Date: 2017-02-21 21:55:20 +0100
From: Dean De Leo <>
To: MonetDB5 devs <>
Version: 11.25.5 (Dec2016-SP1)
CC: @mlkersten

Last updated: 2017-03-03 10:24:09 +0100

Comment 25047

Date: 2017-02-21 21:55:20 +0100
From: Dean De Leo <>

User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.87 Safari/537.36
Build Identifier:

It is currently possible to create types having as part of their name underscores, e.g. "my_type". However apparently it is not possible to refer to them in the function signatures.

Reproducible: Always

Steps to Reproduce:

See attached repro

Actual Results:

The parser raises the error "Type identifier expected" when encountering a type with an underscore as part of a function signature.

Expected Results:

Either the function signature should be accepted or the character _ is considered illegal when defining a new type (atom).

Comment 25048

Date: 2017-02-21 21:55:45 +0100
From: Dean De Leo <>

Created attachment 536
repro.mal

Attached file: repro.mal (application/octet-stream, 232 bytes)
Description: repro.mal

Comment 25049

Date: 2017-02-21 22:02:45 +0100
From: @mlkersten

Type identifiers indeed can not contain the '_', because it separates the name from its index. It is reserved for type variables, which aids type resolution
e.g.

function f(a:any_1, b:any):any_1

tells that the result type is the same as the first argument.
The type for 'b' can be anything.

Comment 25050

Date: 2017-02-21 22:09:01 +0100
From: Dean De Leo <>

sure, but then how do you refer to such types? since they can be created.. :)

Comment 25051

Date: 2017-02-21 22:11:12 +0100
From: @mlkersten

For the time being don't create them.
Once MAL itself is revisited for a clean up, this might be one of the issues
looked into. There is indeed some old cruft.

Comment 25056

Date: 2017-02-24 10:33:46 +0100
From: @mlkersten

A fix has been checked in and the test added

Comment 25107

Date: 2017-03-03 10:24:09 +0100
From: @sjoerdmullender

Dec2016-SP2 has been released, incorporating the fix.