2002  66-70

 A typical imperative language contains an applicative sub-language which approximate the mathematical abstractions of “timeless” function applied to “spaceless” values, where the acture operation sequences and use of storage space during expression evaluation are organized behind the scenes.

 In this setting, values are data structures of low volume, typically a few computer words or less, which means that an illusion of spacelessness can be realized by having intermediate results during expression evaluation stored at the discretion of language implementation, and effecting parameter transmission and assignment operations through value copying.

词汇:

imperative                  命令的, 强制的

approximate                 近似的,大约的