index

A

AddBookItemController class 19

addMember mutation 84

aggregateField function 216

allErrors options 159

association 7

Atom class 167

AtomicReference generic class 168

atoms 163

state management with 172 – 174

thread-safe cache with 170 – 172

thread-safe counter with 165 – 170

Author class 5, 337 – 338

AuthorData class 347

AuthorDataWithFullName class 347

Author entities 46 – 47

Author.myName(author, format) function 290

authorNameDispatch function 291

authorNames function 59, 63

Author objects 7, 11

Author.prolificityLevel helper function 291

authorsById index 46 – 47, 55, 268

automatic generation of data model diagrams 260 – 262

automatic generation of schema-based unit tests 262 – 269

B

BookAttributes class 377

Book class 5, 7, 11, 51 – 52

Book entities 46 – 47

bookInfo function 60, 63

BookInfo record 58, 60

bookInfo schema 151, 155

BookInSearchResults class 52

BookItem class 5, 11 – 12, 51

BookItemQuery class 19

BookItemResult class 19

bookItems member 52

BookLending class 5, 10, 12

Book records 49 – 51, 60, 77

booksByIsbn index 46 – 47, 55, 77

boundaries of systems 143

C

Catalog.authorNames function 115, 121

Catalog.bookInfo function 114, 121

Catalog class 5, 7, 10 – 11

catalogData map 116 – 117

Catalog entity 46 – 47

Catalog index 47

Catalog module 35, 39, 62 – 63

Catalog record 54, 62

Catalog.searchBooksByTitle function 318

class inheritance 8

class members, generic access to 373 – 380

automatic JSON serialization of objects 378 – 380

nested class members 376 – 378

non-nested class members 373 – 376

code modules 31 – 36

collections, reducing 97 – 98

CombinedBook class 231

commit function 88, 173

commit phase 72, 93

compareAndSet() method 168

complexity 13, 27, 164, 198, 341

composition 7

concurrency control 91 – 92, 163

complexity of locks 164 – 165

implementation of reconciliation algorithm 106 – 108

optimistic concurrency control 92 – 93

reconciliation between concurrent mutations 94 – 97

reducing collections 97 – 98

state management with atoms 172 – 174

structural difference 99 – 106

thread-safe cache with atoms 170 – 172

thread-safe counter with atoms 165 – 170

containsKey() method 185

convertJDBCResultSetToListOfMaps function 204

countByBoolField utility function 304

createAuthorObject function 340

createUserObject function 338

current system state 95

D

database operations

data manipulation

advanced 211 – 218

simple 207 – 211

fetching data from database 198 – 204

storing data in the database 204 – 206

data-driven programming 385 – 386

data entities 29 – 31, 38

dataFilePath function 323

data manipulation 43 – 44

best tools for 301 – 305

manipulating data with generic functions 54 – 57

manipulating nested data 299 – 301

representing records as maps 48 – 54

data model diagrams, automatic generation of 260 – 262

data models, designing 44 – 48

data-oriented design 385 – 386

data-oriented programming. See DOP

data safety 82 – 83

data validation 141

advanced 257 – 258

data validation failures 158 – 161

function argument validation 248 – 255

return value validation 255 – 257

data validation failures 158 – 161

DBBook class 231

debugging

determinism 312 – 314

external data sources 329 – 330

reproducibility with any data 318 – 321

reproducibility with numbers and strings 314 – 318

unit tests 321 – 329

deepFreeze() function 177

design phase, OOP 4 – 5

determinism 312 – 314

displayAuthorInfo function 357

displayFullName function 358 – 359

displayProlificity function 358 – 359

DOP (data-oriented programming) 26 – 27, 386

concurrency control

advanced 163

basic 91 – 109

data-driven programming vs. 386

data manipulation 43 – 70

data-oriented design vs. 386

data validation 141

definition 386

easy to understand 36 – 38

flexibility 38 – 42

history of 381 – 383

1958: Lisp 381

1981: Values and objects 382

2000: Ideal hash trees 383

2006: Out of the Tar Pit 383

2007: Clojure 383

2009: Immutability for all 383

parts of 27 – 29

code modules 31 – 36

data entities 29 – 31

state management 71 – 90

unit tests 110

DOP (data-oriented programming) principles

data is immutable 351 – 355

as best practice 384 – 385

benefits of 352 – 354

cost for 354

illustration of 351 – 352

represent data with generic data structures 345 – 350

as best practice 384

benefits of 346 – 347

cost for 347 – 350

illustration of 345 – 346

separate code from data 335 – 344

as best practice 384

benefits of 337 – 343

