Soumettre la recherche
Mettre en ligne
Lecture 6.pdf
•
0 j'aime
•
4 vues
A
AliSarmad15
Suivre
principle Affine Cipher Encryption in Cryptography Part
Lire moins
Lire la suite
Formation
Signaler
Partager
Signaler
Partager
1 sur 29
Télécharger maintenant
Télécharger pour lire hors ligne
Recommandé
4 lexical and syntax
4 lexical and syntax
Munawar Ahmed
sabesta.ppt
sabesta.ppt
NaveedAfzal34
sabesta3.ppt
sabesta3.ppt
NaveedAfzal34
3 describing syntax
3 describing syntax
Munawar Ahmed
UNIT 1 part II.ppt
UNIT 1 part II.ppt
Ranjeet Reddy
CH # 1 preliminaries
CH # 1 preliminaries
Munawar Ahmed
5 Names, bindings,Typechecking and Scopes
5 Names, bindings,Typechecking and Scopes
Munawar Ahmed
4 lexical and syntax analysis
4 lexical and syntax analysis
jigeno
Recommandé
4 lexical and syntax
4 lexical and syntax
Munawar Ahmed
sabesta.ppt
sabesta.ppt
NaveedAfzal34
sabesta3.ppt
sabesta3.ppt
NaveedAfzal34
3 describing syntax
3 describing syntax
Munawar Ahmed
UNIT 1 part II.ppt
UNIT 1 part II.ppt
Ranjeet Reddy
CH # 1 preliminaries
CH # 1 preliminaries
Munawar Ahmed
5 Names, bindings,Typechecking and Scopes
5 Names, bindings,Typechecking and Scopes
Munawar Ahmed
4 lexical and syntax analysis
4 lexical and syntax analysis
jigeno
psychiatric nursing HISTORY COLLECTION .docx
psychiatric nursing HISTORY COLLECTION .docx
PoojaSen20
Russian Escort Service in Delhi 11k Hotel Foreigner Russian Call Girls in Delhi
Russian Escort Service in Delhi 11k Hotel Foreigner Russian Call Girls in Delhi
kauryashika82
Accessible Digital Futures project (20/03/2024)
Accessible Digital Futures project (20/03/2024)
Jisc
On National Teacher Day, meet the 2024-25 Kenan Fellows
On National Teacher Day, meet the 2024-25 Kenan Fellows
Mebane Rash
Making communications land - Are they received and understood as intended? we...
Making communications land - Are they received and understood as intended? we...
Association for Project Management
How to Give a Domain for a Field in Odoo 17
How to Give a Domain for a Field in Odoo 17
Celine George
Dyslexia AI Workshop for Slideshare.pptx
Dyslexia AI Workshop for Slideshare.pptx
callscotland1987
Explore beautiful and ugly buildings. Mathematics helps us create beautiful d...
Explore beautiful and ugly buildings. Mathematics helps us create beautiful d...
christianmathematics
Introduction to Nonprofit Accounting: The Basics
Introduction to Nonprofit Accounting: The Basics
TechSoup
The basics of sentences session 3pptx.pptx
The basics of sentences session 3pptx.pptx
heathfieldcps1
Jual Obat Aborsi Hongkong ( Asli No.1 ) 085657271886 Obat Penggugur Kandungan...
Jual Obat Aborsi Hongkong ( Asli No.1 ) 085657271886 Obat Penggugur Kandungan...
