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|
/* NSC -- new scala compiler
* Copyright 2005 LAMP/EPFL
* @author buraq
*/
// $Id$
package scala.tools.nsc.matching ;
import scala.tools.nsc.util.Position;
mixin class PatternMatchers requires (TransMatcher with PatternNodes) extends AnyRef with PatternNodeCreator {
import global._;
import typer.typed ;
import symtab.Flags;
class PatternMatcher {
protected var optimize = true;
protected var delegateSequenceMatching = false;
protected var doBinding = true;
/** the owner of the pattern matching expression
*/
var owner:Symbol = _ ;
/** the selector expression
*/
protected var selector: Tree = _;
/** the root of the pattern node structure
*/
protected var root: PatternNode = _;
/** the symbol of the result variable
*/
// protected var resultVar: Symbol = _;
def defs = definitions;
/** init method, also needed in subclass AlgebraicMatcher
*/
def initialize(selector: Tree, owner: Symbol, doBinding: Boolean): Unit = {
//Console.println("pm.initialize selector.tpe = "+selector.tpe);
/*
this.mk = new PatternNodeCreator {
val global = PatternMatcher.this.global;
val unit = PatternMatcher.this.unit;
val owner = PatternMatcher.this.owner;
}
*/
/*
this.cf = new CodeFactory {
val global = PatternMatcher.this.global;
val unit = PatternMatcher.this.unit;
val owner = PatternMatcher.this.owner;
}
*/
this.root = pConstrPat(selector.pos, selector.tpe.widen);
//Console.println("selector.tpe "+selector.tpe);
//Console.println("selector.tpe.widen "+selector.tpe.widen);
//Console.println("root.symbol "+root.symbol);
//Console.println("root.symbol.tpe "+root.symbol.tpe);
this.root.and = pHeader(selector.pos,
selector.tpe.widen,
Ident(root.symbol).setType(root.tpe));
//Console.println("resultType = "+resultType);
this.owner = owner;
this.selector = selector;
this.optimize = this.optimize && (settings.target.value == "jvm");
this.doBinding = doBinding;
}
/** pretty printer
*/
def print(): Unit = { Console.println (
root.and.print("", new StringBuffer()).toString()
)}
/** enters a sequence of cases into the pattern matcher
*/
def construct(cases: List[Tree]): Unit = {
cases foreach enter;
}
/** enter a single case into the pattern matcher
*/
protected def enter(caseDef: Tree): Unit = {
caseDef match {
case CaseDef(pat, guard, body) =>
val env = new CaseEnv;
// PatternNode matched = match(pat, root);
val target = enter1(pat, -1, root, root.symbol, env);
// if (target.and != null)
// unit.error(pat.pos, "duplicate case");
if (null == target.and)
target.and = pBody(caseDef.pos, env.getBoundVars(), guard, body);
else if (target.and.isInstanceOf[Body])
updateBody(target.and.asInstanceOf[Body], env.getBoundVars(), guard, body);
else
cunit.error(pat.pos, "duplicate case");
}
}
protected def updateBody(tree: Body, bound: Array[ValDef], guard: Tree , body: Tree): Unit = {
if (tree.guard(tree.guard.length - 1) == EmptyTree) {
//unit.error(body.pos, "unreachable code");
} else {
val bd = new Array[Array[ValDef]](tree.bound.length + 1);
val ng = new Array[Tree](tree.guard.length + 1);
val nb = new Array[Tree](tree.body.length + 1);
System.arraycopy(tree.bound, 0, bd, 0, tree.bound.length);
System.arraycopy(tree.guard, 0, ng, 0, tree.guard.length);
System.arraycopy(tree.body, 0, nb, 0, tree.body.length);
bd(bd.length - 1) = bound;
ng(ng.length - 1) = guard;
nb(nb.length - 1) = body;
tree.bound = bd ;
tree.guard = ng ;
tree.body = nb ;
}
}
protected def patternArgs(tree: Tree):List[Tree] = {
tree match {
case Bind(_, pat) =>
patternArgs(pat);
case Apply(_, args) =>
if ( isSeqApply(tree.asInstanceOf[Apply]) && !delegateSequenceMatching)
args(0) match {
case ArrayValue(_, ts) => // test array values
ts;
//case Sequence(ts) =>
// ts;
case _ =>
args;
}
else args
case Sequence(ts) if (!delegateSequenceMatching) =>
ts;
case ArrayValue(_, ts) => // test array values
ts;
case _ =>
List();
}
}
/** returns true if apply is a "sequence apply". analyzer inserts Sequence nodes if something is a
*
* - last update: discussion with Martin 2005-02-18
*
* - if true, tree.fn must be ignored. The analyzer ensures that the selector will be a subtype
* of fn; it thus assigns the expected type from the context (which is surely a subtype,
* but may have different flags etc.
