The file import strformat echo &"""<{"total":23}>""" Run
compiles fine. The file import strformat echo &"""<{"total:":23}>""" Run does not compile. The only difference is the colon (:) after total in the second file. Aren't they both string constants? The strformat documentation refers to the 'fmt"{expr}"' syntax. Is that a full nim expression, or is more limited? (I didn't see an explanation in in strformat.)