The document discusses the different phases of a compiler:
1. Lexical analysis scans source code and converts it to tokens.
2. Syntax analysis checks token arrangements against the grammar to validate syntax.
3. Semantic analysis checks that rules like type compatibility are followed.
4. Intermediate code is generated for an abstract machine.
5. Code is optimized in the intermediate representation.
6. Code generation produces machine code from the optimized intermediate code.
Token, Pattern and Lexeme defines some key concepts in lexical analysis:
Tokens are valid sequences of characters that can be identified as keywords, constants, identifiers, numbers, operators or punctuation. A lexeme is the sequence of characters that matches a token pattern. Patterns are defined by regular expressions or grammar rules to identify lexemes as specific tokens. The lexical analyzer collects attributes like values for number tokens and symbol table entries for identifiers and passes the tokens and attributes to the parser. Lexical errors occur if a character sequence cannot be scanned as a valid token. Error recovery strategies include deleting or inserting characters to allow tokenization to continue.
The document discusses the different phases of a compiler:
1. Lexical analysis scans source code as characters and converts them into tokens.
2. Syntax analysis checks token arrangements against the grammar to ensure syntactic correctness.
3. Semantic analysis checks that rules like type compatibility are followed.
4. Intermediate code is generated for an abstract machine.
5. Code optimization removes unnecessary code and improves efficiency.
6. Code generation translates the optimized intermediate code to machine language.
The document discusses the different phases of a compiler:
1) The front end checks the syntax and semantics of the source code and the back end translates it to assembly code.
2) The front end contains lexical analysis, preprocessing, syntax analysis, and semantic analysis. The back end contains analysis, optimization, and code generation.
3) Optimization aims to improve the intermediate code to increase performance by reducing complexity and leading to faster execution.
JLex is a lexical analyzer generator for Java that takes a specification file as input and generates a Java source file for a lexical analyzer. It performs lexical analysis faster than a comparable handwritten lexical analyzer. SAX and DOM are XML parser APIs that respectively use event-based and tree-based models to read and process XML documents, with SAX using less memory but DOM allowing arbitrary navigation and modification of the document tree.
It is on simple topic of compiler but first and foremost important topic of compiler. For Lexical Analyzing we coded in C language. So it is easy to understand .
Compiler Construction
Phases of a compiler
Analysis and synthesis phases
-------------------
-> Compilation Issues
-> Phases of compilation
-> Structure of compiler
-> Code Analysis
The document discusses the role and implementation of a lexical analyzer in compilers. A lexical analyzer is the first phase of a compiler that reads source code characters and generates a sequence of tokens. It groups characters into lexemes and determines the tokens based on patterns. A lexical analyzer may need to perform lookahead to unambiguously determine tokens. It associates attributes with tokens, such as symbol table entries for identifiers. The lexical analyzer and parser interact through a producer-consumer relationship using a token buffer.
Token, Pattern and Lexeme defines some key concepts in lexical analysis:
Tokens are valid sequences of characters that can be identified as keywords, constants, identifiers, numbers, operators or punctuation. A lexeme is the sequence of characters that matches a token pattern. Patterns are defined by regular expressions or grammar rules to identify lexemes as specific tokens. The lexical analyzer collects attributes like values for number tokens and symbol table entries for identifiers and passes the tokens and attributes to the parser. Lexical errors occur if a character sequence cannot be scanned as a valid token. Error recovery strategies include deleting or inserting characters to allow tokenization to continue.
The document discusses the different phases of a compiler:
1. Lexical analysis scans source code as characters and converts them into tokens.
2. Syntax analysis checks token arrangements against the grammar to ensure syntactic correctness.
3. Semantic analysis checks that rules like type compatibility are followed.
4. Intermediate code is generated for an abstract machine.
5. Code optimization removes unnecessary code and improves efficiency.
6. Code generation translates the optimized intermediate code to machine language.
The document discusses the different phases of a compiler:
1) The front end checks the syntax and semantics of the source code and the back end translates it to assembly code.
2) The front end contains lexical analysis, preprocessing, syntax analysis, and semantic analysis. The back end contains analysis, optimization, and code generation.
3) Optimization aims to improve the intermediate code to increase performance by reducing complexity and leading to faster execution.
JLex is a lexical analyzer generator for Java that takes a specification file as input and generates a Java source file for a lexical analyzer. It performs lexical analysis faster than a comparable handwritten lexical analyzer. SAX and DOM are XML parser APIs that respectively use event-based and tree-based models to read and process XML documents, with SAX using less memory but DOM allowing arbitrary navigation and modification of the document tree.
It is on simple topic of compiler but first and foremost important topic of compiler. For Lexical Analyzing we coded in C language. So it is easy to understand .
Compiler Construction
Phases of a compiler
Analysis and synthesis phases
-------------------
-> Compilation Issues
-> Phases of compilation
-> Structure of compiler
-> Code Analysis
The document discusses the role and implementation of a lexical analyzer in compilers. A lexical analyzer is the first phase of a compiler that reads source code characters and generates a sequence of tokens. It groups characters into lexemes and determines the tokens based on patterns. A lexical analyzer may need to perform lookahead to unambiguously determine tokens. It associates attributes with tokens, such as symbol table entries for identifiers. The lexical analyzer and parser interact through a producer-consumer relationship using a token buffer.