*
* - so should be
* (( tree.args.length == 1 ) && tree.args(0).isInstanceOf[Sequence])
* but fails
*/
protected def isSeqApply( tree: Apply ): Boolean = {
// Console.print("isSeqApply? "+tree.toString());
// val res =
tree match {
case Apply(_, List(ArrayValue(_,_))) => (tree.tpe.symbol.flags & Flags.CASE) == 0
case _ => false;
}
//Console.println(res);
//res;
}
protected def patternNode(tree:Tree , header:Header , env: CaseEnv ): PatternNode = {
//if(tree!=null) Console.println("patternNode("+tree+","+header+")");
//else scala.Predef.error("got null tree in patternNode");
//Console.println("tree.tpe "+tree.tpe);
//Console.println("tree.getClass() "+tree.getClass());
tree match {
case Bind(name, Typed(Ident( nme.WILDCARD ), tpe)) => // x@_:Type
if (isSubType(header.getTpe(),tpe.tpe)) {
//Console.println("U");
val node = pDefaultPat(tree.pos, tpe.tpe);
env.newBoundVar( tree.symbol, tree.tpe, header.selector );
node;
} else {
//Console.println("X");
val node = pConstrPat(tree.pos, tpe.tpe);
env.newBoundVar( tree.symbol,
tpe.tpe, /*scalac: tree.tpe */
typed(Ident( node.casted )));
node;
}
case Bind(name, Ident(nme.WILDCARD)) => // x @ _
val node = pDefaultPat(tree.pos, header.getTpe());
if ((env != null) && (tree.symbol != defs.PatternWildcard))
env.newBoundVar( tree.symbol, tree.tpe, header.selector);
node;
case Bind(name, pat) =>
val node = patternNode(pat, header, env);
if ((env != null) && (tree.symbol != defs.PatternWildcard)) {
val casted = node.symbol;
val theValue = if (casted == NoSymbol) header.selector else Ident( casted).setType(casted.tpe);
env.newBoundVar(tree.symbol, tree.tpe, theValue);
}
node;
case t @ Apply(fn, args) => // pattern with args
//Console.println("Apply!");
//Console.println("isSeqApply "+isSeqApply(t));
//Console.println("delegateSequenceMatching "+delegateSequenceMatching);
if (isSeqApply(t)) {
if (!delegateSequenceMatching) {
args(0) match {
// case Sequence(ts)=>
case ArrayValue(_, ts)=>
//Console.println("doing pSeqpat ");
val res = pSequencePat(tree.pos, tree.tpe, ts.length);
//Console.println("pSeqpat.casted = "+res.casted);
//Console.println("pSeqpat.casted.pos = "+res.casted.pos);
res
}
} else {
//Console.println("delegating ... ");
val res = pConstrPat(tree.pos, tree.tpe);
res.and = pHeader(tree.pos, header.getTpe(), header.selector);
//res.and.and = pSeqContainerPat(tree.pos, tree.tpe, args(0));
res.and.and = pSeqContainerPat(tree.pos, tree.tpe, Sequence(args(0).asInstanceOf[ArrayValue].elems));
res;
}
} else if ((fn.symbol != null) &&
fn.symbol.isStable &&
!(fn.symbol.isModule &&
((fn.symbol.flags & Flags.CASE) != 0))) {
pVariablePat(tree.pos, tree);
}
else {
/*
Console.println("apply but not seqApply");
Console.println("tree.tpe="+tree.tpe);
Console.println("tree.symbol="+tree.symbol);
*/
pConstrPat(tree.pos, tree.tpe);
}
case Typed(Ident( nme.WILDCARD ), tpe) => // x@_:Type
val doTest = isSubType(header.getTpe(),tpe.tpe);
if(doTest)
pDefaultPat(tree.pos, tpe.tpe)
else
pConstrPat(tree.pos, tpe.tpe);
case t @ Typed(ident, tpe) => // variable pattern
//Console.println("Z");
val doTest = isSubType(header.getTpe(),tpe.tpe);
val node = {
if(doTest)
pDefaultPat(tree.pos, tpe.tpe)
else
pConstrPat(tree.pos, tpe.tpe);
}
//if(t.expr.symbol == NoSymbol) {
// Console.println(t.toString());
// scala.Predef.error("go typed pattern with no symbol in "+cunit.toString());
// }
if ((null != env) /* && (ident.symbol != defs.PatternWildcard) */)
node match {
case ConstrPat(casted) =>
env.newBoundVar(t.expr.symbol,
tpe.tpe,
Ident( casted ).setType(casted.tpe));
case _ =>
env.newBoundVar(t.expr.symbol,
tpe.tpe,
{if(doTest)
header.selector
else
typed(Ident(node
.asInstanceOf[ConstrPat]
.casted))});
}
node;
case Ident(nme.WILDCARD) =>
pDefaultPat(tree.pos, header.getTpe());
case Ident(name) => // pattern without args or variable
// nsc: wildcard's don't have symbols anymore!
