Programming in D: Tutorial and Reference

758 Pages·2015·2.639 MB·English

by  Ali Cehreli

Programming in D
Ali Çehreli

Programming in D
First Edition
Ali Çehreli
Edited by Luís Marques
Programming in D, First Edition
Revision:2015-12-111
The most recent electronic versions of this book are availableonline2.
Copyleft (ɔ) 2009-2015 Ali Çehreli
This work is licensed under the Creative Commons Attribution-
NonCommercial-ShareAlike 4.0 International License. To view a copy of this
license, visit http://creativecommons.org/licenses/by-nc-sa/4.0/.
Edited byLuís Marques3
Cover design byİzgi Yapıcı4
Cover illustration bySarah Reece5
Published byAli Çehreli6
Fonts:
Andada by Carolina Giovagnoli for Huerta Tipográfica
Open Sans by Steve Matteson
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ISBNs:
978-0-692-59943-3 hardcover by IngramSpark
978-0-692-52957-7 paperback by IngramSpark
978-1-515-07460-1 paperback by CreateSpace
978-1-519-95441-1 ePUB by Draft2Digital
1. https://bitbucket.org/acehreli/ddili
2. http://ddili.org/ders/d.en
3. http://www.luismarques.eu
4. http://izgiyapici.com
5. mailto:[email protected]
6. mailto:[email protected]
Contents
Forewordby Andrei Alexandrescu xvii
Preface xix
Acknowledgments.............................................................................................................xix
1.The Hello World Program 1
Compiler installation............................................................................................................1
Source file...................................................................................................................................1
Compiling the hello world program...............................................................................1
Compiler switches.................................................................................................................2
IDE................................................................................................................................................3
Contents of the hello world program............................................................................3
Exercises....................................................................................................................................4
2.writelnandwrite 5
Exercises....................................................................................................................................5
3.Compilation 6
Machine code..........................................................................................................................6
Programming language.......................................................................................................6
Interpreter................................................................................................................................6
Compiler....................................................................................................................................7
4.Fundamental Types 8
Properties of types.................................................................................................................9
size_t......................................................................................................................................10
Exercise....................................................................................................................................10
5.Assignment and Order of Evaluation 11
The assignment operation................................................................................................11
Order of evaluation..............................................................................................................11
Exercise.....................................................................................................................................11
6.Variables 12
Exercise....................................................................................................................................13
7.Standard Input and Output Streams 14
Exercise....................................................................................................................................14
8.Reading from the Standard Input 15
Skipping the whitespace characters............................................................................16
Additional information.....................................................................................................17
Exercise....................................................................................................................................17
9.Logical Expressions 18
Logical Expressions.............................................................................................................18
Grouping expressions........................................................................................................21
Readingboolinput.............................................................................................................21
Exercises..................................................................................................................................22
10.ifStatement 24
Theifblock and its scope...............................................................................................24
Theelseblock and its scope..........................................................................................24
Always use the scope curly brackets............................................................................25
The "if, else if, else" chain..................................................................................................25
Exercises..................................................................................................................................27
11.whileLoop 28
Thecontinuestatement..................................................................................................28
Thebreakstatement..........................................................................................................29
v
Infinite loop............................................................................................................................29
Exercises..................................................................................................................................30
12.Integers and Arithmetic Operations 31
Exercises.................................................................................................................................40
13.Floating Point Types 42
Floating point type properties........................................................................................42
.nan...........................................................................................................................................43
Specifying floating point values....................................................................................43
Overflow is not ignored.....................................................................................................44
Precision..................................................................................................................................45
There is no truncation in division................................................................................45
Which type to use................................................................................................................46
Cannot represent all values.............................................................................................46
Comparing floating point values...................................................................................47
Exercises..................................................................................................................................48
14.Arrays 49
Definition................................................................................................................................49
Containers and elements..................................................................................................50
Accessing the elements......................................................................................................50
Index..........................................................................................................................................51
Fixed-length arrays vs. dynamic arrays......................................................................51
Using.lengthto get or set the number of elements............................................51
An array example................................................................................................................52
Initializing the elements...................................................................................................52
Basic array operations.......................................................................................................53
Exercises..................................................................................................................................55
15.Characters 56
History......................................................................................................................................56
Unicode encodings..............................................................................................................57
The character types of D...................................................................................................58
Character literals.................................................................................................................58
Control characters...............................................................................................................59
Single quote and backslash.............................................................................................59
The std.uni module............................................................................................................60
Limited support for ı and i...............................................................................................61
Problems with reading characters...............................................................................61
D's Unicode support............................................................................................................62
Summary.................................................................................................................................63
16.Slices and Other Array Features 64
Slices..........................................................................................................................................64
Using$, instead ofarray.length................................................................................65
Using.dupto copy..............................................................................................................65
Assignment.............................................................................................................................66
Making a slice longer may terminate sharing.........................................................66
