11. A computer program product for defining expressions in a meta-object model of an application, the computer program product comprising a computer readable medium having computer readable program code tangibly embedded therein, the computer readable program code comprising: computer readable program code configured to locate a string representation of an expression including an identification of a programming language associated with the expression, the string representation of the expression being in a syntax different from a syntax associated with the programming language, and the string representation of the expression to be converted into the expression based on the programming language, wherein the string representation of the expression is defined in the meta-object model of the application; computer readable program code configured to access a data type definition corresponding to the string representation of the expression, the data type definition including a converter for converting one or more of the string representation of the expression into the expression and a string representation of a data value into a data value instance, wherein the data type definition and the converter are part of the meta-object model; and computer readable program code configured to generate an executable runtime representation of the expression based on the expression.
11. A computer program product for defining expressions in a meta-object model of an application, the computer program product comprising a computer readable medium having computer readable program code tangibly embedded therein, the computer readable program code comprising: computer readable program code configured to locate a string representation of an expression including an identification of a programming language associated with the expression, the string representation of the expression being in a syntax different from a syntax associated with the programming language, and the string representation of the expression to be converted into the expression based on the programming language, wherein the string representation of the expression is defined in the meta-object model of the application; computer readable program code configured to access a data type definition corresponding to the string representation of the expression, the data type definition including a converter for converting one or more of the string representation of the expression into the expression and a string representation of a data value into a data value instance, wherein the data type definition and the converter are part of the meta-object model; and computer readable program code configured to generate an executable runtime representation of the expression based on the expression. 18. The computer program product of claim 11 , wherein the expression is a Java expression and the expression language is Java, and wherein the converter is to convert a string representation of the Java expression into the Java expression suitable for processing during runtime.