ZurliaSoop
ComPTIA Overview | Comptia Security+ Book SY0-701
ComPTIA Overview | Comptia Security+ Book SY0-701
bronxfugly43
microwave assisted reaction. General introduction
microwave assisted reaction. General introduction
Maksud Ahmed
Python Notes for mca i year students osmania university.docx
Python Notes for mca i year students osmania university.docx
Ramakrishna Reddy Bijjam
SKILL OF INTRODUCING THE LESSON MICRO SKILLS.pptx
SKILL OF INTRODUCING THE LESSON MICRO SKILLS.pptx
Amanpreet Kaur
SOC 101 Demonstration of Learning Presentation
SOC 101 Demonstration of Learning Presentation
camerronhm
Seal of Good Local Governance (SGLG) 2024Final.pptx
Seal of Good Local Governance (SGLG) 2024Final.pptx
negromaestrong
Asian American Pacific Islander Month DDSD 2024.pptx
Asian American Pacific Islander Month DDSD 2024.pptx
David Douglas School District
Mixin Classes in Odoo 17 How to Extend Models Using Mixin Classes
Mixin Classes in Odoo 17 How to Extend Models Using Mixin Classes
Celine George
Application orientated numerical on hev.ppt
Application orientated numerical on hev.ppt
RamjanShidvankar
2024 State of Marketing Report – by Hubspot
2024 State of Marketing Report – by Hubspot
Marius Sescu
Everything You Need To Know About ChatGPT
Everything You Need To Know About ChatGPT
Expeed Software
Contenu connexe
Dernier
psychiatric nursing HISTORY COLLECTION .docx
psychiatric nursing HISTORY COLLECTION .docx
PoojaSen20
Russian Escort Service in Delhi 11k Hotel Foreigner Russian Call Girls in Delhi
Russian Escort Service in Delhi 11k Hotel Foreigner Russian Call Girls in Delhi
kauryashika82
Accessible Digital Futures project (20/03/2024)
Accessible Digital Futures project (20/03/2024)
Jisc
On National Teacher Day, meet the 2024-25 Kenan Fellows
On National Teacher Day, meet the 2024-25 Kenan Fellows
Mebane Rash
Making communications land - Are they received and understood as intended? we...
Making communications land - Are they received and understood as intended? we...
Association for Project Management
How to Give a Domain for a Field in Odoo 17
How to Give a Domain for a Field in Odoo 17
Celine George
Dyslexia AI Workshop for Slideshare.pptx
Dyslexia AI Workshop for Slideshare.pptx
callscotland1987
Explore beautiful and ugly buildings. Mathematics helps us create beautiful d...
Explore beautiful and ugly buildings. Mathematics helps us create beautiful d...
christianmathematics
Introduction to Nonprofit Accounting: The Basics
Introduction to Nonprofit Accounting: The Basics
TechSoup
The basics of sentences session 3pptx.pptx
The basics of sentences session 3pptx.pptx
heathfieldcps1
Jual Obat Aborsi Hongkong ( Asli No.1 ) 085657271886 Obat Penggugur Kandungan...
Jual Obat Aborsi Hongkong ( Asli No.1 ) 085657271886 Obat Penggugur Kandungan...
ZurliaSoop
ComPTIA Overview | Comptia Security+ Book SY0-701
ComPTIA Overview | Comptia Security+ Book SY0-701
bronxfugly43
microwave assisted reaction. General introduction
microwave assisted reaction. General introduction
Maksud Ahmed
Python Notes for mca i year students osmania university.docx
Python Notes for mca i year students osmania university.docx
Ramakrishna Reddy Bijjam
SKILL OF INTRODUCING THE LESSON MICRO SKILLS.pptx
SKILL OF INTRODUCING THE LESSON MICRO SKILLS.pptx
Amanpreet Kaur
SOC 101 Demonstration of Learning Presentation
SOC 101 Demonstration of Learning Presentation
camerronhm
Seal of Good Local Governance (SGLG) 2024Final.pptx
Seal of Good Local Governance (SGLG) 2024Final.pptx
negromaestrong
Asian American Pacific Islander Month DDSD 2024.pptx
Asian American Pacific Islander Month DDSD 2024.pptx
David Douglas School District
Mixin Classes in Odoo 17 How to Extend Models Using Mixin Classes
Mixin Classes in Odoo 17 How to Extend Models Using Mixin Classes
Celine George
Application orientated numerical on hev.ppt
Application orientated numerical on hev.ppt
RamjanShidvankar
Dernier
(20)
psychiatric nursing HISTORY COLLECTION .docx
psychiatric nursing HISTORY COLLECTION .docx
Russian Escort Service in Delhi 11k Hotel Foreigner Russian Call Girls in Delhi
Russian Escort Service in Delhi 11k Hotel Foreigner Russian Call Girls in Delhi
Accessible Digital Futures project (20/03/2024)
Accessible Digital Futures project (20/03/2024)
On National Teacher Day, meet the 2024-25 Kenan Fellows
On National Teacher Day, meet the 2024-25 Kenan Fellows
Making communications land - Are they received and understood as intended? we...
