Parser – Constant Number Tokens

The get number routine was next to be modified to create a new token upon returning when a valid token is found.  The character parsing part of the routine was left intact except the two instances where no number is found were changed to return a default token pointer.  The token creation lines at the end were replaced with return statements creating a token in a shared pointer.  Two more constructors were added to the token class to these return statements.

The first, in addition to the column and length takes the string of the number and the integer value of the number, and automatically sets the type to constant and the data type to integer.  The integer value member is initialized to the integer value, however, the double value member is set to the integer value in the body to do the conversion from integer to double (which can't be done with an initializer because the types are different).

The other constructor also takes the string of the number, the double value and a flag for whether a decimal point was present, sets the type to constant.  The body checks if the double value is within the range of an integer, and if it is, the sets the data type to integer, and sets the double sub-code only if there was a decimal point.  The translator uses this sub-code to determine if a constant can be used as a double even though the data type is integer (a hidden conversion from integer to double code is not needed).  For values outside the integer range, the data type is set to double (indicating conversion to an integer is not possible).

The body of the second constructor was taken from the get number routine because this code primary sets token members (via access functions), and it seemed appropriate to do this within the token class.  Since the body was not trivial, the constructor was put into the token source and not the header file.  Another reason was that the C-style integer minimum and maximum constants were replaced with C++ standard numerical constants from the limits STL header file (no reason to burden source files including the token header file with another header file).

In the main function operator routine, the call to get number was changed like the call to get identifier with the member token initialization moved below this.  It appears redundant to declare a if-scoped token pointer at each if statement, but if there was a single token pointer for the entire routine, it would first be initialized to a default value, then reinitialized at each if statement.  The if-scoped variable is initialized directly with the return value of the get routine.

[branch parser commit d328c0a720]