Lexical analysis is the first step in compiler construction and involves breaking a program into individual tokens. A Lex program has three sections: declarations, translation rules, and auxiliary code. The declarations section defines regular expressions and global variables. The translation rules section matches regular expressions to tokens and executes C code actions. When a regular expression is matched in the input stream, its corresponding action is executed to return the appropriate token.
The document discusses lexical analysis, which is the first phase of compilation. It involves reading the source code and grouping characters into meaningful sequences called lexemes. Each lexeme is mapped to a token that is passed to the subsequent parsing phase. Regular expressions are used to specify patterns for tokens. A lexical analyzer uses finite automata to recognize tokens based on these patterns. Lexical analyzers may also perform tasks like removing comments and whitespace from the source code.
The document discusses the role and process of a lexical analyzer in compiler design. A lexical analyzer groups input characters into lexemes and produces a sequence of tokens as output for the syntactic analyzer. It strips out comments and whitespace, correlates line numbers with errors, and interacts with the symbol table. Lexical analysis improves compiler efficiency, portability, and allows for simpler parser design by separating lexical and syntactic analysis.
This document discusses compilers, tokenizers, and parsers. It defines a compiler as having two main components: a lexer (tokenizer) that reads input and generates tokens, and a parser that converts tokens into a structured data format. It describes how a tokenizer works by defining states, scanning for patterns, and returning a list of tokens. It recommends optimizations for tokenizers like using little memory, partial reading, and avoiding unnecessary function calls. Finally, it states that the parser analyzes the token stream and constructs an object-oriented tree structure, avoiding non-tail recursion to prevent hitting stack limits.
This document discusses syntax analysis in programming languages. It defines syntax as the arrangement of words and symbols in a program to show their relationships. Syntax analysis determines if a program is valid based on the syntactic rules of the language. Common formal methods for describing syntax include grammars, parse trees, and syntax diagrams. Grammars provide mathematical rules for valid symbol strings, including terminal symbols, non-terminal symbols, and productions.
This document discusses lexical and syntax analysis in language implementation systems. It covers the following key points:
- Lexical analysis breaks source code into lexemes (substrings that belong together) which are associated with tokens. Syntax analysis parses the tokens based on a context-free grammar.
- Reasons to separate lexical and syntax analysis include simplicity, efficiency, and portability of the parts.
- A lexical analyzer identifies tokens by using a state diagram or table-driven implementation to recognize patterns in the source code.
- Parsing approaches include top-down recursive descent and bottom-up LR parsing. Recursive descent parsers use subroutines for each grammar rule while LR parsers reduce handles on the parse stack
Lexical analysis is the process of converting a sequence of characters from a source program into a sequence of tokens. It involves reading the source program, scanning characters, grouping them into lexemes and producing tokens as output. The lexical analyzer also enters tokens into a symbol table, strips whitespace and comments, correlates error messages with line numbers, and expands macros. Lexical analysis produces tokens through scanning and tokenization and helps simplify compiler design and improve efficiency. It identifies tokens like keywords, constants, identifiers, numbers, operators and punctuation through patterns and deals with issues like lookahead and ambiguities.
Lexical analysis involves breaking input text into tokens. It is implemented using regular expressions to specify token patterns and a finite automaton to recognize tokens in the input stream. Lex is a tool that allows specifying a lexical analyzer by defining regular expressions for tokens and actions to perform on each token. It generates code to simulate the finite automaton for token recognition. The generated lexical analyzer converts the input stream into tokens by matching input characters to patterns defined in the Lex source program.
This document provides an introduction to lexical analysis and regular expressions. It discusses topics like input buffering, token specifications, the basic rules of regular expressions, precedence of operators, equivalence of expressions, transition diagrams, and the lex tool for generating lexical analyzers from regular expressions. Key points covered include the definition of regular languages by regular expressions, the use of finite automata to recognize patterns in lexical analysis, and how lex compiles a file written in its language into a C program that acts as a lexical analyzer.
The document discusses the role and implementation of a lexical analyzer. It can be summarized as:
1. A lexical analyzer scans source code, groups characters into lexemes, and produces tokens which it returns to the parser upon request. It handles tasks like removing whitespace and expanding macros.
2. It implements buffering techniques to efficiently scan large inputs and uses transition diagrams to represent patterns for matching tokens.
3. Regular expressions are used to specify patterns for tokens, and flex is a common language for implementing lexical analyzers based on these specifications.
The document discusses lexical analysis of computer programming languages. It introduces lexical analysis as the process of reading a string of characters and categorizing them into tokens based on their roles. This involves constructing regular expressions to define the patterns for different token classes like keywords, identifiers, and numbers. The document then explains how to specify the lexical structure of a language by defining regular expressions for each token class and using them to build a lexical analyzer that takes a string as input and outputs the sequence of tokens.
The document discusses the syntax of programming languages, including terminology, syntactic elements, and formal methods for describing syntax such as grammars, parse trees, and syntax diagrams. Grammars provide formal definitions of programming language syntax through sets of rules defining valid constructs. Context-free grammars like Backus-Naur Form (BNF) are commonly used.