//if (tree.symbol == defs.PatternWildcard)
// pDefaultPat(tree.pos, header.getTpe());
//else
if (tree.symbol.isPrimaryConstructor) {
scala.Predef.error("error may not happen: ident is primary constructor"+tree.symbol); // Burak
} else if (treeInfo.isVariableName(name)) {// Burak
//old scalac
scala.Predef.error("this may not happen"); // Burak
//nsc: desugarize (in case nsc does not do it)
/*
Console.println("Ident("+name+") in unit"+cunit);
Console.println("tree.symbol = "+tree.symbol);
// = treat the same as Bind(name, _)
val node = pDefaultPat(tree.pos, header.getTpe());
if ((env != null) && (tree.symbol != defs.PatternWildcard))
env.newBoundVar( tree.symbol, tree.tpe, header.selector);
node;
*/
} else
pVariablePat(tree.pos, tree); // a named constant Foo
case Select(_, name) => // variable
if (tree.symbol.isPrimaryConstructor)
pConstrPat(tree.pos, tree.tpe);
else
pVariablePat(tree.pos, tree);
case Literal(Constant(value)) =>
pConstantPat(tree.pos, tree.tpe, value);
//case Sequence(ts) =>
case ArrayValue(_, ts) =>
if ( !delegateSequenceMatching ) {
pSequencePat(tree.pos, tree.tpe, ts.length);
} else {
pSeqContainerPat(tree.pos, tree.tpe, tree);
}
case Alternative(ts) =>
if(ts.length < 2)
scala.Predef.error("ill-formed Alternative");
val subroot = pConstrPat(header.pos, header.getTpe());
subroot.and = pHeader(header.pos, header.getTpe(), header.selector.duplicate);
val subenv = new CaseEnv;
var i = 0; while(i < ts.length) {
val target = enter1(ts(i), -1, subroot, subroot.symbol, subenv);
target.and = pBody(tree.pos);
i = i + 1
}
pAltPat(tree.pos, subroot.and.asInstanceOf[Header]);
case _ =>
if(tree == null)
scala.Predef.error("unit = " + cunit + "; tree = null");
else
scala.Predef.error("unit = " + cunit + "; tree = "+tree);
}
}
protected def enter(pat: Tree, index: Int, target: PatternNode, casted: Symbol, env: CaseEnv ): PatternNode = {
target match {
case ConstrPat(newCasted) =>
enter1(pat, index, target, newCasted, env);
case SequencePat(newCasted, len) =>
enter1(pat, index, target, newCasted, env);
case _ =>
enter1(pat, index, target, casted, env);
}
}
private def newHeader(pos: Int, casted: Symbol, index: Int): Header = {
//Console.println("newHeader(pos,"+casted+","+index+")");
//Console.println(" casted.tpe"+casted.tpe);
//Console.println(" casted.pos "+casted.pos+" equals firstpos?"+(casted.pos == Position.FIRSTPOS));
val ident = typed(Ident(casted));
if (casted.pos == Position.FIRSTPOS) {
//Console.println("FIRSTPOS");
//Console.println("DEBUG");
//Console.println();
val t = typed(
Apply(Select( ident, ident.tpe.member(nme.apply)/* scalac: defs.functionApply( 1 )*/),
List( Literal( Constant(index) ) )));
val seqType = t.tpe;
pHeader( pos, seqType, t );
} else {
//Console.println("NOT FIRSTPOS");
// Console.println("newHeader :: casted="+casted);
// Console.println("newHeader :: casted.tpe="+casted.tpe);
//Console.println("newHeader :: ");
val caseAccs = casted.tpe.symbol.caseFieldAccessors;
if (caseAccs.length <= index) System.out.println("selecting " + index + " in case fields of " + casted.tpe.symbol + "=" + casted.tpe.symbol.caseFieldAccessors);//debug
val ts = caseAccs(index);
//Console.println("newHeader :: ts="+ts);
//val accType = casted.tpe.memberType(ts); // old scalac
//val accTree = global.typer.typed(Select(ident, ts)); // !
