How should empty tags be treated?

[agentgt]

Consider the case:

{{}}hello{{}}

I found a lot of varying behavior in mustache implementations.

• In the wontache playground you get an empty string.
• In Mustache.js you get hello. The empty tags appear to be ignored.
• JStachio fails on the second empty tag because it can't handle two empty tags in a row.
• JMustache fails horribly with index out of bounds
• Mustache.java fails with an Empty mustache exception
• Handlebars.js (albeit not mustache) fails on the first empty tag

Perhaps it is out of scope for the spec to dictate what happens on empty tags? That being said I do think Wontache's behavior is incorrect regardless.

[jgonggrijp]

Wontache produces the empty string because it interprets the whole template as a single interpolation tag with }}hello{{ as the key. This playground savestate demonstrates it:

{"data":{"text":"{\n    '}}hello{{': 'x'\n}"},"templates":[{"name":"","text":"{{}}hello{{}}"}]}

Not meaning to defend the behavior though, just clarifying.

I see no use in empty tags, so I don't think it needs specifying, but I'll leave this open for a while so different opinions can be heard.

[determin1st]

mine leaves them alone,
both the empty and blank names

{{}}hello{{}} => {{}}hello{{}}
{{ }}hello{{}} => {{ }}hello{{}}

[determin1st]

oke, now i think that there should be a parse exception - empty clause have no use