' PLEASE GIVE EXAMPLE CODE SO I CAN USE AS REFERENCE & HAVE…

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Step 1: Set Up Your Environment Make sure you have the necessary tools installed on your system: Flex : For writing the scanner. Bison/Yacc : For writing the parser. GCC : For compiling the scanner and parser into an executable. Step 2: Write the Flex Scanner Create a file named scanner.l : Define your token types. Write regular expressions to match keywords, operators, and other tokens. Add rules to skip whitespace and comments. Generate the Scanner with Flex : Run flex -o scanner.c scanner.l to generate scanner.c . Include any necessary header files for token definitions at the beginning of scanner.l . Step 3: Define Tokens in a Header File Create a header file tokens.h : Define each token with an enum or #define macro. This header will be shared with the Bison/Yacc parser. Step 4: Write the Bison/Yacc Parser Create a file named parser.y : Define the grammar for your C-- language subset. Use %token to specify the tokens from the scanner. Write rules for parsing expressions, statements, etc. Implement error reporting with yyerror() . Generate the Parser with Bison/Yacc : Run bison -d -o parser.c parser.y to generate parser.c and parser.h . Step 5: Compile the Scanner and Parser Write a Makefile : Compile the scanner and parser together. Link the object files into a single executable named compile . Step 6: Implement Error Handling Modify the Scanner : Handle unrecognized characters by returning an error token or character code. Modify the Parser : Use Bison/Yacc's error handling features to recover from syntax errors. Print helpful error messages with line numbers. Step 7: Test the Compiler Components Create Test Cases : Write several C-- programs with varying syntax to test your scanner and parser. Run Tests : Use your compile executable to process the test cases and check the outputs. Step 8: Iterative Refinement Debug and Refine : Use the feedback from your tests to refine your scanner and parser. Repeat the testing process after each significant change. Step 9 These are sample Code : Please keep in mind that these examples are oversimplified and would need to be expanded to fully implement the features and syntax of C--. You would need to define tokens in the lex / flex file corresponding to all the lexical elements of C-- and then write grammar rules in the yacc / bison file that define how these tokens can be combined to form valid C-- constructs. Write Flex Scanner (scanner.l) Create a new file named scanner.l and write down the Flex code to match tokens: %{ #include "tokens.h" // Assume this contains enum or #define for token types %} %% /* Keywords */ "int" { return T_INT; } "return" { return T_RETURN; } /* Operators */ "+" { return T_PLUS; } "-" { return T_MINUS; } "*" { return T_ASTERISK; } "/" { return T_SLASH; } /* Symbols */ ";" { return T_SEMICOLON; } "," { return T_COMMA; } "(" { return T_LEFT_PAREN; } ")" { return T_RIGHT_PAREN; } "{" { return T_LEFT_BRACE; } "}" { return T_RIGHT_BRACE; } /* Identifier */ [a-zA-Z_][a-zA-Z0-9_]* { return T_IDENTIFIER; } /* Number */ [0-9]+ { return T_NUMBER; } /* Whitespace */ [ ]+ { /* Ignore whitespaces */ } /* Comments */ "/*" { BEGIN(COMMENT); } "*/" { BEGIN(INITIAL); } .| { /* consume anything that's not the end of comment */ } <> { yyerror("Comment not closed"); return 0; } /* Error Handling */ . { yyerror("Unknown token"); return T_ERROR; } %% Define Token Types in a Header File (tokens.h) Create a new file named tokens.h . This file will have the token type definitions that will be used by both Flex and Bison. #ifndef TOKENS_H #define TOKENS_H enum token_types { T_INT, T_RETURN, T_PLUS, T_MINUS, T_ASTERISK, T_SLASH, T_SEMICOLON, T_COMMA, T_LEFT_PAREN, T_RIGHT_PAREN, T_LEFT_BRACE, T_RIGHT_BRACE, T_IDENTIFIER, T_NUMBER, T_ERROR }; #endif Write Bison Parser (parser.y) Now create a new file named parser.y with the following Bison grammar: %{ #include "tokens.h" void yyerror(const char *s); int yylex(void); %} %token T_INT T_RETURN T_PLUS T_MINUS T_ASTERISK T_SLASH %token T_SEMICOLON T_COMMA T_LEFT_PAREN T_RIGHT_PAREN T_LEFT_BRACE T_RIGHT_BRACE %token T_IDENTIFIER T_NUMBER T_ERROR %% /* Define your grammar rules here */ program : function_definition ; function_definition : T_INT T_IDENTIFIER T_LEFT_PAREN T_RIGHT_PAREN T_LEFT_BRACE statement_list T_RIGHT_BRACE ; statement_list : statement | statement_list statement ; statement : expression_statement | return_statement ; expression_statement : expression T_SEMICOLON ; return_statement : T_RETURN expression T_SEMICOLON ; expression : T_NUMBER | T_IDENTIFIER | expression T_PLUS expression | expression T_MINUS expression | expression T_ASTERISK expression | expression T_SLASH expression ; %% void yyerror(const char *s) { fprintf(stderr, "Error: %s ", s); } int main(void) { return yyparse(); } Compile the Scanner and Parser Now you need to compile your scanner and parser together. You can use a Makefile or manually compile them via the comman

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