Move all non-core string code to string_utils.{hh,cc}

src/color.cc

@@ -2,6 +2,7 @@
 
 #include "exception.hh"
 #include "ranges.hh"
+#include "string_utils.hh"
 
 #include <cstdio>
 

src/commands.cc

@@ -28,6 +28,7 @@
 #include "user_interface.hh"
 #include "window.hh"
 
+#include <cstring>
 #include <functional>
 #include <utility>
 

src/face_registry.cc

@@ -2,6 +2,7 @@
 
 #include "exception.hh"
 #include "ranges.hh"
+#include "string_utils.hh"
 
 namespace Kakoune
 {

src/file.cc

@@ -10,6 +10,7 @@
 #include "unicode.hh"
 
 #include <cerrno>
+#include <cstring>
 #include <sys/mman.h>
 #include <fcntl.h>
 #include <unistd.h>

src/highlighter_group.cc

@@ -1,6 +1,7 @@
 #include "highlighter_group.hh"
 
 #include "ranges.hh"
+#include "string_utils.hh"
 
 namespace Kakoune
 {

src/json_ui.cc

@@ -6,6 +6,7 @@
 #include "file.hh"
 #include "keys.hh"
 #include "ranges.hh"
+#include "string_utils.hh"
 #include "unit_tests.hh"
 #include "value.hh"
 

src/keys.cc

@@ -6,6 +6,7 @@
 #include "unit_tests.hh"
 #include "utf8_iterator.hh"
 #include "utils.hh"
+#include "string_utils.hh"
 
 namespace Kakoune
 {

src/ncurses_ui.cc

@@ -4,6 +4,7 @@
 #include "event_manager.hh"
 #include "keys.hh"
 #include "ranges.hh"
+#include "string_utils.hh"
 
 #include <algorithm>
 

src/option_manager.hh

@@ -8,6 +8,7 @@
 #include "ranges.hh"
 #include "utils.hh"
 #include "vector.hh"
+#include "string_utils.hh"
 
 #include <memory>
 #include <type_traits>

src/parameters_parser.hh

@@ -7,6 +7,7 @@
 #include "array_view.hh"
 #include "optional.hh"
 #include "string.hh"
+#include "string_utils.hh"
 
 namespace Kakoune
 {

src/ranked_match.cc

@@ -3,6 +3,7 @@
 #include "flags.hh"
 #include "unit_tests.hh"
 #include "utf8_iterator.hh"
+#include "optional.hh"
 
 #include <algorithm>
 

src/regex.hh

@@ -2,6 +2,7 @@
 #define regex_hh_INCLUDED
 
 #include "string.hh"
+#include "string_utils.hh"
 #include "exception.hh"
 #include "utf8_iterator.hh"
 

src/register_manager.cc

@@ -2,6 +2,7 @@
 
 #include "assert.hh"
 #include "hash_map.hh"
+#include "string_utils.hh"
 
 namespace Kakoune
 {

src/remote.hh

@@ -5,6 +5,7 @@
 #include "exception.hh"
 #include "utils.hh"
 #include "vector.hh"
+#include "optional.hh"
 
 #include <memory>
 

src/shared_string.cc

@@ -1,6 +1,8 @@
 #include "shared_string.hh"
 #include "buffer_utils.hh"
 
+#include <cstring>
+
 namespace Kakoune
 {
 

src/string.cc

@@ -1,11 +1,7 @@
 #include "string.hh"
 
-#include "exception.hh"
-#include "ranges.hh"
-#include "unit_tests.hh"
-#include "utf8_iterator.hh"
-
 #include <cstdio>
+#include <cstring>
 
 namespace Kakoune
 {
@@ -164,445 +160,4 @@ void String::Data::set_short(const char* data, size_t size)
 
 const String String::ms_empty;
 
