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Language evalutaion criteria:
	- Readibility/Wrietability: maintaining the code is important while improving the sw
		○ Num of constructs-> if large usage of subsets increase -> readibility decrease
		○ Fetaure multiplicity-> making a thing from many different ways -> makes it easier to write code
		○ Opeator overloading-> it improves readibility since it is simplifiying things but hs to be used responsively
		○ Control stuctures-> if a language does not include nice control structures it reduces readibility
	If execution doesnt like the flow of reading it then it can have poor readibility
		○ Data structures-> C does not have boolean even tough it is very useful -> true/false represented by 1/0-> structure increases the readibility
	- Reliability: no bugs and error
		○ Type checking: while assigning a 4 byte value to 1 byte value you get type error: char x; int y; x=y; -> x=char(y); #typecasting
			§ Static type checking= manually processing the code -> does not affect runtime since it occures at compile time
			§ Dynamic type checking= runtime environment will check whether there are errors -> it slows down runtime
			§ Exception handling= some test cases can crash the program so add a section that when encountered an unexpected input that cause error shut down gracefully 
			§ Aliasing= having multiple referances to the same memory location-> char x; char p*;x='a'; print(x) p= 2x; p*='b' -> value of the variable changed 
			§ Readibility/writebility
	- Cost: 
		○ If a language is a very complex language, training the developer costs more
		○ Execution cost
		○ Reliability requires consecutive execution and much more depending on the job
	
Languages has been evolved within its history. There are factors that affected the desing of the languages. Those are:
	- Computer/Device Architecture: 
		○ Von Newman Architecture= memory(where program&data&instuctions has been stored) + cpu(where execution happens)
		○ Programming Methodologies= poweful scientific computers can be bought by certain places at the beginning. We write programs that process data -> data oriented approach -> object oriented approach

IMPLEMENTATION METHODS
Every operation has a binary representation and that are stored in the memory
To accomplish memory -> cpu translation the methods are:
	- Compilation: High level language -compiler-> low level language. Compilers are consists of:
		Frontend of the compiler:
		○ Lexical Analyzer/Scanner: reades ASCII text, certain parts are identified such as ifs and loops 
		○ Syntax Analyzer/Parser: it checks the items detected are in the correct order and checks the grammatical order
		○ Semantic Analyzer: checks types or variables 
		Backend of the compiler:
		○ Intermediate code generator: syntactic details are ignored 
		○ Optimizer: transform the program into more faster form of it 
		○ Code generator: generate the code in the target language 
	- Interpretation
	- Hybrid implementation: pyhton

Describing a language:
Syntax + semantics 
	- Decribing the syntax:
		○ Tokens: add token = + tADD, -  tSUB, .., => tOPP
		○ Token spellings (lexeme of token):  lexeme is unique for a language +ASGN (if C) -> '=', (if pascal) -> ':=', tID->token identifier