- High level languages such as C and Python cannot be understood by computers. We must translate the C and Python source code into something that a machine can make use of. This is done by compilers and interpreters. These are different types of programs but they are also similar in many ways which we will see later. In this summary, we will see the different steps taken to translate human readable code into something machines can understand and execute (we will also see how high-level lanugages are also translated to other high-level languages).
- The first step in comilation/interpretation is called scanning (or lexing or even lexical analysis). It basically turns a stream of characters into tokens which can be composed of one or more characters. Let's look at how the following C line would be lexed:
// This is a program
int average = (min + max) / 2; - This line consists of this stream of characters : (
/,/,T,h,i,s,i,s,a,p,r,o,g,r,a,m,i,n,t,a,v,e,r,a,g,e,=,(,m,i,n,+,m,a,x,),/,2,;,int,average,=,(,min,+,max,),/,2,;).