Remove Serializable from internals

A Java ClassLoader is not Serializable. Therefore we cannot
also make the PrologClassLoader Serializable.

We don't really need to serialize an interpreter, so also
throw away any support for that.

11 files changed, 9 insertions, 434 deletions

diff --git a/src/lang/BlockingPrologControl.java b/src/lang/BlockingPrologControl.java
index 5c3a242..e788982 100644
--- a/src/lang/BlockingPrologControl.java
+++ b/src/lang/BlockingPrologControl.java
@@ -1,7 +1,5 @@
 package com.googlecode.prolog_cafe.lang;
 
-import java.io.Serializable;
-
 /**
  * Prolog thread.<br>
  * The <code>BlockingPrologControl</code> class is an implementation of
@@ -99,7 +97,7 @@ import java.io.Serializable;
  */
 public class BlockingPrologControl
     extends PrologControl
-    implements Runnable, Serializable {
+    implements Runnable {
 
   /** A volatile instance variable holding a thread. */
   private volatile Thread thread;
diff --git a/src/lang/InternalDatabase.java b/src/lang/InternalDatabase.java
index c0b1bc7..0de54be 100644
--- a/src/lang/InternalDatabase.java
+++ b/src/lang/InternalDatabase.java
@@ -1,5 +1,4 @@
 package com.googlecode.prolog_cafe.lang;
-import java.io.Serializable;
 import java.util.LinkedList;
 /**
  * Internal database for dynamic predicates.<br>
@@ -8,7 +7,7 @@ import java.util.LinkedList;
  * @author Naoyuki Tamura (tamura@kobe-u.ac.jp)
  * @version 1.1
  */
-public class InternalDatabase implements Serializable {
+public class InternalDatabase {
     protected static final int DEFAULT_SIZE = 100000;
 
     /** Maximum size of enties. Initial size is <code>100000</code>. */
diff --git a/src/lang/Operation.java b/src/lang/Operation.java
index 458698c..3495b6b 100644
--- a/src/lang/Operation.java
+++ b/src/lang/Operation.java
@@ -1,7 +1,5 @@
 package com.googlecode.prolog_cafe.lang;
 
-import java.io.Serializable;
-
 /**
  * Superclass any single step operation in the Prolog interpreter.
  * <p>
@@ -12,7 +10,7 @@ import java.io.Serializable;
  * @author Naoyuki Tamura (tamura@kobe-u.ac.jp)
  * @version 1.0
  */
-public abstract class Operation implements Serializable {
+public abstract class Operation {
   /**
    * Executes this operation and returns a continuation goal.
    *
diff --git a/src/lang/OutOfLoop.java b/src/lang/OutOfLoop.java
index d9d6689..bb6c123 100644
--- a/src/lang/OutOfLoop.java
+++ b/src/lang/OutOfLoop.java
@@ -1,5 +1,4 @@
 package com.googlecode.prolog_cafe.lang;
-import java.io.Serializable;
 /**
  * A trail entry for out-of-loop flag.<br>
  * This <code>OutOfLoop</code> class is used in 
@@ -10,7 +9,7 @@ import java.io.Serializable;
  * @author Naoyuki Tamura (tamura@kobe-u.ac.jp)
  * @version 1.0
  */
-public class OutOfLoop implements Serializable,Undoable {
+public class OutOfLoop implements Undoable {
     BlockPredicate p;
 
     public OutOfLoop(BlockPredicate _p) {
diff --git a/src/lang/OutOfScope.java b/src/lang/OutOfScope.java
index 5edf778..9c18100 100644
--- a/src/lang/OutOfScope.java
+++ b/src/lang/OutOfScope.java
@@ -1,5 +1,4 @@
 package com.googlecode.prolog_cafe.lang;
-import java.io.Serializable;
 /**
  * A trail entry for out-of-scope flag.<br>
  * This <code>OutOfScope</code> class is used in 
@@ -10,7 +9,7 @@ import java.io.Serializable;
  * @author Naoyuki Tamura (tamura@kobe-u.ac.jp)
  * @version 1.0
  */
-public class OutOfScope implements Serializable,Undoable {
+public class OutOfScope implements Undoable {
     BlockPredicate p;
 