Lexical Analysis, Tokens, Patterns, Lexemes, Example pattern, Stages of a Lexical Analyzer, Regular expressions to the lexical analysis, Implementation of Lexical Analyzer, Lexical analyzer: use as generator.
The document discusses the role and process of lexical analysis using LEX. LEX is a tool that generates a lexical analyzer from regular expression rules. A LEX source program consists of auxiliary definitions for tokens and translation rules that match regular expressions to actions. The lexical analyzer created by LEX reads input one character at a time and finds the longest matching prefix, executes the corresponding action, and places the token in a buffer.
This document discusses the role and implementation of a lexical analyzer. It begins by explaining that the lexical analyzer is the first phase of a compiler that reads source code characters and produces tokens for the parser. It describes how the lexical analyzer interacts with the parser by returning tokens when requested. The document then discusses several tasks of the lexical analyzer, including stripping comments and whitespace, tracking line numbers for errors, and preprocessing macros. It also covers concepts like tokens, patterns, lexemes, and attributes. Finally, it provides an example input and output of a lexical analyzer tokenizing a C program.
This document provides information about the CS213 Programming Languages Concepts course taught by Prof. Taymoor Mohamed Nazmy in the computer science department at Ain Shams University in Cairo, Egypt. It describes the syntax and semantics of programming languages, discusses different programming language paradigms like imperative, functional, and object-oriented, and explains concepts like lexical analysis, parsing, semantic analysis, symbol tables, intermediate code generation, optimization, and code generation which are parts of the compiler design process.
Overview of Language Processor : Fundamentals of LP , Symbol Table , Data Str...Bhavin Darji
Fundamentals of Language Processor
Analysis Phase
Synthesis Phase
Lexical Analysis
Syntax Analysis
Semantic Analysis
Intermediate Code Generation
Symbol Table
Criteria of Classification of Data Structure of Language Processing
Linear Data Structure
Non-linear Data Structure
Symbol Table Organization
Sequential Search Organization
Binary Search Organization
Hash Table Organization
Allocation Data Structure : Stacks and Heaps
Syntax defines the grammatical rules of a programming language. There are three levels of syntax: lexical, concrete, and abstract. Lexical syntax defines tokens like literals and identifiers. Concrete syntax defines the actual representation using tokens. Abstract syntax describes a program's information without implementation details. Backus-Naur Form (BNF) uses rewriting rules to specify a grammar. BNF grammars can be ambiguous. Extended BNF simplifies recursive rules. Syntax analysis transforms a program into an abstract syntax tree used for semantic analysis and code generation.
The document provides an overview of compilers and interpreters. It discusses that a compiler translates source code into machine code that can be executed, while an interpreter executes source code directly without compilation. The document then covers the typical phases of a compiler in more detail, including the front-end (lexical analysis, syntax analysis, semantic analysis), middle-end/optimizer, and back-end (code generation). It also discusses interpreters, intermediate code representation, symbol tables, and compiler construction tools.
This document provides an introduction to compilers and their construction. It defines a compiler as a program that translates a source program into target machine code. The compilation process involves several phases including lexical analysis, syntax analysis, semantic analysis, code optimization, and code generation. An interpreter directly executes source code without compilation. The document also discusses compiler tools and intermediate representations used in the compilation process.
Lexical analysis is the first step in compiler construction and involves breaking a program into individual tokens. A Lex program has three sections: declarations, translation rules, and auxiliary code. The declarations section defines regular expressions and global variables. The translation rules section matches regular expressions to tokens and executes C code actions. When a regular expression is matched in the input stream, its corresponding action is executed to return the appropriate token.
The document discusses lexical analysis, which is the first phase of compilation. It involves reading the source code and grouping characters into meaningful sequences called lexemes. Each lexeme is mapped to a token that is passed to the subsequent parsing phase. Regular expressions are used to specify patterns for tokens. A lexical analyzer uses finite automata to recognize tokens based on these patterns. Lexical analyzers may also perform tasks like removing comments and whitespace from the source code.
The document discusses the role and process of a lexical analyzer in compiler design. A lexical analyzer groups input characters into lexemes and produces a sequence of tokens as output for the syntactic analyzer. It strips out comments and whitespace, correlates line numbers with errors, and interacts with the symbol table. Lexical analysis improves compiler efficiency, portability, and allows for simpler parser design by separating lexical and syntactic analysis.
This document discusses compilers, tokenizers, and parsers. It defines a compiler as having two main components: a lexer (tokenizer) that reads input and generates tokens, and a parser that converts tokens into a structured data format. It describes how a tokenizer works by defining states, scanning for patterns, and returning a list of tokens. It recommends optimizations for tokenizers like using little memory, partial reading, and avoiding unnecessary function calls. Finally, it states that the parser analyzes the token stream and constructs an object-oriented tree structure, avoiding non-tail recursion to prevent hitting stack limits.
This document discusses syntax analysis in programming languages. It defines syntax as the arrangement of words and symbols in a program to show their relationships. Syntax analysis determines if a program is valid based on the syntactic rules of the language. Common formal methods for describing syntax include grammars, parse trees, and syntax diagrams. Grammars provide mathematical rules for valid symbol strings, including terminal symbols, non-terminal symbols, and productions.