Making communications land - Are they received and understood as intended? we...
How to Give a Domain for a Field in Odoo 17
How to Give a Domain for a Field in Odoo 17
Dyslexia AI Workshop for Slideshare.pptx
Dyslexia AI Workshop for Slideshare.pptx
Explore beautiful and ugly buildings. Mathematics helps us create beautiful d...
Explore beautiful and ugly buildings. Mathematics helps us create beautiful d...
Introduction to Nonprofit Accounting: The Basics
Introduction to Nonprofit Accounting: The Basics
The basics of sentences session 3pptx.pptx
The basics of sentences session 3pptx.pptx
Jual Obat Aborsi Hongkong ( Asli No.1 ) 085657271886 Obat Penggugur Kandungan...
Jual Obat Aborsi Hongkong ( Asli No.1 ) 085657271886 Obat Penggugur Kandungan...
ComPTIA Overview | Comptia Security+ Book SY0-701
ComPTIA Overview | Comptia Security+ Book SY0-701
microwave assisted reaction. General introduction
microwave assisted reaction. General introduction
Python Notes for mca i year students osmania university.docx
Python Notes for mca i year students osmania university.docx
SKILL OF INTRODUCING THE LESSON MICRO SKILLS.pptx
SKILL OF INTRODUCING THE LESSON MICRO SKILLS.pptx
SOC 101 Demonstration of Learning Presentation
SOC 101 Demonstration of Learning Presentation
Seal of Good Local Governance (SGLG) 2024Final.pptx
Seal of Good Local Governance (SGLG) 2024Final.pptx
Asian American Pacific Islander Month DDSD 2024.pptx
Asian American Pacific Islander Month DDSD 2024.pptx
Mixin Classes in Odoo 17 How to Extend Models Using Mixin Classes
Mixin Classes in Odoo 17 How to Extend Models Using Mixin Classes
Application orientated numerical on hev.ppt
Application orientated numerical on hev.ppt
En vedette
2024 State of Marketing Report – by Hubspot
2024 State of Marketing Report – by Hubspot
Marius Sescu
Everything You Need To Know About ChatGPT
Everything You Need To Know About ChatGPT
Expeed Software
Product Design Trends in 2024 | Teenage Engineerings
Product Design Trends in 2024 | Teenage Engineerings
Pixeldarts
How Race, Age and Gender Shape Attitudes Towards Mental Health
How Race, Age and Gender Shape Attitudes Towards Mental Health
ThinkNow
AI Trends in Creative Operations 2024 by Artwork Flow.pdf
AI Trends in Creative Operations 2024 by Artwork Flow.pdf
marketingartwork
Skeleton Culture Code
Skeleton Culture Code
Skeleton Technologies
PEPSICO Presentation to CAGNY Conference Feb 2024
PEPSICO Presentation to CAGNY Conference Feb 2024
Neil Kimberley
Content Methodology: A Best Practices Report (Webinar)
Content Methodology: A Best Practices Report (Webinar)
contently
How to Prepare For a Successful Job Search for 2024
How to Prepare For a Successful Job Search for 2024
Albert Qian
Social Media Marketing Trends 2024 // The Global Indie Insights
Social Media Marketing Trends 2024 // The Global Indie Insights
Kurio // The Social Media Age(ncy)
Trends In Paid Search: Navigating The Digital Landscape In 2024
Trends In Paid Search: Navigating The Digital Landscape In 2024
Search Engine Journal
5 Public speaking tips from TED - Visualized summary
5 Public speaking tips from TED - Visualized summary
SpeakerHub
ChatGPT and the Future of Work - Clark Boyd
ChatGPT and the Future of Work - Clark Boyd
Clark Boyd
Getting into the tech field. what next
Getting into the tech field. what next
Tessa Mero
Google's Just Not That Into You: Understanding Core Updates & Search Intent
Google's Just Not That Into You: Understanding Core Updates & Search Intent
Lily Ray
How to have difficult conversations
How to have difficult conversations
Rajiv Jayarajah, MAppComm, ACC
Introduction to Data Science
Introduction to Data Science
Christy Abraham Joy
Time Management & Productivity - Best Practices
Time Management & Productivity - Best Practices
Vit Horky
The six step guide to practical project management
The six step guide to practical project management
MindGenius
Beginners Guide to TikTok for Search - Rachel Pearson - We are Tilt __ Bright...
