Subtopic Notes

5.2 Language Translators

5. System Software

High Level Languages

Advantages
- Close to English/native/human language
- Easier/faster to correct errors/read/write
- Much easier to debug
- Debug at the development stage
- Portable: Works on many different machines/operating systems (not machine-specific, portable)
Disadvantages
- Programs can be larger
- Program can take longer to execute
- Program may not make use of special hardware
Example: C, Python, Java, Pascal etc.

Relate to the specific architecture and hardware of a particular type of computer.
Can refer to machine code, the binary instructions that a computer understands, or an assembly language that needs to be translated into machine code.
Benefits:
- Work directly on registers/CPU/ can address memory addresses directly
- More control over what happens in computer
- Can use machine specific functions
- Code requires less storage/RAM
- Runs faster.
Disadvantage:
- Takes longer to write or debug
- Difficult to understand
- Not Portable

Low-level programming language that is closely related to machine code but is more human-readable.
Uses mnemonic codes and symbols instead of binary instructions
Advantages:
Can make use of special hardware
Use special machine-dependent instructions
Doesn’t take up much space in primary memory
Code performs task relatively quickly

Compiler	Interpreter	Assembler
Translates a high-level language to machine code	Executes a high-level language one statement at a time	Translates low-level assembly language into machine code.
An executable file produced	No executable file produced	An executable file produced.
A single high-level language statement may correspond to multiple machine code instructions.		Each statement in assembly language is translated into one machine code instruction.
Compiler not required to run compiled programs	Interpreted programs cannot be run without the interpreter	Assembler not required to run assembled program
Usually used while distributing program	Used during production stage	Assembled programs are released for general use

Advantages	Disadvantages
Creates an executable file so the code can be tested multiple times without having to recompile so repeated testing takes less time	Larger amounts of source code take time to compile
Compiled programs are run without the compiler	Slower to produce the object code than an interpreter
Optimize code for better performance and efficiency	Code cannot be changed without recompilation
No Dependency on Source Code	The program will not run if there are any errors
More secured as codebase not available for users	Errors cannot be corrected in real-time; Harder to test and debug
	One error may result in other false errors being reported

Advantages	Disadvantages
Easier to debug the program because it translates line-by-line and stops when an error is found	Stops execution at first error, which can slow down debugging for large programs.
Allows error to be fixed in real time	Program can’t run without interpreter
Program can restart at same point when error occurs and refixed	The source code must be available for execution, making it less secured
Effect of changing code seen immediately
A partially completed program can be translated / tested on its own

Two-step translation

Some high-level programming languages, such as Java, require a two-step translation process, involving both compilation and interpretation.
Partially compiled programs can be used on different platforms as they are interpreted when run.
Code is optimized for the CPU as machine code is generated at run time
Two-step translation in Java
- Compilation: Java source code is first converted into an intermediate form called bytecode by the Java compiler.
- Interpretation: The Java Virtual Machine (JVM) then interprets the bytecode, translating it into machine code for execution on the target system.