-Vector<String> split(StringView str, char separator, char escape)
-{
-    Vector<String> res;
-    auto it = str.begin();
-    auto start = it;
-    while (it != str.end())
-    {
-        res.emplace_back();
-        String& element = res.back();
-        while (it != str.end())
-        {
-            auto c = *it;
-            if (c == escape and it + 1 != str.end() and *(it+1) == separator)
-            {
-                element += StringView{start, it+1};
-                element.back() = separator;
-                it += 2;
-                start = it;
-            }
-            else if (c == separator)
-            {
-                element += StringView{start, it};
-                ++it;
-                start = it;
-                break;
-            }
-            else
-                ++it;
-        }
-    }
-    if (start != str.end())
-        res.back() += StringView{start, str.end()};
-    return res;
-}
-
-Vector<StringView> split(StringView str, char separator)
-{
-    Vector<StringView> res;
-    if (str.empty())
-        return res;
-
-    auto beg = str.begin();
-    for (auto it = beg; it != str.end(); ++it)
-    {
-        if (*it == separator)
-        {
-            res.emplace_back(beg, it);
-            beg = it + 1;
-        }
-    }
-    res.emplace_back(beg, str.end());
-    return res;
-}
-
-StringView trim_whitespaces(StringView str)
-{
-    auto beg = str.begin(), end = str.end();
-    while (beg != end and is_blank(*beg))
-        ++beg;
-    while (beg != end and is_blank(*(end-1)))
-        --end;
-    return {beg, end};
-}
-
-
-String escape(StringView str, StringView characters, char escape)
-{
-    String res;
-    res.reserve(str.length());
-    auto cbeg = characters.begin(), cend = characters.end();
-    for (auto it = str.begin(), end = str.end(); it != end; )
-    {
-        auto next = std::find_first_of(it, end, cbeg, cend);
-        if (next != end)
-        {
-            res += StringView{it, next+1};
-            res.back() = escape;
-            res += *next;
-            it = next+1;
-        }
-        else
-        {
-            res += StringView{it, next};
-            break;
-        }
-    }
-    return res;
-}
-
-String unescape(StringView str, StringView characters, char escape)
-{
-    String res;
-    res.reserve(str.length());
-    for (auto it = str.begin(), end = str.end(); it != end; )
-    {
-        auto next = std::find(it, end, escape);
-        if (next != end and next+1 != end and contains(characters, *(next+1)))
-        {
-            res += StringView{it, next+1};
-            res.back() = *(next+1);
-            it = next + 2;
-        }
-        else
-        {
-            res += StringView{it, next == end ? next : next + 1};
-            it = next == end ? next : next + 1;
-        }
-    }
-    return res;
-}
-
-String indent(StringView str, StringView indent)
-{
-    String res;
-    res.reserve(str.length());
-    bool was_eol = true;
-    for (ByteCount i = 0; i < str.length(); ++i)
-    {
-        if (was_eol)
-            res += indent;
-        res += str[i];
-        was_eol = is_eol(str[i]);
-    }
-    return res;
-}
-
-String replace(StringView str, StringView substr, StringView replacement)
-{
-    String res;
-    for (auto it = str.begin(); it != str.end(); )
-    {
-        auto match = std::search(it, str.end(), substr.begin(), substr.end());
-        res += StringView{it, match};
-        if (match == str.end())
-            break;
-
-        res += replacement;
-        it = match + (int)substr.length();
-    }
-    return res;
-}
-
-Optional<int> str_to_int_ifp(StringView str)
-{
-    bool negative = not str.empty() and str[0] == '-';
-    if (negative)
-        str = str.substr(1_byte);
-
-    unsigned int res = 0;
-    for (auto c : str)
-    {
-        if (c < '0' or c > '9')
-            return {};
-        res = res * 10 + c - '0';
-    }
-    return negative ? -res : res;
-}
-
-int str_to_int(StringView str)
-{
-    if (auto val = str_to_int_ifp(str))
-        return *val;
-    throw runtime_error{str + " is not a number"};
-}
-
-InplaceString<15> to_string(int val)
-{
-    InplaceString<15> res;
-    res.m_length = sprintf(res.m_data, "%i", val);
-    return res;
-}
-
-InplaceString<23> to_string(long int val)
-{
-    InplaceString<23> res;
-    res.m_length = sprintf(res.m_data, "%li", val);
-    return res;
-}
-
-InplaceString<23> to_string(long long int val)
-{
-    InplaceString<23> res;
-    res.m_length = sprintf(res.m_data, "%lli", val);
-    return res;
-}
-
-InplaceString<23> to_string(size_t val)
-{
-    InplaceString<23> res;
-    res.m_length = sprintf(res.m_data, "%zu", val);
-    return res;
-}
-
-InplaceString<23> to_string(Hex val)
-{
-    InplaceString<23> res;
-    res.m_length = sprintf(res.m_data, "%zx", val.val);
-    return res;
-}
-
-InplaceString<23> to_string(float val)
-{
-    InplaceString<23> res;
-    res.m_length = sprintf(res.m_data, "%f", val);
-    return res;
-}
-
-InplaceString<7> to_string(Codepoint c)
-{
-    InplaceString<7> res;
-    char* ptr = res.m_data;
-    utf8::dump(ptr, c);
-    res.m_length = (int)(ptr - res.m_data);
-    return res;
-}
-
-bool subsequence_match(StringView str, StringView subseq)
-{
-    auto it = str.begin();
-    for (auto& c : subseq)
-    {
-        if (it == str.end())
-            return false;
-        while (*it != c)
-        {
-            if (++it == str.end())
-                return false;
-        }
-        ++it;
-    }
-    return true;
-}
-
-String expand_tabs(StringView line, ColumnCount tabstop, ColumnCount col)
-{
-    String res;
-    res.reserve(line.length());
-    for (auto it = line.begin(), end = line.end(); it != end; )
-    {
-        if (*it == '\t')
-        {
-            ColumnCount end_col = (col / tabstop + 1) * tabstop;
-            res += String{' ', end_col - col};
-            col = end_col;
-            ++it;
-        }
-        else
-        {
-            auto char_beg = it;
-            auto cp = utf8::read_codepoint(it, end);
-            res += {char_beg, it};
-            col += codepoint_width(cp);
-        }
-    }
-    return res;
-}
-
-Vector<StringView> wrap_lines(StringView text, ColumnCount max_width)
-{
-    if (max_width <= 0)
