CISS-111 Project 2

Write a Java program to demonstrate using Vector, enumerations, regular expressions, HashMap, and record. You will create a program to perform basic parsing of a 6502 assembly language program.

Learning outcomes

Working with files.
Building enumerations.
Working with enumeration methods.
Working with strings and parsing.
Working with Java records.
Exposure to predefined data structures.
Exposure to Vectors.
Exposure to regular expressions.

Token Types

Recall that enumerations are special forms of classes and therefore are subclasses of Object. Using your knowledge of enumerations, create the following enumeration with the constants defined below:

TokenType.java

package hvcc.ciss111;   // <<--- Hey! We're making a package!

public enum TokenType {

    // instructions
    ADC, AND, ASL, BCC, BCS, BEQ, BIT, BMI, BNE, BPL, BRK, BVC, BVS, CLC,
    CLD, CLI, CLV, CMP, CPX, CPY, DEC, DEX, DEY, EOR, INC, INX, INY, JMP,
    JSR, LDA, LDX, LDY, LSR, NOP, ORA, PHA, PHP, PLA, PLP, ROL, ROR, RTI,
    RTS, SBC, SEC, SED, SEI, STA, STX, STY, TAX, TAY, TSX, TXA, TXS, TYA,

    // punctuation
    LPAREN, COMMA, RPAREN,

    // numerics
    ADDRESS, CONST,

    // registers X and Y
    REGISTER
}

This enumeration is centered around a ton of reserved words, some punctuation, numbers, and a couple of registers.

Now write java code to read a program written in 6502 assembly language. This will be an easy introduction to parsing. Everything is space-delimited so that you can use split() to help you out. The entire exercise is about identification.

Numbers

The following Java regex will help identify the values you may find in the program.

#?\$\p{XDigit}{2}(?:\p{XDigit}{2})?

               #? -> match a # zero or one time.
               \$ -> match exactly a $
    \p{XDigit}{2} -> match exactly 2 ({2}) hexadecimal digits (\p{XDigit})
(?:\p{XDigit}{2}) -> This one takes a little more to explain...

The final piece matches everything enclosed in the parentheses, the (?:). Inside of that, we are trying to, again, match exactly 2 ({2}) hexadecimal digits (\p{XDigit}). The key is the final question mark that says to do the parenthetic match zero or one time. The following will match this regex:

$89
#$89
$Ff8b
#$ff8b

Pasting the regex into your Java IDE (especially IntelliJ) will add more backslashes to get the escapes right. So, when you do paste it into the IDE, it will look more like this:

DON'T COPY THIS ONE!

#?\\$\\p{XDigit}{2}(?:\\p{XDigit}{2})?

We will not be using the default namespace for this project. We will be creating our own based on the package details noted below.

Important Note!

Make sure you create the new package in the src folder (right click, select New, and then Package) and give the name hvcc.ciss111. Then, you are ready to start writing code by creating a class in that package!

Project2_lastname.java

package hvcc.ciss111;   // <<--- Hey! We're making a package!

import java.io.FileNotFoundException;
import java.util.Scanner;
import java.io.FileReader;
import java.util.Vector;
import java.util.HashMap;
import static hvcc.ciss111.TokenType.*;

public class Project2 {
    public record Token (TokenType type, String value) {
        // Override the toString() method
    }

    public static void main(String[] args) throws FileNotFoundException {
        Scanner inFile;
        Vector<Token> tokens = new Vector<>();
        HashMap<String, TokenType> opcodes = new HashMap<>();
        TokenType[] list = TokenType.values();
        TokenType tt;

        /* YOUR CODE HERE! */

    }
}

Start by opening the file, setup an EOF loop, and reading lines. Each line can be split() and then begin the identification process. You don't need to create methods, but it may make things easier.

The HashMap is there to help you map strings to enumerations. With each token from the line, classify it and create a Token object and add it to the Vector.

When the file is exhausted, iterate over the Vector and write the objects to the screen.

Test Program

JSR $0606
LDX #$02
LDA $10 , X
CMP $10
BNE $06b6
LDA $11 , X
CMP $11
BEQ $06bf
INX
INX
CPX $03
BEQ $06c2
JMP $06aa
JMP $0735
RTS
LDX $03
DEX
TXA
LDA $10 , X
STA $12 , X
DEX
BPL $06c7
LDA $02
LSR A
BCS $06dc
LSR A
BCS $06ef
LSR A
BCS $06f8
LSR A
BCS $070b
LDA $10
SEC
SBC #$20
STA $10
BCC $06e6
RTS
DEC $11
LDA #$01
CMP $11
BEQ $0716
RTS
INC $10
LDA #$1f
BIT $10
BEQ $0716
RTS
LDA $10
CLC
ADC #$20
STA $10
BCS $0702
RTS
INC $11
LDA #$06
CMP $11
BEQ $0716
RTS
DEC $10
LDA $10
AND #$1f
CMP #$1f
BEQ $0716
RTS
JMP $0735
LDY #$00
LDA $fe
STA ( $00 ) , Y
RTS
LDX $03
LDA #$00
STA ( $10 , X )
LDX #$00
LDA #$01
STA ( $10 , X )
RTS
LDX #$00
NOP
NOP
DEX
BNE $072f
RTS
LDX $03
DEX
TXA
LDA $10 , X
STA $12 , X
DEX
BPL $06c7
LDA $02
LSR A
BCS $06dc
LSR A
BCS $06ef
LSR A
BCS $06f8
LSR A
BCS $070b
LDA $10
SEC
SBC #$20
STA $10
BCC $06e6
RTS

Your output will go to the screen. Since we are using a record and the default output is messy, you will override the toString() method provided to look more like the output below.

