Bottom up parsing
LECTURE 8
Bottom-up parsing is more general than
(deterministic) top-down parsing
And just as efficient
Builds on ideas in top-down parsing
Bottom-up is the preferred method
WHAT IS
Syntax Analysis
LECTURE 6
SYNTAX ANALYSIS
WHAT IS SYNTAX ANALYSIS?
After lexical analysis (scanning), we have a
series of tokens.
In syntax analysis (or parsing), we want to
interpret what those toke
LECTURE 7
REMOVING INDIRECT LEFT RECURSION
REMOVING INDIRECT LEFT RECURSION
Let any ordering of the nonterminals of G be
A1,.,Am,
we will remove indirect left recursion by
constructing an equivalant
FINITE AUTOMATE
1
PATTERNS FOR TOKEN
digit [0-9]
digits digit+
Letter [A Z a-z]
If if
then ten
else else
Relop <|<=|=|<>|>|>=
Idletter(letter|digit)*
Numdigits+ (.digits+)?(E(+|-)?digits+)?
ws (blank|
LECTURE 5
CONSTRUCTION OF AN NFA FROM
REGULAR EXPRESSION
2
CONSTRUCTION OF AN NFA FROM REGULAR
EXPRESSION
Recursive construction
Base cases follow base case definitions of regular
expressions
: -NFA t
CS510
Compiler
Lecture 2
Phase Ordering of Front-Ends
Lexical analysis (lexer)
Break input string into words called tokens
Syntactic analysis (parser)
Recover structure from the text and put it in
CS510
Compiler
Lecture 3
REMMEMBER
3
NFA
4
DFA
5
DFA
Is special case of NFA where:
There are no moves on input
For each state s and input symbol a , there exactly one edge out of
a labeled a.
6
DF
CS510
Compiler
Lecture 4
Syntax Analysis
What is Syntax Analysis?
After lexical analysis (scanning), we have a series of
tokens.
In syntax analysis (or parsing), we want to interpret
what those toke
Cairo University
Institute of Statistical Studies and Research
Computer Science Dept.
Cs510
Compiler
Sheet1
1.
Writearegularexpressiontodescribeinputsoverthealphabetcfw_a,b,cthat
areinsortedorder
2.
W