-        throw runtime_error("Invalid max width");
-
-    using Utf8It = utf8::iterator<const char*>;
-    Utf8It it{text.begin(), text};
-    Utf8It end{text.end(), text};
-    Utf8It line_begin = it;
-    Utf8It last_word_end = it;
-
-    Vector<StringView> lines;
-    while (it != end)
-    {
-        const CharCategories cat = categorize(*it, {});
-        if (cat == CharCategories::EndOfLine)
-        {
-            lines.emplace_back(line_begin.base(), it.base());
-            line_begin = it = it+1;
-            continue;
-        }
-
-        Utf8It word_end = it+1;
-        while (word_end != end and categorize(*word_end, {}) == cat)
-            ++word_end;
-
-        while (word_end > line_begin and
-               utf8::column_distance(line_begin.base(), word_end.base()) >= max_width)
-        {
-            auto line_end = last_word_end <= line_begin ?
-                Utf8It{utf8::advance(line_begin.base(), text.end(), max_width), text}
-              : last_word_end;
-
-            lines.emplace_back(line_begin.base(), line_end.base());
-
-            while (line_end != end and is_horizontal_blank(*line_end))
-                ++line_end;
-
-            if (line_end != end and *line_end == '\n')
-                ++line_end;
-
-            it = line_begin = line_end;
-        }
-        if (cat == CharCategories::Word or cat == CharCategories::Punctuation)
-            last_word_end = word_end;
-
-        if (word_end > line_begin)
-            it = word_end;
-    }
-    if (line_begin != end)
-        lines.emplace_back(line_begin.base(), text.end());
-    return lines;
-}
-
-template<typename AppendFunc>
-void format_impl(StringView fmt, ArrayView<const StringView> params, AppendFunc append)
-{
-    int implicitIndex = 0;
-    for (auto it = fmt.begin(), end = fmt.end(); it != end;)
-    {
-        auto opening = std::find(it, end, '{');
-        if (opening == end)
-        {
-            append(StringView{it, opening});
-            break;
-        }
-        else if (opening != it and *(opening-1) == '\\')
-        {
-            append(StringView{it, opening-1});
-            append('{');
-            it = opening + 1;
-        }
-        else
-        {
-            append(StringView{it, opening});
-            auto closing = std::find(opening, end, '}');
-            if (closing == end)
-                throw runtime_error("Format string error, unclosed '{'");
-
-            const int index = (closing == opening + 1) ?
-                implicitIndex : str_to_int({opening+1, closing});
-
-            if (index >= params.size())
-                throw runtime_error("Format string parameter index too big");
-
-            append(params[index]);
-            implicitIndex = index+1;
-            it = closing+1;
-        }
-    }
-}
-
-StringView format_to(ArrayView<char> buffer, StringView fmt, ArrayView<const StringView> params)
-{
-    char* ptr = buffer.begin();
-    const char* end = buffer.end();
-    format_impl(fmt, params, [&](StringView s) mutable {
-        for (auto c : s)
-        {
-            if (ptr == end)
-                throw runtime_error("buffer is too small");
-            *ptr++ = c;
-        }
-    });
-    if (ptr == end)
-        throw runtime_error("buffer is too small");
-    *ptr = 0;
-
-    return { buffer.begin(), ptr };
-}
-
-String format(StringView fmt, ArrayView<const StringView> params)
-{
-    ByteCount size = fmt.length();
-    for (auto& s : params) size += s.length();
-    String res;
-    res.reserve(size);
-
-    format_impl(fmt, params, [&](StringView s) { res += s; });
-    return res;
-}
-
-UnitTest test_string{[]()
-{
-    kak_assert(String("youpi ") + "matin" == "youpi matin");
-
-    Vector<String> splited = split("youpi:matin::tchou\\:kanaky:hihi\\:", ':', '\\');
-    kak_assert(splited[0] == "youpi");
-    kak_assert(splited[1] == "matin");
-    kak_assert(splited[2] == "");
-    kak_assert(splited[3] == "tchou:kanaky");
-    kak_assert(splited[4] == "hihi:");
-
-    Vector<StringView> splitedview = split("youpi:matin::tchou\\:kanaky:hihi\\:", ':');
-    kak_assert(splitedview[0] == "youpi");
-    kak_assert(splitedview[1] == "matin");
-    kak_assert(splitedview[2] == "");
-    kak_assert(splitedview[3] == "tchou\\");
-    kak_assert(splitedview[4] == "kanaky");
-    kak_assert(splitedview[5] == "hihi\\");
-    kak_assert(splitedview[6] == "");
-
-    Vector<StringView> wrapped = wrap_lines("wrap this paragraph\n respecting whitespaces and much_too_long_words", 16);
-    kak_assert(wrapped.size() == 6);
-    kak_assert(wrapped[0] == "wrap this");
-    kak_assert(wrapped[1] == "paragraph");
-    kak_assert(wrapped[2] == " respecting");
-    kak_assert(wrapped[3] == "whitespaces and");
-    kak_assert(wrapped[4] == "much_too_long_wo");
-    kak_assert(wrapped[5] == "rds");
-
-    Vector<StringView> wrapped2 = wrap_lines("error: unknown type", 7);
-    kak_assert(wrapped2.size() == 3);
-    kak_assert(wrapped2[0] == "error:");
-    kak_assert(wrapped2[1] == "unknown");
-    kak_assert(wrapped2[2] == "type");
-
-    kak_assert(escape("youpi:matin:tchou:", ':', '\\') == "youpi\\:matin\\:tchou\\:");
-    kak_assert(unescape("youpi\\:matin\\:tchou\\:", ':', '\\') == "youpi:matin:tchou:");
-
-    kak_assert(prefix_match("tchou kanaky", "tchou"));
-    kak_assert(prefix_match("tchou kanaky", "tchou kanaky"));
-    kak_assert(prefix_match("tchou kanaky", "t"));
-    kak_assert(not prefix_match("tchou kanaky", "c"));
-
-    kak_assert(subsequence_match("tchou kanaky", "tknky"));
-    kak_assert(subsequence_match("tchou kanaky", "knk"));
-    kak_assert(subsequence_match("tchou kanaky", "tchou kanaky"));
-    kak_assert(not subsequence_match("tchou kanaky", "tchou  kanaky"));
-
-    kak_assert(format("Youhou {1} {} {0} \\{}", 10, "hehe", 5) == "Youhou hehe 5 10 {}");
-
-    char buffer[20];
-    kak_assert(format_to(buffer, "Hey {}", 15) == "Hey 15");
-
-    kak_assert(str_to_int("5") == 5);
-    kak_assert(str_to_int(to_string(INT_MAX)) == INT_MAX);
-    kak_assert(str_to_int(to_string(INT_MIN)) == INT_MIN);
-    kak_assert(str_to_int("00") == 0);
-    kak_assert(str_to_int("-0") == 0);
-
-    kak_assert(replace("tchou/tcha/tchi", "/", "!!") == "tchou!!tcha!!tchi");
-}};
-
 }

