合肥生活安徽新聞合肥交通合肥房產(chǎn)生活服務(wù)合肥教育合肥招聘合肥旅游文化藝術(shù)合肥美食合肥地圖合肥社保合肥醫(yī)院企業(yè)服務(wù)合肥法律

        代做COP 3402、代寫Python/c++語(yǔ)言程序
        代做COP 3402、代寫Python/c++語(yǔ)言程序

        時(shí)間:2025-02-14  來(lái)源:合肥網(wǎng)hfw.cc  作者:hfw.cc 我要糾錯(cuò)



        University of Central Florida
        School of Electrical Engineering & Computer Science
        COP 3402: System Software
        Spring 2025

        Homework #2 (Lexical Analyzer)
         
        Due Sunday, February 16th, 2025 by 11:59 p.m. 
        Goal:
        In this assignment your team have to implement a lexical analyzer for the programming language PL/0. Your program must be capable to read in a source program written in PL/0, identify some errors, and produce, as output, the source program, the source program lexeme table, and the token list. For an example of input and output refer to Appendix A. In the next page we show you the grammar for the programming language PL/0 using the extended Backus-Naur Form (EBNF).

        You will use the given Context Free Grammar (see next page) to identify all symbols the programming language provides you with.  These symbols are shown below:

        Reserved Words: const, var, procedure, call, begin, end, if, fi, then, else, while, do, read, write.        
        Special Symbols: ‘+’, ‘-‘, ‘*’, ‘/’, ‘(‘, ‘)’, ‘=’, ’,’ , ‘.’, ‘ <’, ‘>’,  ‘;’ , ’:’ .
        Identifiers: identsym = letter (letter | digit)* 
        Numbers: numbersym = (digit)+
        Invisible Characters: tab, white spaces, newline
        Comments denoted by: /* . . .   */

        Refer to Appendix B for a declaration of the token symbols that may be useful.


        In this assignment, you will not check syntax.


        Example1: program written in PL/0:

        var x, y;
        x := y * 2.

        Use these rules to read PL/0 grammar expressed in EBNF.

        1.- [ ] means an optional item, 
        2.- { } means repeat 0 or more times.
        3.- Terminal symbols are enclosed in quote marks.
        4.- Symbols without quotes are called no-terminals or a syntactic class.
        5.-A period is used to indicate the end of the definition of a syntactic class.
        6.-The symbol ‘::=’ is read as ‘is defined as’; for example, the following syntactic class:

        program ::= block ".".  

        must be read as follows: 
        a program    is defined as    a block followed by a   dot.
           program             ::=                   block                                ".".  

        Context Free Grammar for PL/0 expressed in EBNF.

        program ::= block "." . 
        block ::= const-declaration  var-declaration  proc-declaration statement.    
        const-declaration ::= [ “const” ident "=" number {"," ident "=" number} “;"].    
        var-declaration  ::= [ "var" ident {"," ident} “;"].
        proc-declaration::= {"procedure" ident ";" block ";" } .
        statement   ::= [ ident ":=" expression
        | "call" ident
                      | "begin" statement { ";" statement } "end" 
                      | "if" condition "then" statement "fi"
                | "if" condition "then" statement “else" statement fi"
                     | "while" condition "do" statement
                | “read” ident
        | “write” ident
                      | empty ] . 
         
        condition ::=  expression  rel-op  expression.
          
        rel-op ::= "="|“<>"|"<"|"<="|">"|">=“.
        expression ::= term { ("+"|"-") term}.
        term ::= factor {("*"|"/") factor}. 
        factor ::= ident | number | "(" expression ")“.

        In this assignment, you will identify valid PL/0 symbols and then translate them into an internal representation called “Tokens”.

        Lexical Grammar for PL/0 expressed in EBNF.

        ident ::= letter {letter | digit}.
        letter ::= "a" | "b" | … | "y" | "z" | "A" | "B" | ... | "Y" | "Z".
        number ::= digit {digit}.
        digit ::= "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9“.
        Lexical Conventions for PL/0:
        A numerical value is assigned to each token (internal representation) as follows: 
        skipsym = 1, identsym = 2, numbersym = 3, plussym = 4, minussym = 5, 
        multsym = 6,  slashsym = 7, fisym = 8,  eqlsym = 9, neqsym = 10, lessym = 11, leqsym = 12, gtrsym = 13, geqsym = 14, lparentsym = 15, rparentsym = 16, commasym = 17, semicolonsym = 18, periodsym = 19, becomessym = 20, 
        beginsym = 21, endsym = 22, ifsym = 23, thensym = 24, whilesym = 25, dosym = 26, callsym = 27, constsym = 28, varsym = 29, procsym = 30, writesym = 31, 
        readsym = 32, elsesym = 33.


