[llvm-commits] [llvm] r43726 - /llvm/trunk/docs/tutorial/LangImpl3.html

[Chris Lattner]

Author: lattner
Date: Mon Nov  5 13:25:14 2007
New Revision: 43726

URL: http://llvm.org/viewvc/llvm-project?rev=43726&view=rev
Log:
mention possibility of using a visitor

Modified:
    llvm/trunk/docs/tutorial/LangImpl3.html

Modified: llvm/trunk/docs/tutorial/LangImpl3.html
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/tutorial/LangImpl3.html?rev=43726&r1=43725&r2=43726&view=diff

==============================================================================
--- llvm/trunk/docs/tutorial/LangImpl3.html (original)
+++ llvm/trunk/docs/tutorial/LangImpl3.html Mon Nov  5 13:25:14 2007
@@ -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