// Simple Interpreter - by Amir // Incomplete yet. import java.util.ArrayList; import java.util.HashMap; import java.util.Scanner; import java.util.StringTokenizer; import java.util.Formatter; public class Interpreter { public HashMap> variables; public ArrayList commands; Interpreter() { variables = new HashMap<>(); commands = new ArrayList<>(); } public static void main(String[] args) { Interpreter interpreter = new Interpreter(); try { interpreter.parseInput(); interpreter.interpret(); } catch (Exception e) { System.err.println(e.getMessage()); } } public void interpret() throws Exception { for (Command command : commands) { StringTokenizer st = new StringTokenizer(command.getCmd()); ArrayList tokens = new ArrayList<>(); while(st.hasMoreTokens()){ tokens.add(st.nextToken()); } String firstToken = tokens.remove(0); if (firstToken.equals(CMD_DECLARATION)) { if (tokens.isEmpty()) { throw new Exception( command.getCmd() + ERR_MSG_DECLARATION + command.getLineNumber()); } String varName = tokens.remove(0); if (tokens.isEmpty()){ } else if (varName.endsWith("=") || st.hasMoreTokens()) { varName = varName.substring(0, varName.length() - 1); } while (st.hasMoreTokens()) { } } else if (firstToken.equals(CMD_PRINT)) { } } } // Initializes commands public void parseInput() throws Exception { Scanner sc = new Scanner(System.in); if (sc.hasNext()) { input = ""; while (sc.hasNextLine()) { input += sc.nextLine() + "\n"; } } sc.close(); int lineNumber = 0; for (String line : input.split("\n")) { lineNumber++; line = line.trim(); if (line.equals("")) { lineNumber--; continue; } else if (!line.endsWith(";")) { throw new Exception(line + ERR_MSG_SEMICOLON + lineNumber); } for (String cmd : line.split(";")) { cmd = cmd.trim(); Command newCommand = new Command(lineNumber, cmd); commands.add(newCommand); } } } public static final String CMD_DECLARATION = "svar"; public static final String CMD_PRINT = "print"; public static final String CMD_ASSIGN = "="; // Error Message : Semicolon public static final String ERR_MSG_SEMICOLON = " <--- Incorrect Instruction!\n" + "You may forgot to put a semicolon at line "; // Error Message : Variable Declaration public static final String ERR_MSG_DECLARATION = " <--- Incorrect Declaration!\n" + "Variable declaration is not valid at line "; // Error Message : Variable Name public static final String ERR_MSG_VARNAME = " <--- Incorrect Variable Name!\n" + "Variable name cannot contain whitespaces. line "; public static String input = "" + " \tsvar \t a b; svar d; \n" + "svar b ;\n\n\n" + "svar c; \n" + "a = b + c ;\n"; } public class Command { private int lineNumber; private String cmd; public Command(int lineNumber, String cmd) { this.lineNumber = lineNumber; this.cmd = cmd; } public int getLineNumber() { return lineNumber; } public String getCmd() { return cmd; } @Override public String toString() { Formatter formatter = new Formatter(); String str = formatter.format("%3d- %s", lineNumber, cmd).toString(); formatter.close(); return str; } } public class Variable { private T value; private String name; public Variable(String name) { this.name = name; } public Variable(String name, T value) { this.name = name; this.setValue(value); } public T getValue() { return value; } public void setValue(T value) { if (this.value == null){ this.value = value; } else { //TODO: Exception handling } } public String getName() { return name; } @Override public String toString(){ return value.toString(); } }

MyInterpreter