Change TypeI#getTypeParameters() to return a Collection<TypeI> instea…

…d of Collection<String>.

This is important for TypedCodeGenerator to ensure that typevars are formatted as written, rather than with NTI's uniquified names.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=166652159

src/com/google/javascript/jscomp/TypedCodeGenerator.java

@@ -19,8 +19,10 @@
 import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.base.Preconditions.checkState;
 
+import com.google.common.base.Function;
 import com.google.common.base.Joiner;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.Iterables;
 import com.google.javascript.rhino.FunctionTypeI;
 import com.google.javascript.rhino.JSDocInfo;
 import com.google.javascript.rhino.Node;
@@ -175,17 +177,25 @@ private String getFunctionAnnotation(Node fnNode) {
       }
     }
 
-    Collection<String> typeParams = funType.getTypeParameters();
+    Collection<TypeI> typeParams = funType.getTypeParameters();
     if (!typeParams.isEmpty()) {
       sb.append(" * @template ");
-      Joiner.on(",").appendTo(sb, typeParams);
+      Joiner.on(",").appendTo(sb, Iterables.transform(typeParams, new Function<TypeI, String>() {
+        @Override public String apply(TypeI var) {
+          return formatTypeVar(var);
+        }
+      }));
       sb.append("\n");
     }
 
     sb.append(" */\n");
     return sb.toString();
   }
 
+  private String formatTypeVar(TypeI var) {
+    return var.toAnnotationString(Nullability.IMPLICIT);
+  }
+
   // TODO(dimvar): it's awkward that we print @constructor after the extends/implements;
   // we should print it first, like users write it. Same for @interface and @record.
   private void appendConstructorAnnotations(StringBuilder sb, FunctionTypeI funType) {

src/com/google/javascript/jscomp/newtypes/JSType.java

@@ -21,12 +21,14 @@
 import static com.google.common.base.Preconditions.checkState;
 
 import com.google.common.annotations.GwtIncompatible;
+import com.google.common.base.Function;
 import com.google.common.base.Joiner;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.LinkedHashMultimap;
+import com.google.common.collect.Lists;
 import com.google.common.collect.Multimap;
 import com.google.common.collect.Sets;
 import com.google.javascript.jscomp.NodeUtil;
@@ -1920,13 +1922,24 @@ public final int getMaxArity() {
   }
 
   @Override
-  public final List<String> getTypeParameters() {
+  public final List<TypeI> getTypeParameters() {
     if (isFunctionType()) {
-      return this.getFunTypeIfSingletonObj().getTypeParameters();
+      return transformTypeParamsToTypeVars(this.getFunTypeIfSingletonObj().getTypeParameters());
     }
     NominalType nt = getNominalTypeIfSingletonObj();
     checkNotNull(nt, this);
-    return nt.getTypeParameters();
+    return transformTypeParamsToTypeVars(nt.getTypeParameters());
+  }
+
+  private List<TypeI> transformTypeParamsToTypeVars(List<String> names) {
+    return Lists.transform(
+        names,
+        new Function<String, TypeI>() {
+          @Override
+          public TypeI apply(String name) {
+            return JSType.fromTypeVar(commonTypes, name);
+          }
+        });
   }
 
   @Override

src/com/google/javascript/rhino/TypeI.java

@@ -200,9 +200,10 @@ public interface TypeI extends Serializable {
   boolean isPartiallyInstantiated();
 
   /**
-   * If this type is a generic nominal type or function, return the names of all type parameters.
+   * If this type is a generic nominal type or function, return the type parameters as type
+   * variables.
    */
-  Collection<String> getTypeParameters();
+  Collection<TypeI> getTypeParameters();
 
   /**
    * Returns a string representation of this type, suitable for printing

src/com/google/javascript/rhino/jstype/JSType.java

@@ -564,10 +564,10 @@ public TemplateTypeMap getTemplateTypeMap() {
   }
 
   @Override
-  public final ImmutableSet<String> getTypeParameters() {
-    ImmutableSet.Builder<String> params = ImmutableSet.builder();
+  public final ImmutableSet<TypeI> getTypeParameters() {
+    ImmutableSet.Builder<TypeI> params = ImmutableSet.builder();
     for (TemplateType type : getTemplateTypeMap().getTemplateKeys()) {
-      params.add(type.toString());
+      params.add(type);
     }
     return params.build();
   }