        Example2: program written in PL/0:

        var w, x;
        read w;
        begin
           x:= 4;
           if w > x then
            w:= w + 1
           else
            w:= x;
           fi
        end
        write w. 


        Remember, in this assignment, you will not check syntax.

        For the scanner 
        x := y + 7;          and          + 7 ; x y :=   are valid inputs
        Constraints:
        Input:
        1.Identifiers can be a maximum of 11 characters in length.
        2.Numbers can be a maximum of 5 digits in length.
        3.Comments should be ignored and not tokenized.
        4.Invisible Characters should be ignored and not tokenized.

        Output:
        1.The token separator in the output's Lexeme List (Refer to Appendix A) can be either a space or a bar ('|').
        2.In your output's Lexeme List, identifiers must show the token and the variable name separated by a space or bar.
        3.In your output's Token list, numbers must show the token and the value separated by a space or bar. The value must be transformed into ASCII Representation.
        4.Be consistent in output. Choose either bars or spaces and stick with them.
        5.The token representation of the Token list will be used in the Parser (HW3). So, PLAN FOR IT!

        Detect the Following Lexical Errors:

        1.Number too long.
        2.Name too long.
        3.Invalid symbols.

        Hint: You could create a transition diagram (DFS) to recognize each lexeme on the source program and once accepted generate the token, otherwise emit an error message.
         
        Submission Instructions:
        Submit to Webcourse:
        1. Source code. (lex.c) 
        2. Instructions to use the program in a readme document.
        3. One run containing the input file (Source Program), and output file. The output file must show:  
         (Source,  Lexeme Table(lexeme-token), Token List)

        Appendix A:

        If the input is:
        var x, y;
        begin
            y := 3;
            x := y + 56;
        end.

        The output will be:
        Source Program:
        var x, y;
        begin
            y := 3;
            x := y + 56;
        end.

        Lexeme Table:

        lexeme    token type     
        var        29        
        x        2
        ,        17        
        y        2
        ;        18
        begin        21
        y        2
        :=        20
        3        3
        ;        18
        x        2
        :=          20        
        y        2
        +        4
        56        3
        ;        18
        end         22
        .        19

        Token List:
        29 2 x 17 2 y 18 21 2 y 20 3 3 18 2 x 20 2 y 4 3 56 18 22 19
         
        Appendix B:

        Declaration of Token Types:
        typedef enum { 
        skipsym = 1, identsym, numbersym, plussym, minussym,
        multsym,  slashsym, fisym, eqsym, neqsym, lessym, leqsym,
        gtrsym, geqsym, lparentsym, rparentsym, commasym, semicolonsym,
        periodsym, becomessym, beginsym, endsym, ifsym, thensym, 
        whilesym, dosym, callsym, constsym, varsym, procsym, writesym,
        readsym , elsesym} token_type;


        Example of Token Representation:
        “29  2 x  17  2 y 18  21  2 x 21  2 y 4  3 56 18  22  19”

        Is Equivalent:
        varsym identsym  x  commasym  identsym  y  semicolonsym  beginsym  identsym  x
        becomessym identsym y plussym numbersym 56 semicolonsym endsym periodsym

         
        Appendix C:

        Example of a PL/0 program: 
        const m = 7, n = 85;  
        var  i,x,y,z,q,r;  
        procedure mult; 
           var a, b;  
          begin 
             a := x;  b := y; z := 0;   
             while b > 0 do    
             begin 
                if x =1 then z := z+a fi;       
                a := 2*a; 
                b := b/2;     
             end   
          end;

        begin
          x := m;
          y := n;
          call mult;
        end.


        Find out the output for this example!


