Notes on using graphviz to visualize abstract syntax trees (ASTs)

README.md

Using graphviz to visualize abstract syntax trees

• Take the above ast.dot file
• Paste it into http://www.webgraphviz.com/
• It will generate a diagram like this:

• After you've written your first lexer and parser, write a function which walks the AST and "compiles" it into graphviz notation like the above

ast.dot

digraph parse_tree {

ratio = fill;
node [style=filled];

program -> functionDecl;
functionDecl -> fun;
functionDecl -> myFun;
functionDecl -> "(";
functionDecl -> ")";
functionDecl -> "{";
functionDecl -> varDecl;
functionDecl -> "}";
varDecl -> var;
varDecl -> aVar;
varDecl -> "=";
varDecl -> addition;
addition -> 1;
addition -> "+";
addition -> 2;

program [color="0.408 0.498 1.000"];
functionDecl [color="0.408 0.498 1.000"];
fun [color="0.641 0.212 1.000"];
myFun [color="0.641 0.212 1.000"];
"(" [color="0.641 0.212 1.000"];
")" [color="0.641 0.212 1.000"];
"{" [color="0.641 0.212 1.000"];
varDecl [color="0.408 0.498 1.000"];
"}" [color="0.641 0.212 1.000"];
var [color="0.641 0.212 1.000"];
aVar [color="0.641 0.212 1.000"];
"=" [color="0.641 0.212 1.000"];
addition [color="0.408 0.498 1.000"];
1 [color="0.641 0.212 1.000"];
"+" [color="0.641 0.212 1.000"];
2 [color="0.641 0.212 1.000"];

}