Entering Lines in Viewer and Editor
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the
Line class can refer to specific entry in a vector
2
@Add(global elements)
class Line {
public:
@put(line elements)
private:
@put(line privates)
};
@End(global elements)
-
a line has private and public elements
3
@def(line elements)
int operator()(int cur, int end) const {
int res {};
@put(get line)
return res;
}
@end(line elements)
-
to calculate the absolute line number, the method must know the current line and the last line
4
@def(line privates)
int line_ { -1 };
bool relative_ { false };
@end(line privates)
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integer for the line
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and a flag, if the line is relative
5
@add(line elements)
operator bool() const {
return line_ >= 0 || relative_;
}
@end(line elements)
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a line is valid, if the number is non-negative
-
or the line is relative
6
@def(get line)
if (! *this) {
res = cur;
} else {
res = line_;
if (relative_) { res += cur; }
}
if (res < 0) { res = 0; }
if (res > end) { res = end; }
@end(get line)
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if the line is not valid, the current line is returned
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otherwise the line is assigned
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if the line is relative, the value is added to the current line
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the result is clamped to the valid interval
7
@add(line privates)
Line(int line, bool relative):
line_ { line }, relative_ { relative }
{}
@end(line privates)
-
constructor copies arguments
8
@add(line elements)
Line() = default;
@end(line elements)
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empty constructor is possible
9
@add(line elements)
static Line relative(int line) {
return Line { line, true };
}
@end(line elements)
10
@add(line elements)
static Line line(int line) {
return Line { line, false };
}
@end(line elements)
11
@add(line elements)
static Line begin() {
return line(0);
}
@end(line elements)
-
create reference to first line
12
@Add(includes)
#include <limits>
@End(includes)
-
needs
std::numeric_limits
13
@add(line elements)
static const int max { std::numeric_limits<int>::max() };
static Line end() {
return line(max);
}
@end(line elements)
-
end refers to a very big line number
14
@Add(global elements)
@Put(range prereqs)
@Put(range vars)
@End(global elements)
15
@Def(range vars)
Line line;
@End(range vars)
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variable holds current line specification
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if any
16
@Add(global elements)
int get_number(std::string &s) {
int res = 0;
while (! s.empty() && isdigit(s[0])) {
res = res * 10 + s[0] - '0';
s.erase(0, 1);
}
return res;
}
@End(global elements)
-
parse a decimal non-negative integer
17
@Add(global elements)
Line get_line(std::string &s) {
Line line {};
do {
@put(parse line)
} while (false);
trim(s);
return line;
}
@End(global elements)
-
parses the head of a string, if it contains a line specification
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the line parts are removed from the input string
18
@def(parse line)
if (s[0] == '.') {
s.erase(0, 1);
line = Line::relative(0);
break;
}
@end(parse line)
-
a
. is treated as the current line
19
@add(parse line)
if (s[0] == '+') {
s.erase(0, 1);
int n = get_number(s);
line = Line::relative(n);
break;
}
@end(parse line)
-
a
+ signals a positive relative offset from the current line
20
@add(parse line)
if (s[0] == '-') {
s.erase(0, 1);
int n = -get_number(s);
line = Line::relative(n);
break;
}
@end(parse line)
-
a
- signals a negative relative offset from the current line
21
@add(parse line)
if (s[0] == '$') {
line = Line::end();
s.erase(0, 1);
continue;
}
@end(parse line)
-
a
$ signals the last line
22
@add(parse line)
if (isdigit(s[0])) {
int n = get_number(s);
line = Line::line(n);
continue;
}
@end(parse line);
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a number without
+ or - signals an absolute line position
23
@Def(do range)
line = get_line(cmd);
@End(do range)
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initialize the line from the command
24
@Add(perform unit-tests)
@put(unit-tests)
@end(perform unit-tests)
-
own fragment for unit-tests
25
@def(unit-tests)
ASSERT(! Line {});
@end(unit-tests)
26
@add(unit-tests)
ASSERT(Line::begin());
ASSERT(Line::end());
@end(unit-tests)
27
@add(unit-tests)
ASSERT(Line::line(0));
@end(unit-tests)
28
@add(unit-tests)
ASSERT(Line::relative(0));
ASSERT(Line::relative(-2));
@end(unit-tests)
29
@add(unit-tests)
ASSERT(Line {}(5, 10) == 5);
@end(unit-tests)
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empty line returns current line
30
@add(unit-tests)
ASSERT(Line::begin()(5, 10) == 0);
ASSERT(Line::end()(5, 10) == 10);
@end(unit-tests)
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begin and end return the correct values
31
@add(unit-tests)
ASSERT(Line::line(0)(5, 10) == 0);
ASSERT(Line::line(6)(5, 10) == 6);
ASSERT(Line::line(20)(5, 10) == 10);
@end(unit-tests)
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absolute lines are returned
-
but may be clamped
32
@add(unit-tests)
ASSERT(
Line::relative(2)(5, 10) == 7
);
@end(unit-tests)
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simple positive relative line
33
@add(unit-tests)
ASSERT(
Line::relative(7)(5, 10) == 10
);
@end(unit-tests)
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too big movement is clamped
34
@add(unit-tests)
ASSERT(Line::relative(-2)(5, 10) == 3);
@end(unit-tests)
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simple negative relative line
35
@add(unit-tests)
ASSERT(Line::relative(-7)(5, 10) == 0);
@end(unit-tests)
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too big negative movement is clamped
36
@add(unit-tests) {
std::string f = "+3";
ASSERT(get_line(f)(5, 10) == 8);
} @end(unit-tests)
37
@add(unit-tests) {
std::string f = ".";
ASSERT(get_line(f)(5, 10) == 5);
} @end(unit-tests)
38
@add(unit-tests) {
std::string f = "$";
ASSERT(get_line(f)(5, 10) == 10);
} @end(unit-tests)
39
@Def(do block range)
if (line) {
next = line(
(curBlock - curInput->blocks.begin() ) + 1,
curInput->blocks.size()
) - 1;
if (next < 0) { next = 0; }
}
@End(do block range)
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parse range over blocks collection
40
@Def(do inputs range)
if (line) {
next = line((curInput - inputs.begin()) + 1, inputs.size()) - 1;
if (next < 0) { next = 0; }
}
@End(do inputs range)
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parse range over input files
41
@Def(do str range)
if (line) {
next = line(Line::max, c.size() + 1) - 1;
if (next < 0) { next = 0; }
}
@End(do str range)
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string ranges do not support relative movement