To have keywords such as print and dump work as reserved words, the lexical analyser must recognize them and return the appropriate TT_PRINT and TT_DUMP token types to the parser. This is best handled by a simple string comparison at the point where an identifier is about to be returned from the scanner. If the identifier is one of the strings print or dump, return the token TT_PRINT or TT_DUMP, otherwise return the identifier token type TT_ID as before.
IF current state of DFA has accepted an identifier THEN
IF lexeme in buffer is "print" THEN
set the token type to be the PRINT token type
ELSEIF lexeme in buffer is "dump" THEN
set the token type to be the DUMP token type
ELSEIF ... match other keywords ... THEN
...
ELSE
set the token type to be the IDENTIFIER token type
ENDIF
ENDIF
...
return the token to the calling function
Make a conscious decision as to whether your string comparison that recognizes the keywords will be case-sensitive (Unix-style) or case-insensitive (DOS-style). Do you want all of "Print", "prInt", "PRINT", and "printT" to be the same as "print"? Are C Language reserved words case-sensitive?
The test files I supply will use lower-case keywords.
If your reserved words are case-insensitive, what about the identifiers in your language? Are they also case-insensitive?