mention possibility of using a visitor
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43726 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/tutorial/LangImpl3.html b/docs/tutorial/LangImpl3.html
index 3733a66..3e62928 100644
--- a/docs/tutorial/LangImpl3.html
+++ b/docs/tutorial/LangImpl3.html
@@ -62,7 +62,7 @@
class ExprAST {
public:
virtual ~ExprAST() {}
- virtual Value *Codegen() = 0;
+ <b>virtual Value *Codegen() = 0;</b>
};
/// NumberExprAST - Expression class for numeric literals like "1.0".
@@ -70,7 +70,7 @@
double Val;
public:
explicit NumberExprAST(double val) : Val(val) {}
- virtual Value *Codegen();
+ <b>virtual Value *Codegen();</b>
};
...
</pre>
@@ -88,6 +88,11 @@
href="http://en.wikipedia.org/wiki/Static_single_assignment_form">Static Single
Assignment</a> - the concepts are really quite natural once you grok them.</p>
+<p>Note that instead of adding virtual methods to the ExprAST class hierarchy,
+it could also make sense to use a visitor pattern or some other way to model
+this. Again, this tutorial won't dwell on good software engineering practices:
+for our purposes, adding virtual methods is simplest.</p>
+
<p>The
second thing we want is an "Error" method like we used for parser, which will
be used to report errors found during code generation (for example, use of an