6. An apparatus for defining expressions comprising: means for locating a generic string representation of an expression, the generic string representation including an identification of a programming language associated with the expression, the generic string to be converted into the expression prior to being processed by a computer system; means for accessing a data type definition corresponding to the programming language associated with the expression, the data type definition including a converter for converting the string representation of the expression into the expression, wherein the converter is further configured to convert a string representation of a numerical value into a corresponding numerical value, wherein the data type definition and the converter are included in a meta object model of an application; and means for generating an executable runtime representation of the expression based on the expression.
6. An apparatus for defining expressions comprising: means for locating a generic string representation of an expression, the generic string representation including an identification of a programming language associated with the expression, the generic string to be converted into the expression prior to being processed by a computer system; means for accessing a data type definition corresponding to the programming language associated with the expression, the data type definition including a converter for converting the string representation of the expression into the expression, wherein the converter is further configured to convert a string representation of a numerical value into a corresponding numerical value, wherein the data type definition and the converter are included in a meta object model of an application; and means for generating an executable runtime representation of the expression based on the expression. 8. The apparatus of claim 6 , wherein the application is a language specification.