diff options
Diffstat (limited to 'sources/scalac/typechecker/Infer.java')
| -rw-r--r-- | sources/scalac/typechecker/Infer.java | 86 |
1 files changed, 67 insertions, 19 deletions
diff --git a/sources/scalac/typechecker/Infer.java b/sources/scalac/typechecker/Infer.java index 0ccbcc1e8d..c08852766d 100644 --- a/sources/scalac/typechecker/Infer.java +++ b/sources/scalac/typechecker/Infer.java @@ -299,7 +299,10 @@ public class Infer implements Modifiers, Kinds { case TypeVar(Type origin, Type.Constraint constr): if (constr.inst == Type.NoType) if (constr.lobounds != Type.List.EMPTY) { + //System.out.println("LOBOUNDS = " + constr.lobounds);//DEBUG constr.inst = Type.lub(constr.lobounds.toArray()); + //System.out.println("MIN = " + constr.inst);//DEBUG + } else { constr.inst = global.definitions.ALL_TYPE; } @@ -309,7 +312,7 @@ public class Infer implements Modifiers, Kinds { } } - private void maximizeVars(Symbol[] tparams, Type[] tvars, int i) + private void solveUpper(Symbol[] tparams, Type[] tvars, int i) throws NoInstance { if (tvars[i] != Type.NoType) { switch (tvars[i]) { @@ -322,9 +325,10 @@ public class Infer implements Modifiers, Kinds { Type bound = tparams[i].info(); boolean cyclic = false; for (int j = 0; j < tvars.length; j++) { - if (bound.contains(tparams[j])) { + if (bound.contains(tparams[j]) || + tparams[j].loBound().isSameAs(tparams[i].type())) { cyclic |= tvars[j] == Type.NoType; - maximizeVars(tparams, tvars, j); + solveUpper(tparams, tvars, j); } } if (!cyclic) @@ -338,6 +342,39 @@ public class Infer implements Modifiers, Kinds { } } + private void solveLower(Symbol[] tparams, Type[] tvars, int i) + throws NoInstance { + if (tvars[i] != Type.NoType) { + //System.out.println("solve lower " + tparams[i]);//DEBUG + switch (tvars[i]) { + case TypeVar(Type origin, Type.Constraint constr): + if (constr.inst != Type.NoType) { + constr.inst = tvars[i] = instantiate(constr.inst); + } else { + Type tvar = tvars[i]; + tvars[i] = Type.NoType; + Type bound = tparams[i].loBound(); + if (bound != Global.instance.definitions.ALL_TYPE) { + boolean cyclic = false; + for (int j = 0; j < tvars.length; j++) { + if (bound.contains(tparams[j]) || + tparams[j].info().isSameAs(tparams[i].type())) { + cyclic |= tvars[j] == Type.NoType; + solveLower(tparams, tvars, j); + } + } + assert !cyclic; + if (!cyclic) + constr.lobounds = new Type.List( + bound.subst(tparams, tvars), constr.lobounds); + } + minimizeVar(tvar); + tvars[i] = ((Type.TypeVar) tvar).constr.inst; + } + } + } + } + private Type[] freshVars(Symbol[] tparams) { Type[] tvars = new Type[tparams.length]; for (int i = 0; i < tvars.length; i++) { @@ -350,14 +387,30 @@ public class Infer implements Modifiers, Kinds { public Type apply(Type t) { switch (t) { case PolyType(Symbol[] tparams, Type restp): + Type restp1 = apply(restp); + Symbol[] tparams1 = Symbol.EMPTY_ARRAY; + Symbol[] newparams1 = Symbol.EMPTY_ARRAY; + switch (restp1) { + case PolyType(_, _): + tparams1 = restp.typeParams(); + newparams1 = restp1.typeParams(); + } Symbol[] newparams = new Symbol[tparams.length]; for (int i = 0; i < tparams.length; i++) newparams[i] = tparams[i].cloneSymbol(); - for (int i = 0; i < tparams.length; i++) + for (int i = 0; i < tparams.length; i++) { newparams[i].setInfo( - newparams[i].info().subst(tparams, newparams)); + newparams[i].info() + .subst(tparams, newparams) + .subst(tparams1, newparams1)); + newparams[i].setLoBound( + newparams[i].loBound() + .subst(tparams, newparams) + .subst(tparams1, newparams1)); + } return Type.PolyType( - newparams, apply(restp).subst(tparams, newparams)); + newparams, restp1.subst(tparams, newparams)); + case OverloadedType(_, _): return map(t); default: @@ -392,7 +445,7 @@ public class Infer implements Modifiers, Kinds { private Symbol[] normalizeArgs(Type[] targs, Symbol[] tparams) { Type.List uninstantiated = Type.List.EMPTY; for (int i = 0; i < targs.length; i++) { - if (targs[i] == Type.NoType) { + if (targs[i] == Global.instance.definitions.ALL_TYPE) { targs[i] = tparams[i].type(); uninstantiated = Type.List.append(uninstantiated, targs[i]); } @@ -421,10 +474,9 @@ public class Infer implements Modifiers, Kinds { try { Type[] targs = new Type[tvars.length]; for (int i = 0; i < tvars.length; i++) { - minimizeVar(tvars[i]); - targs[i] = instantiate(tvars[i]); + solveLower(tparams, tvars, i); } - return targs; + return tvars; } catch (NoInstance ex) { } } @@ -537,7 +589,7 @@ public class Infer implements Modifiers, Kinds { * argument types, result type and expected result type. * If this is not possible, throw a `NoInstance' exception, or, if * `needToSucceed' is false alternatively return `null'. - * Undetermined type arguments are represented by `NoType'. + * Undetermined type arguments are represented by `definitions.ALL_TYPE'. * No check that inferred parameters conform to their bounds is made here. */ private Type[] methTypeArgs(Symbol[] tparams, @@ -587,14 +639,10 @@ public class Infer implements Modifiers, Kinds { } Type[] targs = new Type[tvars.length]; for (int i = 0; i < tvars.length; i++) { - minimizeVar(tvars[i]); - Type instType = ((Type.TypeVar) tvars[i]).constr.inst; - targs[i] = (instType == Type.NoType || instType == global.definitions.ALL_TYPE) - ? Type.NoType - : instantiate(tvars[i]); + solveLower(tparams, tvars, i); } - //System.out.println(" = " + ArrayApply.toString(targs));//DEBUG - return targs; + //System.out.println(" = " + ArrayApply.toString(tvars));//DEBUG + return tvars; } /** Create and attribute type application node. Pass arguments for that @@ -738,7 +786,7 @@ public class Infer implements Modifiers, Kinds { if (ctpe1.isSubType(pt)) { try { for (int i = 0; i < tvars.length; i++) { - maximizeVars(tparams, tvars, i); + solveUpper(tparams, tvars, i); } checkBounds(tparams, tvars, "inferred "); tree.setType(restype.subst(tparams, tvars)); |