PPT-Lexical Analysis

Hira Waseem Lecture hirawaseemmscs20studentsmcsedupk The Role of the Lexical Analyzer As the first phase of a compiler the main task of the lexical analyzer is to read the input characters of the source program group them into lexemes . what is the main Task of the Lexical analyzer. Read the input characters of the source program, group them into lexemes and produce the tokens for the lexemes.. Find out the token for the following code:. LEXEME. TOKEN. PATTERN. print. print. p,r,i,n,t. (. leftpar. (. 4. number. 4. *. arith. * . 5. number. 5. ). rightpar. ). userAnswer. ID. Letter followed by letters and digits. “Game of Jones”. literal. CSci210.BA4. Chapter 4 Topics. Introduction. Lexical and Syntax Analysis. The Parsing Problem. Recursive-Descent Parsing. Bottom-Up Parsing. Introduction. Syntax analyzers . almost always based on a formal description of the syntax of the source language (grammars) . a`to' alalloall'aiagliallaallecon`with' colcollocoll'coicoglicollacolleda`from' daldallodall'daidaglidalladalledi`of' deldellodell'deideglidelladellein`in' nelnellonell'neineglinellanellesu`on' sulsul AND . VOCABULARY. Bring. a . discourse. . dimention. . to. . teach. . vocabulary. Not . abandoning. . vocabulary. . teaching. , . instead. . offering. a . supplement. . to. . conventional. SVEM21 . 3. Structuralist Semantics. Jordan Zlatev. 1. General characteristics. Semantic approaches can be:. Onomasilogical. . (from concept/domain to lexeme) vs. . semasiological. . (from lexeme to concept/meaning). Hira. . Waseem. Lecture. hirawaseem.mscs20@students.mcs.edu.pk. The Role of the Lexical Analyzer. As the first phase of a compiler, the main task of the lexical analyzer is . to read . the input characters of the source program, group them into lexemes, . lexical representations: . a . variationist. perspective . Gregory R. Guy. phonoLAM. group. July 2013. The problem of lexical scope. Some phonological generalizations are valid . only for . a subset of the lexicon . Quick . Quiz – look up answers you don’t know on your iPad. What is orthography?. What is morphology?. Name four invasions and state the impact that they had on the English language.. In Middle English, what was the language of power (law, church, nobility)?. Linguistic Variation. Gregory R. Guy. Pennsylvania State University. 8 November . 2013. Issues, order of presentation. Theories and models: . Bybee. , . Pierrehumbert. ; Exemplar Theory vs. conventional phonology. lexical analyzer. parser. symbol table. source program. token. get next token. Important Issue: . . What are Responsibilities of each Box ?. Focus on Lexical Analyzer and Parser. 2. Why to separate Lexical analysis and parsing. Prof. Steven A. Demurjian. Computer Science & Engineering Department. The University of Connecticut. 371 Fairfield Way, Unit 2155. Storrs, CT 06269-3155. steve@engr.uconn.edu. http://www.engr.uconn.edu/~steve. We . look at two of the tasks involved in the compilation process. break the source code into lexemes units . (lexical analysis) . the goal is to identify each lexeme and assign it to its proper . token. Languages. Lexical and Syntax Analysis. (Sections 4.1, 4.2, 4.3). Dr. Vamsi Paruchuri . University of Central Arkansas. vparuchuri@uca.edu. Introduction . Lexical Analysis. The Parsing Problem. Topics .