cost for 343 – 344

illustration of 335 – 337

separate data schema from data representation 355 – 363

as best practice 385

benefits of 357 – 361

cost for 361 – 362

illustration of 355 – 356

DSLs (domain specific languages) 386

DynamicAccess class 366, 369

dynamic data type 56, 349

dynamic getters 380

dynamic keyword 289

dynamic type 349

dysGreet multimethod 286 – 288

E

enum 146

equals() method 373

errorsText function 159, 356

external data sources, debugging 329 – 330

F

feature fields 67

fetchResponseBody function 230

fields array 160

fields property 145

FP (functional programming) 13, 28, 59, 75, 336 – 337, 381

fullName function 338 – 339, 343, 348

function arguments, validation of 248 – 255

G

generic functions, manipulating data with 54 – 57

getAsString() method 369, 376

getBookLendings function 39

getBookLendings method 34

getIn function 188

Getter class 372

greetDispatch dispatch function 278

greetDog method 280

greet function 275

greetLang multimethod 282, 284

greet method 273, 279

greet multimethod 280

H

HAMT (Hash Array Mapped Trie) 383

handle method 19

hashCode() method 373 – 374

Hash map 96

heterogeneous maps 49, 252

homogeneous maps 49, 252

I

IAnimal interface 273

Immutable.fromJS() function 186

immutable functions 76

Immutable.set() map 187

Immutable.setIn() map 187

Immutable.stringify() function 192

implementation phase, OOP 12

indexes 46

inheritance 7

innovation 384

isLibrarian function 39

isSuperMember function 40

items property 145

J

Java, persistent data structures and 184 – 186

JavaScript, persistent data structures and 186 – 188

java.util.concurrent.atomic package 168

JDBC (Java database connectivity) 202

joinArrays function 237

JSON.parse function 122

JSON schema 143 – 149

automatic serialization of objects 378 – 380

schema composition 154 – 157

schema flexibility and strictness 149 – 153

JSON.stringify() function 53, 192

K

keyList 206

L

late binding 203

lendingRatio function 303

lent variable 303

Librarian::blockMember method 8

Librarian class 5, 10 – 11, 22

Librarian entity 342

Librarian record type 68

librariansByEmail index 65

librariansByEmail map 66

librarians hash maps 79

Librarian user type 65

Library.addMember function 79, 127

Library class 5, 9 – 10, 33, 126

libraryData.catalog data object 40

libraryData map 187

libraryData.userManagement data object 40

Library hash map 78

Library module 33 – 36, 39, 62 – 63

Library object 7, 10

Library record 62

Library root class 9

LISP (LISt Processing) 381

List static factory method 51

Lodash functions

at 205 – 206, 388

concat 388

every 389

filter 188, 201, 389

find 389

flatMap 300 – 301

flatten 388

forEach 389

get 55 – 57, 61, 166, 173, 185, 188, 352, 366, 376, 388

groupBy 389

has 388

intersection 105, 388

isArray 389

isEmpty 389

isEqual 111, 188, 389

isObject 389

keyBy 236 – 237, 389

map 59, 188 – 189, 389

merge 388

nth 388

omit 388

pick 346

reduce 188, 389

set 75 – 76, 80, 185, 388

set method 166, 173, 352

size 185, 389

sortBy 389

sum 388

union 193, 388

uniq 388

update 297, 305

values 388

M

many-to-many association relation 8

maps

dynamic getters for string maps 364 – 367

accessing nested map fields 366 – 367

accessing non-nested map fields 365 – 366

representing client requests as 225 – 227

representing records as 48 – 54

representing server responses as 227 – 231

typed getters for 370 – 372

accessing nested map fields 371 – 372

accessing non-nested map fields 370 – 371

updating values in 296 – 299

value getters for 367 – 370

accessing nested map fields 368 – 370

accessing non-nested map fields 367 – 368

Map static factory method 51

Map<String, Object> type 349

Member class 5, 10 – 11, 15

MemberCode entity 15

MemberData entity 15

Member objects 7, 10

Member record type 68

membersByEmail index 65

Member user type 65

multimethod library 278 – 280, 289

multimethods

integrating in production systems 289 – 293

with dynamic dispatch 286 – 289

with multiple dispatch 281 – 286

with single dispatch 277 – 281

multipleBookInfo function 235

multiple dispatch 285

mutations 71

calculation phase of 72, 93

commit phase of 83 – 85

definition 72

reconciliation between concurrent 94 – 97

unit tests for 126 – 133

writing with persistent data structures 191 – 192

mutexes 163

Mutex object 165

N

nested data

accessing nested map fields

with dynamic getters 366 – 367

with typed getters 371 – 372

with value getters 368 – 370