val accTree = typed(Apply(Select(ident, ts), List())); // nsc !
val accType = accTree.tpe;
//Console.println("newHeader :: accType="+accType);
//Console.println("newHeader :: accType.resultType ="+accType.resultType);
//Console.println("accTree.tpe =="+accTree.tpe);
accType match {
// scala case accessor
case MethodType(_, _) =>
//Console.println("Hello?!");
pHeader(pos, accType.resultType, Apply(accTree, List()));
// jaco case accessor
case _ =>
//Console.println("Hola?!");
pHeader(pos, accType, accTree);
}
}
}
/** main enter function
*
* invariant: ( curHeader == (Header)target.and ) holds
*/
protected def enter1(pat: Tree, index: Int, target: PatternNode, casted: Symbol, env: CaseEnv): PatternNode = {
//System.err.println("enter(" + pat + ", " + index + ", " + target + ", " + casted + ")");
val patArgs = patternArgs(pat); // get pattern arguments
var curHeader = target.and.asInstanceOf[Header]; // advance one step in intermediate representation
if (curHeader == null) { // check if we have to add a new header
//assert index >= 0 : casted;
if (index < 0) { scala.Predef.error("error entering:" + casted); return null }
target.and = {curHeader = newHeader(pat.pos, casted, index); curHeader};
curHeader.or = patternNode(pat, curHeader, env);
enter(patArgs, curHeader.or, casted, env);
}
else {
// find most recent header
while (curHeader.next != null)
curHeader = curHeader.next;
// create node
var patNode = patternNode(pat, curHeader, env);
var next: PatternNode = curHeader;
// add branch to curHeader, but reuse tests if possible
while (true) {
if (next.isSameAs(patNode)) { // test for patNode already present --> reuse
// substitute... !!!
patNode match {
case ConstrPat(ocasted) =>
env.substitute(ocasted, typed(Ident(next.asInstanceOf[ConstrPat].casted)));
case _ =>
}
return enter(patArgs, next, casted, env);
} else if (next.isDefaultPat() || // default case reached, or
((next.or == null) && // no more alternatives and
(patNode.isDefaultPat() || next.subsumes(patNode)))) {
// new node is default or subsumed
var header = pHeader(patNode.pos,
curHeader.getTpe(),
curHeader.selector);
{curHeader.next = header; header};
header.or = patNode;
return enter(patArgs,
patNode,
casted,
env);
}
else if (next.or == null) {
return enter(patArgs, {next.or = patNode; patNode}, casted, env); // add new branch
} else
next = next.or;
}
error("must not happen");
null
}
}
/** calls enter for an array of patterns, see enter
*/
protected def enter(pats:List[Tree], target1: PatternNode , casted1: Symbol , env: CaseEnv): PatternNode = {
var target = target1;
var casted = casted1;
target match {
case ConstrPat(newCasted) =>
casted = newCasted;
case SequencePat(newCasted, len) =>
casted = newCasted;
case _ =>
}
var i = 0; while(i < pats.length) {
target = enter1(pats(i), i, target, casted, env);
i = i + 1
}
target;
}
protected def nCaseComponents(tree: Tree): int = {
tree match {
case Apply(fn, _) =>
val tpe = tree.tpe.symbol.primaryConstructor.tpe;
//Console.println("~~~ " + tree.type() + ", " + tree.type().symbol.primaryConstructor());
tpe match {
