cssparser: remove SyntaxError

return DOMException instead

2 files changed, 34 insertions, 24 deletions

diff --git a/src/css/cssparser.nim b/src/css/cssparser.nim
index 57cfc87e..222ad92d 100644
--- a/src/css/cssparser.nim
+++ b/src/css/cssparser.nim
@@ -3,6 +3,8 @@ import streams
 import sugar
 import unicode
 
+import js/exception
+import utils/opt
 import utils/twtstr
 
 type
@@ -74,8 +76,6 @@ type
 
   CSSAnB* = tuple[A, B: int]
 
-  SyntaxError = object of ValueError
-
 # For debugging
 proc `$`*(c: CSSParsedItem): string =
   if c of CSSToken:
@@ -519,7 +519,7 @@ proc consumeSimpleBlock(state: var CSSParseState): CSSSimpleBlock =
   of CSS_LBRACE_TOKEN: ending = CSS_RBRACE_TOKEN
   of CSS_LPAREN_TOKEN: ending = CSS_RPAREN_TOKEN
   of CSS_LBRACKET_TOKEN: ending = CSS_RBRACKET_TOKEN
-  else: raise newException(Exception, "Parse error!")
+  else: doAssert false
   
   result = CSSSimpleBlock(token: t)
   while state.at < state.tokens.len:
@@ -717,45 +717,49 @@ proc parseListOfRules*(cvals: seq[CSSComponentValue]): seq[CSSRule] =
       CSSParsedItem(cval)
   return state.parseListOfRules()
 
-proc parseRule(state: var CSSParseState): CSSRule =
+proc parseRule(state: var CSSParseState): Result[CSSRule, DOMException] =
   while state.has() and state.peek() == CSS_WHITESPACE_TOKEN:
     discard state.consume()
   if not state.has():
-    raise newException(SyntaxError, "EOF reached!")
+    return err(newDOMException("Unexpected EOF", "SyntaxError"))
 
+  var res: CSSRule
   if state.peek() == CSS_AT_KEYWORD_TOKEN:
-    result = state.consumeAtRule()
+    res = state.consumeAtRule()
   else:
     let q = state.consumeQualifiedRule()
     if q.isSome:
-      result = q.get
+      res = q.get
     else:
-      raise newException(SyntaxError, "No qualified rule found!")
+      return err(newDOMException("No qualified rule found!", "SyntaxError"))
 
   while state.has() and state.peek() == CSS_WHITESPACE_TOKEN:
     discard state.consume()
   if state.has():
-    raise newException(SyntaxError, "EOF not reached!")
+    return err(newDOMException("EOF not reached", "SyntaxError"))
+  return ok(res)
 
-proc parseRule(inputStream: Stream): CSSRule =
+proc parseRule*(inputStream: Stream): Result[CSSRule, DOMException] =
   var state = CSSParseState()
   state.tokens = tokenizeCSS(inputStream)
   return state.parseRule()
 
-proc parseDeclaration(state: var CSSParseState): CSSDeclaration =
+proc parseDeclaration(state: var CSSParseState):
+    Result[CSSDeclaration, DOMException] =
   while state.has() and state.peek() == CSS_WHITESPACE_TOKEN:
     discard state.consume()
 
   if not state.has() or state.peek() != CSS_IDENT_TOKEN:
-    raise newException(SyntaxError, "No ident token found!")
+    return err(newDOMException("No ident token found", "SyntaxError"))
 
   let d = state.consumeDeclaration()
   if d.isSome:
-    return d.get
+    return ok(d.get)
 
-  raise newException(SyntaxError, "No declaration found!")
+  return err(newDOMException("No declaration found", "SyntaxError"))
 
-proc parseDeclaration*(inputStream: Stream): CSSDeclaration =
+proc parseDeclaration*(inputStream: Stream):
+    Result[CSSDeclaration, DOMException] =
   var state = CSSParseState()
   state.tokens = tokenizeCSS(inputStream)
   return state.parseDeclaration()
@@ -790,20 +794,23 @@ proc parseListOfDeclarations2*(inputStream: Stream): seq[CSSDeclaration] =
   state.tokens = tokenizeCSS(inputStream)
   return state.parseListOfDeclarations2()
 
-proc parseComponentValue(state: var CSSParseState): CSSComponentValue =
+proc parseComponentValue(state: var CSSParseState):
+    Result[CSSComponentValue, DOMException] =
   while state.has() and state.peek() == CSS_WHITESPACE_TOKEN:
     discard state.consume()
   if not state.has():
-    raise newException(SyntaxError, "EOF reached!")
+    return err(newDOMException("Unexpected EOF", "SyntaxError"))
 
-  result = state.consumeComponentValue()
+  let res = state.consumeComponentValue()
 
   while state.has() and state.peek() == CSS_WHITESPACE_TOKEN:
     discard state.consume()
   if state.has():
-    raise newException(SyntaxError, "EOF not reached!")
+    return err(newDOMException("EOF not reached", "SyntaxError"))
+  return ok(res)
 
-proc parseComponentValue*(inputStream: Stream): CSSComponentValue =
+proc parseComponentValue*(inputStream: Stream):
+    Result[CSSComponentValue, DOMException] =
   var state: CSSParseState
   state.tokens = tokenizeCSS(inputStream)
   return state.parseComponentValue()
diff --git a/src/html/dom.nim b/src/html/dom.nim
index 4d71c3a3..16335399 100644
--- a/src/html/dom.nim
+++ b/src/html/dom.nim
@@ -1581,10 +1581,13 @@ func formmethod*(element: Element): FormMethod =
   return FORM_METHOD_GET
 
 proc parseColor(element: Element, s: string): RGBAColor =
-  return cssColor(parseComponentValue(newStringStream(s)))
-    #TODO TODO TODO return element style
-    # For now we just use white.
-    .get(rgb(255, 255, 255))
+  let cval = parseComponentValue(newStringStream(s))
+  #TODO TODO TODO return element style
+  # For now we just use white.
+  let ec = rgb(255, 255, 255)
+  if cval.isErr:
+    return ec
+  return cssColor(cval.get).get(ec)
 
 #TODO ??
 func target0*(element: Element): string =