Infer types of bool/null/string literals.

pkg/front_end/lib/src/fasta/kernel/body_builder.dart

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library fasta.body_builder;
 
 import '../fasta_codes.dart'
     show FastaMessage, codeExpectedButGot, codeExpectedFunctionBody;
 
 import '../parser/parser.dart' show FormalParameterType, optional;
@@ skipping 946 matching lines @@
   void handleStringPart(Token token) {
     debugEvent("StringPart");
     push(token);
   }
 
   @override
   void endLiteralString(int interpolationCount, Token endToken) {
     debugEvent("endLiteralString");
     if (interpolationCount == 0) {
       Token token = pop();
-      push(new StringLiteral(unescapeString(token.lexeme))
-        ..fileOffset = token.charOffset);
+      String value = unescapeString(token.lexeme);
+      push(astFactory.stringLiteral(value, token));
     } else {
       List parts = popList(1 + interpolationCount * 2);
       Token first = parts.first;
       Token last = parts.last;
       Quote quote = analyzeQuote(first.lexeme);
       List<Expression> expressions = <Expression>[];
       // Contains more than just \' or \".
       if (first.lexeme.length > 1) {
-        expressions.add(
-            new StringLiteral(unescapeFirstStringPart(first.lexeme, quote)));
+        String value = unescapeFirstStringPart(first.lexeme, quote);
+        expressions.add(astFactory.stringLiteral(value, first));
       }
       for (int i = 1; i < parts.length - 1; i++) {
         var part = parts[i];
         if (part is Token) {
           if (part.lexeme.length != 0) {
-            expressions.add(new StringLiteral(unescape(part.lexeme, quote)));
+            String value = unescape(part.lexeme, quote);
+            expressions.add(astFactory.stringLiteral(value, part));
           }
         } else {
           expressions.add(toValue(part));
         }
       }
       // Contains more than just \' or \".
       if (last.lexeme.length > 1) {
-        expressions
-            .add(new StringLiteral(unescapeLastStringPart(last.lexeme, quote)));
+        String value = unescapeLastStringPart(last.lexeme, quote);
+        expressions.add(astFactory.stringLiteral(value, last));
       }
-      push(new StringConcatenation(expressions)
-        ..fileOffset = endToken.charOffset);
+      push(astFactory.stringConcatenation(expressions, endToken));
     }
   }
 
   @override
   void handleScript(Token token) {
     debugEvent("Script");
   }
 
   @override
   void handleStringJuxtaposition(int literalCount) {
@@ skipping 284 matching lines @@
     push(new ListLiteral(expressions,
         typeArgument: typeArgument, isConst: constKeyword != null)
       ..fileOffset = constKeyword?.charOffset ?? beginToken.charOffset);
   }
 
   @override
   void handleLiteralBool(Token token) {
     debugEvent("LiteralBool");
     bool value = optional("true", token);
     assert(value || optional("false", token));
-    push(new BoolLiteral(value)..fileOffset = token.charOffset);
+    push(astFactory.boolLiteral(value, token));
   }
 
   @override
   void handleLiteralDouble(Token token) {
     debugEvent("LiteralDouble");
     push(astFactory.doubleLiteral(double.parse(token.lexeme), token));
   }
 
   @override
   void handleLiteralNull(Token token) {
@@ skipping 1816 matching lines @@
   } else if (node is PrefixBuilder) {
     return node.name;
   } else if (node is ThisAccessor) {
     return node.isSuper ? "super" : "this";
   } else if (node is FastaAccessor) {
     return node.plainNameForRead;
   } else {
     return internalError("Unhandled: ${node.runtimeType}");
   }
 }