Programming in D

Contents....5

Foreword by Andrei Alexandrescu....17

Preface....19

Acknowledgments....19

The Hello World Program....21

Compiler installation....21

Source file....21

Compiling the hello world program....21

Compiler switches....22

IDE....23

Contents of the hello world program....23

Exercises....24

writeln and write....25

Exercises....25

Compilation....26

Machine code....26

Programming language....26

Interpreter....26

Compiler....27

Compilation error....27

Fundamental Types....28

Properties of types....29

size_t....30

Exercise....30

Assignment and Order of Evaluation....31

The assignment operation....31

Order of evaluation....31

Exercise....31

Variables....32

Exercise....33

Standard Input and Output Streams....34

Exercise....34

Reading from the Standard Input....35

Skipping the whitespace characters....36

Additional information....37

Exercise....37

Logical Expressions....38

Logical Expressions....38

Grouping expressions....41

Reading bool input....41

Exercises....41

if Statement....44

The if block and its scope....44

The else block and its scope....44

Always use the scope curly brackets....45

The "if, else if, else" chain....45

Exercises....47

while Loop....48

The continue statement....48

The break statement....49

Unconditional loop....49

Exercises....50

Integers and Arithmetic Operations....51

Integer types....52

Number of bits of a type....52

Choosing a type....53

Overflow....53

Truncation....53

.min and .max....54

Increment: ++....54

Decrement: --....54

Addition: +....55

Subtraction: -....55

Multiplication: *....56

Division: /....56

Remainder (modulus): %....56

Power: ^^....57

Arithmetic operations with assignment....57

Negation: -....57

Plus sign: +....58

Post-increment: ++....58

Post-decrement: --....58

Operator precedence....59

Detecting overflow....59

Preventing overflow....59

Preventing truncation....60

Exercises....61

Floating Point Types....62

Floating point type properties....62

.nan....63

Specifying floating point values....63

Observations....64

Overflow is not ignored....64

Precision....65

There is no truncation in division....65

Which type to use....66

Cannot represent all values....66

Unorderedness....67

isNaN() for .nan equality comparison....67

Exercises....68

Arrays....69

Definition....69

Containers and elements....70

Accessing the elements....70

Index....71

Fixed-length arrays vs. dynamic arrays....71

Using .length to get or set the number of elements....71

An array example....72

Initializing the elements....72

Basic array operations....73

Copying fixed-length arrays....73

Adding elements to dynamic arrays....73

Removing elements from dynamic arrays....74

Combining arrays....74

Sorting the elements....75

Reversing the elements....75

Exercises....75

Characters....77

History....77

ASCII Table....77

IBM Code Pages....77

ISO/IEC 8859 Code Pages....78

Unicode....78

Unicode encodings....78

The character types of D....79

Character literals....79

Control characters....80

Single quote and backslash....80

The std.uni module....81

Limited support for ı and i....82

Problems with reading characters....82

D's Unicode support....83

Summary....84

Slices and Other Array Features....85

Slices....85

Using $, instead of array.length....86

Using .dup to copy....86

Assignment....87

Making a slice longer may terminate sharing....87

Using capacity to determine whether sharing will be terminated....89

Reserving room for elements....90

Operations on all elements....90

Multi-dimensional arrays....92

Summary....94

Exercise....94

Strings....95

readln and strip, instead of readf....95

formattedRead for parsing strings....96

Double quotes, not single quotes....97

string, wstring, and dstring are immutable....97

Potentially confusing length of strings....98

String literals....99

String concatenation....99

Comparing strings....100

Lowercase and uppercase are different....100

Exercises....101

Redirecting the Standard Input and Output Streams....102

Redirecting the standard output to a file with operator >....102

Redirecting the standard input from a file with operator <....102

Redirecting both standard streams....103

Piping programs with operator |....103

Exercise....103

Files....104

Fundamental concepts....104

The producer and the consumer....104

Access rights....104

Opening a file....104

Closing a file....105

Writing to and reading from files....105

eof() to determine the end of a file....105

The std.file module....105

std.stdio.File struct....106

Writing to a file....106

Reading from a file....106

Exercise....107

auto and typeof....108

auto....108

typeof....108

Exercise....109

Name Scope....110

Defining names closest to their first use....110

for Loop....112

The sections of the while loop....112

The sections of the for loop....112

The sections may be empty....113

The name scope of the loop variable....114

Exercises....114

Ternary Operator ?:....115

The type of the ternary expression....116

Exercise....117

Literals....118

Integer literals....118

The types of integer literals....118

The L suffix....119

The U suffix....119

Floating point literals....120

The types of floating point literals....120