src/string.hh

@@ -1,14 +1,11 @@
 #ifndef string_hh_INCLUDED
 #define string_hh_INCLUDED
 
-#include "array_view.hh"
+#include "memory.hh"
 #include "hash.hh"
-#include "optional.hh"
 #include "units.hh"
 #include "utf8.hh"
-#include "vector.hh"
 
-#include <cstring>
 #include <climits>
 
 namespace Kakoune
@@ -331,108 +328,6 @@ inline StringView operator"" _sv(const char* str, size_t)
     return StringView{str};
 }
 
-Vector<String> split(StringView str, char separator, char escape);
-Vector<StringView> split(StringView str, char separator);
-
-StringView trim_whitespaces(StringView str);
-
-String escape(StringView str, StringView characters, char escape);
-String unescape(StringView str, StringView characters, char escape);
-
-String indent(StringView str, StringView indent = "    ");
-
-String replace(StringView str, StringView substr, StringView replacement);
-
-template<typename Container>
-String join(const Container& container, char joiner, bool esc_joiner = true)
-{
-    const char to_escape[2] = { joiner, '\\' };
-    String res;
-    for (const auto& str : container)
-    {
-        if (not res.empty())
-            res += joiner;
-        res += esc_joiner ? escape(str, {to_escape, 2}, '\\') : str;
-    }
-    return res;
-}
-
-inline bool prefix_match(StringView str, StringView prefix)
-{
-    return str.substr(0_byte, prefix.length()) == prefix;
-}
-
-bool subsequence_match(StringView str, StringView subseq);
-
-String expand_tabs(StringView line, ColumnCount tabstop, ColumnCount col = 0);
-
-Vector<StringView> wrap_lines(StringView text, ColumnCount max_width);
-
-int str_to_int(StringView str); // throws on error
-Optional<int> str_to_int_ifp(StringView str);
-
-inline String option_to_string(StringView opt) { return opt.str(); }
-inline void option_from_string(StringView str, String& opt) { opt = str.str(); }
-inline bool option_add(String& opt, StringView val) { opt += val; return not val.empty(); }
-
-template<size_t N>
-struct InplaceString
-{
-    static_assert(N < 256, "InplaceString cannot handle sizes >= 256");
-
-    constexpr operator StringView() const { return {m_data, ByteCount{m_length}}; }
-    operator String() const { return {m_data, ByteCount{m_length}}; }
-
-    unsigned char m_length;
-    char m_data[N];
-};
-
-struct Hex { size_t val; };
-constexpr Hex hex(size_t val) { return {val}; }
-
-InplaceString<15> to_string(int val);
-InplaceString<23> to_string(long int val);
-InplaceString<23> to_string(size_t val);
-InplaceString<23> to_string(long long int val);
-InplaceString<23> to_string(Hex val);
-InplaceString<23> to_string(float val);
-InplaceString<7>  to_string(Codepoint c);
-
-template<typename RealType, typename ValueType>
-decltype(auto) to_string(const StronglyTypedNumber<RealType, ValueType>& val)
-{
-    return to_string((ValueType)val);
-}
-
-namespace detail
-{
-
-template<typename T> constexpr bool is_string = std::is_convertible<T, StringView>::value;
-
-template<typename T, class = std::enable_if_t<not is_string<T>>>
-decltype(auto) format_param(const T& val) { return to_string(val); }
-
-template<typename T, class = std::enable_if_t<is_string<T>>>
-StringView format_param(const T& val) { return val; }
-
-}
-
-String format(StringView fmt, ArrayView<const StringView> params);
-
-template<typename... Types>
-String format(StringView fmt, Types&&... params)
-{
-    return format(fmt, ArrayView<const StringView>{detail::format_param(std::forward<Types>(params))...});
-}
-
-StringView format_to(ArrayView<char> buffer, StringView fmt, ArrayView<const StringView> params);
-
-template<typename... Types>
-StringView format_to(ArrayView<char> buffer, StringView fmt, Types&&... params)
-{
-    return format_to(buffer, fmt, ArrayView<const StringView>{detail::format_param(std::forward<Types>(params))...});
-}
-
 }
 