// I'm not sure if this is a good idea, but obviously, currently all case classes
// without constructor arguments have type NoType
case NoType =>
error("this cannot happen");
0
case MethodType(args, _) =>
args.length;
case PolyType(tvars, MethodType(args, _)) =>
args.length;
case PolyType(tvars, _) =>
0;
case _ =>
error("not yet implemented;" +
"pattern matching for " + tree + ": " + tpe);
}
}
return 0;
}
//////////// generator methods
def toTree(): Tree = {
if (optimize && isSimpleIntSwitch())
intSwitchToTree();
else /* if (false && optimize && isSimpleSwitch())
switchToTree();
else */ {
//print();
generalSwitchToTree();
}
}
case class Break(res:Boolean) extends java.lang.Throwable;
case class Break2() extends java.lang.Throwable;
// TODO disentangle this
protected def isSimpleSwitch(): Boolean = {
print();
var patNode = root.and;
while (patNode != null) {
var node = patNode;
while (({node = node.or; node}) != null) {
node match {
case VariablePat(tree) =>
Console.println(((tree.symbol.flags & Flags.CASE) != 0));
case ConstrPat(_) =>
Console.println(node.getTpe().toString() + " / " + ((node.getTpe().symbol.flags & Flags.CASE) != 0));
var inner = node.and;
def funct(inner: PatternNode): Boolean = {
//outer: while (true) {
inner match {
case _h:Header =>
if (_h.next != null)
throw Break(false);
funct(inner.or)
case DefaultPat() =>
funct(inner.and);
case b:Body =>
if ((b.guard.length > 1) ||
(b.guard(0) != EmptyTree))
throw Break(false);
throw Break2() // break outer
case _ =>
Console.println(inner);
throw Break(false);
}
}
var res = false;
var set = false;
try {
funct(inner)
} catch {
case ex: Break =>
res = ex.res;
set = true;
case ex: Break2 =>
}
if(set) return res;
case _ =>
return false;
}
}
patNode = patNode.nextH();
}
return true;
}
protected def isSimpleIntSwitch(): Boolean = {
if (isSameType(selector.tpe.widen, defs.IntClass.tpe)) {
var patNode = root.and;
while (patNode != null) {
var node = patNode;
while (({node = node.or; node}) != null) {
node match {
case ConstantPat(_) => ;
case _ =>
return false;
}
node.and match {
case _b:Body =>
if ((_b.guard.length > 1) ||
(_b.guard(0) != EmptyTree) ||
(_b.bound(0).length > 0))
return false;
case _ =>
return false;
}
}
patNode = patNode.nextH();
}
return true;
} else
return false;
}
class TagBodyPair(tag1: Int, body1: Tree, next1:TagBodyPair ) {
var tag: int = tag1;
var body: Tree = body1;
var next: TagBodyPair = next1;
def length(): Int = {
if (null == next) 1 else (next.length() + 1);
}
}
protected def numCases(patNode1: PatternNode): Int = {
var patNode = patNode1;
var n = 0;
while (({patNode = patNode.or; patNode}) != null)
patNode match {
case DefaultPat() => ;
case _ =>
n = n + 1;
}
n;
}
protected def defaultBody(patNode1: PatternNode, otherwise: Tree ): Tree = {
var patNode = patNode1;
while (patNode != null) {
var node = patNode;
while (({node = node.or; node}) != null)
node match {
case DefaultPat() =>
return node.and.bodyToTree();
case _ =>
}
patNode = patNode.nextH();
}
otherwise;
}
/** This method translates pattern matching expressions that match
* on integers on the top level.
