Scanners added.

Moving Positions, Chars to new packages.
Added Source positions.
Added untyped trees module.
Factored out behavior between typed and untyped trees.

1 files changed, 171 insertions, 0 deletions

diff --git a/src/dotty/tools/dotc/parsing/Tokens.scala b/src/dotty/tools/dotc/parsing/Tokens.scala
new file mode 100644
index 000000000..f573df49d
--- /dev/null
+++ b/src/dotty/tools/dotc/parsing/Tokens.scala
@@ -0,0 +1,171 @@
+package dotty.tools
+package dotc
+package parsing
+
+import collection.mutable
+import collection.immutable.BitSet
+import scala.annotation.switch
+
+object Tokens {
+
+  final val minToken = EMPTY
+  final val maxToken = XMLSTART
+
+  type TokenSet = BitSet
+
+  def tokenRange(lo: Int, hi: Int): TokenSet = BitSet(lo to hi: _*)
+
+  def showTokenDetailed(token: Int) = debugString(token)
+
+  def showToken(token: Int) = {
+    val str = tokenString(token)
+    if (keywords contains token) s"'$str'" else str
+  }
+
+  val tokenString, debugString = new Array[String](maxToken + 1)
+
+  def enter(token: Int, str: String, debugStr: String = ""): Unit = {
+    tokenString(token) = str
+    debugString(token) = if (debugStr.isEmpty) str else debugStr
+  }
+
+  /** special tokens */
+  final val EMPTY = 0;             enter(EMPTY, "<empty>") // a missing token, used in lookahead
+  final val ERROR = 1;             enter(ERROR, "erroneous token") // an erroneous token
+  final val EOF = 2;               enter(EOF, "eof")
+
+  /** literals */
+  final val CHARLIT = 3;           enter(CHARLIT, "character literal")
+  final val INTLIT = 4;            enter(INTLIT, "integer literal")
+  final val LONGLIT = 5;           enter(LONGLIT, "long literal")
+  final val FLOATLIT = 6;          enter(FLOATLIT, "float literal")
+  final val DOUBLELIT = 7;         enter(DOUBLELIT, "double literal")
+  final val STRINGLIT = 8;         enter(STRINGLIT, "string literal")
+  final val STRINGPART = 9;        enter(STRINGPART, "string literal", "string literal part")
+  final val INTERPOLATIONID = 10;  enter(INTERPOLATIONID, "string interpolator")
+  final val SYMBOLLIT = 11;        enter(SYMBOLLIT, "symbol literal") // TODO: deprecate
+
+  final val literalTokens = tokenRange(CHARLIT, SYMBOLLIT)
+
+  /** identifiers */
+  final val IDENTIFIER = 12;       enter(IDENTIFIER, "identifier")
+  final val BACKQUOTED_IDENT = 13; enter(BACKQUOTED_IDENT, "identifier", "backquoted ident")
+
+  final val identifierTokens = BitSet(IDENTIFIER, BACKQUOTED_IDENT)
+
+  def isIdentifier(token : Int) =
+    token >= IDENTIFIER && token <= BACKQUOTED_IDENT
+
+  /** alphabetic keywords */
+  final val IF = 20;               enter(IF, "if")
+  final val FOR = 21;              enter(FOR, "for")
+  final val ELSE = 22;             enter(ELSE, "else")
+  final val THIS = 23;             enter(THIS, "this")
+  final val NULL = 24;             enter(NULL, "null")
+  final val NEW = 25;              enter(NEW, "new")
+  final val WITH = 26;             enter(WITH, "with")
+  final val SUPER = 27;            enter(SUPER, "super")
+  final val CASE = 28;             enter(CASE, "case")
+  final val CASECLASS = 29;        enter(CASECLASS, "case class")
+  final val CASEOBJECT = 30;       enter(CASEOBJECT, "case object")
+  final val VAL = 31;              enter(VAL, "val")
+  final val ABSTRACT = 32;         enter(ABSTRACT, "abstract")
+  final val FINAL = 33;            enter(FINAL, "final")
+  final val PRIVATE = 34;          enter(PRIVATE, "private")
+  final val PROTECTED = 35;        enter(PROTECTED, "protected")
+  final val OVERRIDE = 36;         enter(OVERRIDE, "override")
+  final val IMPLICIT = 37;         enter(IMPLICIT, "implicit")
+  final val VAR = 38;              enter(VAR, "var")
+  final val DEF = 39;              enter(DEF, "def")
+  final val TYPE = 40;             enter(TYPE, "type")
+  final val EXTENDS = 41;          enter(EXTENDS, "extends")
+  final val TRUE = 42;             enter(TRUE, "true")
