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Topics of the course
• Understand current “state-of-the-art”
• Describe languages formally
• Understand implementation concepts
• Understand design concepts
With what purpose?
• More skillful use of languages
• Evaluation of languages
• Learning to learn languages
• New languages
Organization
• Lectures (notes on my website)
• Textbook (Sebesta, 8/e)
• Reference materials on Sebesta website
Evaluation
5 assignments 20%
1 project 20%
1 midterm exam 20%
1 final exam 40%
Why programming languages?
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if (n<0) x := x+1;else x := 2x;n++;
Computer
processing
Why programming languages?
Human
effort1949
2007
???
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01010101011011010001010101010110011000101010101101010101010101010110110100010101010001100110001010101011010101011101010101101101000101010101011001100010101010110101010101010101011011010001010101001110011000101010101101010101
Computer
processing
Why programming languages?
Human
effort
1949
Computer
processing
Why programming languages?
Human
effort
2007
Language design
Question 1
Domain specific OR General purpose?
Maple
Excel
Photoshop
awk
JAVA
C,C++,C#
Pascal
libraries
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Language design - constraints
Humans:
Creative
Intuitive
Forgetful
Prone to error
Computers:
Precise
Logical
von Neumann architecture
von Neumann Architecture(Sebesta)
Execution of Machine Code(Sebesta)
• Fetch-execute-cycle
(on a von Neumann architecture)
initialize the program counter
repeat forever
fetch the instruction pointed by the counter
increment the counter
decode the instruction
execute the instruction
end repeat
Move data
I/O data
Operate on data (test, compute)
Reset program counter
Instruction setMemory codes
Execution of Machine Code(Sebesta)
• Fetch-execute-cycle
(on a von Neumann architecture)
initialize the program counter
repeat forever
fetch the instruction pointed by the counter
increment the counter
decode the instruction
execute the instruction
end repeat
Instruction setMove dataOperate on dataI/O dataReset program counter
Memory codes
Primitive data types
arrays
records
objects
Reset program counter
if
switch
counted
recursion
branch
goto
selection repetition
logicalsubprogram
Language Evolution from machine level
Instruction set
Sample slide page
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