        Rubric:

        Integrity:
        Plagiarism or Resubmission of Old Programs: -100 points
        Compilation & Execution:
        Programs That Don't Compile: -100 points
        Program Cannot Reproduce any output in the terminal: -10 points
        Program is white-space dependent: -10 points
        For example, a+b should be properly tokenized.
        For example, 4hello is two tokens: a number and an identifier.
        Submission Files:
        Missing lex.c: -100 points
        Missing readme File: -5 points
        Missing Input or Output File: -5 points
        Partial Missing: -2.5 points for either input or output file
        Lexical Error Detection:
        Not Detecting All Three Lexical Errors: -15 points
        Each lexical error detection is worth 5 points.
        Output Formatting:
        Output Significantly Unaligned with Appendix A: -5 points
        Late Submissions:
        One Day Late: -10 points
        Two Days Late: -20 points

        No email submission will be accepted. 

        請(qǐng)加QQ:99515681  郵箱:99515681@qq.com   WX:codinghelp




         

        掃一掃在手機(jī)打開當(dāng)前頁(yè)
      1. 上一篇:CP414編程代寫、代做Java/Python程序
      2. 下一篇:代做Operating Systems 、代寫C++程序語(yǔ)言
      3. 無(wú)相關(guān)信息
        合肥生活資訊

        合肥圖文信息
        急尋熱仿真分析?代做熱仿真服務(wù)+熱設(shè)計(jì)優(yōu)化
        急尋熱仿真分析?代做熱仿真服務(wù)+熱設(shè)計(jì)優(yōu)化
        出評(píng) 開團(tuán)工具
        出評(píng) 開團(tuán)工具
        挖掘機(jī)濾芯提升發(fā)動(dòng)機(jī)性能
        挖掘機(jī)濾芯提升發(fā)動(dòng)機(jī)性能
        海信羅馬假日洗衣機(jī)亮相AWE  復(fù)古美學(xué)與現(xiàn)代科技完美結(jié)合
        海信羅馬假日洗衣機(jī)亮相AWE 復(fù)古美學(xué)與現(xiàn)代
        合肥機(jī)場(chǎng)巴士4號(hào)線
        合肥機(jī)場(chǎng)巴士4號(hào)線
        合肥機(jī)場(chǎng)巴士3號(hào)線
        合肥機(jī)場(chǎng)巴士3號(hào)線
        合肥機(jī)場(chǎng)巴士2號(hào)線
        合肥機(jī)場(chǎng)巴士2號(hào)線
        合肥機(jī)場(chǎng)巴士1號(hào)線
        合肥機(jī)場(chǎng)巴士1號(hào)線
      4. 短信驗(yàn)證碼 酒店vi設(shè)計(jì) NBA直播 幣安下載

        關(guān)于我們 | 打賞支持 | 廣告服務(wù) | 聯(lián)系我們 | 網(wǎng)站地圖 | 免責(zé)聲明 | 幫助中心 | 友情鏈接 |

        Copyright © 2025 hfw.cc Inc. All Rights Reserved. 合肥網(wǎng) 版權(quán)所有
        ICP備06013414號(hào)-3 公安備 42010502001045

        主站蜘蛛池模板: 国产午夜精品一区理论片| 一区二区三区福利视频免费观看| 成人乱码一区二区三区av| 无码人妻一区二区三区一| 精品无码国产一区二区三区AV | 亚洲av无码片vr一区二区三区| 久久久精品人妻一区亚美研究所 | 另类免费视频一区二区在线观看| 精品视频一区二区三区四区五区| 中文字幕AV一区中文字幕天堂| 久久91精品国产一区二区| 在线观看一区二区三区av| 人成精品视频三区二区一区| 亚洲福利一区二区| 大香伊蕉日本一区二区| 一区二区三区四区视频| 波多野结衣一区二区免费视频| 无码人妻精品一区二区三区夜夜嗨| 久久人妻无码一区二区| 无码精品人妻一区二区三区人妻斩| 另类ts人妖一区二区三区| 亚洲国产综合精品中文第一区| 精品国产一区二区三区AV | 精品一区二区三区免费视频| 精品欧洲av无码一区二区三区| 亚洲视频在线一区二区| 无码国产精品一区二区免费16| 一区二区三区在线播放| 国产一区二区三区美女| 日本一区免费电影| 国产一区二区在线| 亚洲欧美日韩一区二区三区在线| 九九久久99综合一区二区| 中日韩一区二区三区| 波多野结衣中文一区二区免费| 少妇一晚三次一区二区三区| 无码国产精品一区二区免费| 91久久精品午夜一区二区| 精品国产a∨无码一区二区三区 | 亚洲视频一区在线观看| 日韩精品乱码AV一区二区|