fixes #101, minor improvements

* improved error reporting on wrong tags
 * removed a debug `echo` call
 * fixed problems with sparse objects and Option (#101)

test/tnative.nim

@@ -264,6 +264,19 @@ suite "Serialization":
     let input = [none(int32), some(42'i32), none(int32)]
     let output = blockOnlyDumper().dump(input)
     assertStringEqual "- !!null ~\n- 42\n- !!null ~\n", output
+  
+  dualTest "Load Option of seq":
+    let input = "- !!null\n- [a, b]"
+    var result: array[0..1, Option[seq[string]]]
+    load(input, result)
+    assert not result[0].isSome
+    assert result[1].get()[0] == "a"
+    assert result[1].get()[1] == "b"
+  
+  test "Dump Option of seq":
+    let input = [none(seq[string]), some(@["a", "b"])]
+    let output = Dumper().dump(input)
+    assertStringEqual "- !!null ~\n- [a, b]\n", output
 
   dualTest "Load Table[int, string]":
     let input = "23: dreiundzwanzig\n42: zweiundvierzig"

yaml/loading.nim

@@ -38,6 +38,7 @@ proc load*[K](input: Stream | string, target: var K)
     if e.parent of IOError: raise (ref IOError)(e.parent)
     if e.parent of OSError: raise (ref OSError)(e.parent)
     elif e.parent of YamlParserError: raise (ref YamlParserError)(e.parent)
+    elif e.parent of YamlConstructionError: raise (ref YamlConstructionError)(e.parent)
     else: internalError("Unexpected exception: " & $e.parent.name)
 
 proc loadAs*[K](input: Stream | string): K {.raises:

yaml/native.nim

@@ -827,8 +827,8 @@ proc hasSparse(t: typedesc): bool {.compileTime.} =
 
 proc getOptionInner(fType: NimNode): NimNode {.compileTime.} =
   if fType.kind == nnkBracketExpr and len(fType) == 2 and
-      fType[1].kind == nnkSym:
+      fType[0].kind == nnkSym:
-    return newIdentNode($fType[1])
+    return fType[1]
   else: return nil
 
 proc checkMissing(
@@ -850,7 +850,7 @@ proc checkMissing(
         when `o`.`field`.hasCustomPragma(defaultVal):
           `o`.`field` = `o`.`field`.getCustomPragmaVal(defaultVal)
         elif hasSparse(`t`) and `o`.`field` is Option:
-          `o`.`field` = none(`optionInner`)
+          `o`.`field` = none[`optionInner`]()
         else:
           raise constructionError(`s`, `m`, "While constructing " & `tName` &
               ": Missing field: " & `fName`)
@@ -1447,17 +1447,20 @@ proc constructChild*[T](
     of yamlScalar:
       if item.scalarProperties.tag notin [yTagQuestionMark, yTagExclamationMark,
                                yamlTag(T)]:
-        raise ctx.input.constructionError(item.startPos, "Wrong tag for " & typetraits.name(T))
+        raise ctx.input.constructionError(
+          item.startPos, "Wrong tag for " & typetraits.name(T) & ": " & $item.scalarProperties.tag)
       elif item.scalarProperties.anchor != yAnchorNone:
         raise ctx.input.constructionError(item.startPos, "Anchor on non-ref type")
     of yamlStartMap:
       if item.mapProperties.tag notin [yTagQuestionMark, yamlTag(T)]:
-        raise ctx.input.constructionError(item.startPos, "Wrong tag for " & typetraits.name(T))
+        raise ctx.input.constructionError(
+          item.startPos, "Wrong tag for " & typetraits.name(T) & ": " & $item.mapProperties.tag)
       elif item.mapProperties.anchor != yAnchorNone:
         raise ctx.input.constructionError(item.startPos, "Anchor on non-ref type")
     of yamlStartSeq:
       if item.seqProperties.tag notin [yTagQuestionMark, yamlTag(T)]:
-        raise ctx.input.constructionError(item.startPos, "Wrong tag for " & typetraits.name(T))
+        raise ctx.input.constructionError(
+          item.startPos, "Wrong tag for " & typetraits.name(T) & ": " & $item.seqProperties.tag)
       elif item.seqProperties.anchor != yAnchorNone:
         raise ctx.input.constructionError(item.startPos, "Anchor on non-ref type")
     of yamlAlias:
@@ -1474,7 +1477,8 @@ proc constructChild*(
   if item.kind == yamlScalar:
     if item.scalarProperties.tag notin
         [yTagQuestionMark, yTagExclamationMark, yamlTag(string)]:
-      raise ctx.input.constructionError(item.startPos, "Wrong tag for string")
+      raise ctx.input.constructionError(
+        item.startPos, "Wrong tag for string: " & $item.scalarProperties.tag)
     elif item.scalarProperties.anchor != yAnchorNone:
       raise ctx.input.constructionError(item.startPos, "Anchor on non-ref type")
   ctx.constructObject(result)
@@ -1486,7 +1490,8 @@ proc constructChild*[T](
   let item = ctx.input.peek()
   if item.kind == yamlStartSeq:
     if item.seqProperties.tag notin [yTagQuestionMark, yamlTag(seq[T])]:
-      raise ctx.input.constructionError(item.startPos, "Wrong tag for " & typetraits.name(seq[T]))
+      raise ctx.input.constructionError(
+        item.startPos, "Wrong tag for " & typetraits.name(seq[T]) & ": " & $item.seqProperties.tag)
     elif item.seqProperties.anchor != yAnchorNone:
       raise ctx.input.constructionError(item.startPos, "Anchor on non-ref type")
   ctx.constructObject(result)
@@ -1498,7 +1503,8 @@ proc constructChild*[I, T](
   let item = ctx.input.peek()
   if item.kind == yamlStartSeq:
     if item.seqProperties.tag notin [yTagQuestionMark, yamlTag(array[I, T])]:
-      raise ctx.input.constructionError(item.startPos, "Wrong tag for " & typetraits.name(array[I, T]))
+      raise ctx.input.constructionError(
+        item.startPos, "Wrong tag for " & typetraits.name(array[I, T]) & ": " & $item.seqProperties.tag)
     elif item.seqProperties.anchor != yAnchorNone:
       raise ctx.input.constructionError(item.startPos, "Anchor on non-ref type")
   ctx.constructObject(result)
@@ -1528,7 +1534,7 @@ when defined(JS):
     let e = ctx.input.peek()
     if e.kind == yamlScalar:
       if e.scalarProperties.tag notin [yTagQuestionMark, yTagTimestamp]:
-        raise ctx.input.constructionError(e.startPos, "Wrong tag for Time")
+        raise ctx.input.constructionError(e.startPos, "Wrong tag for Time: " & $e.scalarProperties.tag)
       elif guessType(e.scalarContent) != yTypeTimestamp:
         raise ctx.input.constructionError(e.startPos, "Invalid timestamp")
       elif e.scalarProperties.anchor != yAnchorNone:

yaml/presenter.nim

@@ -547,7 +547,6 @@ proc doPresent(
               ctx.target.write("%YAML 1.1")
               ctx.newline()
               wroteDirectivesEnd = true
-              echo "write --- because %YAML"
           of ovNone: discard
           for v in ctx.handles:
             if v.handle == "!":