Operations on all elements..............................................................................................69
Multi-dimensional arrays................................................................................................71
Summary.................................................................................................................................72
Exercise....................................................................................................................................73
17.Strings 74
readlnandstrip, instead ofreadf...........................................................................74
formattedReadfor parsing strings.............................................................................75
vi
Double quotes, not single quotes...................................................................................76
string,wstring, anddstringare immutable......................................................76
Potentially confusing length of strings.......................................................................77
String literals.........................................................................................................................78
String concatenation..........................................................................................................78
Comparing strings...............................................................................................................79
Lowercase and uppercase are different......................................................................79
Exercises.................................................................................................................................80
18.Redirecting the Standard Input and Output Streams 81
Redirecting the standard output to a file with operator>..................................81
Redirecting the standard input from a file with operator<..............................81
Redirecting both standard streams..............................................................................82
Piping programs with operator|..................................................................................82
Exercise....................................................................................................................................82
19.Files 83
Fundamental concepts......................................................................................................83
std.stdio.Filestruct.....................................................................................................85
Exercise....................................................................................................................................86
20.autoandtypeof 87
auto...........................................................................................................................................87
typeof......................................................................................................................................87
Exercise....................................................................................................................................88
21.Name Scope 89
Defining names closest to their first use....................................................................89
22.forLoop 91
The sections of thewhileloop.......................................................................................91
The sections of theforloop............................................................................................91
The sections may be empty.............................................................................................92
The name scope of the loop variable...........................................................................93
Exercises..................................................................................................................................93
23.Ternary Operator?: 94
The type of the ternary expression..............................................................................95
Exercise....................................................................................................................................96
24.Literals 97
Integer literals.......................................................................................................................97
Floating point literals.........................................................................................................99
Character literals.................................................................................................................99
String literals......................................................................................................................100
Literals are calculated at compile time.....................................................................101
Exercises................................................................................................................................101
25.Formatted Output 103
format_character................................................................................................................104
width........................................................................................................................................106
precision..................................................................................................................................106
flags..........................................................................................................................................107
Positional parameters......................................................................................................108
Formatted element output.............................................................................................109
format....................................................................................................................................110
Exercises................................................................................................................................110
vii
26.Formatted Input 111
Format specifier characters...........................................................................................112
Exercise..................................................................................................................................112
27.do-whileLoop 113
Exercise..................................................................................................................................114
28.Associative Arrays 115
Definition...............................................................................................................................115
Adding key-value pairs....................................................................................................116
Initialization........................................................................................................................116
Removing key-value pairs..............................................................................................116
Determining the presence of a key.............................................................................117
Properties..............................................................................................................................117
Example.................................................................................................................................118
Exercises................................................................................................................................118
29.foreachLoop 119
Theforeachsyntax..........................................................................................................119
continueandbreak........................................................................................................120
foreachwith arrays.........................................................................................................120
foreachwith strings andstd.range.stride.....................................................120
foreachwith associative arrays.................................................................................121
foreachwith number ranges......................................................................................121
foreachwith structs, classes, and ranges...............................................................121
The counter is automatic only for arrays................................................................122
The copy of the element, not the element itself....................................................122
The integrity of the container must be preserved...............................................123
foreach_reverseto iterate in the reverse direction.........................................123
Exercise..................................................................................................................................123
30.switchandcase 125
Thegotostatement...........................................................................................................125
The expression must be an integer, string, orbooltype..................................127
Value ranges.........................................................................................................................128
Distinct values.....................................................................................................................128
Thefinal switchstatement......................................................................................128
When to use..........................................................................................................................129
Exercises................................................................................................................................129
31.enum 130
Effects of magic constants on code quality.............................................................130
Theenumsyntax.................................................................................................................130
Actual values and base types.........................................................................................131
enumvalues that are not of anenumtype..................................................................131
Properties..............................................................................................................................132
Converting from the base type.....................................................................................133
Exercise..................................................................................................................................133
32.Functions 134
Parameters............................................................................................................................135
Calling a function..............................................................................................................137
Doing work...........................................................................................................................137
