Pointers and Polynomials

Abstract

The Pascal identifier types that we have met so far are all examples of fixed structures in the sense that, when they are declared at the head of a program segment, they allocate a fixed amount of space into which we can store values. We have met simple types such as REAL and INTEGER, and structured types such as ARRAYs and RECORDs. Each of these has a specific role to play and contributes to the richness and versatility of the Pascal language. However once a program is compiled and running, if we try to access any element outside the declared bounds, an error will be caused. There is nothing we can do but alter the program. Thus the types already discussed cannot easily cope with situations in which we are not sure beforehand how large our structures are likely to be.