Beginners Guide to TikTok for Search - Rachel Pearson - We are Tilt __ Bright...
RachelPearson36
En vedette
(20)
2024 State of Marketing Report – by Hubspot
2024 State of Marketing Report – by Hubspot
Everything You Need To Know About ChatGPT
Everything You Need To Know About ChatGPT
Product Design Trends in 2024 | Teenage Engineerings
Product Design Trends in 2024 | Teenage Engineerings
How Race, Age and Gender Shape Attitudes Towards Mental Health
How Race, Age and Gender Shape Attitudes Towards Mental Health
AI Trends in Creative Operations 2024 by Artwork Flow.pdf
AI Trends in Creative Operations 2024 by Artwork Flow.pdf
Skeleton Culture Code
Skeleton Culture Code
PEPSICO Presentation to CAGNY Conference Feb 2024
PEPSICO Presentation to CAGNY Conference Feb 2024
Content Methodology: A Best Practices Report (Webinar)
Content Methodology: A Best Practices Report (Webinar)
How to Prepare For a Successful Job Search for 2024
How to Prepare For a Successful Job Search for 2024
Social Media Marketing Trends 2024 // The Global Indie Insights
Social Media Marketing Trends 2024 // The Global Indie Insights
Trends In Paid Search: Navigating The Digital Landscape In 2024
Trends In Paid Search: Navigating The Digital Landscape In 2024
5 Public speaking tips from TED - Visualized summary
5 Public speaking tips from TED - Visualized summary
ChatGPT and the Future of Work - Clark Boyd
ChatGPT and the Future of Work - Clark Boyd
Getting into the tech field. what next
Getting into the tech field. what next
Google's Just Not That Into You: Understanding Core Updates & Search Intent
Google's Just Not That Into You: Understanding Core Updates & Search Intent
How to have difficult conversations
How to have difficult conversations
Introduction to Data Science
Introduction to Data Science
Time Management & Productivity - Best Practices
Time Management & Productivity - Best Practices
The six step guide to practical project management
The six step guide to practical project management
Beginners Guide to TikTok for Search - Rachel Pearson - We are Tilt __ Bright...
Beginners Guide to TikTok for Search - Rachel Pearson - We are Tilt __ Bright...
Lecture 6.pdf
1.
Lecture 6 Chapter 4 Lexical
and Syntax Analysis Principles of Programming languages
2.
ISBN 0-321-49362-1 Chapter 4 Lexical
and Syntax Analysis
3.
Copyright © 2007
Addison-Wesley. All rights reserved. 1-3 Chapter 4 Topics • Introduction • Lexical Analysis • The Parsing Problem • Recursive-Descent Parsing • Bottom-Up Parsing
4.
Copyright © 2007
Addison-Wesley. All rights reserved. 1-4 Introduction • Language implementation systems must analyze source code, regardless of the specific implementation approach • Nearly all syntax analysis is based on a formal description of the syntax of the source language (BNF)
5.
Copyright © 2007
Addison-Wesley. All rights reserved. 1-5 Syntax Analysis • The syntax analysis portion of a language processor nearly always consists of two parts: – A low-level part called a lexical analyzer (mathematically, a finite automaton based on a regular grammar) – A high-level part called a syntax analyzer, or parser (mathematically, a push-down automaton based on a context-free grammar, or BNF)
6.
Copyright © 2007
Addison-Wesley. All rights reserved. 1-6
7.
Copyright © 2007
Addison-Wesley. All rights reserved. 1-7
8.
Copyright © 2007
Addison-Wesley. All rights reserved. 1-8 Lexical Analysis • A lexical analyzer is a pattern matcher for character strings • A lexical analyzer is a “front-end” for the parser • Identifies substrings of the source program that belong together - lexemes – Lexemes match a character pattern, which is associated with a lexical category called a token – sum is a lexeme; its token may be IDENT
9.
