If we think about the computer as an FSM, Imperative program specifies commands to update the machine state. Each statement causes a change in the state. The state changes a million times per second.
Even if there is a meaning to a program beyond the hardware details, it is often obscured such that only a handful of experts can truly comprehend it.
As study of languages has progressed, different paradigms have emerged, which aim to allow the program to be structured in a more comprehensible manner; where the abstract notions are more easily representable and understandable.
Each paradigm has brought to the table a way of not just organizing code, but a way for developers to organize thoughts on how to tackle a specific problem; be it structural programming, object oriented programming, data flow programming or any other paradigm.
I found the following statement very cogent about functional programming.
"Functional programming aims to give each program a straightforward mathematical meaning. It simplifies our mental image of execution, for there are no state changes. Execution is the reduction of an expression to its value, replacing equals by equals. Most function definitions can be understood within elementary mathematics."
Functional programming paradigm and functional programming languages have been around for a long time. However, until recently their adoption has been limited, largely marginalized to academic and niche domains.
This has been due to the fact that functional programming languages have been traditionally slower then the other prevalent solutions.
However, this is changing. The change is largely dictated by changes in the direction hardware industry has gone.
Rather than focusing on creating increasingly powerful and fast processors with single core, the focus has shifted to multi-core solutions. With advances in networking and storage, the cost of having distributed systems has gone down.
If we talk about functional programming at a depth that just scratches the surface, then the following 2 properties are the most important
- Functional programming encourages writing functions that have no side effects.
- Immutability is a corner stone of functional programming paradigm. Use of immutable references, providing solid support for persistent datastructures.
Just looking at these two facts, one can immediately start working out and relating how the changes in the hardware industry are synergetic with functional programming.
A deeper analysis of how these trends have help emerge functional programming languages stronger is outside the purview of this post. We will get to that eventually.
Functional programming languages have been hovering on the horizon for a long time, may be their time to truly shine has finally come.