*/
def intSwitchToTree(): Tree = {
def insert1(tag: Int, body: Tree, current: TagBodyPair): TagBodyPair = {
if (current == null)
return new TagBodyPair(tag, body, null);
else if (tag > current.tag)
return new TagBodyPair(current.tag, current.body, insert1(tag, body, current.next));
else
return new TagBodyPair(tag, body, current);
}
//print();
val ncases = numCases(root.and);
val matchError = ThrowMatchError(selector.pos, Ident(root.symbol));
// without a case, we return a match error if there is no default case
if (ncases == 0)
return defaultBody(root.and, matchError);
// for one case we use a normal if-then-else instruction
else if (ncases == 1) {
root.and.or match {
case ConstantPat(value) =>
return If(Equals(selector, Literal(value)),
(root.and.or.and).bodyToTree(),
defaultBody(root.and, matchError));
case _ =>
return generalSwitchToTree();
}
}
//
// if we have more than 2 cases than use a switch statement
val _h:Header = root.and.asInstanceOf[Header];
val next = _h.next;
var mappings: TagBodyPair = null;
var defaultBody1: Tree = matchError;
var patNode = root.and;
while (patNode != null) {
var node = patNode.or;
while (node != null) {
node match {
case DefaultPat() =>
if (defaultBody1 != null)
scala.Predef.error("not your day today");
defaultBody1 = node.and.bodyToTree();
node = node.or;
case ConstantPat( value: Int )=>
mappings = insert1(
value,
node.and.bodyToTree(),
mappings);
node = node.or;
}
}
patNode = patNode.nextH();
}
var n = mappings.length();
var nCases: List[CaseDef] = Nil;
while (mappings != null) {
nCases = CaseDef(Literal(mappings.tag),
mappings.body) :: nCases;
mappings = mappings.next;
}
/*
val tags = new Array[Int](n);
val bodies = new Array[Tree](n);
n = 0;
while (mappings != null) {
tags(n) = mappings.tag;
bodies(n) = mappings.body;
n = n + 1;
mappings = mappings.next;
}
return Switch(selector, tags, bodies, defaultBody1, resultType);
*/
nCases = CaseDef(Ident(nme.WILDCARD), defaultBody1) :: nCases;
return Match(selector, nCases)
}
var exit:Symbol = null;
/** simple optimization: if the last pattern is `case _' (no guards), we won't generate the ThrowMatchError
*/
def generalSwitchToTree(): Tree = {
this.exit = currentOwner.newLabel(root.pos, "exit")
.setInfo(new MethodType(List(resultType), resultType));
//Console.println("resultType:"+resultType.toString());
val result = exit.newValueParameter(root.pos, "result").setInfo( resultType );
//Console.println("generalSwitchToTree: "+root.or);
/*
val ts = List(ValDef(root.symbol, selector));
val res = If(toTree(root.and),
LabelDef(exit, List(result), Ident(result)),
ThrowMatchError(selector.pos, resultType // , Ident(root.symbol)
));
return Block(ts, res);
*/
return Block(
List(
ValDef(root.symbol, selector),
toTree(root.and),
ThrowMatchError(selector.pos, Ident(root.symbol))),
LabelDef(exit, List(result), Ident(result)))
}
/*protected*/ def toTree(node1: PatternNode): Tree = {
def optimize1(selType:Type, alternatives1: PatternNode ): Boolean = {
var alts = alternatives1;
if (!optimize || !isSubType(selType, defs.ScalaObjectClass.tpe))
return false;
var cases = 0;
while (alts != null) {
alts match {
case ConstrPat(_) =>
if (alts.getTpe().symbol.hasFlag(Flags.CASE))
cases = cases +1;
else
return false;
case DefaultPat() =>
;
case _ =>
return false;
}
alts = alts.or;
}
return cases > 2;
} // def optimize
var node = node1;
var res: Tree = typed(Literal(Constant(false))); //.setInfo(defs.BooleanClass);
//Console.println("pm.toTree res.tpe "+res.tpe);
while (node != null)
node match {
case _h:Header =>
val selector = _h.selector;
val next = _h.next;
//res = And(mkNegate(res), toTree(node.or, selector));
//Console.println("HEADER TYPE = " + selector.type);
if (optimize1(node.getTpe(), node.or))
res = Or(res, toOptTree(node.or, selector));
else
res = Or(res, toTree(node.or, selector));
node = next;
case _b:Body =>
var bound = _b.bound;
val guard = _b.guard;
val body = _b.body;
if ((bound.length == 0) &&
(guard.length == 0) &&
(body.length == 0)) {
return Literal(Constant(true));
} else if (!doBinding)
bound = Predef.Array[Array[ValDef]]( Predef.Array[ValDef]() );
var i = guard.length - 1; while(i >= 0) {
val ts:Seq[Tree] = bound(i).asInstanceOf[Array[Tree]];
val temp = currentOwner.newValue(body(i).pos, cunit.fresh.newName("r$"))