Copyright © 2007
Addison-Wesley. All rights reserved. 1-9 Lexical Analysis (continued) • The lexical analyzer is usually a function that is called by the parser when it needs the next token • Three approaches to building a lexical analyzer: – Write a formal description of the tokens and use a software tool that constructs table-driven lexical analyzers given such a description – Design a state diagram that describes the tokens and write a program that implements the state diagram – Design a state diagram that describes the tokens and hand-construct a table-driven implementation of the state diagram
10.
Copyright © 2007
Addison-Wesley. All rights reserved. 1-10
11.
Copyright © 2007
Addison-Wesley. All rights reserved. 1-11
12.
Copyright © 2007
Addison-Wesley. All rights reserved. 1-12
13.
Copyright © 2007
Addison-Wesley. All rights reserved. 1-13
14.
Copyright © 2007
Addison-Wesley. All rights reserved. 1-14
15.
Copyright © 2007
Addison-Wesley. All rights reserved. 1-15
16.
Copyright © 2007
Addison-Wesley. All rights reserved. 1-16
17.
Copyright © 2007
Addison-Wesley. All rights reserved. 1-17
18.
Copyright © 2007
Addison-Wesley. All rights reserved. 1-18
19.
Copyright © 2007
Addison-Wesley. All rights reserved. 1-19
20.
Copyright © 2007
Addison-Wesley. All rights reserved. 1-20 Advantages of Using BNF to Describe Syntax • Provides a clear and concise syntax description • The parser can be based directly on the BNF • Parsers based on BNF are easy to maintain
21.
Copyright © 2007
Addison-Wesley. All rights reserved. 1-21 Reasons to Separate Lexical and Syntax Analysis • Simplicity - less complex approaches can be used for lexical analysis; separating them simplifies the parser • Efficiency - separation allows optimization of the lexical analyzer • Portability - parts of the lexical analyzer may not be portable, but the parser always is portable
22.
Copyright © 2007
Addison-Wesley. All rights reserved. 1-22 State Diagram Design – A naïve state diagram would have a transition from every state on every character in the source language - such a diagram would be very large!
23.
Copyright © 2007
Addison-Wesley. All rights reserved. 1-23 Lexical Analysis (cont.) • In many cases, transitions can be combined to simplify the state diagram – When recognizing an identifier, all uppercase and lowercase letters are equivalent • Use a character class that includes all letters – When recognizing an integer literal, all digits are equivalent - use a digit class
24.
Copyright © 2007
Addison-Wesley. All rights reserved. 1-24 Lexical Analysis (cont.) • Reserved words and identifiers can be recognized together (rather than having a part of the diagram for each reserved word) – Use a table lookup to determine whether a possible identifier is in fact a reserved word
25.
Copyright © 2007
Addison-Wesley. All rights reserved. 1-25 Lexical Analysis (cont.) • Convenient utility subprograms: – getChar - gets the next character of input, puts it in nextChar, determines its class and puts the class in charClass – addChar - puts the character from nextChar into the place the lexeme is being accumulated, lexeme – lookup - determines whether the string in lexeme is a reserved word (returns a code)
26.
Copyright © 2007
Addison-Wesley. All rights reserved. 1-26 State Diagram
27.
Copyright © 2007
Addison-Wesley. All rights reserved. 1-27 Lexical Analysis (cont.) Implementation (assume initialization): /* Global variables */ int charClass; char lexeme [100]; char nextChar; int lexLen; int Letter = 0; int DIGIT = 1; int UNKNOWN = -1;
28.
Copyright © 2007
Addison-Wesley. All rights reserved. 1-28 Lexical Analysis (cont.) int lex() { lexLen = 0; static int first = 1; /* If it is the first call to lex, initialize by calling getChar */ if (first) { getChar(); first = 0; } getNonBlank(); switch (charClass) { /* Parse identifiers and reserved words */ case LETTER: addChar(); getChar(); while (charClass == LETTER || charClass == DIGIT){ addChar(); getChar(); } return lookup(lexeme); break; …
29.
Copyright © 2007
Addison-Wesley. All rights reserved. 1-29 Lexical Analysis (cont.) … /* Parse integer literals */ case DIGIT: addChar(); getChar(); while (charClass == DIGIT) { addChar(); getChar(); } return INT_LIT; break; } /* End of switch */ } /* End of function lex */
Télécharger maintenant