The return value.................................................................................................................137
Thereturnstatement.....................................................................................................138
voidfunctions....................................................................................................................138
viii
The name of the function...............................................................................................139
Code quality through functions...................................................................................139
Exercises................................................................................................................................143
33.Immutability 145
Immutable variables........................................................................................................145
Immutable parameters....................................................................................................148
Immutability of the slice versus the elements.......................................................152
How to use............................................................................................................................153
Summary...............................................................................................................................154
34.Value Types and Reference Types 155
Value types............................................................................................................................155
Reference variables...........................................................................................................156
Reference types...................................................................................................................157
Fixed-length arrays are value types, slices are reference types......................161
Experiment...........................................................................................................................161
Summary...............................................................................................................................163
35.Function Parameters 164
Parameters are always copied......................................................................................164
Referenced variables are not copied..........................................................................165
Parameter qualifiers.........................................................................................................167
Summary...............................................................................................................................175
Exercise..................................................................................................................................176
36.Lvalues and Rvalues 177
Limitations of rvalues......................................................................................................177
Usingauto refparameters to accept both lvalues and rvalues..................178
Terminology.........................................................................................................................179
37.Lazy Operators 180
38.Program Environment 181
The return value ofmain()...........................................................................................181
Standard error streamstderr.....................................................................................183
Parameters ofmain()......................................................................................................183
Command line options and thestd.getoptmodule........................................184
Environment variables....................................................................................................186
Starting other programs.................................................................................................186
Summary...............................................................................................................................187
Exercises................................................................................................................................187
39.Exceptions 188
Thethrowstatement to throw exceptions..............................................................188
Thetry-catchstatement to catch exceptions.....................................................193
Exception properties........................................................................................................198
Kinds of errors....................................................................................................................199
Summary...............................................................................................................................201
40.scope 202
41.assertandenforce 204
Syntax....................................................................................................................................204
static assert.................................................................................................................205
asserteven ifabsolutely true.......................................................................................206
No value nor side effect..................................................................................................206
Disablingassertchecks...............................................................................................207
enforcefor throwing exceptions..............................................................................207
ix
How to use...........................................................................................................................207
Exercises...............................................................................................................................208
42.Unit Testing 210
Causes of bugs.....................................................................................................................210
Discovering the bugs........................................................................................................210
Unit testing for catching bugs......................................................................................211
Activating the unit tests..................................................................................................212
unittestblocks.................................................................................................................212
Testing for exceptions......................................................................................................213
Test driven development.................................................................................................214
Exercise..................................................................................................................................216
43.Contract Programming 217
inblocks for preconditions...........................................................................................217
outblocks for postconditions......................................................................................218
Disabling contract programming..............................................................................220
inblocks versusenforcechecks...............................................................................220
Exercise..................................................................................................................................221
44.Lifetimes and Fundamental Operations 223
Lifetime of a variable.......................................................................................................223
Lifetime of a parameter..................................................................................................223
Fundamental operations...............................................................................................224
45.ThenullValue and theisOperator 228
Thenullvalue...................................................................................................................228
Theisoperator.................................................................................................................229
The!isoperator...............................................................................................................229
Assigning thenullvalue...............................................................................................229
Summary..............................................................................................................................230
46.Type Conversions 232
Automatic type conversions.........................................................................................232
Explicit type conversions................................................................................................237
Summary..............................................................................................................................240
47.Structs 241
Definition..............................................................................................................................241
Accessing the members..................................................................................................243
Construction.......................................................................................................................244
Copying and assignment...............................................................................................246
Struct literals......................................................................................................................248
staticmembers...............................................................................................................248
Exercises................................................................................................................................251
48.Variable Number of Parameters 253
Default arguments............................................................................................................253
Variadic functions.............................................................................................................255
Exercise.................................................................................................................................258
49.Function Overloading 260
Overload resolution..........................................................................................................261
Function overloading for user-defined types.........................................................261
Limitations..........................................................................................................................262
Exercise.................................................................................................................................263
50.Member Functions 264
Defining member functions.........................................................................................264
x