Estimation of type-cast sets

A method for estimating type-cast sets of a program, comprising:

• initializing type-cast sets corresponding to declared types in the program;
• identifying an assigment statement in the program;
• and
• estimating at least one type-cast set corresponding to the assignment statement, wherein said estimating comprises:
• initializing type-cast sets for corresponding declared types in the program;
• identifying an assigment statement in the program, wherein the assignment statement includes a left hand side expression and a right hand side expression;
• computing types-represented sets for both left hand side expression and right hand side expression of the assignment statement;
• and
• constructing a type-cast set for each element in the types-represented set of the left hand side expression based on the types-represented sets of the left hand side expression and the right hand side expression;
• and
• determining the validity of the program that is being developed with respect to a pre-determined programming style guideline using the type-cast sets computed from the program.

A system having processor, comprising:

• a program;
• a type-cast set estimation mechanism for estimating type-cast sets of the program, wherein each of the type-cast sets corresponds to a declared type in the program, wherein the type-cast set estimation mechanism comprises:
• an assignment statement identification mechanism for identifying an assigment statement in the program, wherein the identified assignment statement includes a left hand side expression and a right hand side expression;
• a types-represented set estimation mechanism for computing types-represented sets for both the left hand side expression and the right hand side expression;
• and
• a type-cast set construction mechanism for constructing a type-cast set for each element in the types-represented set of the left hand side expression based on the types-represented sets of the left hand side expression and the right hand side expression;
• and
• an application development tool for evaluating the validity of the program that is being developed with respect to a pre-determined programming style guideline based on the type-cast sets computed from the program.

A system having processor for estimating type-cast sets of a program, comprising:

• an assignment statement identification mechanism capable of identifying an assigment statement in a program, wherein the identified assignment statement includes a left hand side expression and a right hand side expression;
• a types-represented set estimation mechanism capable of computing types-represented sets for both the left hand side expression and the right hand side expression;
• and
• a type-cast set construction mechanism capable of constructing a type-cast set for each element in the types-represented set of the left hand side expression based on the types-represented sets of the left hand side expression and the right hand side expression, wherein the types-represented set estimation mechanism comprises:
• an expression analyzer capable of determining the format of an expression;
• and
• a plurality of types-represented set constructors, each of which is for computing the types-represented set of the expression according to the format of the expression, and
• determining the validity of the program that is being developed with respect to a pre-determined programming style guideline using the type-cast sets computed from the program.

An article comprising a storage medium having stored thereon instructions that, when executed by a machine, result in the following:

• receiving a program;
• estimating type-cast sets of the program, wherein each of the type-cast sets corresponds to a declared type in the program wherein said estimating type-cast sets comprises:
• initializing type-cast sets for corresponding declared types in the program;
• identifying an assigment statement in the program, wherein the assignment statement includes a left hand side expression and a right hand side expression;
• computing types-represented sets for both the left hand side expression and the right hand side expression of the assignment statement;
• and
• constructing a type-cast set for each element in the types-represented set of the left hand side expression based on the types-represented sets of the left hand side expression and the right hand side expression;
• and
• determining the validity of the program that is being developed with respect to a pre-determined programming style guideline using the type-cast sets computed from the program.

An article comprising a storage medium having stored thereon instructions for estimating type-cast sets of a program that, when executed by a machine, result in the following:

• initializing type-cast sets corresponding to the declared types in the program;
• identifying an assigment statement in the program;
• and
• estimating at least one type-cast set corresponding to the assignment statement, wherein said estimating comprises:
• computing types-represented sets for both left hand side expression and right hand side expression of the assignment statement;
• and
• constructing a type-cast set for each element in the types-represented set of the left hand side expression based on the types-represented sets of the left hand side expression and the right hand side expression;
• and
• determining the validity of the program that is being developed with respect to a pre-determined programming style guideline using the type-cast sets computed from the program.