.setFlag(Flags.SYNTHETIC).setInfo(resultType);
var res0: Tree =
//Block(
// List(Assign(Ident(resultVar), body(i))),
// Literal(Constant(true)));
Block(
List(
ValDef(temp, body(i)),
Apply(Ident(exit), List(Ident(temp)))),
Literal(Constant(true))
); // forward jump
if (guard(i) != EmptyTree)
res0 = And(guard(i), res0);
res = Or(Block(ts.toList, res0), res);
i = i - 1
}
return res;
case _ =>
scala.Predef.error("I am tired");
}
return res;
}
class TagNodePair(tag1: int, node1: PatternNode, next1: TagNodePair) {
var tag: int = tag1;
var node: PatternNode = node1;
var next: TagNodePair = next1;
def length(): Int = {
return if (null == next) 1 else (next.length() + 1);
}
}
protected def toOptTree(node1: PatternNode, selector: Tree): Tree = {
def insert2(tag: Int, node: PatternNode, current: TagNodePair): TagNodePair = {
if (current == null)
return new TagNodePair(tag, node, null);
else if (tag > current.tag)
return new TagNodePair(current.tag, current.node, insert2(tag, node, current.next));
else if (tag == current.tag) {
val old = current.node;
({current.node = node; node}).or = old;
return current;
} else
return new TagNodePair(tag, node, current);
}
def insertNode(tag:int , node:PatternNode , current:TagNodePair ): TagNodePair = {
val newnode = node.dup();
newnode.or = null;
return insert2(tag, newnode, current);
}
var node = node1;
//System.err.println("pm.toOptTree called"+node);
var cases: TagNodePair = null;
var defaultCase: PatternNode = null;
while (node != null)
node match {
case ConstrPat(casted) =>
cases = insertNode(node.getTpe().symbol.tag, node, cases);
node = node.or;
case DefaultPat() =>
defaultCase = node;
node = node.or;
case _ =>
scala.Predef.error("errare humanum est");
}
var n = cases.length();
/*
val tags = new Array[int](n);
val bodies = new Array[Tree](n);
n = 0;
while (null != cases) {
tags(n) = cases.tag;
bodies(n) = toTree(cases.node, selector);
n = n + 1;
cases = cases.next;
}
*/
/*
return
Switch(
Apply(
Select(selector.duplicate, defs.ScalaObjectClass_tag),
List()),
tags,
bodies,
{ if (defaultCase == null) Literal(false) else toTree(defaultCase.and) },
defs.boolean_TYPE());
*/
var nCases: List[CaseDef] = Nil;
while (cases != null) {
nCases = CaseDef(Literal(Constant(cases.tag)),
toTree(cases.node, selector)) :: nCases;
cases = cases.next;
}
val defBody = if (defaultCase == null)
Literal(Constant(false))
else
toTree(defaultCase.and);
nCases = CaseDef(Ident(nme.WILDCARD), defBody) :: nCases;
return Match(Apply(Select(selector.duplicate, defs.ScalaObjectClass_tag),
List()),
nCases);
}
protected def toTree(node:PatternNode , selector:Tree ): Tree = {
//Console.println("pm.toTree("+node+","+selector+")");
//Console.println("pm.toTree selector.tpe = "+selector.tpe+")");
if(selector.tpe == null)
scala.Predef.error("cannot go on");
if (node == null)
return Literal(Constant(false));
else
node match {
case DefaultPat() =>
return toTree(node.and);
case ConstrPat(casted) =>
return If(gen.mkIsInstanceOf(selector.duplicate, node.getTpe()),
Block(
List(ValDef(casted,
gen.mkAsInstanceOf(selector.duplicate, node.getTpe(), true))),
toTree(node.and)),
toTree(node.or, selector.duplicate));
case SequencePat(casted, len) =>
return (
Or(
And(
And(gen.mkIsInstanceOf(selector.duplicate, node.getTpe()),
Equals(
typed(
Apply(
Select(
gen.mkAsInstanceOf(selector.duplicate,
node.getTpe(),
true),
node.getTpe().member(nme.length) /*defs.Seq_length*/),
List())
),
typed(
Literal(Constant(len))
))),
Block(
List(
ValDef(casted,
gen.mkAsInstanceOf(selector.duplicate, node.getTpe(), true))),
toTree(node.and))),
toTree(node.or, selector.duplicate)));
case ConstantPat(value) =>
//Console.println("selector = "+selector);
//Console.println("selector.tpe = "+selector.tpe);
return If(Equals(selector.duplicate,
typed(Literal(Constant(value))).setType(node.tpe)),
toTree(node.and),
toTree(node.or, selector.duplicate));
case VariablePat(tree) =>
return If(Equals(selector.duplicate, tree),
toTree(node.and),
toTree(node.or, selector.duplicate));
case AltPat(header) =>
return If(toTree(header),
toTree(node.and),
toTree(node.or, selector.duplicate));
case _ =>
scala.Predef.error("can't plant this tree");
}
}
}
}
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