This document discusses lexical and syntax analysis in language implementation systems. It covers the following key points:
- Lexical analysis breaks source code into lexemes (substrings that belong together) which are associated with tokens. Syntax analysis parses the tokens based on a context-free grammar.
- Reasons to separate lexical and syntax analysis include simplicity, efficiency, and portability of the parts.
- A lexical analyzer identifies tokens by using a state diagram or table-driven implementation to recognize patterns in the source code.
- Parsing approaches include top-down recursive descent and bottom-up LR parsing. Recursive descent parsers use subroutines for each grammar rule while LR parsers reduce handles on the parse stack
Lexical analysis is the process of converting a sequence of characters from a source program into a sequence of tokens. It involves reading the source program, scanning characters, grouping them into lexemes and producing tokens as output. The lexical analyzer also enters tokens into a symbol table, strips whitespace and comments, correlates error messages with line numbers, and expands macros. Lexical analysis produces tokens through scanning and tokenization and helps simplify compiler design and improve efficiency. It identifies tokens like keywords, constants, identifiers, numbers, operators and punctuation through patterns and deals with issues like lookahead and ambiguities.
Lexical analysis involves breaking input text into tokens. It is implemented using regular expressions to specify token patterns and a finite automaton to recognize tokens in the input stream. Lex is a tool that allows specifying a lexical analyzer by defining regular expressions for tokens and actions to perform on each token. It generates code to simulate the finite automaton for token recognition. The generated lexical analyzer converts the input stream into tokens by matching input characters to patterns defined in the Lex source program.
This document provides an introduction to lexical analysis and regular expressions. It discusses topics like input buffering, token specifications, the basic rules of regular expressions, precedence of operators, equivalence of expressions, transition diagrams, and the lex tool for generating lexical analyzers from regular expressions. Key points covered include the definition of regular languages by regular expressions, the use of finite automata to recognize patterns in lexical analysis, and how lex compiles a file written in its language into a C program that acts as a lexical analyzer.
The document discusses the role and implementation of a lexical analyzer. It can be summarized as:
1. A lexical analyzer scans source code, groups characters into lexemes, and produces tokens which it returns to the parser upon request. It handles tasks like removing whitespace and expanding macros.
2. It implements buffering techniques to efficiently scan large inputs and uses transition diagrams to represent patterns for matching tokens.
3. Regular expressions are used to specify patterns for tokens, and flex is a common language for implementing lexical analyzers based on these specifications.
The document discusses lexical analysis of computer programming languages. It introduces lexical analysis as the process of reading a string of characters and categorizing them into tokens based on their roles. This involves constructing regular expressions to define the patterns for different token classes like keywords, identifiers, and numbers. The document then explains how to specify the lexical structure of a language by defining regular expressions for each token class and using them to build a lexical analyzer that takes a string as input and outputs the sequence of tokens.
The document discusses the syntax of programming languages, including terminology, syntactic elements, and formal methods for describing syntax such as grammars, parse trees, and syntax diagrams. Grammars provide formal definitions of programming language syntax through sets of rules defining valid constructs. Context-free grammars like Backus-Naur Form (BNF) are commonly used.
Lexical Analysis, Tokens, Patterns, Lexemes, Example pattern, Stages of a Lexical Analyzer, Regular expressions to the lexical analysis, Implementation of Lexical Analyzer, Lexical analyzer: use as generator.
The document discusses the role and process of lexical analysis using LEX. LEX is a tool that generates a lexical analyzer from regular expression rules. A LEX source program consists of auxiliary definitions for tokens and translation rules that match regular expressions to actions. The lexical analyzer created by LEX reads input one character at a time and finds the longest matching prefix, executes the corresponding action, and places the token in a buffer.
This document discusses the role and implementation of a lexical analyzer. It begins by explaining that the lexical analyzer is the first phase of a compiler that reads source code characters and produces tokens for the parser. It describes how the lexical analyzer interacts with the parser by returning tokens when requested. The document then discusses several tasks of the lexical analyzer, including stripping comments and whitespace, tracking line numbers for errors, and preprocessing macros. It also covers concepts like tokens, patterns, lexemes, and attributes. Finally, it provides an example input and output of a lexical analyzer tokenizing a C program.
This document provides information about the CS213 Programming Languages Concepts course taught by Prof. Taymoor Mohamed Nazmy in the computer science department at Ain Shams University in Cairo, Egypt. It describes the syntax and semantics of programming languages, discusses different programming language paradigms like imperative, functional, and object-oriented, and explains concepts like lexical analysis, parsing, semantic analysis, symbol tables, intermediate code generation, optimization, and code generation which are parts of the compiler design process.
Overview of Language Processor : Fundamentals of LP , Symbol Table , Data Str...Bhavin Darji
Fundamentals of Language Processor
Analysis Phase
Synthesis Phase
Lexical Analysis
Syntax Analysis
Semantic Analysis
Intermediate Code Generation
Symbol Table
Criteria of Classification of Data Structure of Language Processing
Linear Data Structure
Non-linear Data Structure
Symbol Table Organization
Sequential Search Organization
Binary Search Organization
Hash Table Organization
Allocation Data Structure : Stacks and Heaps
Syntax defines the grammatical rules of a programming language. There are three levels of syntax: lexical, concrete, and abstract. Lexical syntax defines tokens like literals and identifiers. Concrete syntax defines the actual representation using tokens. Abstract syntax describes a program's information without implementation details. Backus-Naur Form (BNF) uses rewriting rules to specify a grammar. BNF grammars can be ambiguous. Extended BNF simplifies recursive rules. Syntax analysis transforms a program into an abstract syntax tree used for semantic analysis and code generation.