Character literals....120

String literals....121

Double-quoted string literals....121

Wysiwyg string literals....121

Delimited string literals....121

Token string literals....122

Types of string literals....122

Literals are calculated at compile time....122

Exercises....122

Formatted Output....123

format_character....124

width....126

separator....126

precision....127

flags....127

Positional parameters....128

Formatted element output....129

format....130

Checked format string....131

Exercises....131

Formatted Input....132

Format specifier characters....133

Exercise....133

do-while Loop....134

Exercise....135

Associative Arrays....136

Definition....136

Adding key-value pairs....137

Initialization....137

Removing key-value pairs....137

Determining the presence of a key....138

Properties....138

Example....139

Exercises....139

foreach Loop....140

The foreach syntax....140

continue and break....141

foreach with arrays....141

foreach with strings and std.range.stride....141

foreach with associative arrays....142

foreach with number ranges....142

foreach with structs, classes, and ranges....142

The counter is automatic only for arrays....143

The copy of the element, not the element itself....143

The integrity of the container must be preserved....144

foreach_reverse to iterate in the reverse direction....144

Exercise....145

switch and case....146

The goto statement....146

The expression must be an integer, string, or bool type....148

Value ranges....149

Distinct values....149

The final switch statement....149

When to use....150

Exercises....150

enum....151

Effects of magic constants on code quality....151

The enum syntax....151

Actual values and base types....152

enum values that are not of an enum type....152

Properties....153

Converting from the base type....154

Exercise....154

Functions....155

Parameters....156

Calling a function....158

Doing work....158

The return value....158

The return statement....159

void functions....159

The name of the function....160

Code quality through functions....160

Code duplication is harmful....160

Commented lines of code as functions....164

Exercises....164

Immutability....166

Immutable variables....166

enum constants....166

immutable variables....168

const variables....169

Immutable parameters....169

const parameters....170

immutable parameters....171

Should a parameter be const or immutable?....171

Immutability of the slice versus the elements....173

const and immutable are transitive....174

.dup and .idup....174

How to use....174

Summary....175

Value Types and Reference Types....176

Value types....176

The use of assert checks below....176

Value identity....177

Address-of operator, &....177

Reference variables....177

Reference types....178

The difference in the assignment operation....180

Variables of reference types may not be referencing any object....181

Fixed-length arrays are value types, slices are reference types....182

Experiment....182

Summary....184

Function Parameters....185

Parameters are always copied....185

Referenced variables are not copied....186

Surprising reference semantics of slices....186

Surprising reference semantics of associative arrays....187

Parameter qualifiers....188

in....188

out....188

const....189

immutable....190

ref....190

auto ref....191

inout....191

lazy....193

scope....194

shared....194

return....195

Summary....196

Exercise....197

Lvalues and Rvalues....198

Limitations of rvalues....198

Rvalues don't have memory addresses....198

Rvalues cannot be assigned new values....198

Rvalues cannot be passed to functions by reference....199

Using auto ref parameters to accept both lvalues and rvalues....199

Terminology....200

Lazy Operators....201

Program Environment....202

The return value of main()....202

main() always returns a value....202

Specifying the return value....203

Standard error stream stderr....204

Parameters of main()....204

Command line options and the std.getopt module....205

Environment variables....207

Starting other programs....207

Summary....208

Exercises....208

Exceptions....209

The throw statement to throw exceptions....209

The exception types Exception and Error....210

Thrown exception terminates all scopes....210

When to use throw....214

The try-catch statement to catch exceptions....214

catch blocks are considered sequentially....216

The finally block....218

When to use the try-catch statement....218

Exception properties....219

Kinds of errors....220

User errors....220

Programmer errors....221

Unexpected situations....222

Summary....222

scope....223

assert and enforce....225

Syntax....225

static assert....226

assert even if absolutely true....227

No value nor side effect....227

Disabling assert checks....228

enforce for throwing exceptions....228

How to use....228

Exercises....229

Unit Testing....231

Causes of bugs....231

Discovering the bugs....231

Unit testing for catching bugs....232

Activating the unit tests....233

unittest blocks....233

Testing for exceptions....234

Test driven development....235

Unit tests before bug fixes....236

Exercise....237

Contract Programming....238

in blocks for preconditions....238

out blocks for postconditions....239