 #endif // string_hh_INCLUDED

src/string_utils.cc

@@ -0,0 +1,451 @@
+#include "string_utils.hh"
+
+#include "exception.hh"
+#include "utf8_iterator.hh"
+#include "unit_tests.hh"
+
+namespace Kakoune
+{
+
+Vector<String> split(StringView str, char separator, char escape)
+{
+    Vector<String> res;
+    auto it = str.begin();
+    auto start = it;
+    while (it != str.end())
+    {
+        res.emplace_back();
+        String& element = res.back();
+        while (it != str.end())
+        {
+            auto c = *it;
+            if (c == escape and it + 1 != str.end() and *(it+1) == separator)
+            {
+                element += StringView{start, it+1};
+                element.back() = separator;
+                it += 2;
+                start = it;
+            }
+            else if (c == separator)
+            {
+                element += StringView{start, it};
+                ++it;
+                start = it;
+                break;
+            }
+            else
+                ++it;
+        }
+    }
+    if (start != str.end())
+        res.back() += StringView{start, str.end()};
+    return res;
+}
+
+Vector<StringView> split(StringView str, char separator)
+{
+    Vector<StringView> res;
+    if (str.empty())
+        return res;
+
+    auto beg = str.begin();
+    for (auto it = beg; it != str.end(); ++it)
+    {
+        if (*it == separator)
+        {
+            res.emplace_back(beg, it);
+            beg = it + 1;
+        }
+    }
+    res.emplace_back(beg, str.end());
+    return res;
+}
+
+StringView trim_whitespaces(StringView str)
+{
+    auto beg = str.begin(), end = str.end();
+    while (beg != end and is_blank(*beg))
+        ++beg;
+    while (beg != end and is_blank(*(end-1)))
+        --end;
+    return {beg, end};
+}
+
+
+String escape(StringView str, StringView characters, char escape)
+{
+    String res;
+    res.reserve(str.length());
+    auto cbeg = characters.begin(), cend = characters.end();
+    for (auto it = str.begin(), end = str.end(); it != end; )
+    {
+        auto next = std::find_first_of(it, end, cbeg, cend);
+        if (next != end)
+        {
+            res += StringView{it, next+1};
+            res.back() = escape;
+            res += *next;
+            it = next+1;
+        }
+        else
+        {
+            res += StringView{it, next};
+            break;
+        }
+    }
+    return res;
+}
+
+String unescape(StringView str, StringView characters, char escape)
+{
+    String res;
+    res.reserve(str.length());
+    for (auto it = str.begin(), end = str.end(); it != end; )
+    {
+        auto next = std::find(it, end, escape);
+        if (next != end and next+1 != end and contains(characters, *(next+1)))
+        {
+            res += StringView{it, next+1};
+            res.back() = *(next+1);
+            it = next + 2;
+        }
+        else
+        {
+            res += StringView{it, next == end ? next : next + 1};
+            it = next == end ? next : next + 1;
+        }
+    }
+    return res;
+}
+
+String indent(StringView str, StringView indent)
+{
+    String res;
+    res.reserve(str.length());
+    bool was_eol = true;
+    for (ByteCount i = 0; i < str.length(); ++i)
+    {
+        if (was_eol)
+            res += indent;
+        res += str[i];
+        was_eol = is_eol(str[i]);
+    }
+    return res;
+}
+
+String replace(StringView str, StringView substr, StringView replacement)
+{
+    String res;
+    for (auto it = str.begin(); it != str.end(); )
+    {
+        auto match = std::search(it, str.end(), substr.begin(), substr.end());
+        res += StringView{it, match};
+        if (match == str.end())
+            break;
+
+        res += replacement;
+        it = match + (int)substr.length();
+    }
+    return res;
+}
+
+Optional<int> str_to_int_ifp(StringView str)
+{
+    bool negative = not str.empty() and str[0] == '-';
+    if (negative)
+        str = str.substr(1_byte);
+
+    unsigned int res = 0;
+    for (auto c : str)
+    {
+        if (c < '0' or c > '9')
+            return {};
+        res = res * 10 + c - '0';
+    }
+    return negative ? -res : res;
+}
+
+int str_to_int(StringView str)
+{
+    if (auto val = str_to_int_ifp(str))
