1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
|
proc `$`*(x: int): string {.magic: "IntToStr", noSideEffect.}
## The stringify operator for an integer argument. Returns `x`
## converted to a decimal string. ``$`` is Nim's general way of
## spelling `toString`:idx:.
proc `$`*(x: int64): string {.magic: "Int64ToStr", noSideEffect.}
## The stringify operator for an integer argument. Returns `x`
## converted to a decimal string.
proc `$`*(x: float): string {.magic: "FloatToStr", noSideEffect.}
## The stringify operator for a float argument. Returns `x`
## converted to a decimal string.
proc `$`*(x: bool): string {.magic: "BoolToStr", noSideEffect.}
## The stringify operator for a boolean argument. Returns `x`
## converted to the string "false" or "true".
proc `$`*(x: char): string {.magic: "CharToStr", noSideEffect.}
## The stringify operator for a character argument. Returns `x`
## converted to a string.
##
## .. code-block:: Nim
## assert $'c' == "c"
proc `$`*(x: cstring): string {.magic: "CStrToStr", noSideEffect.}
## The stringify operator for a CString argument. Returns `x`
## converted to a string.
proc `$`*(x: string): string {.magic: "StrToStr", noSideEffect.}
## The stringify operator for a string argument. Returns `x`
## as it is. This operator is useful for generic code, so
## that ``$expr`` also works if ``expr`` is already a string.
proc `$`*[Enum: enum](x: Enum): string {.magic: "EnumToStr", noSideEffect.}
## The stringify operator for an enumeration argument. This works for
## any enumeration type thanks to compiler magic.
##
## If a ``$`` operator for a concrete enumeration is provided, this is
## used instead. (In other words: *Overwriting* is possible.)
proc `$`*(t: typedesc): string {.magic: "TypeTrait".}
## Returns the name of the given type.
##
## For more procedures dealing with ``typedesc``, see
## `typetraits module <typetraits.html>`_.
##
## .. code-block:: Nim
## doAssert $(type(42)) == "int"
## doAssert $(type("Foo")) == "string"
## static: doAssert $(type(@['A', 'B'])) == "seq[char]"
proc isNamedTuple(T: typedesc): bool =
# Taken from typetraits.
when T isnot tuple: result = false
else:
var t: T
for name, _ in t.fieldPairs:
when name == "Field0":
return compiles(t.Field0)
else:
return true
return false
proc `$`*[T: tuple|object](x: T): string =
## Generic ``$`` operator for tuples that is lifted from the components
## of `x`. Example:
##
## .. code-block:: Nim
## $(23, 45) == "(23, 45)"
## $(a: 23, b: 45) == "(a: 23, b: 45)"
## $() == "()"
result = "("
var firstElement = true
const isNamed = T is object or isNamedTuple(T)
when not isNamed:
var count = 0
for name, value in fieldPairs(x):
if not firstElement: result.add(", ")
when isNamed:
result.add(name)
result.add(": ")
else:
count.inc
when compiles($value):
when value isnot string and value isnot seq and compiles(value.isNil):
if value.isNil: result.add "nil"
else: result.addQuoted(value)
else:
result.addQuoted(value)
firstElement = false
else:
result.add("...")
firstElement = false
when not isNamed:
if count == 1:
result.add(",") # $(1,) should print as the semantically legal (1,)
result.add(")")
proc collectionToString[T](x: T, prefix, separator, suffix: string): string =
result = prefix
var firstElement = true
for value in items(x):
if firstElement:
firstElement = false
else:
result.add(separator)
when value isnot string and value isnot seq and compiles(value.isNil):
# this branch should not be necessary
if value.isNil:
result.add "nil"
else:
result.addQuoted(value)
else:
result.addQuoted(value)
result.add(suffix)
proc `$`*[T](x: set[T]): string =
## Generic ``$`` operator for sets that is lifted from the components
## of `x`. Example:
##
## .. code-block:: Nim
## ${23, 45} == "{23, 45}"
collectionToString(x, "{", ", ", "}")
proc `$`*[T](x: seq[T]): string =
## Generic ``$`` operator for seqs that is lifted from the components
## of `x`. Example:
##
## .. code-block:: Nim
## $(@[23, 45]) == "@[23, 45]"
collectionToString(x, "@[", ", ", "]")
proc `$`*[T, U](x: HSlice[T, U]): string =
## Generic ``$`` operator for slices that is lifted from the components
## of `x`. Example:
##
## .. code-block:: Nim
## $(1 .. 5) == "1 .. 5"
result = $x.a
result.add(" .. ")
result.add($x.b)
when not defined(nimNoArrayToString):
proc `$`*[T, IDX](x: array[IDX, T]): string =
## Generic ``$`` operator for arrays that is lifted from the components.
collectionToString(x, "[", ", ", "]")
proc `$`*[T](x: openArray[T]): string =
## Generic ``$`` operator for openarrays that is lifted from the components
## of `x`. Example:
##
## .. code-block:: Nim
## $(@[23, 45].toOpenArray(0, 1)) == "[23, 45]"
collectionToString(x, "[", ", ", "]")
|