The document provides an overview of compilers and interpreters. It discusses that a compiler translates source code into machine code that can be executed, while an interpreter executes source code directly without compilation. The document then covers the typical phases of a compiler in more detail, including the front-end (lexical analysis, syntax analysis, semantic analysis), middle-end/optimizer, and back-end (code generation). It also discusses interpreters, intermediate code representation, symbol tables, and compiler construction tools.
This document provides an introduction to compilers and their construction. It defines a compiler as a program that translates a source program into target machine code. The compilation process involves several phases including lexical analysis, syntax analysis, semantic analysis, code optimization, and code generation. An interpreter directly executes source code without compilation. The document also discusses compiler tools and intermediate representations used in the compilation process.
A compiler is a program that translates a program written in a source language into a target language. It has two main parts: analysis and synthesis. The analysis part breaks down the source code using lexical analysis, syntax analysis, and semantic analysis. The synthesis part constructs the target program using intermediate code generation, code optimization, and code generation. A compiler translates the source code into assembly code, which is then assembled into machine code and linked with libraries to create an executable program.
The document discusses the functions and purposes of translators in computing. It describes:
1) Interpreters and compilers translate programs from high-level languages to machine code. Compilers translate the entire program at once, while interpreters translate instructions one at a time as the program runs.
2) Translation from high-level languages to machine code involves multiple stages including lexical analysis, syntax analysis, code generation, and optimization.
3) Linkers and loaders are used to combine separately compiled modules into a complete executable program by resolving addresses and linking the modules together.
The document discusses the different phases of a compiler: lexical analysis, syntax analysis, semantic analysis, intermediate code generation, code optimization, and code generation. It explains that a compiler takes source code as input and translates it into an equivalent language. The compiler performs analysis and synthesis in multiple phases, with each phase transforming the representation of the source code. Key activities include generating tokens, building a syntax tree, type checking, generating optimized intermediate code, and finally producing target machine code. Symbol tables are also used to store identifier information as the compiler runs.
PSEUDOCODE TO SOURCE PROGRAMMING LANGUAGE TRANSLATORijistjournal
Pseudocode is an artificial and informal language that helps developers to create algorithms. In this papera software tool is described, for translating the pseudocode into a particular source programminglanguage. This tool compiles the pseudocode given by the user and translates it to a source programminglanguage. The scope of the tool is very much wide as we can extend it to a universal programming toolwhich produces any of the specified programming language from a given pseudocode. Here we present thesolution for translating the pseudocode to a programming language by using the different stages of acompiler
SOFTWARE TOOL FOR TRANSLATING PSEUDOCODE TO A PROGRAMMING LANGUAGEIJCI JOURNAL
Pseudocode is an artificial and informal language that helps programmers to develop algorithms. In this
paper a software tool is described, for translating the pseudocode into a particular programming
language. This tool takes the pseudocode as input, compiles it and translates it to a concrete programming
language. The scope of the tool is very much wide as we can extend it to a universal programming tool
which produces any of the specified programming language from a given pseudocode. Here we present the
solution for translating the pseudocode to a programming language by implementing the stages of a
compiler
SOFTWARE TOOL FOR TRANSLATING PSEUDOCODE TO A PROGRAMMING LANGUAGEIJCI JOURNAL
Pseudocode is an artificial and informal language that helps programmers to develop algorithms. In this
paper a software tool is described, for translating the pseudocode into a particular programming
language. This tool takes the pseudocode as input, compiles it and translates it to a concrete programming
language. The scope of the tool is very much wide as we can extend it to a universal programming tool
which produces any of the specified programming language from a given pseudocode. Here we present the
solution for translating the pseudocode to a programming language by implementing the stages of a
compiler.
This document provides an overview of compilers and their various phases. It begins by introducing compilers and their importance for increasing programmer productivity and enabling reverse engineering. It then covers the classification of programming languages and the history of compilers. The rest of the document details each phase of the compiler process, including lexical analysis, syntax analysis, semantic analysis, intermediate code generation, code optimization, code generation, and the role of the symbol table. It provides definitions and examples for each phase to explain how a source program is translated from a high-level language into executable machine code.
The document discusses the differences between compilers and interpreters. It states that a compiler translates an entire program into machine code in one pass, while an interpreter translates and executes code line by line. A compiler is generally faster than an interpreter, but is more complex. The document also provides an overview of the lexical analysis phase of compiling, including how it breaks source code into tokens, creates a symbol table, and identifies patterns in lexemes.
The document discusses the phases of a compiler and their functions. It describes:
1) Lexical analysis converts the source code to tokens by recognizing patterns in the input. It identifies tokens like identifiers, keywords, and numbers.
2) Syntax analysis/parsing checks that tokens are arranged according to grammar rules by constructing a parse tree.
3) Semantic analysis validates the program semantics and performs type checking using the parse tree and symbol table.
The document discusses the phases of a compiler:
1) Lexical analysis scans the source code and converts it to tokens which are passed to the syntax analyzer.