+        return *val;
+    throw runtime_error{str + " is not a number"};
+}
+
+InplaceString<15> to_string(int val)
+{
+    InplaceString<15> res;
+    res.m_length = sprintf(res.m_data, "%i", val);
+    return res;
+}
+
+InplaceString<23> to_string(long int val)
+{
+    InplaceString<23> res;
+    res.m_length = sprintf(res.m_data, "%li", val);
+    return res;
+}
+
+InplaceString<23> to_string(long long int val)
+{
+    InplaceString<23> res;
+    res.m_length = sprintf(res.m_data, "%lli", val);
+    return res;
+}
+
+InplaceString<23> to_string(size_t val)
+{
+    InplaceString<23> res;
+    res.m_length = sprintf(res.m_data, "%zu", val);
+    return res;
+}
+
+InplaceString<23> to_string(Hex val)
+{
+    InplaceString<23> res;
+    res.m_length = sprintf(res.m_data, "%zx", val.val);
+    return res;
+}
+
+InplaceString<23> to_string(float val)
+{
+    InplaceString<23> res;
+    res.m_length = sprintf(res.m_data, "%f", val);
+    return res;
+}
+
+InplaceString<7> to_string(Codepoint c)
+{
+    InplaceString<7> res;
+    char* ptr = res.m_data;
+    utf8::dump(ptr, c);
+    res.m_length = (int)(ptr - res.m_data);
+    return res;
+}
+
+bool subsequence_match(StringView str, StringView subseq)
+{
+    auto it = str.begin();
+    for (auto& c : subseq)
+    {
+        if (it == str.end())
+            return false;
+        while (*it != c)
+        {
+            if (++it == str.end())
+                return false;
+        }
+        ++it;
+    }
+    return true;
+}
+
+String expand_tabs(StringView line, ColumnCount tabstop, ColumnCount col)
+{
+    String res;
+    res.reserve(line.length());
+    for (auto it = line.begin(), end = line.end(); it != end; )
+    {
+        if (*it == '\t')
+        {
+            ColumnCount end_col = (col / tabstop + 1) * tabstop;
+            res += String{' ', end_col - col};
+            col = end_col;
+            ++it;
+        }
+        else
+        {
+            auto char_beg = it;
+            auto cp = utf8::read_codepoint(it, end);
+            res += {char_beg, it};
+            col += codepoint_width(cp);
+        }
+    }
+    return res;
+}
+
+Vector<StringView> wrap_lines(StringView text, ColumnCount max_width)
+{
+    if (max_width <= 0)
+        throw runtime_error("Invalid max width");
+
+    using Utf8It = utf8::iterator<const char*>;
+    Utf8It it{text.begin(), text};
+    Utf8It end{text.end(), text};
+    Utf8It line_begin = it;
+    Utf8It last_word_end = it;
+
+    Vector<StringView> lines;
+    while (it != end)
+    {
+        const CharCategories cat = categorize(*it, {});
+        if (cat == CharCategories::EndOfLine)
+        {
+            lines.emplace_back(line_begin.base(), it.base());
+            line_begin = it = it+1;
+            continue;
+        }
+
+        Utf8It word_end = it+1;
+        while (word_end != end and categorize(*word_end, {}) == cat)
+            ++word_end;
+
+        while (word_end > line_begin and
+               utf8::column_distance(line_begin.base(), word_end.base()) >= max_width)
+        {
+            auto line_end = last_word_end <= line_begin ?
+                Utf8It{utf8::advance(line_begin.base(), text.end(), max_width), text}
+              : last_word_end;
+
+            lines.emplace_back(line_begin.base(), line_end.base());
+
+            while (line_end != end and is_horizontal_blank(*line_end))
+                ++line_end;
+
+            if (line_end != end and *line_end == '\n')
+                ++line_end;
+
+            it = line_begin = line_end;
+        }
+        if (cat == CharCategories::Word or cat == CharCategories::Punctuation)
+            last_word_end = word_end;
+
+        if (word_end > line_begin)
+            it = word_end;
+    }
+    if (line_begin != end)
+        lines.emplace_back(line_begin.base(), text.end());
+    return lines;
+}
+
+template<typename AppendFunc>
+void format_impl(StringView fmt, ArrayView<const StringView> params, AppendFunc append)
+{
+    int implicitIndex = 0;
+    for (auto it = fmt.begin(), end = fmt.end(); it != end;)
+    {
+        auto opening = std::find(it, end, '{');
+        if (opening == end)
+        {
+            append(StringView{it, opening});
+            break;
+        }
