What is a compiler used for?

The compiler transforms source code written in a high-level programming language (e.g., C++, Java, Dart) into machine code or intermediate code that can be executed by a processor or virtual machine.

Main functions:

• Lexical analysis: Breaks the source code into tokens.
• Syntax analysis: Checks the grammatical structure of the code.
• Semantic analysis: Verifies type correctness and expression meanings.
• Intermediate code generation: Creates a representation of the code that is more suitable for optimization.
• Code optimization: Improves the performance and size of the generated code.
• Target code generation: Produces executable code for a specific architecture or virtual machine.

In the context of Flutter:

• AOT (Ahead-of-Time) compilation: Used to create native machine code for ARM or x64 for release builds on iOS and Android, ensuring high performance.
• JIT (Just-in-Time) compilation: Used in "debug" or "dev" mode for quick iteration and Hot Reload support. DartVM compiles code at runtime.