     public OutOfScope(BlockPredicate _p) {
diff --git a/src/lang/PrologClassLoader.java b/src/lang/PrologClassLoader.java
index 6f407a9..d2b0330 100644
--- a/src/lang/PrologClassLoader.java
+++ b/src/lang/PrologClassLoader.java
@@ -1,5 +1,4 @@
 package com.googlecode.prolog_cafe.lang;
-import java.io.Serializable;
 import java.lang.reflect.Constructor;
 /**
  * Prolog class loader.
@@ -8,7 +7,7 @@ import java.lang.reflect.Constructor;
  * @author Naoyuki Tamura (tamura@kobe-u.ac.jp)
  * @version 1.1
  */
-public class PrologClassLoader extends ClassLoader implements Serializable {
+public class PrologClassLoader extends ClassLoader {
     /** Initialize using the {@link ClassLoader#getSystemClassLoader()}.  */
     public PrologClassLoader() {
     }
diff --git a/src/lang/PrologException.java b/src/lang/PrologException.java
index 98ca075..0af28c5 100644
--- a/src/lang/PrologException.java
+++ b/src/lang/PrologException.java
@@ -1,5 +1,4 @@
 package com.googlecode.prolog_cafe.lang;
-import java.io.Serializable;
 /**
  * The superclass of classes for Prolog exceptions.<br>
  *
@@ -7,7 +6,7 @@ import java.io.Serializable;
  * @author Naoyuki Tamura (tamura@kobe-u.ac.jp)
  * @version 1.0
  */
-public abstract class PrologException extends RuntimeException implements Serializable {
+public abstract class PrologException extends RuntimeException {
 
     /** Constructs a new Prolog exception. */
     public PrologException() {}
diff --git a/src/lang/Term.java b/src/lang/Term.java
index 0c45e00..824acf0 100644
--- a/src/lang/Term.java
+++ b/src/lang/Term.java
@@ -1,5 +1,4 @@
 package com.googlecode.prolog_cafe.lang;
-import java.io.Serializable;
 /**
  * The superclass of classes for term structures.
  * The subclasses of <code>Term</code> must override
@@ -9,7 +8,7 @@ import java.io.Serializable;
  * @author Naoyuki Tamura (tamura@kobe-u.ac.jp)
  * @version 1.0
  */
-public abstract class Term implements Serializable,Comparable<Term> {
+public abstract class Term implements Comparable<Term> {
 
     /** Holds an integer value <code>0</code>. */
     public static final int EQUAL  =  0;
diff --git a/src/lang/Token.java b/src/lang/Token.java
index 7fd3d07..4fabdb7 100644
--- a/src/lang/Token.java
+++ b/src/lang/Token.java
@@ -10,7 +10,7 @@ import java.io.*;
  * @author Naoyuki Tamura (tamura@kobe-u.ac.jp)
  * @version 1.2.5
  */
-public class Token implements Serializable {
+public class Token {
 
