Serialization of TOML multi line string

[Vindaar]

In the application where I also stumble on the problem to serialize empty TOML arrays, I also have some multi line strings. As far as I understand the TOML standard, a string in a single quotation mark cannot contain newlines.

So locally I've applied a patch like:

basti at void in ~/src/nim/parsetoml ツ git diff
diff --git a/src/parsetoml.nim b/src/parsetoml.nim
index 06d41f1..f8a5a56 100644
--- a/src/parsetoml.nim
+++ b/src/parsetoml.nim
@@ -1510,8 +1510,12 @@ proc toTomlString*(value: TomlValueRef): string =
   of TomlValueKind.Int: $value.intVal
   of TomlValueKind.Float: $value.floatVal
   of TomlValueKind.Bool: $value.boolVal
-  of TomlValueKind.Datetime: $value.dateTimeVal
-  of TomlValueKind.String: "\"" & value.stringVal & "\""
+  of TomlValueKind.Datetime: $value.datetimeVal
+  of TomlValueKind.String:
+    if '\n' in value.stringVal:
+      "'''" & value.stringVal & "\n'''"
+    else:
+      "\"" & value.stringVal & "\""
   of TomlValueKind.Array:
     if value.arrayVal.len == 0:
       "[]"

On the one hand this feels a bit like a hack. But I mainly didn't open a PR for this, because I'm not sure how to decide whether to use a regular multi line string with quotation marks or one with single ticks. In my use case I want the string to be literal anyway.

Any ideas for how to deal with this?

[PMunch]

The easiest would probably be to always use the most lenient string representation. But otherwise this seems like a solution that would work. Only problem is that you seem to add an extra newline to the string?

[Vindaar]

While that sounds reasonable, isn't it also a question of intent? The user may or may not depend on the escaping mechanism in their data, no?

Only problem is that you seem to add an extra newline to the string?

Ah, yeah. I mainly did that for readability in my output.