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Diffstat (limited to 'src/reflect/scala/reflect/internal/Names.scala')
| -rw-r--r-- | src/reflect/scala/reflect/internal/Names.scala | 527 |
1 files changed, 527 insertions, 0 deletions
diff --git a/src/reflect/scala/reflect/internal/Names.scala b/src/reflect/scala/reflect/internal/Names.scala new file mode 100644 index 0000000000..18671871ae --- /dev/null +++ b/src/reflect/scala/reflect/internal/Names.scala @@ -0,0 +1,527 @@ +/* NSC -- new Scala compiler + * Copyright 2005-2011 LAMP/EPFL + * @author Martin Odersky + */ + +package scala.reflect +package internal + +import scala.io.Codec +import java.security.MessageDigest +import language.implicitConversions + +/** The class Names ... + * + * @author Martin Odersky + * @version 1.0, 05/02/2005 + */ +trait Names extends api.Names { + implicit def promoteTermNamesAsNecessary(name: Name): TermName = name.toTermName + +// Operations ------------------------------------------------------------- + + private final val HASH_SIZE = 0x8000 + private final val HASH_MASK = 0x7FFF + private final val NAME_SIZE = 0x20000 + + final val nameDebug = false + + /** Memory to store all names sequentially. */ + var chrs: Array[Char] = new Array[Char](NAME_SIZE) + private var nc = 0 + + /** Hashtable for finding term names quickly. */ + private val termHashtable = new Array[TermName](HASH_SIZE) + + /** Hashtable for finding type names quickly. */ + private val typeHashtable = new Array[TypeName](HASH_SIZE) + + /** The hashcode of a name. */ + private def hashValue(cs: Array[Char], offset: Int, len: Int): Int = + if (len > 0) + (len * (41 * 41 * 41) + + cs(offset) * (41 * 41) + + cs(offset + len - 1) * 41 + + cs(offset + (len >> 1))) + else 0; + + /** Is (the ASCII representation of) name at given index equal to + * cs[offset..offset+len-1]? + */ + private def equals(index: Int, cs: Array[Char], offset: Int, len: Int): Boolean = { + var i = 0 + while ((i < len) && (chrs(index + i) == cs(offset + i))) + i += 1; + i == len + } + + /** Enter characters into chrs array. */ + private def enterChars(cs: Array[Char], offset: Int, len: Int) { + var i = 0 + while (i < len) { + if (nc + i == chrs.length) { + val newchrs = new Array[Char](chrs.length * 2) + compat.Platform.arraycopy(chrs, 0, newchrs, 0, chrs.length) + chrs = newchrs + } + chrs(nc + i) = cs(offset + i) + i += 1 + } + if (len == 0) nc += 1 + else nc = nc + len + } + + /** Create a term name from the characters in cs[offset..offset+len-1]. */ + def newTermName(cs: Array[Char], offset: Int, len: Int): TermName = + newTermName(cs, offset, len, cachedString = null) + + def newTermName(cs: Array[Char]): TermName = newTermName(cs, 0, cs.length) + def newTypeName(cs: Array[Char]): TypeName = newTypeName(cs, 0, cs.length) + + /** Create a term name from the characters in cs[offset..offset+len-1]. + * TODO - have a mode where name validation is performed at creation time + * (e.g. if a name has the string "$class" in it, then fail if that + * string is not at the very end.) + */ + protected def newTermName(cs: Array[Char], offset: Int, len: Int, cachedString: String): TermName = { + val h = hashValue(cs, offset, len) & HASH_MASK + var n = termHashtable(h) + while ((n ne null) && (n.length != len || !equals(n.start, cs, offset, len))) + n = n.next + + if (n ne null) n + else { + // The logic order here is future-proofing against the possibility + // that name.toString will become an eager val, in which case the call + // to enterChars cannot follow the construction of the TermName. + val ncStart = nc + enterChars(cs, offset, len) + if (cachedString ne null) new TermName_S(ncStart, len, h, cachedString) + else new TermName_R(ncStart, len, h) + } + } + protected def newTypeName(cs: Array[Char], offset: Int, len: Int, cachedString: String): TypeName = + newTermName(cs, offset, len, cachedString).toTypeName + + /** Create a term name from string. */ + def newTermName(s: String): TermName = newTermName(s.toCharArray(), 0, s.length(), null) + + /** Create a type name from string. */ + def newTypeName(s: String): TypeName = newTermName(s).toTypeName + + /** Create a term name from the UTF8 encoded bytes in bs[offset..offset+len-1]. */ + def newTermName(bs: Array[Byte], offset: Int, len: Int): TermName = { + val chars = Codec.fromUTF8(bs, offset, len) + newTermName(chars, 0, chars.length) + } + + def newTermNameCached(s: String): TermName = + newTermName(s.toCharArray(), 0, s.length(), cachedString = s) + + def newTypeNameCached(s: String): TypeName = + newTypeName(s.toCharArray(), 0, s.length(), cachedString = s) + + /** Create a type name from the characters in cs[offset..offset+len-1]. */ + def newTypeName(cs: Array[Char], offset: Int, len: Int): TypeName = + newTermName(cs, offset, len, cachedString = null).toTypeName + + /** Create a type name from the UTF8 encoded bytes in bs[offset..offset+len-1]. */ + def newTypeName(bs: Array[Byte], offset: Int, len: Int): TypeName = + newTermName(bs, offset, len).toTypeName + + def nameChars: Array[Char] = chrs + @deprecated("", "2.9.0") def view(s: String): TermName = newTermName(s) + +// Classes ---------------------------------------------------------------------- + + /** The name class. + * TODO - resolve schizophrenia regarding whether to treat Names as Strings + * or Strings as Names. Give names the key functions the absence of which + * make people want Strings all the time. + */ + sealed abstract class Name(protected val index: Int, protected val len: Int) extends NameApi with Function1[Int, Char] { + type ThisNameType >: Null <: Name + protected[this] def thisName: ThisNameType + + /** Index into name table */ + def start: Int = index + + /** The next name in the same hash bucket. */ + def next: ThisNameType + + /** The length of this name. */ + final def length: Int = len + final def isEmpty = length == 0 + final def nonEmpty = !isEmpty + + def nameKind: String + def isTermName: Boolean + def isTypeName: Boolean + def toTermName: TermName + def toTypeName: TypeName + def companionName: Name + def bothNames: List[Name] = List(toTermName, toTypeName) + + /** Return the subname with characters from from to to-1. */ + def subName(from: Int, to: Int): ThisNameType + + /** Return a new name of the same variety. */ + def newName(str: String): ThisNameType + + /** Return a new name based on string transformation. */ + def mapName(f: String => String): ThisNameType = newName(f(toString)) + + /** Copy bytes of this name to buffer cs, starting at position `offset`. */ + final def copyChars(cs: Array[Char], offset: Int) = + compat.Platform.arraycopy(chrs, index, cs, offset, len) + + /** @return the ascii representation of this name */ + final def toChars: Array[Char] = { + val cs = new Array[Char](len) + copyChars(cs, 0) + cs + } + + /** Write to UTF8 representation of this name to given character array. + * Start copying to index `to`. Return index of next free byte in array. + * Array must have enough remaining space for all bytes + * (i.e. maximally 3*length bytes). + */ + final def copyUTF8(bs: Array[Byte], offset: Int): Int = { + val bytes = Codec.toUTF8(chrs, index, len) + compat.Platform.arraycopy(bytes, 0, bs, offset, bytes.length) + offset + bytes.length + } + + /** @return the hash value of this name */ + final override def hashCode(): Int = index + + // Presently disabled. + // override def equals(other: Any) = paranoidEquals(other) + private def paranoidEquals(other: Any): Boolean = { + val cmp = this eq other.asInstanceOf[AnyRef] + if (cmp || !nameDebug) + return cmp + + other match { + case x: String => + Console.println("Compared " + debugString + " and String '" + x + "'") + case x: Name => + if (this.isTermName != x.isTermName) { + val panic = this.toTermName == x.toTermName + Console.println("Compared '%s' and '%s', one term, one type.%s".format(this, x, + if (panic) " And they contain the same name string!" + else "" + )) + } + case _ => + } + false + } + + /** @return the i'th Char of this name */ + final def apply(i: Int): Char = chrs(index + i) + + /** @return the index of first occurrence of char c in this name, length if not found */ + final def pos(c: Char): Int = pos(c, 0) + + /** @return the index of first occurrence of char c in this name, length if not found */ + final def pos(s: String): Int = pos(s, 0) + + /** Returns the index of the first occurrence of character c in + * this name from start, length if not found. + * + * @param c the character + * @param start ... + * @return the index of the first occurrence of c + */ + final def pos(c: Char, start: Int): Int = { + var i = start + while (i < len && chrs(index + i) != c) i += 1 + i + } + + /** Returns the index of the first occurrence of nonempty string s + * in this name from start, length if not found. + * + * @param s the string + * @param start ... + * @return the index of the first occurrence of s + */ + final def pos(s: String, start: Int): Int = { + var i = pos(s.charAt(0), start) + while (i + s.length() <= len) { + var j = 1 + while (s.charAt(j) == chrs(index + i + j)) { + j += 1 + if (j == s.length()) return i + } + i = pos(s.charAt(0), i + 1) + } + len + } + + /** Returns the index of last occurrence of char c in this + * name, -1 if not found. + * + * @param c the character + * @return the index of the last occurrence of c + */ + final def lastPos(c: Char): Int = lastPos(c, len - 1) + + final def lastPos(s: String): Int = lastPos(s, len - s.length) + + /** Returns the index of the last occurrence of char c in this + * name from start, -1 if not found. + * + * @param c the character + * @param start ... + * @return the index of the last occurrence of c + */ + final def lastPos(c: Char, start: Int): Int = { + var i = start + while (i >= 0 && chrs(index + i) != c) i -= 1 + i + } + + /** Returns the index of the last occurrence of string s in this + * name from start, -1 if not found. + * + * @param s the string + * @param start ... + * @return the index of the last occurrence of s + */ + final def lastPos(s: String, start: Int): Int = { + var i = lastPos(s.charAt(0), start) + while (i >= 0) { + var j = 1; + while (s.charAt(j) == chrs(index + i + j)) { + j += 1 + if (j == s.length()) return i; + } + i = lastPos(s.charAt(0), i - 1) + } + -s.length() + } + + /** Does this name start with prefix? */ + final def startsWith(prefix: Name): Boolean = startsWith(prefix, 0) + + /** Does this name start with prefix at given start index? */ + final def startsWith(prefix: Name, start: Int): Boolean = { + var i = 0 + while (i < prefix.length && start + i < len && + chrs(index + start + i) == chrs(prefix.start + i)) + i += 1; + i == prefix.length + } + + /** Does this name end with suffix? */ + final def endsWith(suffix: Name): Boolean = endsWith(suffix, len) + + /** Does this name end with suffix just before given end index? */ + final def endsWith(suffix: Name, end: Int): Boolean = { + var i = 1 + while (i <= suffix.length && i <= end && + chrs(index + end - i) == chrs(suffix.start + suffix.length - i)) + i += 1; + i > suffix.length + } + + final def containsName(subname: String): Boolean = containsName(newTermName(subname)) + final def containsName(subname: Name): Boolean = { + var start = 0 + val last = len - subname.length + while (start <= last && !startsWith(subname, start)) start += 1 + start <= last + } + final def containsChar(ch: Char): Boolean = { + var i = index + val max = index + len + while (i < max) { + if (chrs(i) == ch) + return true + i += 1 + } + false + } + + /** Some thoroughly self-explanatory convenience functions. They + * assume that what they're being asked to do is known to be valid. + */ + final def startChar: Char = apply(0) + final def endChar: Char = apply(len - 1) + final def startsWith(char: Char): Boolean = len > 0 && startChar == char + final def startsWith(name: String): Boolean = startsWith(newTermName(name)) + final def endsWith(char: Char): Boolean = len > 0 && endChar == char + final def endsWith(name: String): Boolean = endsWith(newTermName(name)) + + def dropRight(n: Int): ThisNameType = subName(0, len - n) + def drop(n: Int): ThisNameType = subName(n, len) + def stripSuffix(suffix: Name): ThisNameType = + if (this endsWith suffix) dropRight(suffix.length) else thisName + + def indexOf(ch: Char) = { + val idx = pos(ch) + if (idx == length) -1 else idx + } + def indexOf(ch: Char, fromIndex: Int) = { + val idx = pos(ch, fromIndex) + if (idx == length) -1 else idx + } + def lastIndexOf(ch: Char) = lastPos(ch) + def lastIndexOf(ch: Char, fromIndex: Int) = lastPos(ch, fromIndex) + + /** Replace all occurrences of `from` by `to` in + * name; result is always a term name. + */ + def replace(from: Char, to: Char): Name = { + val cs = new Array[Char](len) + var i = 0 + while (i < len) { + val ch = this(i) + cs(i) = if (ch == from) to else ch + i += 1 + } + newTermName(cs, 0, len) + } + + /** TODO - reconcile/fix that encode returns a Name but + * decode returns a String. + */ + + /** !!! Duplicative but consistently named. + */ + def decoded: String = decode + def encoded: String = "" + encode + // def decodedName: ThisNameType = newName(decoded) + def encodedName: ThisNameType = encode + + /** Replace operator symbols by corresponding \$op_name. */ + def encode: ThisNameType = { + val str = toString + val res = NameTransformer.encode(str) + if (res == str) thisName else newName(res) + } + + /** Replace \$op_name by corresponding operator symbol. */ + def decode: String = { + if (this containsChar '$') { + val str = toString + val res = NameTransformer.decode(str) + if (res == str) str + else res + } + else toString + } + + /** TODO - find some efficiency. */ + def append(ch: Char) = newName("" + this + ch) + def append(suffix: String) = newName("" + this + suffix) + def append(suffix: Name) = newName("" + this + suffix) + def prepend(ch: Char) = newName("" + ch + this) + def prepend(prefix: String) = newName("" + prefix + this) + def prepend(prefix: Name) = newName("" + prefix + this) + + def decodedName: ThisNameType = newName(decode) + def isOperatorName: Boolean = decode != toString + def longString: String = nameKind + " " + decode + def debugString = { val s = decode ; if (isTypeName) s + "!" else s } + } + + implicit val NameTag = ClassTag[Name](classOf[Name]) + + /** A name that contains no operator chars nor dollar signs. + * TODO - see if it's any faster to do something along these lines. + * Cute: now that exhaustivity kind of works, the mere presence of + * this trait causes TermName and TypeName to stop being exhaustive. + * Commented out. + */ + // trait AlphaNumName extends Name { + // final override def encode = thisName + // final override def decodedName = thisName + // final override def decode = toString + // final override def isOperatorName = false + // } + + /** TermName_S and TypeName_S have fields containing the string version of the name. + * TermName_R and TypeName_R recreate it each time toString is called. + */ + private class TermName_S(index0: Int, len0: Int, hash: Int, override val toString: String) extends TermName(index0, len0, hash) { + protected def createCompanionName(h: Int): TypeName = new TypeName_S(index, len, h, toString) + override def newName(str: String): TermName = newTermNameCached(str) + } + private class TypeName_S(index0: Int, len0: Int, hash: Int, override val toString: String) extends TypeName(index0, len0, hash) { + protected def createCompanionName(h: Int): TermName = new TermName_S(index, len, h, toString) + override def newName(str: String): TypeName = newTypeNameCached(str) + } + + private class TermName_R(index0: Int, len0: Int, hash: Int) extends TermName(index0, len0, hash) { + protected def createCompanionName(h: Int): TypeName = new TypeName_R(index, len, h) + override def toString = new String(chrs, index, len) + } + + private class TypeName_R(index0: Int, len0: Int, hash: Int) extends TypeName(index0, len0, hash) { + protected def createCompanionName(h: Int): TermName = new TermName_R(index, len, h) + override def toString = new String(chrs, index, len) + } + + sealed abstract class TermName(index0: Int, len0: Int, hash: Int) extends Name(index0, len0) { + type ThisNameType = TermName + protected[this] def thisName: TermName = this + + var next: TermName = termHashtable(hash) + termHashtable(hash) = this + def isTermName: Boolean = true + def isTypeName: Boolean = false + def toTermName: TermName = this + def toTypeName: TypeName = { + val h = hashValue(chrs, index, len) & HASH_MASK + var n = typeHashtable(h) + while ((n ne null) && n.start != index) + n = n.next + + if (n ne null) n + else createCompanionName(h) + } + def newName(str: String): TermName = newTermName(str) + def companionName: TypeName = toTypeName + def subName(from: Int, to: Int): TermName = + newTermName(chrs, start + from, to - from) + + def nameKind = "term" + protected def createCompanionName(h: Int): TypeName + } + + implicit val TermNameTag = ClassTag[TermName](classOf[TermName]) + + sealed abstract class TypeName(index0: Int, len0: Int, hash: Int) extends Name(index0, len0) { + type ThisNameType = TypeName + protected[this] def thisName: TypeName = this + + var next: TypeName = typeHashtable(hash) + typeHashtable(hash) = this + def isTermName: Boolean = false + def isTypeName: Boolean = true + def toTermName: TermName = { + val h = hashValue(chrs, index, len) & HASH_MASK + var n = termHashtable(h) + while ((n ne null) && n.start != index) + n = n.next + + if (n ne null) n + else createCompanionName(h) + } + def toTypeName: TypeName = this + def newName(str: String): TypeName = newTypeName(str) + def companionName: TermName = toTermName + def subName(from: Int, to: Int): TypeName = + newTypeName(chrs, start + from, to - from) + + def nameKind = "type" + override def decode = if (nameDebug) super.decode + "!" else super.decode + protected def createCompanionName(h: Int): TermName + } + + implicit val TypeNameTag = ClassTag[TypeName](classOf[TypeName]) +} |