2) Syntax analysis/parsing checks the token arrangements against the language grammar and generates a parse tree.
3) Semantic analysis checks that the parse tree follows the language rules by using the syntax tree and symbol table, performing type checking.
4) Intermediate code generation represents the program for an abstract machine in a machine-independent form like 3-address code.
A compiler is a program that translates one programming language into another. It has six main phases: lexical analysis, syntax analysis, semantic analysis, intermediate code generation, code optimization, and code generation. It also uses a symbol table to store identifiers and their properties and handles errors detected in each phase.
The document defines different phases of a compiler and describes Lexical Analysis in detail. It discusses:
1) A compiler converts a high-level language to machine language through front-end and back-end phases including Lexical Analysis, Syntax Analysis, Semantic Analysis, Intermediate Code Generation, Code Optimization and Code Generation.
2) Lexical Analysis scans the source code and groups characters into tokens by removing whitespace and comments. It identifies tokens like identifiers, keywords, operators etc.
3) A lexical analyzer generator like Lex takes a program written in the Lex language and produces a C program that acts as a lexical analyzer.
The document discusses the lexical analysis phase of a compiler. In lexical analysis, the source code is divided into tokens. Common token types include keywords, identifiers, and special symbols. Lexical analyzers perform pattern matching and techniques used for lexical analysis can also be applied to other areas like query languages. Lex is a tool that can generate an automaton recognizer for regular expressions to specify lexical analyzers. The role of a lexical analyzer is to read input characters and produce a sequence of tokens for the parser to use in syntax analysis.
The document discusses the different phases of a compiler including lexical analysis, syntax analysis, semantic analysis, intermediate code generation, code optimization, and code generation. It provides details on each phase and the techniques involved. The overall structure of a compiler is given as taking a source program through various representations until target machine code is generated. Key terms related to compilers like tokens, lexemes, and parsing techniques are also introduced.
The document discusses the phases of a compiler. It describes the six main phases as lexical analysis, syntax analysis, semantic analysis, intermediate code generation, code optimization, and code generation. Lexical analysis breaks source code into tokens. Syntax analysis groups tokens into a syntax tree. Semantic analysis determines meaning and checks syntax. Intermediate code generation produces machine-independent code. Code optimization improves efficiency. Code generation translates intermediate code into target machine instructions.
match the following attributes to the parts of a compilerstrips ou.pdfarpitaeron555
match the following attributes to the parts of a compiler
strips out the comments and whitespace
converts text into lexemes
generates an Abstrat Symbol Tree
recursive descent or table driven
uses BNF or EBNF definitions
a. lexer
b. parser
Solution
The Program and Portfolio Management Maturity Model is an effective tool for organizations to
decide quickly what PPM improvements they should make to enhance their organization\'s
ability to optimize investments, execute big changes and deliver value.
Overview
Key Findings
Real project, program and portfolio management, when operating at the level of well-integrated
practices, is the key enabler that allows organizations to identify and execute strategic change.
Any meaningful undertakings to enhance or evolve the program and portfolio management
(PPM) function must pay more than lip service to organizational structure, business model and
culture to have any chance of success.
Competitive pressures and changing market conditions are forcing organizations toward Level 3,
and most organizations still aren\'t ready to make the leap.
Recommendations
At any level of PPM maturity, focus first on helping the organization make well-informed
investment choices. This will improve the odds of project success more than any other factor.
For organizations that require enterprisewide change and capabilities, it is worth the effort to
pursue Level 4, where enterprise PPM practices are built.
Identify objectives for your enterprise, and use them to identify the most salient improvement
opportunities for your enterprise.
Meticulously manage the change involved in maturing/improving your PPM capabilities.
Analysis
Project/program/portfolio management office (PMO) leaders, program managers and portfolio
managers are frequently challenged by ineffective processes, lack of stakeholder engagement and
difficult-to-quantify value. 1 Part of the problem is failure to match their processes, people and
technology approaches to the maturity level of their organizations. 2
The Gartner Program and Portfolio Management (PPM) Maturity Model assessment is designed
to help PPM leaders understand best practices around large project management, as well as PPM
to handle delivery of strategic value. This model assumes that organizations progress through a
maturity curve and that each level of organizational maturity directly affects the level of
investment and types of PPM approaches organizations choose to adopt.
arsing
A parser is an algorithm that determines whether a given input string is in a language and, as a
side-effect, usually produces a parse tree for the input. There is a procedure for generating a
parser from a given context-free grammar.
Recursive-Descent Parsing
Recursive-descent parsing is one of the simplest parsing techniques that is used in practice.
Recursive-descent parsers are also called top-down parsers, since they construct the parse tree
top down (rather than bottom up).
The basic idea of recursive-descent par.
Using Static Analysis in Program DevelopmentPVS-Studio
The document discusses static analysis, which allows checking program code before execution. It describes the static analysis process, which involves lexing, parsing, and abstract syntax tree (AST) creation. Various static analysis techniques are then performed on the AST, including AST walker analysis, data flow analysis, and path-sensitive data flow analysis. The document provides examples of how ASTs represent code and are used in static analysis.