Disabling contract programming....241

in blocks versus enforce checks....241

Exercise....242

Lifetimes and Fundamental Operations....244

Lifetime of a variable....244

Lifetime of a parameter....244

Fundamental operations....245

Initialization....246

Finalization....247

Assignment....248

The null Value and the is Operator....249

The null value....249

The is operator....250

The !is operator....250

Assigning the null value....250

Summary....251

Type Conversions....253

Automatic type conversions....253

Integer promotions....254

Arithmetic conversions....254

Slice conversions....255

const conversions....256

immutable conversions....256

enum conversions....257

bool conversions....257

Explicit type conversions....258

Construction syntax....258

to() for most conversions....259

assumeUnique() for fast immutable conversions....259

The cast operator....260

Summary....261

Structs....262

Definition....262

struct defines a type, not a variable....263

Coding convenience....263

Accessing the members....264

Construction....265

Constructing objects as immutable....266

Trailing members need not be specified....266

Specifying default values for members....267

Constructing by the {} syntax....267

Copying and assignment....267

Careful with members that are of reference types!....268

Struct literals....269

static members....269

static this() for initialization and static ~this() for finalization....271

Exercises....272

Variable Number of Parameters....274

Default arguments....274

Special keywords as default arguments....275

Variadic functions....276

Variadic function arguments have a short lifetime....278

Exercise....279

Function Overloading....281

Overload resolution....282

Function overloading for user-defined types....282

Limitations....283

Exercise....284

Member Functions....285

Defining member functions....285

toString() for string representations....286

Example: increment() member function....287

Exercises....289

const ref Parameters and const Member Functions....291

immutable objects....291

ref parameters that are not const....291

const ref parameters....291

Non-const member functions....292

const member functions....292

inout member functions....293

How to use....294

Constructor and Other Special Functions....295

Constructor....295

Constructor syntax....295

Compiler-generated automatic constructor....296

Accessing the members by this.....296

User-defined constructors....297

First assignment to a member is construction....298

User-defined constructor disables compiler-generated constructor....298

static opCall instead of the default constructor....299

Calling other constructors....300

Constructor qualifiers....300

Immutability of constructor parameters....302

Type conversions through single-parameter constructors....303

Disabling the default constructor....303

Destructor....304

Destructor is executed automatically....304

Destructor example....305

Postblit....307

Disabling postblit....308

Assignment operator....308

Assigning from other types....309

Summary....310

Operator Overloading....311

Overloadable operators....313

Unary operators....313

Binary operators....314

Element indexing and slicing operators....315

Other operators....316

Defining more than one operator at the same time....316

Return types of operators....317

opEquals() for equality comparisons....319

opCmp() for sorting....320

opCall() to call objects as functions....322

Indexing operators....323

Indexing operators example....324

Slicing operators....326

opCast for type conversions....328

Catch-all operator opDispatch....330

Inclusion query by opBinaryRight!"in"....330

Example of the in operator....331

Exercise....332

Classes....335

Comparing with structs....335

Classes are reference types....335

Class variables may be null....335

Class variables versus class objects....336

Copying....336

Assignment....337

Definition....337

Construction....338

Destruction....338

Member access....339

Operator overloading....339

Member functions....339

The is and !is operators....340

Summary....340

Inheritance....341

Warning: Inherit only if "is a"....343

Inheritance from at most one class....343

Hierarchy charts....344

Accessing superclass members....344

Constructing superclass members....345

Overriding the definitions of member functions....346

Using the subclass in place of the superclass....347

Inheritance is transitive....348

Abstract member functions and abstract classes....349

Example....350

Summary....353

Exercises....353

Object....355

typeid and TypeInfo....355

toString....357

opEquals....357

opCmp....360

opCmp for string members....361

toHash....362

Hash table indexes....362

Selecting members for toHash....363

Calculating hash values....363

Hash values for structs....364

Exercises....364

Interfaces....367

Definition....367

Inheriting from an interface....367

Inheriting from more than one interface....368

Inheriting from interface and class....369

Inheriting interface from interface....369

static member functions....369

final member functions....371

How to use....372

Abstraction....372

Example....373

Summary....374

destroy and scoped....376

An example of calling destructors late....376

