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A lexical analyzer that can identify lexemes and tokens found in a source code file provided by the user. Once the analyzer has identified the lexemes of the language and matched them to a token group, the program then prints each lexeme and token pair to the screen

License: GNU General Public License v3.0

Makefile 1.39% C++ 98.61%

lexical-analyzer's Introduction

Lexical-Analyzer

Author: Mostofa Adib Shakib

BNF Grammer Rule

P   ::=     S
S   ::=     V:=E | read(V) | write(V) | while C do S od | S;S
C   ::=     E < E | E > E | E = E | E <> E | E <= E | E >= E
E   ::=     T | E + T | E - T
T   ::=     F | T * F | T / F
F   ::=     (E) | N | V
V   ::=     a | b | … | y | z | aV | bV | … | yV | zV
N   ::=     0 | 1 | … | 8 | 9 | 0N | 1N | … | 8N | 9N

Lexeme & Token Pair

|      Lexeme      |     Token     |
| ---------------  | ------------- |
|       :=         |  ASSIGN_OP    |
|       +          |  ADD_OP       |
|       do         |  KEY_DO       |
|       <          |  LESSER_OP    |
|       -          |  SUB_OP       |
|       od         |  KEY_OD       |
|       >          |  GREATER_OP   |
|       *          |  MULT_OP      |
|   variable name  |  IDENT        |
|       =          |  EQUAL_OP     |
|       /          |  DIV_OP       |
|     integer      |  INT_LIT      |
|       <>         |  NEQUAL_OP    |
|      read        |  KEY_READ     |
|       (          |  LEFT_PAREN   |
|       <=         |  LEQUAL_OP    |
|     write        |  KEY_WRITE    |
|       )          |  RIGHT_PAREN  |
|      >=          |  GEQUAL_OP    |
|     while        |  KEY_WHILE    |
|       ;          |  SEMICOLON    |

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