TCP/IP is a communication protocol suite that includes TCP, IP, and other protocols used to interconnect devices on the internet and private networks. TCP/IP functions as an abstraction layer and is divided into four layers: the application layer, transport layer, internet layer, and physical/link layer. The transport layer maintains end-to-end communications using TCP or UDP. The internet layer routes packets between networks using IP. The physical layer operates on a local link using protocols like Ethernet. Network devices can be assigned addresses statically, through configuration, or dynamically assigned by a server.
The document discusses the language processing system in computers. It states that high-level languages written by programmers are converted to binary machine language in multiple steps. First, a compiler converts source code into assembly language, then an assembler converts assembly code into object code. A linker links all code components and a loader loads the executable machine code into memory to be executed. Compilers check for errors and convert the entire program at once, while interpreters translate code line-by-line and require the source code during execution.
This document proposes a hybrid VANET-enhanced transportation system using identity-based signatures and IoT. It aims to address privacy and security issues in VANET systems. The system uses an identity-based signature scheme that achieves unforgeability against chosen-message attacks without random oracles. It also develops efficient outsourcing algorithms for exponential operations to reduce computational costs. Finally, it designs a privacy-preserving protocol for VANETs using the outsourcing computations and identity-based signature scheme. This protocol hides the real identity of vehicles using a proxy re-signature from RSUs while still allowing traceability by the transportation authority if needed. The goal is to provide an anonymous yet traceable and secure
This document provides an introduction to computers and their characteristics. It defines a computer as a digital device that stores information in memory and manipulates it according to instructions. It then lists and describes 7 key characteristics of computers: speed, accuracy, diligence, versatility, power of remembering, no IQ (intelligence quotient), and no feelings. It concludes by noting computers' ability to store large amounts of data in both internal memory and external storage devices.
This document summarizes different types of computers based on their purpose, data handling abilities, and functionality. It describes general purpose and specific purpose computers, analog, digital, and hybrid computers. It also discusses different types of computers like supercomputers, mainframes, desktops, laptops, palmtops, and workstations. The document concludes by describing the basic components of a computer including memory, storage devices, input/output devices, the central processing unit, and its main components like the arithmetic logic unit and control unit.
This document defines a computer and outlines its key characteristics. It begins by defining a computer as a digital device that stores information using input devices and manipulates that information to produce output according to instructions. It then lists and describes 7 key characteristics of computers: 1) Speed - computers can perform millions of instructions per second very fast; 2) Accuracy - computations are performed with a high level of accuracy; 3) Diligence - computers can work for hours without tiring or making errors; 4) Versatility - computers can perform different types of tasks; 5) Memory - computers can store large amounts of data; 6) No IQ - computers need instructions to work and cannot make their own decisions; 7) No feelings - computers do
Creativity for Innovation and SpeechmakingMattVassar1
Tapping into the creative side of your brain to come up with truly innovative approaches. These strategies are based on original research from Stanford University lecturer Matt Vassar, where he discusses how you can use them to come up with truly innovative solutions, regardless of whether you're using to come up with a creative and memorable angle for a business pitch--or if you're coming up with business or technical innovations.
Post init hook in the odoo 17 ERP ModuleCeline George
In Odoo, hooks are functions that are presented as a string in the __init__ file of a module. They are the functions that can execute before and after the existing code.
How to Download & Install Module From the Odoo App Store in Odoo 17Celine George
Custom modules offer the flexibility to extend Odoo's capabilities, address unique requirements, and optimize workflows to align seamlessly with your organization's processes. By leveraging custom modules, businesses can unlock greater efficiency, productivity, and innovation, empowering them to stay competitive in today's dynamic market landscape. In this tutorial, we'll guide you step by step on how to easily download and install modules from the Odoo App Store.
8+8+8 Rule Of Time Management For Better ProductivityRuchiRathor2
This is a great way to be more productive but a few things to
Keep in mind:
- The 8+8+8 rule offers a general guideline. You may need to adjust the schedule depending on your individual needs and commitments.
- Some days may require more work or less sleep, demanding flexibility in your approach.
- The key is to be mindful of your time allocation and strive for a healthy balance across the three categories.
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This slide will represent how to create user notification in Odoo 17. Odoo allows us to create and send custom notifications on some events or actions. We have different types of notification such as sticky notification, rainbow man effect, alert and raise exception warning or validation.
Cross-Cultural Leadership and CommunicationMattVassar1
Business is done in many different ways across the world. How you connect with colleagues and communicate feedback constructively differs tremendously depending on where a person comes from. Drawing on the culture map from the cultural anthropologist, Erin Meyer, this class discusses how best to manage effectively across the invisible lines of culture.
3. Lexical Analysis
The first phase of scanner works as a text
scanner. This phase scans the source code as
a stream of characters and converts it into
meaningful lexemes. Lexical analyzer
represents these lexemes in the form of
tokens as:
<token-name, attribute-value>
4. Syntax Analysis
The next phase is called the syntax analysis
or parsing. It takes the token produced by
lexical analysis as input and generates a
parse tree (or syntax tree). In this phase,
token arrangements are checked against the
source code grammar, i.e., the parser checks
if the expression made by the tokens is
syntactically correct.