destroy() to execute the destructor....377

When to use....377

Example....377

scoped() to call the destructor automatically....380

Summary....381

Modules and Libraries....383

static this() and static ~this()....383

File and module names....383

Packages....384

Importing modules....384

Selective imports....385

Local imports....385

Locations of modules....386

Long and short module names....386

Renamed imports....386

Importing a package as a module....387

Deprecating features....387

Adding module definitions to the program....388

Libraries....389

Using libraries of other languages....389

Encapsulation and Protection Attributes....392

Encapsulation....393

Protection attributes....393

Definition....394

Module imports are private by default....394

When to use encapsulation....395

Example....396

Universal Function Call Syntax (UFCS)....398

Properties....401

Calling functions without parentheses....401

Property functions that return values....401

Property functions that are used in assignment....402

Properties are not absolutely necessary....403

When to use....404

Contract Programming for Structs and Classes....406

Preconditions and postconditions for member functions....406

Preconditions and postconditions for object consistency....407

invariant() blocks for object consistency....408

Contract inheritance....409

Unintentionally disabling preconditions....411

Summary....411

Templates....413

Function templates....414

More than one template parameter....415

Type deduction....416

Explicit type specification....416

Template instantiation....417

Template specializations....417

Struct and class templates....418

Default template parameters....420

Every template instantiation yields a distinct type....421

A compile-time feature....421

Class template example: stack data structure....421

Function template example: binary search algorithm....424

Summary....426

Pragmas....428

pragma(msg)....428

pragma(lib)....428

pragma(inline)....428

pragma(startaddress)....430

pragma(mangle)....430

alias and with....432

alias....432

Shortening a long name....432

Design flexibility....433

Revealing hidden names of superclasses....434

with....436

Summary....437

alias this....438

Multiple inheritance....438

Pointers....441

The concept of a reference....441

The ref variables in foreach loops....441

ref function parameters....442

Reference types....442

Syntax....443

Pointer value and the address-of operator &....444

The access operator *....445

The . (dot) operator to access a member of the pointee....445

Modifying the value of a pointer....446

Pointers are risky....448

The element one past the end of an array....448

Using pointers with the array indexing operator []....449

Producing a slice from a pointer....450

void* can point at any type....450

Using pointers in logical expressions....451

new returns a pointer for some types....452

The .ptr property of arrays....453

The in operator of associative arrays....453

When to use pointers....454

When required by libraries....454

When referencing variables of value types....454

As member variables of data structures....455

When accessing memory directly....455

Examples....455

A simple linked list....455

Observing the contents of memory by ubyte*....457

Exercises....460

Bit Operations....462

Representation of data at the lowest level....462

Transistor....462

Bit....462

Byte....462

Register....462

Binary number system....463

The sign bit of signed integer types....464

Hexadecimal number system....464

Bit operations....466

Complement operator: ~....466

And operator: &....467

Or operator: |....467

Xor operator: ^....468

Right-shift operator: >>....468

Unsigned right-shift operator: >>>....469

Left-shift operator: <<....469

Operators with assignment....470

Semantics....470

| is a union set....470

& is an intersection set....470

|= sets selected bits to 1....471

&= clears selected bits....471

& determines whether a bit is 1 or not....471

Right-shifting by one is the equivalent of dividing by two....472

Left-shifting by one is the equivalent of multiplying by two....472

Common uses....472

Flags....472

Masking....473

Exercises....474

Conditional Compilation....476

debug....476

debug(tag)....478

debug(level)....478

version(tag) and version(level)....479

Assigning identifiers to debug and version....480

static if....480

static assert....481

Type traits....482

Summary....483

is Expression....484

is (T)....484

is (T Alias)....484

is (T : OtherT)....485

is (T Alias : OtherT)....485

is (T == Specifier)....485

Whether the same type....485

Whether matches the same specifier....486

is (T identifier == Specifier)....487

is (/* ... */ Specifier, TemplateParamList)....488

Function Pointers, Delegates, and Lambdas....491

Function pointers....491

Member function pointers....491

Definition....492

Calling a function pointer....492

When to use....492

Function pointer as a parameter....493

Function pointer as a member....495

Anonymous functions....496

Shorter syntax....496

Lambda syntax instead of a single return statement....497

Delegates....499

Shorter syntax....500

An object and a member function as a delegate....500

Delegate properties....502

