v ;;Quote: programs should always be simple even if their tasks are complex

vi ;;Quote: Jackson's design method dissects the problem into parts and structures those parts into a solution

vi+;;Quote: Jackson's method gives a procedure for designing programs which is simple and self-evidently correct

vii ;;Quote: if you must optimize, do it after writing a perfectly clear and unoptimized solution

vii ;;Quote: optimization makes a system less reliable, harder to maintain, more expensive to build, and harder to optimize

11 ;;Quote: both accessing and modifying a data structure can be associated with its components

16 ;;Quote: hierarchy allows large and complex programs out of simple components; complexity only through number of components and levels

19 ;;Quote: Jackson's diagrams show the components of an entity; not a flowchart

21 ;;Quote: Jackson's diagrams indicate repetition, sequence, and selection by boxes

23 ;;Quote: should only have one form of iteration; reduces design complexity

23 ;;Quote: repeat..until is harder to use correctly since first iteration does not test the conditional; loop body has two distinct contexts

32 ;;Quote: need to dissect the structure of problem data down to elementary data types, and the structure of the program down to primitive operations

33 ;;Quote: a primitive operation should be used in many places in many different programs

33 ;;Quote: limit span of attention through top-down design; only one use of each program component

34 ;;Quote: if programs are structured as trees then always know the origin of any component

34 ;;Quote: if a program reuses components then the context of a statement depends on the prior execution history; requires a trace to debug

36 ;;Quote: generalized components are only created by bottom-up design

36 ;;Quote: a generalized component should be seen as an operation of an abstract machine; internals are inaccessible

36 ;;Quote: the top-down designer creates tree structures; at a level with no shared components

49 ;;Quote: many programs read and process serial input

63 ;;Quote: many programs become an iteration over data records; this is wrong

64 ;;Quote: an iteration of data records prevents the expression of important relationships between records

64 ;;Quote: a data structure should contain all relationships relevant to the program

101 ;;Quote: a data structure reflects the problem; this includes error handling

101 ;;Quote: should design data structures so that erroneous data does not interfere with processing of good data

106 ;;Quote: components must rely on the correctness of any module it gets data from

123 ;;Quote: to backtrack in a Jackson program/data structure tree use 'posit..admit..'; creates a restartable block

151 ;;Quote: structure and operations of a program must correspond with structure and components of the data it processes

151 ;;Quote: structure clashes--when data structures do not correspond 1-1

166 ;;Quote: synchronization--current place in the program text must correspond with current place in data structure

166 ;;Quote: JacksonDesignMethod uses unstructured temporary files to avoid structure clashes

237 ;;Quote: Jackson bases program structure on the data structures of serial files

237 ;;Quote: program inversion turns a program to process a complete file, into one processing one record at a time

251 ;;Quote: only an unoptimized design can have a clearly understood and simple structure

251+;;Quote: to prevent logical errors during optimization, one must understand the program fully

251 ;;Quote: apparently innocuous changes to a program can have surprising and disastrous effects

259 ;;Quote: reducing the size of a program is usually more important than increasing speed of execution

268 ;;Quote: common subroutines from bottom-up design are reused; those from top-down design are for optimization

279 ;;Quote: data structures model the problem environment; good foundation from program structures

279 ;;Quote: Jackson avoids recursive data structures because they occur rarely in data processing

280 ;;Quote: the most important limitation on data structures is that they are hierarchical but must be explored sequentially

280+;;Quote: the serial file is the fundamental data structure; explored sequentially

280 ;;Quote: many files are serial because they are chronologically ordered

280 ;;Quote: Jackson sees a system as many individual programs, one for each relevant entity in the real world

280 ;;Quote: in design, each individual program should have one input and one output file for transactions on an entity such as employees or suppliers

280 ;;Quote: need an overall control program to direct individual transactions and to transfer program output to other programs or to system output

280 ;;Quote: create a master file by inverting the programs for entities of a class; e.g., class of employees

283 ;;Quote: can not find logic errors by testing because they depend on combinations of circumstances; should make testing unnecessary