5. Semantic Analysis
Semantic analysis checks whether the parse
tree constructed follows the rules of
language. For example, assignment of values
is between compatible data types, and adding
string to an integer. Also, the semantic
analyzer keeps track of identifiers, their types
and expressions; whether identifiers are
declared before use or not, etc. The semantic
analyzer produces an annotated syntax tree
as an output.
6. Intermediate Code Generation
After semantic analysis, the compiler
generates an intermediate code of the source
code for the target machine. It represents a
program for some abstract machine. It is in
between the high-level language and the
machine language. This intermediate code
should be generated in such a way that it
makes it easier to be translated into the
target machine code.
7. Code Optimization
The next phase does code optimization of the
intermediate code. Optimization can be
assumed as something that removes
unnecessary code lines, and arranges the
sequence of statements in order to speed up
the program execution without wasting
resources (CPU, memory).
8. In this phase, the code generator takes the
optimized representation of the intermediate
code and maps it to the target machine
language. The code generator translates the
intermediate code into a sequence of
(generally) re-locatable machine code.
Sequence of instructions of machine code
performs the task as the intermediate code
would do.
9. It is a data-structure maintained throughout
all the phases of a compiler. All the
identifiers’ names along with their types are
stored here. The symbol table makes it easier
for the compiler to quickly search the
identifier record and retrieve it. The symbol
table is also used for scope management.
10. The tasks of the Error Handling process are to detect
each error, report it to the user, and then make some
recovery strategy and implement them to handle the
error. During this whole process processing time of the
program should not be slow.
Functions of Error Handler:
Error Detection
Error Report
Error Recovery
11. Logic errors occur when programs operate incorrectly but do not
terminate abnormally (or crash). Unexpected or undesired outputs or other
behaviour may result from a logic error, even if it is not immediately
recognized as such.
A run-time error is an error that takes place during the execution of a
program and usually happens because of adverse system parameters or
invalid input data. The lack of sufficient memory to run an application or a
memory conflict with another program and logical error is an example of
this. Logic errors occur when executed code does not produce the expected
result. Logic errors are best handled by meticulous program debugging.
Compile-time errors rise at compile-time, before the execution of the
program. Syntax error or missing file reference that prevents the program
from successfully compiling is an example of this.
12. The compiler writer can use some specialized tools that
help in implementing various phases of a compiler. These
tools assist in the creation of an entire compiler or its parts.
Some commonly used compiler construction tools include:
Parser Generator –
It produces syntax analyzers (parsers) from the input that is
based on a grammatical description of programming
language or on a context-free grammar. It is useful as the
syntax analysis phase is highly complex and consumes
more manual and compilation time.
Example: PIC, EQM
13.
14.
It generates lexical analyzers from the input that consists of
regular expression description based on tokens of a language. It
generates a finite automaton to recognize the regular
expression.
Example: Lex
15. Syntax directed translation engines –
It generates intermediate code with three address format
from the input that consists of a parse tree. These engines
have routines to traverse the parse tree and then produces
the intermediate code. In this, each node of the parse tree
is associated with one or more translations.
Automatic code generators –
It generates the machine language for a target machine.
Each operation of the intermediate language is translated
using a collection of rules and then is taken as an input
by the code generator. A template matching process is
used. An intermediate language statement is replaced by
its equivalent machine language statement using
templates.
16. Data-flow analysis engines –
It is used in code optimization. Data flow analysis is a
key part of the code optimization that gathers the
information, that is the values that flow from one part
of a program to another.
Compiler construction toolkits –
It provides an integrated set of routines that aids in
building compiler components or in the construction of
various phases of compiler.
17. Lexical analysis is the first phase of a compiler. It takes
the modified source code from language preprocessors
that are written in the form of sentences. The lexical
analyzer breaks these syntaxes into a series of tokens,
by removing any whitespace or comments in the source
code.
If the lexical analyzer finds a token invalid, it generates
an error. The lexical analyzer works closely with the
syntax analyzer. It reads character streams from the
source code, checks for legal tokens, and passes the
data to the syntax analyzer when it demands.
18.
19. Lexemes are said to be a sequence of characters
(alphanumeric) in a token. There are some predefined rules
for every lexeme to be identified as a valid token. These
rules are defined by grammar rules, by means of a pattern.
A pattern explains what can be a token, and these patterns
are defined by means of regular expressions.
In programming language, keywords, constants, identifiers,
strings, numbers, operators, and punctuations symbols can
be considered as tokens.
int value = 100;
For example, in C language, the variable declaration line
20. int value = 100;
contains the tokens:
int (keyword), value (identifier), = (operator), 100
(constant) and ; (symbol).
Specifications of Tokens
Let us understand how the language theory undertakes
the following terms:
Alphabets
Any finite set of symbols {0,1} is a set of binary
alphabets, {0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F} is a set of
Hexadecimal alphabets, {a-z, A-Z} is a set of English
language alphabets.
21. Any finite sequence of alphabets is called a
string. Length of the string is the total
number of occurrence of alphabets, e.g., the
length of the string A is 14 and is denoted by
A = 14. A string having no alphabets, i.e. a
string of zero length is known as an empty
string and is denoted by ε (epsilon).
22. A language is considered as a finite set of strings over
some finite set of alphabets. Computer languages are
considered as finite sets, and mathematically set
operations can be performed on them. Finite languages
can be described by means of regular expressions
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