     public static boolean isSolo(int c) {
 	return (c =='!' || c ==';');
diff --git a/src/lang/Token.java.bak b/src/lang/Token.java.bak
deleted file mode 100644
index 03455ff..0000000
--- a/src/lang/Token.java.bak
+++ /dev/null
@@ -1,414 +0,0 @@
-package com.googlecode.prolog_cafe.lang;
-import java.util.*;
-import java.io.*;
-/**
- * The <code>Token</code> class contains methods
- * for character input/output.<br>
- * <font color="red">This document is under construction.</font>
- *
- * @author Mutsunori Banbara (banbara@kobe-u.ac.jp)
- * @author Naoyuki Tamura (tamura@kobe-u.ac.jp)
- * @version 1.2
- */
-public class Token implements Serializable {
-
-    public static boolean isSolo(int c) {
-	return (c =='!' || c ==';');
-    }
-
-    public static boolean isSymbol(int c) {
-	switch (c) {
-	case '+':
-	case '-':
-	case '*':
-	case '/':
-	case '\\':
-	case '^':
-	case '<':
-	case '>':
-	case '=':
-	case '`':
-	case '~':
-	case ':':
-	case '.':
-	case '?':
-	case '@':
-	case '#':
-	case '$':
-	case '&':
-	    return true;
-	default:
-	    return false;
-	}
-    }
-
-    /*
-      public static int read_token(StringBuffer s, PushbackReader in) 
-
-      This method reads one token from the input "in", sets the string, 
-      and returns the token type.
-      
-      Type		String
-      -2		"error message"
-      -1		"end_of_file"
-      '.'		"."		full stop
-      ' '		" "		space or comment or unknown chars
-      ','		","
-      '('		"("
-      ')'		")"
-      '['		"["
-      ']'		"]"
-      '{'		"{"
-      '}'		"}"
-      ','		","
-      '|'		"|"
-      'I'		"decimal"	positive integer
-      'D'		"decimal"	positive double 
-      'A'		"atom name"
-      'V'		"variable name"
-      'S'		"string"
-    */
-    public static int read_token(StringBuffer s, PushbackReader in) 
-	throws IOException {
-
-	int c, c1;
-	int rc;
-
-	c = in.read(); // get 1st. char
-	if(c == -1) {
-	    s.append("end_of_file");
-	    return -1;
-	}
-	if (Character.isDigit((char)c)) {
-	    rc = read_number(c, s, in);
-	    if (rc == 1) 
-		rc = 'I';
-	    else if (rc == 2) 
-		rc = 'D';
-	    return rc;
-	}
-	if (Character.isLowerCase((char)c)) {
-	    rc = read_word(c, s, in);
-	    if (rc > 0)
-		rc = 'A';
-	    return rc;
-	}
-	if (Character.isUpperCase((char) c) || c == '_') {
-	    rc = read_word(c, s, in);
-	    if (rc > 0)
-		rc = 'V';
-	    return rc;
-	}
-	switch (c) {
-	case '(':
-	case ')':
-	case '[':
-	case ']':
-	case '{':
-	case '}':
-	case ',':
-	case '|':
-	    s.append((char)c);
-	    return c;
-	case '.':		/* full stop or symbol */
-	    c1 = in.read();
-	    if (c1 == -1 || c1 <= ' ') {
-		s.append(".");
-		return '.';
-	    }
-	    in.unread(c1);
-	    break;
-	case '%':		/* one line comment */
-	    s.append(" ");
-	    while ((c1 = in.read()) != '\n') {
-		if (c1 == -1)
-		    return ' ';
-	    }
-	    return ' ';
-	case '/':		/* start of comment or symbol */
-	    if ((c1 = in.read()) == '*') {
-		s.append(" ");
-		while (true) {
-		    while ((c1 = in.read()) != '*') {
-			if(c1 == -1) {
-			    s.append("unexpected end_of_file");
-			    return -2;
-			}
-		    }
-		    if ((c1 = in.read()) == '/')
-			return ' ';