Lazy parameters are delegates....502

Lazy variadic functions....503

toString() with a delegate parameter....503

Summary....505

foreach with Structs and Classes....507

foreach support by range member functions....507

Example....508

std.range.retro to iterate in reverse....508

foreach support by opApply and opApplyReverse member functions....509

Overloading opApply to iterate in different ways....511

Loop counter....512

Loop counter with range functions....512

Loop counter with opApply....513

Warning: The collection must not mutate during the iteration....514

Exercises....515

Nested Functions, Structs, and Classes....516

static when a closure is not needed....517

Classes nested inside classes....518

Summary....519

Unions....520

Anonymous unions....521

Dissecting other members....521

Examples....522

Communication protocol....522

Discriminated union....523

Labels and goto....526

goto....526

Finalization area....526

continue and break for outer loops....527

The problem of skipping constructors....527

Loop labels....528

goto in case sections....528

Summary....528

Tuples....529

Tuple and tuple()....529

Member properties....529

Expanding the members as a list of values....530

Compile-time foreach....530

Returning multiple values from functions....531

AliasSeq....532

AliasSeq consisting of values....532

Indexing and slicing....533

AliasSeq consisting of types....533

foreach with AliasSeq....534

.tupleof property....534

Summary....535

More Templates....536

The shortcut syntax....536

Template name space....537

Eponymous templates....537

Kinds of templates....538

Function, class, and struct templates....538

Member function templates....538

Union templates....539

Interface templates....541

Kinds of template parameters....541

Type template parameters....541

Value template parameters....541

this template parameters for member functions....544

alias template parameters....545

Tuple template parameters....547

typeof(this), typeof(super), and typeof(return)....549

Template specializations....550

Meta programming....550

Compile-time polymorphism....552

Code bloat....553

Template constraints....554

Tuple parameter of single element....555

Named constraints....555

Using templates in multi-dimensional operator overloading....557

Multi-dimensional operator overloading example....559

Summary....562

More Functions....563

Return type attributes....563

auto functions....563

ref functions....563

auto ref functions....565

inout functions....565

Behavioral attributes....566

pure functions....566

nothrow functions....570

@nogc functions....571

Code safety attributes....571

@safe functions....572

@trusted functions....572

@system functions....572

Compile time function execution (CTFE)....572

The __ctfe variable....574

Summary....574

Mixins....576

Template mixins....576

Template mixins must use local imports....577

Identifying the type that is mixing in....578

String mixins....578

Mixin name spaces....579

String mixins in operator overloading....580

Mixed in destructors....581

Importing text files....581

Example....582

Ranges....584

History....584

Ranges are an integral part of D....585

Traditional implementations of algorithms....585

Phobos ranges....586

Iterating by shortening the range....587

InputRange....588

InputRange example....588

The std.array module to use slices as ranges....590

Automatic decoding of strings as ranges of dchar....591

Ranges without actual elements....592

Infinite ranges....593

Functions that return ranges....594

std.range and std.algorithm modules....595

Laziness....597

ForwardRange....597

BidirectionalRange....599

RandomAccessRange....600

Infinite RandomAccessRange....600

Finite RandomAccessRange....602

OutputRange....606

Using slices as OutputRange....607

Range templates....609

Summary....609

More Ranges....610

Range kind templates....610

ElementType and ElementEncodingType....613

More range templates....613

Run-time polymorphism with inputRangeObject() and outputRangeObject()....614

Summary....615

static foreach....616

Parallelism....619

taskPool.parallel()....621

Work unit size....622

Task....622

Exceptions....624

Member functions of Task....625

taskPool.asyncBuf()....626

taskPool.map()....628

taskPool.amap()....630

taskPool.reduce()....631

Multiple functions and tuple results....634

TaskPool....634

Summary....635

Message Passing Concurrency....636

Concepts....636

Starting threads....637

Thread identifiers....638

Message Passing....639

Example....640

Expecting different types of messages....643

Receiving any type of message....644

Waiting for messages up to a certain time....645

Exceptions during the execution of the worker....645

Detecting thread termination....648

OwnerTerminated exception....648

LinkTerminated exception....649

Receiving exceptions as messages....649

Mailbox management....650

Priority messages....651

Thread names....651

Summary....653

Data Sharing Concurrency....654

Sharing is not automatic....654

shared to share mutable data between threads....655

A race condition example....656

synchronized to avoid race conditions....657

shared static this() for single initialization and shared static ~this() for single finalization....661

