Introduction | Notion

Programming Languages

<aside> 💡 Programming languages communicate computational instructions.

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Originally , these languages were directly connected to the architecture → Low level Language.
- In this design, memory locations would store the values and registers were used to do arithmetic operations.
- e.g.: Doing a simple addition operation of two values:
  - Load a value from memory location $M$ into Register $R_1$.
  - Load another value from memory location $M'$ into Register $R_2$.
  - Add the contents of register $R_1$ and $R_2$ and store back the result in $R_1$.
  - Write the value in $R_1$ to desired location $M_r$.
As seen above, this was tedious and error prone. Simple operations required many instructions.
As a solution to this problem , a concept of abstraction was introduced.

Various abstractions are used. Abstractions simply means showing only useful information and hiding the rest.

Some abstractions we may have seen:
- Assigning values to named variables. (Instead of assigning it to a specific memory location in the memory).
- Conditional Execution. ( To execute a bunch of statements if some condition is satisfied)
- Iterations.
- Functions, procedures and recursion.
- Aggregate Data Structures - arrays, lists, dictionaries.
These are high ideas and needed some mechanism to translate these into low level language that is understood by the computers.
- Compilers and Interpreters are such mechanisms.
What is the catch?
- We will have less control over how the code is mapped to the architecture. So we may not be able to optimize the code to the highest level possible.
But there are now fewer errors and takes less time to code.

So there is a trade off between expressiveness for efficiency.