-		    in.unread(c1);
-		}
-	    }
-	    in.unread(c1);
-	    break;
-	case '\'':
-	    rc = read_quoted(c, s, in);
-	    if (rc > 0)
-		rc = 'A';
-	    return rc;
-	case '"':
-	    rc = read_quoted(c, s, in);
-	    if (rc > 0)
-		rc = 'S';
-	    return rc;
-	default:
-	    break;
-	}
-	if (isSolo(c)) {
-	    s.append((char)c);
-	    return 'A';
-	}
-	if (isSymbol(c)) {
-	    rc = read_symbol(c, s, in);
-	    if (rc > 0)
-		rc = 'A';
-	    return rc;
-	}
-	s.append(" ");
-	return ' ';
-    }
-
-    public static int read_number(int c, StringBuffer s, PushbackReader in) 
-	throws IOException {
-
-	int c1, c2;
-	in.unread(c);
-	for (;;) {
-	    c1 = in.read();
-	    if (! Character.isDigit((char)c1))
-		break;
-	    s.append((char) c1);
-	}
-	if (c1 != '.'){
-	    in.unread(c1);
-	    return 1;
-	}
-	c2 = in.read();
-	if (! Character.isDigit((char)c2)){
-	    in.unread(c2);
-	    in.unread(c1);
-	    return 1;
-	}
-	s.append((char)c1);
-	in.unread(c2);
-	for (;;) {
-	    c1 = in.read();
-	    if (! Character.isDigit((char) c1))
-		break;
-	    s.append((char) c1);
-	}
-	in.unread(c1);
-	return 2;
-    }
-
-    public static int read_word(int c, StringBuffer s, PushbackReader in)
-	throws IOException {
-	int c1;
-	
-	in.unread(c);
-	for (;;) {
-	    c1 = in.read();
-	    if (! Character.isLetterOrDigit((char)c1) && c1 != '_')
-		break;
-	    s.append((char)c1);
-	}
-	in.unread(c1);
-	return 1;
-    }
-
-    public static int read_quoted(int quote, StringBuffer s, PushbackReader in) 
-	throws IOException {
-	int rc;
-	int c1;
-	
-	for (;;) {
-	    c1 = in.read();
-	    if (c1 == -1 || c1 == '\n') {
-		in.unread(c1);
-		return -2;
-	    } else if (c1 == quote){
-		c1 = in.read();
-		if (c1 != quote) {
-		    in.unread(c1);
-		    return 1;
-		}
-		c1 = quote;
-	    } 
-	    else if (c1 == '\\') {
-		rc = escapeSequences(c1, s, in);
-		if (rc > 0)
-		    continue;
-		else
-		    return -2;
-	    }
-	    s.append((char)c1);
-	}
-    }
-
-    public static int escapeSequences(int backslash, StringBuffer s, PushbackReader in)	
-	throws IOException {
-
-	int c;
-	c = in.read();
-	switch (c) {
-	case 'b': // backspace
-	    s.append((char) 8); break; 
-	case 't': // horizontal tab 
-	    s.append((char) 9); break;
-	case 'n': // newline
-	    s.append((char)10); break;
-	case 'v': // vertical tab
-	    s.append((char)11); break;
-	case 'f': // form feed
-	    s.append((char)12); break;
-	case 'r': // carriage return
-	    s.append((char)13); break;
-	case 'e': // escape
-	    s.append((char)27); break;
-	case 'd':  // delete
-	    s.append((char)127); break;
-	case 'a': // alarm
-	    s.append((char)7); break;
-	default:
-	    s.append((char)c); 
-	    return 2;
-	}
-	return 1;
-    }
-
-
-    public static int read_symbol(int c, StringBuffer s, PushbackReader in) 
-	throws IOException {
-	int c1;
-	s.append((char)c);
-	//	in.unread(c); 
-	for (;;) {
-	    c1 = in.read();
-	    if (! isSymbol(c1))
-		break;
-	    s.append((char)c1);
-	}
-	in.unread(c1);
-	return 1;
-    }
-
-
-    /* Write */
-    public static void write_string(String s, PrintWriter out) {
-	out.print(s); 
-    }
-
-    public static void writeq_string(String s, PrintWriter out) {
