HỌC TỐT TIẾNG ANH 11 THEO CHƯƠNG TRÌNH GLOBAL SUCCESS ĐÁP ÁN CHI TIẾT - CẢ NĂ...
U Xml Defense presentation
1. uXML
An Experiment in Common Representation
of Different Programming Paradigms
Kunal S. Pathak
2. Outline
History Extensibility
Objective Drawbacks
Applications Future Work
Architecture Summary
Tools Questions
Examples Thank you
3. History
Before UNCOL After UNCOL
Programming Programming
Machines languages Machines
languages
1 1
1 1
2 2 U
2 N 2
3 3 C
:
O :
: :
N
L N
M M
4. Examples of UNCOL
Sun’s Java framework
GNU Compiler Collection
Microsoft’s .NET and Phoenix
framework
5. Objective
Different from that of UNCOL
Design an XML schema (uXML) to
represent the semantics of different
programming paradigms
Test the uXML against various
programming languages
Develop tools that use uXML
7. Architecture
uXML format
C Program <uXML language="abc"
scope="static">
Interpreter Program
(XV) output
<function name="func">
P Program <returns type="void"/>
<block>
... uXML
... Schema
Valid-
</block>
J Program ation
</function>
...
...
L Program <call>
<variable name=”func” / Software
> Code Analysis Metrics
</call>
Y Program ...
</uXML>
Front end Back end
8. Architecture cont.
Compiler framework - Activation record,
Symbol table, Display, Calling sequence,
Datatypes
Back end parser - uXML visitor
Front end parsers - C, P, J, L and Y
9. Tools in uXML
Code interpreter - xv
• Visit uXML nodes and execute the
respective code
Code analysis - xv, xsl
• Count the appropriate uXML nodes
10. Why XML in uXML?
Program = Syntax tree = XML
Human understandable
Retains the semantics of the program
Many XML processing tools
- XSL, XSL-FO, XQuery, etc
Universally accepted
11. Few uXML elements
<var/>, <variable/>, <constant/>
<assign/>, <operator/>, <for-loop/>,
<iterate/>, <cast/>
<function/>, <class/>, <constructor/>,
<block/>, <call/>
‘scope’ and ‘var-declaration’ attribute of
<uXML/>
12. PL features handled by uXML
Iterations, if-else, arrays, pointers
Function definition/call, nested
procedures, functions as first-class
objects
Static vs. Dynamic Typing and Scoping
Classes, Constructors, Inheritance
13. Front end Parsers
C - Similar to Dennis Ritchie’s C
P - Similar to Niklaus Wirth’s Pascal
J - Similar to Sun Microsystem’s Java
L - Similar to John McCarthy’s Lisp
Y - Similar to Van Rossum’s Python
14. Features of C language
Imperative/Declarative language
Multi-dimensional arrays, type casting
Pointers and Function pointers (FP)
Passing/returning FP, Passing/returning
array of FP, FP within FP
15. Sample C code
1.Clike - Factorial calculation
1.uXML - uXML equivalent
2.Clike - Function pointer
16. Features of P language
Imperative/Declarative language
Features similar to those of C except
pointers
Nested procedures and procedure
parameters
Non-local variable access using static
and dynamic scoping
17. Sample P code
1.Plike - Static vs. Dynamic scoping
1.uXML - uXML equivalent
2.Plike - Procedure parameters
18. Features of J language
Object oriented language
Class and constructor definitions
Inheritance and hierarchical constructor
calls
Object instantiation prior to usage
20. Features of L language
Functional language
Functions as first-class objects
Operators are functions
defun / lambda functions
let, setq, map, reduce features
21. Sample L code
1.Llike - Reduce
1.uXML - uXML equivalent
2.Llike - Let
3.Llike - Defun
22. Features of Y language
Imperative/Dynamic language
No variable declaration required,
Dynamic typing
Multi-dimensional mix arrays
lambda function definition
map, reduce features
24. Features of Code Analysis tool
Name/count of function, variable, class,
constructor definitions
Count of function/constructor calls
Count of methods overridden
McCabe Cyclomatic complexity
Helstead Metrics, Maintainability index
25. Software Metrics
Function defined : 1
void main()
____________________________________________
function void main() {
Function calls : 1 int i = 2 * 2 + 2, j = 1;
main do {
____________________________________________ i = i - 1;
Variables defined : 2
i : int print("i=",i,(j+2));
j : int }while(i);
____________________________________________
Constants used: 8
int : 2 i = 5;
int : 2 }
int : 2
int : 1
int : 1
string : i=
int : 2
int : 5
____________________________________________
McCabe Cyclomatic Complexity : 3
____________________________________________
Classes defined : 0
____________________________________________
Functions overriden : 0
_____________________________________
Nested Block Depth : 1
26. Helstead Metrics
function void main() {
int i = 2 * 2 + 2, j = 1;
do {
i = i - 1;
print("i=",i,(j+2));
}while(i);
i = 5;
}
Helstead Metrics :
N1 = 9, n1 = 7, N2 = 16, n2 = 7
Program Length N => N1 + N2 = 25
Vocabulary Size n => n1 + n2 = 14
Program Volume V => N * log2(n) = 95.18387305144009
Difficulty Level D => (n1 / 2) * (N2 / n2) = 8.0
Program Level L => 1/D = 0.125
Effort to implement E => V*D = 761.4709844115207
Time to implement T = E/18 = 42.303943578417815
No. of bugs delivered B => E^(2/3)/3000 = 3.333333333333333E-4
