Remove nested error handling and clean up some

src/Main.purs

@@ -19,14 +19,11 @@ import Web.DOM.Document (contentType
   )
 import Web.DOM.DOMParser (makeDOMParser, parseSVGFromString)
 import Web.DOM.Element (toNode) as Element
-import Web.DOM.HTMLCollection (length)
 import Web.DOM.Node (appendChild, nodeName, setTextContent)
 import Web.DOM.NonElementParentNode (getElementById)
 import Web.DOM.ParentNode (firstElementChild)
 import Web.HTML (window)
 import Web.HTML.HTMLDocument (toDocument)
-import Web.HTML.HTMLMetaElement (setContent)
-import Web.HTML.HTMLDivElement (fromElement)
 import Web.HTML.Window (document)
 
 -- Consider DOM.Simple.Types
@@ -36,26 +33,24 @@ main = do
   w <- window
   d <- document w
   let dd = toDocument d
-  dUrl <- url dd
-  let containerID = "svgContainer"
   domParser <- makeDOMParser
-  let mySVG = ternaryGraph 100.0 50.0 50.0 10
-  svgDoc <- parseSVGFromString mySVG domParser
+
+  let containerID = "svg-container"
   maybeElement <- getElementById containerID $ toNonElementParentNode dd
-  case maybeElement of
-    Nothing -> do 
-      throw $ "Unable to find " <> containerID 
-    Just e -> do 
-      let node = Element.toNode e
-      case svgDoc of
-        Left error -> throw error
-        Right doc -> do
-          log $ nodeName (toNode doc)
-          elMay <- firstElementChild $ toParentNode doc
-          case elMay of
-            Nothing -> throw "oops"
-            Just el -> do
-              let svgNode = Element.toNode el
-              log $ nodeName svgNode 
-              newNode <- importNode svgNode true dd
-              appendChild newNode node
+  node <- case maybeElement of
+    Nothing -> throw $ "Unable to find " <> containerID 
+    Just e -> pure $ Element.toNode e
+
+  let mySVG = ternaryGraph 100.0 50.0 50.0 10
+  svgDocMay <- parseSVGFromString mySVG domParser
+  svgDoc <- case svgDocMay of
+    Left error -> throw error
+    Right doc -> pure doc
+
+  elMay <- firstElementChild $ toParentNode svgDoc
+  svgNode <- case elMay of
+    Nothing -> throw "no child in svg doc"
+    Just el -> pure $ Element.toNode el
+  
+  newNode <- importNode svgNode true dd
+  appendChild newNode node