Knuth, emphasis on function as well as form is basic to design problems

The Art of Computer Programming, Volume 1
2.2 LINEAR LISTS
2.2.1 Stacks, Queues, and Deques, pg. 238

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We must decide in each case how much structure to represent in our tables, and how accessible to make each piece of information.  To make such decisions, we need to know what operations are to be performed on the data.  For each problem considered in this chapter, therefore, we consider not only the data structure but also the class of operations to be done on the data; the design of computer representations depends on the desired function of the data as well as on its intrinsic  properties.  Indeed, an emphasis on function as well as form is basic to design problems in general.