11-07-2012, 12:53 PM
Programming Languages
Programming Languages.ppt (Size: 570.5 KB / Downloads: 19)
Reasons for Studying Concepts of Programming Languages
Increased ability to express ideas
Improved background for choosing appropriate languages
Increased ability to learn new languages
Better understanding of significance of implementation
Overall advancement of computing
Programming Domains
Scientific applications
Large number of floating point computations
Fortran
Business applications
Produce reports, use decimal numbers and characters
COBOL
Artificial intelligence
Symbols rather than numbers manipulated
LISP
Systems programming
Need efficiency because of continuous use
C
Web Software
Eclectic collection of languages: markup (e.g., XHTML), scripting (e.g., PHP), general-purpose (e.g., Java)
Language Evaluation Criteria
Readability: the ease with which programs can be read and understood
Writability: the ease with which a language can be used to create programs
Reliability: conformance to specifications (i.e., performs to its specifications)
Cost: the ultimate total cost
Evaluation Criteria: Writability
Simplicity and orthogonality
Few constructs, a small number of primitives, a small set of rules for combining them
Support for abstraction
The ability to define and use complex structures or operations in ways that allow details to be ignored
Expressivity
A set of relatively convenient ways of specifying operations
Example: the inclusion of for statement in many modern languages
Implementation Methods
Compilation
Programs are translated into machine language
Pure Interpretation
Programs are interpreted by another program known as an interpreter
Hybrid Implementation Systems
A compromise between compilers and pure interpreters