Add line wrapping support to the terminal

src/interpreter/FileLispInterpreter.java

@@ -0,0 +1,5 @@
+package interpreter;
+
+public class FileLispInterpreter extends LispInterpreter {
+
+}

src/interpreter/LispInterpreter.java

@@ -7,7 +7,7 @@ import error.LispException;
 import parser.LispParser;
 import sexpression.SExpression;
 
-public class LispInterpreter {
+public abstract class LispInterpreter {
 
     protected RuntimeEnvironment environment;
     private LispParser parser;

src/interpreter/LispInterpreterBuilderImpl.java

@@ -166,7 +166,7 @@ public class LispInterpreterBuilderImpl implements LispInterpreterBuilder {
     }
 
     private LispInterpreter createInterpreter() {
-        return isInteractive ? new InteractiveLispInterpreter() : new LispInterpreter();
+        return isInteractive ? new InteractiveLispInterpreter() : new FileLispInterpreter();
     }
 
     public static class InterpreterAlreadyBuiltException extends CriticalLispException {

src/terminal/LispTerminal.java

@@ -11,6 +11,7 @@ public class LispTerminal implements Runnable {
     private IOSafeTerminal terminal;
     private boolean isFinished;
     private String currentLine;
+    private TerminalPosition origin;
 
     public LispTerminal() {
         try {
@@ -23,6 +24,7 @@ public class LispTerminal implements Runnable {
 
         this.isFinished = false;
         this.currentLine = "";
+        this.origin = terminal.getCursorPosition();
     }
 
     public void run() {
@@ -71,42 +73,80 @@ public class LispTerminal implements Runnable {
     private void doEnter() {
         terminal.putCharacter('\n');
         currentLine = "";
+        origin = terminal.getCursorPosition();
     }
 
     private void moveCursorLeft() {
         TerminalPosition cursorPosition = terminal.getCursorPosition();
-        terminal.setCursorPosition(cursorPosition.withRelativeColumn(-1));
+
+        if (isPossibleToMoveLeft(cursorPosition))
+            if (cursorPosition.getColumn() == 0)
+                terminal.setCursorPosition(terminal.getTerminalSize().getColumns(), cursorPosition.getRow() - 1);
+            else
+                terminal.setCursorPosition(cursorPosition.withRelativeColumn(-1));
+    }
+
+    private boolean isPossibleToMoveLeft(TerminalPosition cursorPosition) {
+        return distanceFromOrigin(cursorPosition) > 0;
+    }
+
+    private int distanceFromOrigin(TerminalPosition cursorPosition) {
+        return cursorPosition.getColumn()
+               + (terminal.getTerminalSize().getColumns() * (cursorPosition.getRow() - origin.getRow()));
     }
 
     private void moveCursorRight() {
         TerminalPosition cursorPosition = terminal.getCursorPosition();
 
-        if (cursorPosition.getColumn() < currentLine.length())
+        if (isPossibleToMoveRight(cursorPosition))
+            advanceCursor(cursorPosition);
+    }
+
+    private void advanceCursor(TerminalPosition cursorPosition) {
+        if (isCursorAtEndOfRow(cursorPosition))
+            terminal.setCursorPosition(0, cursorPosition.getRow() + 1);
+        else
             terminal.setCursorPosition(cursorPosition.withRelativeColumn(1));
     }
 
+    private boolean isCursorAtEndOfRow(TerminalPosition cursorPosition) {
+        return cursorPosition.getColumn() == terminal.getTerminalSize().getColumns() - 1;
+    }
+
+    private boolean isPossibleToMoveRight(TerminalPosition cursorPosition) {
+        return distanceFromOrigin(cursorPosition) < currentLine.length();
+    }
+
     private void doBackspace() {
         TerminalPosition cursorPosition = terminal.getCursorPosition();
 
-        if (cursorPosition.getColumn() > 0) {
+        if (isPossibleToMoveLeft(cursorPosition)) {
-            String remaining = currentLine.substring(cursorPosition.getColumn(), currentLine.length());
+            String remaining = currentLine.substring(distanceFromOrigin(cursorPosition), currentLine.length());
-            currentLine = currentLine.substring(0, cursorPosition.getColumn() - 1) + remaining;
+            currentLine = currentLine.substring(0, distanceFromOrigin(cursorPosition) - 1) + remaining;
-            terminal.setCursorPosition(cursorPosition.withRelativeColumn(-1));
+
+            if (cursorPosition.getColumn() == 0)
+                terminal.setCursorPosition(terminal.getTerminalSize().getColumns(), cursorPosition.getRow() - 1);
+            else
+                terminal.setCursorPosition(cursorPosition.withRelativeColumn(-1));
 
             for (char c : remaining.toCharArray())
                 terminal.putCharacter(c);
 
             terminal.putCharacter(' ');
-            terminal.setCursorPosition(cursorPosition.withRelativeColumn(-1));
+
+            if (cursorPosition.getColumn() == 0)
+                terminal.setCursorPosition(terminal.getTerminalSize().getColumns(), cursorPosition.getRow() - 1);
+            else
+                terminal.setCursorPosition(cursorPosition.withRelativeColumn(-1));
         }
     }
 
     private void doDelete() {
         TerminalPosition cursorPosition = terminal.getCursorPosition();
 
-        if (cursorPosition.getColumn() < currentLine.length()) {
+        if (isPossibleToMoveRight(cursorPosition)) {
-            String remaining = currentLine.substring(cursorPosition.getColumn() + 1, currentLine.length());
+            String remaining = currentLine.substring(distanceFromOrigin(cursorPosition) + 1, currentLine.length());
-            currentLine = currentLine.substring(0, cursorPosition.getColumn()) + remaining;
+            currentLine = currentLine.substring(0, distanceFromOrigin(cursorPosition)) + remaining;
 
             for (char c : remaining.toCharArray())
                 terminal.putCharacter(c);
@@ -119,18 +159,20 @@ public class LispTerminal implements Runnable {
     private void doCharacter(KeyStroke keyStroke) {
         TerminalPosition cursorPosition = terminal.getCursorPosition();
 
-        if (cursorPosition.getColumn() < currentLine.length()) {
+        if (isPossibleToMoveRight(cursorPosition)) {
             String remaining = keyStroke.getCharacter()
-                               + currentLine.substring(cursorPosition.getColumn(), currentLine.length());
+                               + currentLine.substring(distanceFromOrigin(cursorPosition), currentLine.length());
-            currentLine = currentLine.substring(0, cursorPosition.getColumn()) + remaining;
+            currentLine = currentLine.substring(0, distanceFromOrigin(cursorPosition)) + remaining;
 
             for (char c : remaining.toCharArray())
                 terminal.putCharacter(c);
 
-            terminal.setCursorPosition(cursorPosition.withRelativeColumn(1));
+            advanceCursor(cursorPosition);
         } else {
             terminal.putCharacter(keyStroke.getCharacter());
             currentLine += keyStroke.getCharacter();
+
+            advanceCursor(cursorPosition);
         }
     }