fix issue #258

source/dyaml/loader.d

@@ -385,3 +385,11 @@ struct Loader
 
     auto rootNode = loader.load();
 }
+
+//Issue #258 - https://github.com/dlang-community/D-YAML/issues/258
+@safe unittest
+{
+    auto yaml = "{\n\"root\": {\n\t\"key\": \"value\"\n    }\n}";
+    auto doc = Loader.fromString(yaml).load();
+    assert(doc.isValid);
+}

source/dyaml/scanner.d

@@ -57,6 +57,8 @@ alias isBreakOrSpace = among!(' ', '\0', '\n', '\r', '\u0085', '\u2028', '\u2029
 
 alias isWhiteSpace = among!(' ', '\t', '\0', '\n', '\r', '\u0085', '\u2028', '\u2029');
 
+alias isNonLinebreakWhitespace = among!(' ', '\t');
+
 alias isNonScalarStartCharacter = among!('-', '?', ':', ',', '[', ']', '{', '}',
     '#', '&', '*', '!', '|', '>', '\'', '"', '%', '@', '`', ' ', '\t', '\0', '\n',
     '\r', '\u0085', '\u2028', '\u2029');
@@ -800,8 +802,16 @@ struct Scanner
 
             for(;;)
             {
-                findNextNonSpace();
+                //All whitespace in flow context is ignored, even whitespace
-
+                // not allowed in other contexts
+                if (flowLevel_ > 0)
+                {
+                    while(reader_.peekByte().isNonLinebreakWhitespace) { reader_.forward(); }
+                }
+                else
+                {
+                    findNextNonSpace();
+                }
                 if(reader_.peekByte() == '#') { scanToNextBreak(); }
                 if(scanLineBreak() != '\0')
                 {