For CS 280
1.The language has identifiers, which are defined to be a letter followed by zero or moreletters or numbers. This will be the Token ID.
2.The language has integer constants, which are defined to be one or more digits. This willbe the Token INT.
3.The language has string constants, which are a double-quoted sequence of characters,all on the same line. This will be the Token STR.
4.A string constant can include escape sequences: a backslash followed by a character.The sequence \n should be interpreted as a newline. The sequence \ should beinterpreted as a backslash. All other escapes should simply be interpreted as thecharacter after the backslash.
5.The language has reserved the keywords print, let, if, loop, begin, end. They will beTokens PRINT LET IF LOOP BEGIN END.
6.The language has several operators. They are + - * / ! ( ) which will be Tokens PLUSMINUS STAR SLASH BANG LPAREN RPAREN
7.The language recognizes a semicolon as the token SC
8.A comment is all characters from // to the end of the line; it is ignored and is not returnedas a token. NOTE that a // in the middle of an STR is NOT a comment!1
9.Whitespace between tokens can be used for readability, and it serves to delimit tokens.
10.An error will be denoted by the ERR token.
11.End of file will be denoted by the DONE token.