+  final val FALSE = 43;            enter(FALSE, "false")
+  final val OBJECT = 44;           enter(OBJECT, "object")
+  final val CLASS = 45;            enter(CLASS, "class")
+  final val IMPORT = 46;           enter(IMPORT, "import")
+  final val PACKAGE = 47;          enter(PACKAGE, "package")
+  final val YIELD = 48;            enter(YIELD, "yield")
+  final val DO = 49;               enter(DO, "do")
+  final val TRAIT = 50;            enter(TRAIT, "trait")
+  final val SEALED = 51;           enter(SEALED, "sealed")
+  final val THROW = 52;            enter(THROW, "throw")
+  final val TRY = 53;              enter(TRY, "try")
+  final val CATCH = 54;            enter(CATCH, "catch")
+  final val FINALLY = 55;          enter(FINALLY, "finally")
+  final val WHILE = 56;            enter(WHILE, "while")
+  final val RETURN = 57;           enter(RETURN, "return")
+  final val MATCH = 58;            enter(MATCH, "match")
+  final val FORSOME = 59;          enter(FORSOME, "forSome") // TODO: deprecate
+  final val LAZY = 61;             enter(LAZY, "lazy")
+  final val THEN = 62;             enter(THEN, "then")
+
+  final val alphaKeywords = tokenRange(IF, LAZY)
+
+  /** special symbols */
+  final val COMMA = 70;            enter(COMMA, "','")
+  final val SEMI = 71;             enter(DOT, "'.'")
+  final val DOT = 72;              enter(SEMI, "';'")
+  final val NEWLINE = 78;          enter(NEWLINE, "';'", "new line")
+  final val NEWLINES = 79;         enter(NEWLINES, "';'", "new lines")
+
+  /** special keywords */
+  final val USCORE = 73;           enter(USCORE, "_")
+  final val COLON = 74;            enter(COLON, ":")
+  final val EQUALS = 75;           enter(EQUALS, "==")
+  final val LARROW = 76;           enter(LARROW, "<-")
+  final val ARROW = 77;            enter(ARROW, "=>")
+  final val SUBTYPE = 80;          enter(SUBTYPE, "<:")
+  final val SUPERTYPE = 81;        enter(SUPERTYPE, ">:")
+  final val HASH = 82;             enter(HASH, "#")
+  final val AT = 83;               enter(AT, "@")
+  final val VIEWBOUND = 84;        enter(VIEWBOUND, "<%") // TODO: deprecate
+
+  final val symbolicKeywords = tokenRange(USCORE, VIEWBOUND)
+  final val symbolicTokens = tokenRange(COMMA, VIEWBOUND)
+  final val keywords = alphaKeywords | symbolicKeywords
+
+  /** parentheses */
+  final val LPAREN = 90;           enter(LPAREN, "'('")
+  final val RPAREN = 91;           enter(RPAREN, "')'")
+  final val LBRACKET = 92;         enter(LBRACKET, "'['")
+  final val RBRACKET = 93;         enter(RBRACKET, "']'")
+  final val LBRACE = 94;           enter(LBRACE, "'{'")
+  final val RBRACE = 95;           enter(RBRACE, "'}'")
+
+  /** XML mode */
+  final val XMLSTART = 96;         enter(XMLSTART, "$XMLSTART$<") // TODO: deprecate
+
+  final val allTokens = tokenRange(minToken, maxToken)
+
+  final val atomicExprTokens = literalTokens | identifierTokens | BitSet(
+    USCORE, NULL, THIS, SUPER, TRUE, FALSE, RETURN, XMLSTART)
+
+  final val canStartExpressionTokens = atomicExprTokens | BitSet(
+    LBRACE, LPAREN, IF, DO, WHILE, FOR, NEW, TRY, THROW)
+
+  final val canStartTypeTokens = literalTokens | identifierTokens | BitSet(
+    THIS, SUPER, USCORE, LPAREN, AT)
+
+  final val templateIntroTokens = BitSet(CLASS, TRAIT, OBJECT, CASECLASS, CASEOBJECT)
+
+  final val dclIntroTokens = BitSet(DEF, VAL, VAR, TYPE)
+
+  final val defIntroTokens = templateIntroTokens | dclIntroTokens
+
+  final val localModifierTokens = BitSet(
+    ABSTRACT, FINAL, SEALED, IMPLICIT, LAZY)
+
+  final val modifierTokens = localModifierTokens | BitSet(
+    PRIVATE, PROTECTED, OVERRIDE)
+
+  /** Is token only legal as start of statement (eof also included)? */
+  final val mustStartStatTokens = defIntroTokens | modifierTokens | BitSet(
+    CASE, IMPORT, PACKAGE)
+
+  final val canStartStatTokens = canStartExpressionTokens | mustStartStatTokens | BitSet(
+    AT)
+
+  final val canEndStatTokens = atomicExprTokens | BitSet(
+    TYPE, RPAREN, RBRACE, RBRACKET)
+}