+        else if (opening != it and *(opening-1) == '\\')
+        {
+            append(StringView{it, opening-1});
+            append('{');
+            it = opening + 1;
+        }
+        else
+        {
+            append(StringView{it, opening});
+            auto closing = std::find(opening, end, '}');
+            if (closing == end)
+                throw runtime_error("Format string error, unclosed '{'");
+
+            const int index = (closing == opening + 1) ?
+                implicitIndex : str_to_int({opening+1, closing});
+
+            if (index >= params.size())
+                throw runtime_error("Format string parameter index too big");
+
+            append(params[index]);
+            implicitIndex = index+1;
+            it = closing+1;
+        }
+    }
+}
+
+StringView format_to(ArrayView<char> buffer, StringView fmt, ArrayView<const StringView> params)
+{
+    char* ptr = buffer.begin();
+    const char* end = buffer.end();
+    format_impl(fmt, params, [&](StringView s) mutable {
+        for (auto c : s)
+        {
+            if (ptr == end)
+                throw runtime_error("buffer is too small");
+            *ptr++ = c;
+        }
+    });
+    if (ptr == end)
+        throw runtime_error("buffer is too small");
+    *ptr = 0;
+
+    return { buffer.begin(), ptr };
+}
+
+String format(StringView fmt, ArrayView<const StringView> params)
+{
+    ByteCount size = fmt.length();
+    for (auto& s : params) size += s.length();
+    String res;
+    res.reserve(size);
+
+    format_impl(fmt, params, [&](StringView s) { res += s; });
+    return res;
+}
+
+UnitTest test_string{[]()
+{
+    kak_assert(String("youpi ") + "matin" == "youpi matin");
+
+    Vector<String> splited = split("youpi:matin::tchou\\:kanaky:hihi\\:", ':', '\\');
+    kak_assert(splited[0] == "youpi");
+    kak_assert(splited[1] == "matin");
+    kak_assert(splited[2] == "");
+    kak_assert(splited[3] == "tchou:kanaky");
+    kak_assert(splited[4] == "hihi:");
+
+    Vector<StringView> splitedview = split("youpi:matin::tchou\\:kanaky:hihi\\:", ':');
+    kak_assert(splitedview[0] == "youpi");
+    kak_assert(splitedview[1] == "matin");
+    kak_assert(splitedview[2] == "");
+    kak_assert(splitedview[3] == "tchou\\");
+    kak_assert(splitedview[4] == "kanaky");
+    kak_assert(splitedview[5] == "hihi\\");
+    kak_assert(splitedview[6] == "");
+
+    Vector<StringView> wrapped = wrap_lines("wrap this paragraph\n respecting whitespaces and much_too_long_words", 16);
+    kak_assert(wrapped.size() == 6);
+    kak_assert(wrapped[0] == "wrap this");
+    kak_assert(wrapped[1] == "paragraph");
+    kak_assert(wrapped[2] == " respecting");
+    kak_assert(wrapped[3] == "whitespaces and");
+    kak_assert(wrapped[4] == "much_too_long_wo");
+    kak_assert(wrapped[5] == "rds");
+
+    Vector<StringView> wrapped2 = wrap_lines("error: unknown type", 7);
+    kak_assert(wrapped2.size() == 3);
+    kak_assert(wrapped2[0] == "error:");
+    kak_assert(wrapped2[1] == "unknown");
+    kak_assert(wrapped2[2] == "type");
+
+    kak_assert(escape("youpi:matin:tchou:", ':', '\\') == "youpi\\:matin\\:tchou\\:");
+    kak_assert(unescape("youpi\\:matin\\:tchou\\:", ':', '\\') == "youpi:matin:tchou:");
+
+    kak_assert(prefix_match("tchou kanaky", "tchou"));
+    kak_assert(prefix_match("tchou kanaky", "tchou kanaky"));
+    kak_assert(prefix_match("tchou kanaky", "t"));
+    kak_assert(not prefix_match("tchou kanaky", "c"));
+
+    kak_assert(subsequence_match("tchou kanaky", "tknky"));
+    kak_assert(subsequence_match("tchou kanaky", "knk"));
+    kak_assert(subsequence_match("tchou kanaky", "tchou kanaky"));
+    kak_assert(not subsequence_match("tchou kanaky", "tchou  kanaky"));
+
+    kak_assert(format("Youhou {1} {} {0} \\{}", 10, "hehe", 5) == "Youhou hehe 5 10 {}");
+
+    char buffer[20];
+    kak_assert(format_to(buffer, "Hey {}", 15) == "Hey 15");
+
+    kak_assert(str_to_int("5") == 5);
+    kak_assert(str_to_int(to_string(INT_MAX)) == INT_MAX);
+    kak_assert(str_to_int(to_string(INT_MIN)) == INT_MIN);
+    kak_assert(str_to_int("00") == 0);
+    kak_assert(str_to_int("-0") == 0);
+
+    kak_assert(replace("tchou/tcha/tchi", "/", "!!") == "tchou!!tcha!!tchi");
+}};
+
+}