27. Extensibility of uXML
uXML schema - Add new programming
language feature
Front end compilers - Write a new
language
Software Metric tool - Add new metrics
to measure the software
28. Drawbacks
uXML code has larger code size
All / Advanced features of languages not
covered
Many programming paradigms not
included in uXML schema
29. Future Work
Update uXML schema to incorporate
different paradigms
Make uXML compiler more efficient
Robust programming language
converter tool
Source code as part of comments in
equivalent uXML code
30. Misc. details of uXML
Developed in Java
Used Eclipse, JavaCC and xv tools
Source code version control
Approximately 150 test programs written
Approximately 6 months of time
31. Summary
uXML schema represents OO,
procedural and functional paradigms
Room to add more programming
paradigms
Common representation helps develop
powerful code analysis tools
All features of PL can’t be covered
32. uXML mentors
Dr. James Heliotis
• Idea of uXML
• Programming language features
Dr. Axel Schreiner
• xv tool
• XML processing tools
Name, Started in Dec 2007, Masters in CS (Languages and Tools)
I would like to tell the Applications of uXML first so that audiences understand what is the significance of uXML before understanding the core of it.
Tools - developed the tools that uses uXML.
Examples - uXML nodes,
Extensibility - how you can add new components easily and extend uXML,
Drawbacks - everything has drawbacks,
Future Work - Things that I might think of adding in uXML, Summary, Q&A
THANK YOU
1960 form intermediate between problem-oriented languages and machine language
M*N to M+N
Explain the advantage of having a UIL - compilers, machine, etc.
Why UNCOL failed? - Ambitious, no advanced compilers, not enough memory, slow machines
JVM - Bytecode is IL. Scala, JRuby, Jython, Groovy, Rhino. Small M, large N
GNU - C, C++, Java converts to GENERIC, Small M, Large N
.NET - CIL. VB, C#, F#, VC++, ASP. Large M, small N
Phoenix - Framework for building compilers, CIL -> IR, tools like memory tracing, code coverage, block counting, Large M, small N
UNCOL - Already many tools
Execution vs. Representation of semantics
To prove - develop tools
Explain these as applications of a universal intermediate language
s/w metrics tool - A common tool that does the code analysis of programs written in different paradigm
education tool - compile framework, programs can be compared by metrics
language converter - ambitious idea
program structure - Extract the structure of a program
The idea is how quickly can you develop a tool that is handy for wide range of languages
2 tools so far - Interpreter and Code Analysis
IR is validated against the uXML schema
Activation record - Enter the block, Leave the block,
Symbol table - Add/remove symbol (datatype, mutable, name)
Display - Data structure containing list of activation records to access the non-local variables
Calling Sequence - Steps to be taken while calling/returing a function. Prototype for static/dynamic access
Datatypes - Function, Int, Char, String, Overloaded function type
2 parts - Backend and Front end
Programs are syntax trees. XML is also represented as trees
Understandable - semantics are retain, no for loops in bytecode
Processing tools - Extracting the data is easy, formatting, translating, thus many end users
as oppose to MSIL or bytecode that has just 1 user and that is interpreter itself
Definition of each node
Explain &#x2018;scope&#x2019; and &#x2018;var-declaration&#x2019; attributes in brief
Scoping - Context where values and expr are associated, how local variables are bound
Static scoping - variable association at compile time
Dynamic scoping - variable association at runtime
All languages contain if-else, while, for so won&#x2019;t mention explicitly
Alike Java instantiation of object is needed before usage, else compiler throws error.
1st parameter to the function/field is an object whose member is getting accessed.
Parametric Polymorphism or Generics - Object as 1st parameter decides whose method to call
Closures
Why operators are function? Code metrics
MCC - No. of linearly independent paths in the source code, control flow graph. Give eg.
Helstead Metrics -
Maintainability index - VS 2008 uses Helstead to calculate this factor.
Operators : N1 = Total , n1 = distinct
Operands : N2 = Total , n2 = distinct
Analogy of a book -
Difficulty - increases with repetitive operands
Volume - How much information to be absorbed
Effort - efforts to write the code
Time - in secs and 18 is stroud number - humans detect 5 to 20 moments/discrete events /sec - not used much
jeh pointed out, Compare the programs with respect to difficulty, efforts, etc.
Advanced features - thread, read/write, file handling, interface, etc
Missing programming paradigm - Logical, Aspect-oriented, Process oriented, etc.
uXML compiler can be improved to make it execute faster
Comments - Part of Y language
There are lot of articles, however these points to some of the finest articles that helped me in developing the project.
