clean up to_dot_string string concatenation

Rather than appending separator at the end within a loop and then having
to pop off the trailing separator characters we consume the first entry
from the iter and then loop over the rest of the elements in the iter
adding the separator then key/values

1 files changed, 16 insertions, 11 deletions

diff --git a/src/lib.rs b/src/lib.rs
index f35641c..13968d9 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -12,6 +12,9 @@ static INDENT: &str = "    ";
 
 // TODO: should we use a hashmap that retains insertion order?
 
+// TODO: support adding edge based on index of nodes?
+
+
 /// Most of this comes from core rust. Where to provide attribution?
 /// The text for a graphviz label on a node or edge.
 #[derive(Clone, PartialEq, Eq, Debug)]
@@ -246,6 +249,9 @@ where Ty: GraphType
         writeln!(w, "{}{} {} {{", strict, self.graph.as_slice(), id)?;
 
         // TODO: add global graph attributes
+        for a in self.graph.attributes {
+
+        }
 
         for n in self.graph.nodes {
             // TODO: handle render options
@@ -327,9 +333,7 @@ pub struct Graph<'a, Ty = Directed> {
     // TODO: support multiple comments
     pub comment: Option<String>,
 
-    pub graph_attributes: Option<Vec<String>>,
-
-    // pub nodes: Vec<&'a Node<'a>>,
+    pub attributes: HashMap<String, AttributeText<'a>>,
 
     pub nodes: Vec<Node<'a>>,
 
@@ -351,7 +355,7 @@ impl<'a> Graph<'a, Directed> {
             id: id,
             strict: false,
             comment: None,
-            graph_attributes: None,
+            attributes: HashMap::new(),
             nodes: Vec::new(),
             edges: Vec::new(),
             ty: PhantomData,
@@ -369,7 +373,7 @@ impl<'a> Graph<'a, Undirected> {
             id: id,
             strict: false,
             comment: None,
-            graph_attributes: None,
+            attributes: HashMap::new(),
             nodes: Vec::new(),
             edges: Vec::new(),
             ty: PhantomData,
@@ -470,13 +474,14 @@ impl<'a> Node<'a> {
         // I think we introduce a AttributeText enum which encodes how to write out the attribute value
         if !self.attributes.is_empty() {
             dot_string.push_str(" [");
-            for (key, value) in &self.attributes {
-                dot_string.push_str(format!("{}={}, ", key, value.to_dot_string()).as_str());
+            let mut iter = self.attributes.iter();
+            let first = iter.next().unwrap();
+            dot_string.push_str(format!("{}={}", first.0, first.1.to_dot_string()).as_str());
+            for (key, value) in iter {
+                dot_string.push_str(", ");
+                dot_string.push_str(format!("{}={}", key, value.to_dot_string()).as_str());
             }
-            // remove trailing comma and spae
-            // TODO: make this less shitty
-            dot_string.pop();
-            dot_string.pop();
+
             dot_string.push_str("]");
         }
         dot_string.push_str(";");