In this unit, we will delve into the process of building a simple compiler for a functional programming language. This will provide a practical understanding of the principles and techniques we've discussed so far.
A compiler for a functional programming language is designed to interpret and translate high-level functional programming code into machine code that a computer can execute. The structure of such a compiler is similar to that of other compilers, but with some unique considerations due to the nature of functional programming.
The first step in building a compiler is lexical analysis, also known as scanning. This process involves breaking down the source code into individual words or tokens. Each token represents a logically cohesive sequence of characters, such as keywords, identifiers, operators, and punctuation.
The next step is syntax analysis or parsing. This process involves analyzing the tokens produced during lexical analysis to ensure they form a grammatically correct 'sentence' based on the programming language's syntax rules. The result of this step is a parse tree, which represents the syntactic structure of the source code.
Semantic analysis is the process of adding semantic information to the parse tree and building a symbol table, which stores variable names along with information about their declaration and occurrences in the code. This step also involves type checking, where the compiler checks whether the operations are performed on compatible data types.
After semantic analysis, the compiler generates an intermediate code of the source code. This code is a lower-level representation of the source code, which maintains the logical structure of the original code.
The next step is code optimization. This process involves refining the intermediate code to improve the runtime performance and the efficiency of the output code. The optimization can be performed on various aspects, such as memory usage, CPU usage, and overall execution time.
The final step in building a compiler is code generation. The optimized intermediate code is translated into the target machine language. The output of this step is the machine code that can be executed by the computer.
Now that we've covered the theory, it's time to put it into practice. In this exercise, you will build a simple compiler for a functional programming language of your choice. You will apply all the steps we've discussed, from lexical analysis to code generation. This exercise will give you a hands-on understanding of the compiler construction process and the unique considerations when dealing with functional programming languages.