manipulating 299 – 301

nested class members 376 – 378

NoMethodError exception 280

O

object, meaning of term 382

object data type 144

Object.freeze() function 177

Object type 349, 365, 367

OOP (object-oriented programming) 3 – 4, 334, 381

project example 4 – 12

design phase 4 – 5

implementation phase 12

UML class diagram 6 – 12

separating code from data 335 – 336

sources of complexity 13 – 24

complex class hierarchies 20 – 24

many relations between classes 14 – 16

not trivial data serialization 18 – 20

unpredictable code behavior 16 – 18

OpenLibraryBook class 231

optimistic concurrency control strategy 92

Optional class 359

P

persistent data structures

efficiency of 178 – 183

libraries for 184 – 188

Java 184 – 186

JavaScript 186 – 188

need for 175 – 178

serialization and deserialization 192

structural diff 193 – 195

writing mutations with 191 – 192

writing queries with 188 – 189

polymorphism 273 – 277

positional collection 46

previous states, restoring 86 – 89

previousSystemData references 87

previous system state 95

Q

queries

unit tests for 121 – 125

writing with persistent data structures 188 – 189

R

reconciliation algorithm 106 – 108

record, definition 48

record type 385

reflection 374, 380

RegExp constructor 328

renameResultKeys function 209

REPL (Read Eval Print Loop) 313

reproducibility

with any data 318 – 321

with numbers and strings 314 – 318

return values, validation of 255 – 257

S

schema-based unit tests, automatic generation of 262 – 269

schema composition 154 – 157

schema flexibility and strictness 149 – 153

searchBooksByTitle function 60, 62 – 63

search method 19

SearchQuery object 19

SearchResult object 19

search results, calculating 58 – 64

simplicity 13, 341, 343

state management 71 – 72

commit phase of mutations 83 – 85

data safety 82 – 83

ensuring system state integrity 85 – 86

multiple versions of system data 72 – 74

restoring previous states 86 – 89

structural sharing 74 – 81

with atoms 172 – 174

statically-typed languages, data access in

dynamic getters for string maps 364 – 367

accessing nested map fields 366 – 367

accessing non-nested map fields 365 – 366

generic access to class members 373 – 380

automatic JSON serialization of objects 378 – 380

nested class members 376 – 378

non-nested class members 373 – 376

typed getters for maps 370 – 372

accessing nested map fields 371 – 372

accessing non-nested map fields 370 – 371

value getters for maps 367 – 370

accessing nested map fields 368 – 370

accessing non-nested map fields 367 – 368

strict mode, JavaScript 177

string maps 44

structural difference 99 – 106, 193 – 195

structural sharing 72, 74 – 81

SuperMembersByEmail index 66

swap method 166, 172 – 173

switch statements 276

System.addMember function 127

System class 84 – 85, 126

SystemConsistency class 106 – 108

SystemData class 108, 172 – 173

SystemState class 84 – 86, 88, 127

SystemState.commit function 127

SystemState.commit method 85

SystemState.get function 127

system state integrity, ensuring 85 – 86

SystemState object 132 – 133

T

toJS() method 187

toJSON() method 192

toString() method 373

toUpperCase string method 365

tree of function calls 113 – 115

Typed getters Approach 380

TypeError exception 177

U

UML class diagrams 6 – 12

unit tests 110

automatic generation of 262 – 269

debugging 321 – 329

for data manipulation code 112 – 121

tree of function calls 113 – 115

for mutations 126 – 133

for queries 121 – 125

simplicity of data-oriented test cases 110 – 112

unit tests for data manipulation 112 – 121

UnSupportedOperationException exception 179, 185

unwind function 307

unwind operator 305 – 309

updating values in maps eloquently 296 – 299

usage relations 8

User class 5, 10 – 11, 20, 24, 338

UserManagement.addMember function 127

UserManagement class 67, 126

UserManagement hash map 78

UserManagement.isLibrarian function 66

UserManagement module 35, 39 – 40, 67

UserManagement record 65 – 66

User record type 68

uuid third-party library 322

UUID (universal unique identifier) 322

V

validate function 147, 158, 356

value getters 380

valueSeq method 189

VIPMember class 22

VIPMembersByEmail index 66

W

web services

internals of 222 – 224

passing information forward 231 – 234

representing client requests as maps 225 – 227

representing server responses as maps 227 – 231

search result enrichment 234 – 243

while loop 170

word boundaries regular expression 327