Atomic operations....662

atomicOp....662

cas....663

Summary....664

Fibers....665

Call stack....665

Recursion....666

Usage....667

Fibers in range implementations....668

std.concurrency.Generator for presenting fibers as ranges....672

Fibers in asynchronous input and output....674

Exceptions and fibers....678

Cooperative multitasking....679

Summary....680

Memory Management....681

Memory....681

The garbage collector....681

Starting and delaying garbage collection cycles....682

Allocating memory....683

Memory block attributes....685

Example of extending a memory area....687

Alignment....688

The .alignof property....688

The .offsetof property....690

The align attribute....692

Constructing variables at specific memory locations....693

Constructing a struct object at a specific location....693

Constructing a class object at a specific location....694

Destroying objects explicitly....697

Constructing objects at run time by name....698

Summary....699

User Defined Attributes (UDA)....700

Example....702

The benefit of user defined attributes....704

Summary....705

Operator Precedence....706

Chaining....706

Associativity....707

Unordered operator groups....707

The precedence of =>....707

Comma operator....708

Exercise Solutions....709

The Hello World Program....709

writeln and write....709

Fundamental Types....709

Assignment and Order of Evaluation....709

Variables....710

Standard Input and Output Streams....710

Reading from the Standard Input....710

Logical Expressions....710

The if Statement....711

The while Loop....712

Integers and Arithmetic Operations....713

Floating Point Types....714

Arrays....715

Slices and Other Array Features....717

Strings....718

Redirecting the Standard Input and Output Streams....718

Files....718

auto and typeof....719

The for Loop....719

The Ternary Operator ?:....720

Literals....720

Formatted Output....721

Formatted Input....721

The do-while Loop....722

Associative Arrays....722

The foreach Loop....723

switch and case....723

enum....725

Functions....726

Function Parameters....726

Program Environment....727

assert and enforce....727

Unit Testing....729

Contract Programming....731

Structs....732

Variable Number of Parameters....734

Function Overloading....736

Member Functions....737

Operator Overloading....739

Inheritance....743

Object....746

Pointers....747

Bit Operations....750

foreach with Structs and Classes....750

Index....754

A....755

B....755

C....756

D....757

E....757

F....758

G....758

H....759

I....759

J....760

K....760

L....760

M....760

N....761

O....761

P....762

Q....763

R....763

S....763

T....764

U....765

V....766

W....766

X....766

Y....766

The main aim of this book is to teach D to readers who are new to computer programming. Although having experience in other programming languages is certainly helpful, this book starts from the basics.

D is a multi-paradigm system programming language that combines a wide range of powerful programming concepts from the lowest to the highest levels. It has C-like syntax and static typing. It pragmatically combines efficiency, control, and modeling power, with safety and programmer productivity in mind.

Each chapter is based on the contents of the previous ones, introducing as few new concepts as possible. It is recommended that the book is read in linear fashion, without skipping chapters if possible.

Although this book was written with beginners in mind, it covers almost all features of D. More experienced programmers can use the book as a D language reference by starting from the index section.

Blurbs from the back cover:

• "D is pristine, clean, immensely powerful, and arguably the actual state-of-the-art programming language. Ali's book is a gem. Clear, concise, and complete." - Olivier Henley
• "I have been using Ali's online D book to teach D at the university level. It is up-to-date, complete, and most importantly, extremely readable. Having a print version is even better! This is now the 'go-to' book for learning D programming." - Chuck Allison, Professor and Chair, Computer Science Department, Utah Valley University
• "Ali's explanations are succinct and on target. I like that he provides rationale for why D was designed in a particular way and how I can use it most effectively. This is the best computer language book I've read." - Robbin Carlson, Luthier and Enterprise Architect
• "I taught a CS2 Data Structures class in D with more success and student appreciation than when using either C++ or Java as it's an ideal language to express the relevant concepts at all scales, from detailed to big picture, without needless complexity. Ali Çehreli's tutorial played a central role supporting students especially during the first half of the course -- without it the course simply would not have worked, so "many thanks Ali" -- and an important part of that is its linearity -- it can be read with only backward dependencies. This meant that with hard work even students of little experience and only moderate current abilities could get up to speed, and we saw just that. It is hard to overstate this factor. I unreservedly recommend this book to all." - Dr. Carl Sturtivant, University of Minnesota Department of Computer Science & Engineering
• "This book is one of the best guides through the language that I've seen." - Andrew Wray, D Enthusiast
• "I encourage anyone considering D to read this book. Not exactly 'D for Dummies' but it's easy to follow even if you don't have much experience with compiled languages." - bachmeier, Reddit user
• "Having worked through the book, I have to say this is one of the easiest to follow and distraction free read there is and the fact that it made learning a new language a total breeze really impressed me." - Imran Khan, Student