Transformation Process

Transformation of expressions can be implemented in several steps:

  1. Test whether the input matches a pattern; keeping bindings between pattern variables and parts of the input.

  2. Construct the output: create a version of the output pattern with substitutions from the bindings.

  3. Keep trying: one transformation may enable another, so continue until the result does not change (reaches a fixed point).

Contents    Page-10    Prev    Next    Page+10    Index