Token type JSR
Token type ADDRESS, value = $0606
Token type LDX
Token type CONST, value = #$02
Token type LDA
Token type ADDRESS, value = $10
Token type COMMA
Token type REGISTER, value = X
Token type CMP
Token type ADDRESS, value = $10
Token type BNE
Token type ADDRESS, value = $06b6
Token type LDA
Token type ADDRESS, value = $11
Token type COMMA
Token type REGISTER, value = X
Token type CMP
Token type ADDRESS, value = $11
Token type BEQ
Token type ADDRESS, value = $06bf
Token type INX
Token type INX
Token type CPX
Token type ADDRESS, value = $03
Token type BEQ
Token type ADDRESS, value = $06c2
Token type JMP
Token type ADDRESS, value = $06aa
Token type JMP
Token type ADDRESS, value = $0735
Token type RTS
Token type LDX
Token type ADDRESS, value = $03
Token type DEX
Token type TXA
Token type LDA
Token type ADDRESS, value = $10
Token type COMMA
Token type REGISTER, value = X
Token type STA
Token type ADDRESS, value = $12
Token type COMMA
Token type REGISTER, value = X
Token type DEX
Token type BPL
Token type ADDRESS, value = $06c7
Token type LDA
Token type ADDRESS, value = $02
Token type LSR
Token type REGISTER, value = A
Token type BCS
Token type ADDRESS, value = $06dc
Token type LSR
Token type REGISTER, value = A
Token type BCS
Token type ADDRESS, value = $06ef
Token type LSR
Token type REGISTER, value = A
Token type BCS
Token type ADDRESS, value = $06f8
Token type LSR
Token type REGISTER, value = A
Token type BCS
Token type ADDRESS, value = $070b
Token type LDA
Token type ADDRESS, value = $10
Token type SEC
Token type SBC
Token type CONST, value = #$20
Token type STA
Token type ADDRESS, value = $10
Token type BCC
Token type ADDRESS, value = $06e6
Token type RTS
Token type DEC
Token type ADDRESS, value = $11
Token type LDA
Token type CONST, value = #$01
Token type CMP
Token type ADDRESS, value = $11
Token type BEQ
Token type ADDRESS, value = $0716
Token type RTS
Token type INC
Token type ADDRESS, value = $10
Token type LDA
Token type CONST, value = #$1f
Token type BIT
Token type ADDRESS, value = $10
Token type BEQ
Token type ADDRESS, value = $0716
Token type RTS
Token type LDA
Token type ADDRESS, value = $10
Token type CLC
Token type ADC
Token type CONST, value = #$20
Token type STA
Token type ADDRESS, value = $10
Token type BCS
Token type ADDRESS, value = $0702
Token type RTS
Token type INC
Token type ADDRESS, value = $11
Token type LDA
Token type CONST, value = #$06
Token type CMP
Token type ADDRESS, value = $11
Token type BEQ
Token type ADDRESS, value = $0716
Token type RTS
Token type DEC
Token type ADDRESS, value = $10
Token type LDA
Token type ADDRESS, value = $10
Token type AND
Token type CONST, value = #$1f
Token type CMP
Token type CONST, value = #$1f
Token type BEQ
Token type ADDRESS, value = $0716
Token type RTS
Token type JMP
Token type ADDRESS, value = $0735
Token type LDY
Token type CONST, value = #$00
Token type LDA
Token type ADDRESS, value = $fe
Token type STA
Token type LPAREN
Token type ADDRESS, value = $00
Token type RPAREN
Token type COMMA
Token type REGISTER, value = Y
Token type RTS
Token type LDX
Token type ADDRESS, value = $03
Token type LDA
Token type CONST, value = #$00
Token type STA
Token type LPAREN
Token type ADDRESS, value = $10
Token type COMMA
Token type REGISTER, value = X
Token type RPAREN
Token type LDX
Token type CONST, value = #$00
Token type LDA
Token type CONST, value = #$01
Token type STA
Token type LPAREN
Token type ADDRESS, value = $10
Token type COMMA
Token type REGISTER, value = X
Token type RPAREN
Token type RTS
Token type LDX
Token type CONST, value = #$00
Token type NOP
Token type NOP
Token type DEX
Token type BNE
Token type ADDRESS, value = $072f
Token type RTS
Token type LDX
Token type ADDRESS, value = $03
Token type DEX
Token type TXA
Token type LDA
Token type ADDRESS, value = $10
Token type COMMA
Token type REGISTER, value = X
Token type STA
Token type ADDRESS, value = $12
Token type COMMA
Token type REGISTER, value = X
Token type DEX
Token type BPL
Token type ADDRESS, value = $06c7
Token type LDA
Token type ADDRESS, value = $02
Token type LSR
Token type REGISTER, value = A
Token type BCS
Token type ADDRESS, value = $06dc
Token type LSR
Token type REGISTER, value = A
Token type BCS
Token type ADDRESS, value = $06ef
Token type LSR
Token type REGISTER, value = A
Token type BCS
Token type ADDRESS, value = $06f8
Token type LSR
Token type REGISTER, value = A
Token type BCS
Token type ADDRESS, value = $070b
Token type LDA
Token type ADDRESS, value = $10
Token type SEC
Token type SBC
Token type CONST, value = #$20
Token type STA
Token type ADDRESS, value = $10
Token type BCC
Token type ADDRESS, value = $06e6
Token type RTS

Submit the project to the Learning Management System as Project2_lastname.java.