- Removed file from encoded positions

2 files changed, 56 insertions, 83 deletions

diff --git a/sources/ch/epfl/lamp/util/Position.java b/sources/ch/epfl/lamp/util/Position.java
index 91c9d702a3..486ef7add6 100644
--- a/sources/ch/epfl/lamp/util/Position.java
+++ b/sources/ch/epfl/lamp/util/Position.java
@@ -8,20 +8,43 @@
 
 package ch.epfl.lamp.util;
 
+/**
+ * This class represents a position in a source file. Such a position
+ * is defined by a source file (mandatory), a line number (optional)
+ * and a column number (optional, may be specified only if the line
+ * number is defined).
+ *
+ * Line (Column) numbers range from 0 to Integer.MAX_VALUE. A value of
+ * 0 indicates that the line (column) is undefined, 1 represents the
+ * first line (column). Negative values are prohibited.
+ *
+ * The class provides also functions to encode a line number and a
+ * column number into one single integer. The encode line (column)
+ * numbers range from 0 to LINE_MASK (COLUMN_MASK), where 0 indicates
+ * that the line (column) is the undefined and 1 represents the first
+ * line (column). Line (Column) numbers greater than LINE_MASK
+ * (COLUMN_MASK) are replaced by LINE_MASK (COLUMN_MASK). Furthermore,
+ * if the encoded line number is LINE_MASK, the column number is
+ * always set to 0.
+ *
+ * The following properties hold:
+ * - the undefined position is 0: encode(0,0) == 0
+ * - encodings are non-negative : encode(line,column) >= 0
+ * - position order is preserved:
+ *   (line1 < line2) || (line1 == line2 && column1 < column2)
+ * implies
+ *   encode(line1,column1) <= encode(line2,column2)
+ */
 public class Position {
 
     //########################################################################
     // Public Constants
 
-    /** Number of bits used to encode the file */
-    public static final int FILE_BITS   = 6;
     /** Number of bits used to encode the line number */
-    public static final int LINE_BITS   = 16;
+    public static final int LINE_BITS   = 20;
     /** Number of bits used to encode the column number */
-    public static final int COLUMN_BITS = 32 - LINE_BITS - FILE_BITS;
+    public static final int COLUMN_BITS = 31 - LINE_BITS; // no negatives => 31
 
-    /** Mask to decode the file */
-    public static final int FILE_MASK   = (1 << FILE_BITS) - 1;
     /** Mask to decode the line number */
     public static final int LINE_MASK   = (1 << LINE_BITS) - 1;
     /** Mask to decode the column number */
@@ -31,24 +54,18 @@ public class Position {
     public static final int NOPOS       = 0;
 
     /** The first position in a source file */
-    public static final int FIRSTPOS    = encode(null, 1, 1);
+    public static final int FIRSTPOS    = encode(1, 1);
 
     //########################################################################
     // Public Functions
 
-    /** Encodes a position into a single int. */
-    public static int encode(SourceFile file, int line, int column) {
-        int fileId = file == null ? 0 : file.id() & FILE_MASK;
-        if (fileId < 0 || FILE_MASK < fileId) fileId = 0;
-        if (line < 0  || LINE_MASK < line) line = 0;
-        if (column < 0 || COLUMN_MASK < column) column = 0;
-        return (((fileId << LINE_BITS) | line) << COLUMN_BITS) | column;
-    }
-
-    /** Returns the file of the encoded position. */
-    public static SourceFile file(int position) {
-        int fileId = (position >> (COLUMN_BITS + LINE_BITS)) & FILE_MASK;
-        return SourceFile.fromId(fileId);
+    /** Encodes a position into a single integer. */
+    public static int encode(int line, int column) {
+        assert line >= 0 : line;
+        assert line == 0 ? column == 0 : column >= 0 : line + "," + column;
+        if (line >= LINE_MASK) { line = LINE_MASK; column = 0; }
+        if (column > COLUMN_MASK) column = COLUMN_MASK;
+        return (line << COLUMN_BITS) | column;
     }
 
     /** Returns the line number of the encoded position. */
@@ -77,11 +94,6 @@ public class Position {
     // Public Constructors
 
     /** Initializes a new instance. */
-    public Position(int position) {
-        this(file(position), line(position), column(position));
-    }
-
-    /** Initializes a new instance. */
     public Position(String source) {
         this(new SourceFile(source, new byte[0]));
     }
@@ -92,20 +104,23 @@ public class Position {
     }
 
