A TLex object is used to perform lexical analysis.
The class is used to:
store a string
maintain an extraction mark to indicate the current lexical element being analysed
maintain a pointer to indicate the next character to be examined.
Member functions provide facilities to allow analysis and extraction of
lexical elements from a TLex object, and a variety of string-to-number
conversions.
The TLex class provides general-purpose lexical analysis
functions, using the locale-dependent functions of TChar to
identify whether characters are digits, letters etc. The data for these locale-dependent
functions is held in kernel-side locale tables. Thus, TLex functions
which use them, require an executive call. If an application requires very
fast lexical analysis of a language which is not locale-specific, then there
may be some advantage in designing and implementing a special-purpose lexical
analyzer class.