+	public void test_setGetFunctionInteger() {
+		shiaat.set("A1", "45");
+		assertEquals(45, shiaat.evaluate("A1"));
+	}
+
+	@Test
+	public void test_setGetFunctionIntegerNegative() {
+		shiaat.set("A1", "-45");
+		assertEquals(-45, shiaat.evaluate("A1"));
+	}
+
 	@Test
-	public void test() {
-		fail("Not yet implemented");
-
+	public void test_setGetFunctionIntegerBad() {
+		shiaat.set("A1", "45A");
+		assertEquals("#Error", shiaat.evaluate("A1"));
+	}
+
+	@Test
+	public void test_setGetFunctionString() {
+		shiaat.set("A1", "'45A'");
+		assertEquals("45A", shiaat.evaluate("A1"));
+	}
+
+	@Test
+	public void test_setGetFunctionInvalidString1() {
+		shiaat.set("A1", "'45A");
+		assertEquals("#Error", shiaat.evaluate("A1"));
 	}
 
+	@Test
+	public void test_setGetFunctionInvalidString2() {
+		shiaat.set("A1", "45A'");
+		assertEquals("#Error", shiaat.evaluate("A1"));
+	}
+
+	@Test
+	public void test_setGetFunctionIntegerFormula() {
+		shiaat.set("A1", "=45");
+		assertEquals(45, shiaat.evaluate("A1"));
+	}
+
+	@Test
+	public void test_setGetFunctionStringFormula() {
+		shiaat.set("A1", "='45A'");
+		assertEquals("45A", shiaat.evaluate("A1"));
+	}
+
+	@Test
+	public void test_setGetFunctionStringFormulaBroken1() {
+		shiaat.set("A1", "=45A'");
+		assertEquals("#Error", shiaat.evaluate("A1"));
+	}
+
+	@Test
+	public void test_setGetFunctionStringFormulaBroken2() {
+		shiaat.set("A1", "='45A");
+		assertEquals("#Error", shiaat.evaluate("A1"));
+	}
+
+	@Test
+	public void test_setGetFunctionReference() {
+		shiaat.set("A1", "'Yo'");
+		shiaat.set("A2", "=A1");
+		assertEquals("Yo", shiaat.evaluate("A2"));
+	}
 }