MSE Specification
MSE is a file format to store FM3 compliant metamodels and models.
NB all MSE files must use UTF-8 encoding.
Root := Document ?
Document := OPEN ElementNode \* CLOSE
ElementNode := OPEN NAME Serial ? AttributeNode \* CLOSE
Serial := OPEN ID INTEGER CLOSE
AttributeNode := OPEN Name ValueNode \* CLOSE
ValueNode := Primitive | Reference | ElementNode
Primitive := STRING | NUMBER | Boolean | Unlimited
Boolean := TRUE | FALSE
Unlimited := NIL
Reference := IntegerReference | NameReference
IntegerReference := OPEN REF INTEGER CLOSE
NameReference := OPEN REF NAME CLOSE
OPEN := "("
CLOSE := ")"
ID := "id:"
REF := "ref:"
TRUE := "true"
FALSE := "false"
NAME := letter ( letter | digit ) \* ( "." letter ( letter | digit ) ) \*
INTEGER := digit +
NUMBER := "-" ? digit + ( "." digit + ) ? ( ( "e" | "E" ) ( "-" | "+" ) ? digit + ) ?
STRING := ( "'" \[^'] \* "'" ) +
digit := \[0-9]
letter := \[a-zA-Z_]
Whitespace are the usual suspects, and comments are
comment := "\"" \[^"] \* "\""
On the nodes and commands
An MSE implementation MUST support all nodes and commands below
- Element node
- defines an element in the model. An element node contains: 1) the name of its type, 2) an optional ID command and 3) any number of attribute nodes.
- Attribute node
- defines an attribute of an element in the model. An attribute node contains: 1) the name of the attribute, 2) any number of value nodes. An attribute node belongs to the element of its enclosing element node.
- value node
- defines the value of an attribute of an element in the model. An value node is either a primitive value or any of the commands that returns an element or value. A value node belongs to the attribute of its enclosing attribute node.
- ID command
- assign an identifier to an element. An ID command contains: 1) the command "id:", 2) an identifier. An ID command node belongs to the element of its enclosing element node. The scope of identifiers is local to the level of the MSE file. They are only used for the purpose of import and export, to refer to elements on the level of the MSE file. They are not known to the model. If you need the notion of identfiers in your model, please add them at the model level yourself.
- REF command
- returns the element identified by an identifier. A reference command contains: 1) the command "idref:", 2) an identifier. Reference nodes are valid values nodes.
- REF command metamodels only
- returns the element identified by its unique name. A reference command contains: 1) the command "ref:", 2) a name. Reference nodes are valid values nodes. The names Object, String, Boolean, Number, Date are reserved for FM3's built-in types.
Change list
Edit of February 24, 2009
- Fixed format of floating point numbers, now covers all variations of Smalltalk, Java and C/C- MSE Specification — gosh, and I assumed IEEE to be a standard.
- Removed references to deprecated idref command.
Edit of December 3, 2007
- Added comment about comments
Edit of November 11, 2007
- Disallow 0 as unique ID
Edit of October 12, 2007
- Put \"" around -,.,' and e.
- Made all non-terminals conform (<>).
Edit of October 11, 2007
- Changed the definition of
number
to not allowd
as exponent separator. - Fixed the definition of
string
. - Fixed the definition of
name
. - Made
unlimited
optional. - Removed the
path:
command, never used and thus yet another violation of YAGNI. - Removed
<name>
from the list of possible primitives, please quote all strings!