Curtin University Programming Languages Semester 2, 2016 Assignment Due Date: 14th October, 2016 Objective The objective of this assignment is to gain some practical experience in writing a language specification using EBNF and in writing parsers and syntax checkers using YACC (GNU Bison) and Lex (GNU Flex). Task 1 -EBNF specification You are to derive the EBNF notation for the PL2016 language. The syntax graphs describing the language are included in the Appendix of this document. Your specification must be clear and consistent (use the same set of extensions throughout your solution). Task 2 – Syntax checker You are to design, using YACC and Lex, a parser and syntax checker named PL2016_check for legal PL2016 programs. You will need to parse the input stream of characters into reserved words, numbers and identifiers using Lex. These symbols will be passed to YACC which will check to see if the sequence of tokens fits the PL2016 language. Study the syntax graphs supplied and the BNF you have derived and convert the rules to YACC rules. A correct PL2016 program should parse without any syntax errors. If there is an error YACC outputs "syntax error". Therefore, for an incorrect PL2016 program this error will occur as soon as the syntax is detected to be incorrect. To enable readability and understanding, display all the symbols to the screen as the PL2016 code is being parsed.Requirements You are required to submit the following items for assessment: 1. The typed EBNF description of PL2016 derived from the syntax graphs provided. 2. A typed report that contains a description of how you built the parser and syntax checker for the PL2016 language. The report must be presented in a professional manner. 3. Fully documented YACC and Lex source code. The final executable is to be named PL2016_check and must run on the Linux lab machines. You are to also specify how to build PL2016_check. The command line arguments to PL2016_check are as follows: PL2016_check < PL2016_program_file (where the PL2016_program_file is user specified). The Lex and YACC fully documented code, the executable file named PL2016_check and the instructions on how to compile the source files must be placed in a directory called ~/proglang/assignment (where ~ is your home directory). The hard copy of the report should be handed in via the office in the Computer Science building before 9:00am on the due date. The electronic files containing your source code and documentation must be submitted via blackboard by 9.00am on the date specified. Please ensure that your spelling of the file names is correct! To protect against plagiarism, you must ensure that all files and directories are adequately protecteddeclaraton_unit implementaton_unit basic_program ident formal_parameters declaraton_unit DECLARATION OF ident CONST VAR type_declaraton procedure_interface functon_interface DECLARATION END constant_declaraton variable_declaraton procedure_interface PROCEDURE ident formal_parameters functon_interface FUNCTION ident type_declaraton TYPE : type ; ident formal_parameters ( ) ; number constant_declaraton = ; , ident ident variable_declaraton : ; , ident basic_type array_type type ident enumerated_type basic_type range_type ident enumerated_type { } , range range_type [ ] range array_type ARRAY ident [ ] OF type number range .. number ident implementaton_unit IMPLEMENTATION OF block . specifcaton_part block implementaton_part specifcaton_part VAR procedure_declaraton functon_declaraton constant_declaraton variable_declaraton CONST procedure_declaraton PROCEDURE ident ; block ; functon_declaraton FUNCTION ident ; block ; implementaton_part compound_statement statement if_statement while_statement assignment procedure_call do_statement for_statement assignment ident := expression procedure_call CALL ident if_statement IF expression THEN compound_statement END IF while_statement WHILE expression DO compound_statement END WHILE do_statement DO compound_statement WHILE expression END DO for_statement FOR EACH ident DO compound_statement END FOR compound_statement BEGIN statement END ; expression term term + - term id_num id_num * / id_num ident number number 0..9 ident a..z compound_statement IN ident