This procedure loads numeric constants and constant identifiers to the expression. For constant identifiers the constant value is first loaded to NumericConstant variable from where it is moved to the Value field of the expression.

These two functions check and process decimal and hexadecimal integer constants. The value is stored in the IntegerNumericConstant variable.

This function checks and processes string constants. It processes characters enclosed with single quotes, control characters and characters defined with the ASCII code (#code).