PA3CS 280 Fall 2022 Programming Assignment 3 November 22, 2022 Due Date: Sunday, December 11,...

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PA3CS 280  Fall 2022  Programming Assignment 3  November 22, 2022 Due Date: Sunday, December 11, 2022, 23:59  Total Points: 20 In this programming assignment, you will be building an interpreter for our programming  language. The grammar rules of the language and its tokens were given in Programming  Assignments 1 and 2. You are required to modify the parser you have implemented for the  language to implement an interpreter for it. The specifications of the grammar rules are described  in EBNF notations.     1. Prog ::= PROGRAM IDENT StmtList END PROGRAM  2. StmtList ::= Stmt; { Stmt; }  3. Stmt ::= DeclStmt | ControlStmt   4. DeclStmt ::= ( INT | FLOAT | BOOL ) VarList   5. VarList ::= Var { ,Var }  6. ControlStmt ::= AssigStmt | IfStmt | PrintStmt   7. PrintStmt ::= PRINT (ExprList)  8. IfStmt ::= IF (Expr) THEN StmtList [ ELSE StmtList ] END IF  9. AssignStmt ::= Var = Expr  10. Var ::= IDENT  11. ExprList ::= Expr { , Expr }  12. Expr ::= LogORExpr ::= LogANDExpr { || LogANDRxpr }  13. LogANDExpr ::= EqualExpr { && EqualExpr }  14. EqualExpr ::= RelExpr  [== RelExpr ]   15. RelExpr ::= AddExpr  [ (  ) AddExpr ]  16. AddExpr :: MultExpr { ( + | - ) MultExpr }  17. MultExpr ::= UnaryExpr { ( * | / ) UnaryExpr }  18. UnaryExpr ::= ( - | + | ! ) PrimaryExpr | PrimaryExpr  19. PrimaryExpr ::= IDENT | ICONST | RCONST | SCONST | BCONST | ( Expr )) The following points describe the programming language. You have already implemented all of  the syntactic rules of the language as part of the parser implementation. The points related to the  dynamic semantics (i.e. run-time checks) of the language must be implemented in your interpreter.  These include points 5-12 in the following list. These points are: Table of Operators Precedence Levels    Precedence Operator Description Associativity  1 Unary +, -,  and !  Unary plus, minus, and  logical NOT  Right-to-Left  (ignored)  2 *, / Multiplication and  Division  Left-to-Right 3 +, - Addition and  Subtraction  Left-to-Right  4  Relational operators   (no cascading)  5 == Equality operator (no cascading)  6 && Logical AND Left-to-Right  7 || Logical OR Left-to-Right 1. The language has three types: INT, FLOAT and BOOL.  2. The precedence rules of operators in the language are as shown in the table of operators’  precedence levels.  3. A used variable in an expression must have been defined previously by an assignment  statement.  4. It is illegal to use the name of the program as a variable anywhere in the program.  5. The scope of a declared variable extends from the point of its declaration statement to the End  of the Program.  6. The PLUS, MINUS, MULT, DIV, AND, OR operators are left associative.  7. A variable has to be declared in a declaration statement.  8. An IfStmt evaluates a logical expression (Expr) as a condition. If the logical condition value  is true, then the StmtList in the Then-part are executed, otherwise they are not. An else part for  an IfSmt is optional. Therefore, If an Else-part is defined, the StmtList in the Else-part are  executed when the logical condition value is false.  9. A PrintStmt evaluates the list of expressions (ExprList), and prints their values in order from  left to right followed by a newline.  10. The ASSOP operator (=) in the AssignStmt assigns a value to a variable. It evaluates the Expr  on the right-hand side and saves its value in a memory location associated with the left-hand  side variable (Var). A left-hand side variable of a numeric type can be assigned a value of  either one of the numeric types (i.e., INT, FLOAT) of the language. For example, an integer  variable can be assigned a real value, and a real variable can be assigned an integer value. In  either case, conversion of the value to the type of the variable must be applied. A BOOL var  in the left-hand side of an assignment statement must be assigned a Boolean value only.  11. The binary operations for addition, subtraction, multiplication, and division are performed  upon two numeric operands (i.e., INT, FLOAT) of the same or different types. If the operands  are of the same type, the type of the result is the same type as the operator’s operands.  Otherwise, the type of the result is FLOAT.   