     /** Initializes a new instance. */
+    public Position(SourceFile file, int position) {
+        this(file, line(position), column(position));
+    }
+
+    /** Initializes a new instance. */
     public Position(SourceFile file, int line, int column) {
         this.file = file;
         this.line = line;
         this.column = column;
+        assert file != null;
+        assert line >= 0 : line;
+        assert line == 0 ? column == 0 : column >= 0 : line + "," + column;
     }
 
     //########################################################################
     // Public Methods
 
-    /** Returns an int encoding this position. */
-    public int encode() {
-        return encode(file, line, column);
-    }
-
     /** Returns the file of this position. */
     public SourceFile file() {
         return file;
@@ -121,14 +136,22 @@ public class Position {
         return column;
     }
 
+    /** Returns an int encoding the line and column of this position. */
+    public int encodedLineColumn() {
+        return encode(line, column);
+    }
+
     /** Returns a string representation of this position. */
     public String toString() {
-        return file.name() + ":" + line + ":" + column;
+        StringBuffer buffer = new StringBuffer(file.name());
+        if (line > 0) buffer.append(":").append(line);
+        if (line > 0 && column > 0) buffer.append(":").append(column);
+        return buffer.toString();
     }
 
     /** Returns the hash code of this position. */
     public int hashCode() {
-        return encode();
+        return file.hashCode() ^ encodedLineColumn();
     }
 
     /** Returns true iff the given object represents the same position. */
diff --git a/sources/ch/epfl/lamp/util/SourceFile.java b/sources/ch/epfl/lamp/util/SourceFile.java
index 44dbf82506..68a6739cab 100644
--- a/sources/ch/epfl/lamp/util/SourceFile.java
+++ b/sources/ch/epfl/lamp/util/SourceFile.java
@@ -30,29 +30,6 @@ public class SourceFile {
     public static final byte SU = 0x1A;
 
     //########################################################################
-    // Public Functions
-
-    /** Returns the source file with the given id. */
-    public static SourceFile fromId(int id) {
-        if (id <= 0 || files.size() < id) return UNKNOWN;
-        return (SourceFile)files.get(id - 1);
-    }
-
-    /** Releases all source file. */
-    public static void releaseAll() {
-        files.clear();
-    }
-
-    //########################################################################
-    // Private Variables
-
-    /** The unknown source file */
-    private static final SourceFile UNKNOWN = new SourceFile();
-
-    /** The list containing all source files */
-    private static final ArrayList files = new ArrayList();
-
-    //########################################################################
     // Private Fields
 
     /** The name of this source file */
@@ -61,9 +38,6 @@ public class SourceFile {
     /** The content of source this file */
     private final byte[] bytes;
 
-    /** The id of this source file */
-    private final int id;
-
     /** The encoding of this source file or null if unspecified */
     private String encoding;
 
@@ -74,16 +48,6 @@ public class SourceFile {
     private int nextIndex  = 0;
 
     //########################################################################
-    // Private Constructors
-
-    /** Initializes a new instance. */
-    private SourceFile() {
-        this.name = "<<unknown source file>>";
-        this.bytes = normalize(new byte[0]);
-        this.id = 0;
-    }
-
-    //########################################################################
     // Public Constructors
 
     /** Initializes a new instance. */
@@ -105,8 +69,6 @@ public class SourceFile {
     public SourceFile(String name, byte[] bytes) {
         this.name = name;
         this.bytes = normalize(bytes);
-        this.id = files.size() + 1;
-        files.add(this);
     }
 
     //########################################################################
@@ -122,11 +84,6 @@ public class SourceFile {
         return bytes;
     }
 
-    /** Returns the id of this source file. */
-    public int id() {
-        return id;
-    }
-
     /** Sets the encoding of the file. */
     public void setEncoding(String encoding) {
         this.encoding = encoding;
@@ -165,14 +122,7 @@ public class SourceFile {
         return new Position(this, line, column);
     }
 
-    /**
-     * Returns the integer encoding the position of the given line and
-     * column of this source file.
-     */
-    public int getEncodedPosition(int line, int column) {
-        return Position.encode(this, line, column);
-    }
-
+    /** Returns the name of this source file. */
     public String toString() {
         return name;
     }