Parser – Support Functions

There will a few support functions that will be used by the main functions:

    skip_whitespace() - skips white space at the current position
    scan_word()  - scan for a word of an identifier
    scan_string()  - scan for string constant counting or copying the string
    search_table()  - searches Operator Table for one or two words

The skip_whitespace() function will be called before the main parsing functions are called. It will also be used by get_identifier() before scanning for the second word if the command of the identifier is part of a two word command.

The scan_word() function will be used by get_identifier() to actually check and get the identifier. This functionality is in it's own function so that it can be used twice if the identifier is a command that is part of a two word command.

The scan_string() function will be used by get_string() to first count the size of the string so that the memory  can be allocated and then called again to copy the string. The reason for the double scan is the possibility of the presence two double-quotes in the string, which are only counted and copied as one character (so a simple copy after the string length is counted won't work).

The search_table() function will be used by get_identifier() and get_operator() to search the Operator Table. There will be two string arguments for searching two word commands. The second string will be optional, passed as NULL when searching for one word or operator.