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 | with Ada.Unchecked_Deallocation;
package body Iterators.Text_IO is
use Ada.Text_IO;
type File_Access is access File_Type;
type String_Access is access String;
procedure Free is new Ada.Unchecked_Deallocation (File_Type, File_Access);
procedure Free is new Ada.Unchecked_Deallocation (String, String_Access);
type Iterator is new Std.Strings.Iterator with record
File : File_Access;
Line : String_Access;
-- TODO: these pointers should be refcounted, in case the file is not
-- read in its entirety.
end record;
----------
-- Next --
----------
overriding
function Next (This : in out Iterator)
return Std.Strings.Iterators.Cursor'Class
is
begin
if This.File = null then
return Std.Strings.Iterators.New_Empty_Cursor;
elsif End_Of_File (This.File.all) then
Close (This.File.all);
Free (This.File);
Free (This.Line);
return Std.Strings.Iterators.New_Empty_Cursor;
else
Free (This.Line);
This.Line := new String'(Get_Line (This.File.all));
return Std.Strings.Iterators.New_Const_Cursor (This.Line.all);
end if;
end Next;
-----------
-- Lines --
-----------
function Lines (File_Name : String)
return Std.Strings.Iterator'Class
is
begin
return Iter : Iterator do
begin
Iter.File := new File_Type;
Open (Iter.File.all, In_File, File_Name);
exception
when others =>
if Iter.File /= null then
Free (Iter.File);
end if;
end;
end return;
end Lines;
-------------------------
-- Ada iterator things --
-------------------------
--------------
-- Finalize --
--------------
overriding procedure Finalize (This : in out Ada_Iterator) is
begin
if Is_Open (This.File) then
Close (This.File);
end if;
end Finalize;
-----------------
-- Has_Element --
-----------------
function Has_Element (Cursor : Ada_Cursor) return Boolean
is (not Cursor.EOF);
-----------
-- Lines --
-----------
function Get_Lines (File_Name : String) return Ada_Iterator is
begin
return This : Ada_Iterator (File_Name'Length) do
This.Name := File_Name;
Open (This.File, In_File, File_Name);
end return;
end Get_Lines;
-----------
-- First --
-----------
overriding function First (This : Ada_Iterator) return Ada_Cursor is
begin
if End_Of_File (This.File) then
return (EOF => True, Line => Null_Unbounded_String);
else
declare
Line : constant String := Get_Line (This.File);
begin
return (EOF => False, Line => To_Unbounded_String (Line));
end;
end if;
end First;
overriding function Next
(This : Ada_Iterator;
Position : Ada_Cursor) return Ada_Cursor
is (if Position.EOF
then raise Use_Error with "EOF already reached"
else This.First);
-------------
-- Element --
-------------
function Element (This : aliased Ada_Iterator'Class;
Pos : Ada_Cursor) return String
is (To_String (Pos.Line));
-------------
-- Iterate --
-------------
function Iterate (This : aliased Ada_Iterator)
return Ada_Iterator_Interfaces.Forward_Iterator'Class
is
begin
This'Unrestricted_Access.Finalize;
return Get_Lines (This.Name);
end Iterate;
end Iterators.Text_IO;
|