-	char[] ch;
-
-	ch = s.toCharArray();
-	if ((getStringType(s) == 3)){
-	    out.print("\'");
-	    for (int i=0; i<ch.length; i++) {
-		if (ch[i] == '\'')
-		    out.print("\\\'");
-		else if (ch[i] == '\\')
-		    out.print("\\\\");
-		else if (ch[i] == 8)  // backspace
-		    out.print("\\b");
-		else if (ch[i] == 9)  // horizontal tab 
-		    out.print("\\t");
-		else if (ch[i] == 10) // newline
-		    out.print("\\n");
-		else if (ch[i] == 11) // vertical tab
-		    out.print("\\v");
-		else if (ch[i] == 12) // form feed
-		    out.print("\\f");
-		else if (ch[i] == 13) // carriage return
-		    out.print("\\r");
-		else if (ch[i] == 27) // escape
-		    out.print("\\e");
-		else if (ch[i] == 127) // delete
-		    out.print("\\d");
-		else if (ch[i] == 7) // alarm
-		    out.print("\\a");
-		else 
-		    out.print(ch[i]);
-	    }
-	    out.print("\'");
-	} else {
-	    write_string(s, out);
-	}
-    }
-
-    public static String toQuotedString(String s) {
-	StringBuffer quoted = new StringBuffer(s.length() * 2);
-	char[] ch;
-
-	ch = s.toCharArray();
-	if ((getStringType(s) == 3)){
-	    quoted.append("\'");
-	    for (int i=0; i<ch.length; i++) {
-		if (ch[i] == '\'')
-		    quoted.append("\\\'");
-		else if (ch[i] == '\\')
-		    quoted.append("\\\\");
-		else if (ch[i] == 8)  // backspace
-		    quoted.append("\\b");
-		else if (ch[i] == 9)  // horizontal tab 
-		    quoted.append("\\t");
-		else if (ch[i] == 10) // newline
-		    quoted.append("\\n");
-		else if (ch[i] == 11) // vertical tab
-		    quoted.append("\\v");
-		else if (ch[i] == 12) // form feed
-		    quoted.append("\\f");
-		else if (ch[i] == 13) // carriage return
-		    quoted.append("\\r");
-		else if (ch[i] == 27) // escape
-		    quoted.append("\\e");
-		else if (ch[i] == 127) // delete
-		    quoted.append("\\d");
-		else if (ch[i] == 7) // alarm
-		    quoted.append("\\a");
-		else 
-		    quoted.append(ch[i]);
-	    }
-	    quoted.append("\'");
-	    return quoted.toString();
-	} else {
-	    return s;
-	}
-    }
-
-
-    /*
-     * return value:
-     *   0 : if string is a lower case alphnum
-     *   1 : if string is a symbol
-     *   2 : if string is a solo
-     *   3 : others
-     */
-    public static int getStringType(String s) {
-	char[] p;
-
-	if (s.equals("[]") || s.equals("{}")) 
-	    return 0;
-	if (s.equals("")   || s.equals("."))
-	    return 3;
-	if (s.equals("!")  || s.equals(";"))
-	    return 2;
-	p = s.toCharArray(); // string --> chars[]
-	if (Character.isLowerCase(p[0])){
-	    for (int i=1; i<p.length; i++){
-		if (! Character.isLetterOrDigit(p[i]) && ((int)p[i]) != '_')
-		    return 3;
-	    }
-	    return 0;
-	}
-	if (isSymbol((int) p[0])){
-	    for (int i=1; i<p.length; i++){
-		if (! isSymbol((int) p[i]))
-		    return 3;
-	    }
-	    return 1;
-	}
-	return 3;
-    }
-}
diff --git a/src/lang/Trail.java b/src/lang/Trail.java
index 2b6fcd0..686d750 100644
--- a/src/lang/Trail.java
+++ b/src/lang/Trail.java
@@ -1,5 +1,4 @@
 package com.googlecode.prolog_cafe.lang;
-import java.io.Serializable;
 /**
  * Trail stack.<br>
  * The class <code>Trail</code> represents a trail stack.<br>