12. The binary logic operations for the AND and OR operators are applied on two Boolean  operands only.  13. The LTHAN and GTHAN relational operators and the EQUAL operator operate upon two  operands of compatible types. The evaluation of a relational expression, based on LTHAN or  GTHAN operators, or an Equality expression, based on the Equal operator, produce either a  true or false value.  14. The unary sign operators (+ or -) are applied upon one numeric operand (i.e., INT, FLOAT).  While the unary NOT operator is applied upon a one Boolean operand (i.e., BOOL).  15. It is an error to use a variable in an expression before it has been assigned.   Interpreter Requirements:  I. Implement an interpreter for the language based on the recursive-descent parser developed in  Programming Assignment 2. You need to modify the parser functions to include the required  actions of the interpreter for evaluating expressions, determining the type of expression values,  executing the statements, and checking run-time errors. You may use the lexical analyzer you  wrote for Programming Assignment 1 and the parser you wrote for Programming Assignment  2. Otherwise you may use the provided implementations for the lexical analyzer and parser  when they are posted. Rename the parse.cpp file as parserInt.cpp to reflect the applied changes  on the current parser implementation for building an interpreter. The interpreter should provide  the following: • It performs syntax analysis of the input source code statement by statement, then executes  the statement if there is no syntactic or semantic error.  • It builds information of variables types in the symbol table for all the defined variables.  • It evaluates expressions and determines their values and types. You need to implement the  overloaded operator functions for the Value class.  • The results of an unsuccessful parsing and interpreting are a set of error messages printed  by the parser/interpreter functions, as well as the error messages that might be detected by  the lexical analyzer.   • Any failures due to the process of parsing or interpreting the input program should  cause the process of interpretation to stop and return back.   • In addition to the error messages generated due to parsing, the interpreter generates error  messages due to its semantics checking. The assignment does not specify the exact error  messages that should be printed out by the interpreter. However, the format of the messages  should be the line number, followed by a colon and a space, followed by some descriptive  text, similar to the format used in Programming Assignment 2. Suggested messages of the  interpreter’s semantics check might include messages such as "Run-Time Error-Illegal  Mixed Type Operands", " Run-Time Error-Illegal Assignment Operation", "Run-Time  Error-Illegal Division by Zero", etc. Provided Files  You are given the following files for the process of building an interpretation. These are “lex.h’,  “lex.cpp”, “val.h”, “parseInt.h”, and “parseInt.cpp” with definitions and partial implementations  of some functions. You need to complete the implementation of the interpreter in the provided  copy of “parseInt.cpp. “parse.cpp” will be posted later on. “val.h” includes the following:  • A class definition, called Value, representing a value object in the interpreted source code  for constants, variables or evaluated expressions. It includes:  o Four data members of the Value class for holding a value as either an integer, float,   string, or boolean.  o A data member holding the type of the value as an enum type defined as:  enum ValType { VINT, VREAL, VSTRING, VBOOL, VERR };  o Getter methods to return the value of an object based on its type   o Getter methods to return the type of the value of an object.   o Setter methods to update the value of an object.  o Overloaded constructors to initialize an object based on the type of their parameters.  o Member methods to check the type of the Value object.  o Overloaded operators’ functions for the arithmetic operators (+, -, *, and /)  o Overloaded operators’ functions for the relational operators (==, >, and , operator

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CS 280 Fall 2022 Programming Assignment 3 November 22, 2022Due Date: Sunday, December 11, 2022, 23:59 Total Points: 20In this programming assignment, you will be building an interpreter...

Answer To: CS 280 Fall 2022 Programming Assignment 3 November 22, 2022Due Date: Sunday, December 11,...

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