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/* Copyright (C) 2018 Curtis McEnroe <june@causal.agency>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <err.h>
#include <stdlib.h>
#include <sysexits.h>
#include <wchar.h>
#include "edi.h"
static struct Table alloc(size_t cap) {
struct Slice *slices = malloc(sizeof(*slices) * cap);
if (!slices) err(EX_OSERR, "malloc");
return (struct Table) { 0, slices };
}
struct Table tableInsert(struct Table prev, size_t at, struct Slice ins) {
if (!prev.len) {
struct Table next = alloc(1);
next.slices[next.len++] = ins;
return next;
}
struct Table next = alloc(prev.len + 2);
struct Span span = { 0, 0 };
for (size_t i = 0; i < prev.len; ++i) {
span = spanNext(span, prev.slices[i].len);
if (span.at == at) {
next.slices[next.len++] = ins;
next.slices[next.len++] = prev.slices[i];
} else if (span.at < at && span.to > at) {
next.slices[next.len++] = (struct Slice) {
prev.slices[i].ptr,
at - span.at,
};
next.slices[next.len++] = ins;
next.slices[next.len++] = (struct Slice) {
&prev.slices[i].ptr[at - span.at],
prev.slices[i].len - (at - span.at),
};
} else {
next.slices[next.len++] = prev.slices[i];
}
}
if (span.to == at) {
next.slices[next.len++] = ins;
}
return next;
}
struct Table tableDelete(struct Table prev, struct Span del) {
if (!prev.len) return TableEmpty;
struct Table next = alloc(prev.len + 1);
struct Span span = { 0, 0 };
for (size_t i = 0; i < prev.len; ++i) {
span = spanNext(span, prev.slices[i].len);
if (span.at >= del.at && span.to <= del.to) {
(void)prev.slices[i];
} else if (span.at < del.at && span.to > del.to) {
next.slices[next.len++] = (struct Slice) {
prev.slices[i].ptr,
del.at - span.at,
};
next.slices[next.len++] = (struct Slice) {
&prev.slices[i].ptr[del.to - span.at],
prev.slices[i].len - (del.to - span.at),
};
} else if (span.at < del.at && span.to > del.at) {
next.slices[next.len++] = (struct Slice) {
prev.slices[i].ptr,
del.at - span.at,
};
} else if (span.at < del.to && span.to > del.to) {
next.slices[next.len++] = (struct Slice) {
&prev.slices[i].ptr[del.to - span.at],
prev.slices[i].len - (del.to - span.at),
};
} else {
next.slices[next.len++] = prev.slices[i];
}
}
return next;
}
#ifdef TEST
#include <assert.h>
static struct Span span(size_t at, size_t to) {
return (struct Span) { at, to };
}
static struct Slice slice(const wchar_t *str) {
return (struct Slice) { str, wcslen(str) };
}
static int eq(struct Table table, const wchar_t *str) {
for (size_t i = 0; i < table.len; ++i) {
if (wcsncmp(str, table.slices[i].ptr, table.slices[i].len)) {
return 0;
}
str = &str[table.slices[i].len];
}
return 1;
}
int main() {
struct Table abc = tableInsert(TableEmpty, 0, slice(L"ABC"));
assert(eq(abc, L"ABC"));
assert(eq(tableInsert(abc, 0, slice(L"D")), L"DABC"));
assert(eq(tableInsert(abc, 3, slice(L"D")), L"ABCD"));
assert(eq(tableInsert(abc, 1, slice(L"D")), L"ADBC"));
assert(eq(tableDelete(abc, span(0, 1)), L"BC"));
assert(eq(tableDelete(abc, span(2, 3)), L"AB"));
assert(eq(tableDelete(abc, span(1, 2)), L"AC"));
assert(eq(tableDelete(abc, span(0, 3)), L""));
}
#endif
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