MOFM2T11 — set of problems with the currently described operations

There are a set of problems with the currently described operations within the MOF Models to Text Transformation Language specification for the addition of new operations to extends the OCL standard library. Specifically, redundant, misleading or plain missing operations. >From now on I'll refer as "OCL specification" the following document : Object Constraint Language specification version 2.0 formal/06-05-01 . Likewise, "MTL specification" will refer to the following : MOF Models to Text Transformation Language version 1.0 formal/2008-01-16. I'll describe the aforementionned issues in three parts from now : A - Redundant operations "toUpper()" and "toLower()" operations are both specified for the String type in section 8.3.1 . Both of these are already defined in the OCL specification in section A.2.1.3 Table A.1 . They should then be removed from the MTL specification. B - Misleading operations Early adopters and testers of our implementation have confirmed that the "strtok(String, Integer) : String" as described in the MTL specification at section 8.3.1 isn't useable as is. Specifically, the integer flag makes it awkard to use : cannot be entirely used in a loop as they need to have the flag at "0" for the first call ... and plain weird to use in any other place, yet again because of this flag. Replacing this operation with a Java-like "tokenise" with no integer flag and returning the whole set of tokens would be easier to consume in a loop or use in templates/queries. C - Missing operations This is a different matter. The following list will consist on the one hand of things we found plain missing from the MTL specification and, on the other hand, of repetitive tasks our early adopters and testers have reported as bothersome to write in OCL and hindering the readability of scripts as a whole. First of all, the MTL specification describes a "substitute(String, String)" operation that can be used to "Substitute substring r in self by substring t and returns the resulting string.". From this we can say that three operations are missing from the spec (more details in the full list at the end of this report) : 1) substituteAll( String substring, String replacement ) : String 2) replace( String substring, String replacement ) : String 3) replaceAll( String substring, String replacement ) : String Further usage from these adopter and testers have shown that some usual operations are impossible (or plain bothersome) to write in OCL. These include (again, detailed description in the full list below) : String operations 4) startsWith( String substring ) : Boolean 5) endsWith( String substring ) : Boolean 6) trim( ) : String OclAny operations 7) ancestors( ) : Sequence(T) 8) ancestors( OclAny type ) : Sequence(T) 9) siblings( ) : Sequence(T) 10) siblings( OclAny type ) : Sequence(T) 11) descendants( ) : Sequence(T) 12) descendants( OclAny type ) : Sequence(T) Likewise, the "toString()" operation described in the MTL specification on both Real and Integer types isn't sufficient for a text generation language this same toString operation should be added to the standard type OclAny so that the user can obtain the String representation of each and every element. To sum this up, here is the full list of operations we would like to add to (or alter within) the MTL specification: C.1 - String operations C.1.a - modifications operation "strtok( String s1, Integer flag ) : String Breaks the string self into a sequence of tokens each of which is delimited by any character in string s1. The parameter flag should be 0 when strtok is called for the first time, 1 subsequently." should be altered to be "strtok( String s1, Integer flag ) : Sequence(T) Returns a sequence containing all parts of self split around delimiters defined by the characters in String delim." C.1.b - additions 1) endsWith( String substring ) : Boolean Returns true if self ends with the substring substring, false otherwise. 2) startsWith( String substring ) : Boolean Returns true if self starts with the substring substring, false otherwise. 3) substituteAll( String substring, String replacement ) : String Substitutes all substrings substring in self by substring replacement and returns the resulting string. If there is no occurrence of the substring, The original string is returned. substring and replacement are not treated as regular expressions. 4) replace( String substring, String replacement ) : String Substitutes the first occurence of substring substring in self by substring replacement and returns the resulting string. If there is no occurrence of the substring, The original string is returned. substring and replacement are treated as regular expressions. 5) replaceAll( String substring, String replacement ) : String Substitutes all substrings substring in self by substring replacement and returns the resulting string. If there is no occurrence of the substring, The original string is returned. substring and replacement are treated as regular expressions. 6) trim( ) : String Removes all leading and trailing spaces of self. C.2 - OclAny operations C.2.a - additions 7) ancestors( ) : Sequence(T) Returns all super-elements of self. 8) ancestors( OclAny type ) : Sequence(T) Returns all super-elements of self which type is equal to type. 9) siblings( ) : Sequence(T) Returns all siblings of self. 10) siblings( OclAny type ) : Sequence(T) Returns all siblings of self which type is equal to type. 11) descendants( ) : Sequence(T) Returns all direct and indirect children of self. 12) descendants( OclAny type ) : Sequence(T) Returns all direct and indirect children of self which type is equal to type. 13) toString( ) : String Returns the String representation of self.