src/string_utils.hh

@@ -0,0 +1,115 @@
+#ifndef string_utils_hh_INCLUDED
+#define string_utils_hh_INCLUDED
+
+#include "string.hh"
+#include "vector.hh"
+#include "optional.hh"
+
+namespace Kakoune
+{
+
+Vector<String> split(StringView str, char separator, char escape);
+Vector<StringView> split(StringView str, char separator);
+
+StringView trim_whitespaces(StringView str);
+
+String escape(StringView str, StringView characters, char escape);
+String unescape(StringView str, StringView characters, char escape);
+
+String indent(StringView str, StringView indent = "    ");
+
+String replace(StringView str, StringView substr, StringView replacement);
+
+template<typename Container>
+String join(const Container& container, char joiner, bool esc_joiner = true)
+{
+    const char to_escape[2] = { joiner, '\\' };
+    String res;
+    for (const auto& str : container)
+    {
+        if (not res.empty())
+            res += joiner;
+        res += esc_joiner ? escape(str, {to_escape, 2}, '\\') : str;
+    }
+    return res;
+}
+
+inline bool prefix_match(StringView str, StringView prefix)
+{
+    return str.substr(0_byte, prefix.length()) == prefix;
+}
+
+bool subsequence_match(StringView str, StringView subseq);
+
+String expand_tabs(StringView line, ColumnCount tabstop, ColumnCount col = 0);
+
+Vector<StringView> wrap_lines(StringView text, ColumnCount max_width);
+
+int str_to_int(StringView str); // throws on error
+Optional<int> str_to_int_ifp(StringView str);
+
+inline String option_to_string(StringView opt) { return opt.str(); }
+inline void option_from_string(StringView str, String& opt) { opt = str.str(); }
+inline bool option_add(String& opt, StringView val) { opt += val; return not val.empty(); }
+
+template<size_t N>
+struct InplaceString
+{
+    static_assert(N < 256, "InplaceString cannot handle sizes >= 256");
+
+    constexpr operator StringView() const { return {m_data, ByteCount{m_length}}; }
+    operator String() const { return {m_data, ByteCount{m_length}}; }
+
+    unsigned char m_length;
+    char m_data[N];
+};
+
+struct Hex { size_t val; };
+constexpr Hex hex(size_t val) { return {val}; }
+
+InplaceString<15> to_string(int val);
+InplaceString<23> to_string(long int val);
+InplaceString<23> to_string(size_t val);
+InplaceString<23> to_string(long long int val);
+InplaceString<23> to_string(Hex val);
+InplaceString<23> to_string(float val);
+InplaceString<7>  to_string(Codepoint c);
+
+template<typename RealType, typename ValueType>
+decltype(auto) to_string(const StronglyTypedNumber<RealType, ValueType>& val)
+{
+    return to_string((ValueType)val);
+}
+
+namespace detail
+{
+
+template<typename T> constexpr bool is_string = std::is_convertible<T, StringView>::value;
+
+template<typename T, class = std::enable_if_t<not is_string<T>>>
+decltype(auto) format_param(const T& val) { return to_string(val); }
+
+template<typename T, class = std::enable_if_t<is_string<T>>>
+StringView format_param(const T& val) { return val; }
+
+}
+
+String format(StringView fmt, ArrayView<const StringView> params);
+
+template<typename... Types>
+String format(StringView fmt, Types&&... params)
+{
+    return format(fmt, ArrayView<const StringView>{detail::format_param(std::forward<Types>(params))...});
+}
+
+StringView format_to(ArrayView<char> buffer, StringView fmt, ArrayView<const StringView> params);
+
+template<typename... Types>
+StringView format_to(ArrayView<char> buffer, StringView fmt, Types&&... params)
+{
+    return format_to(buffer, fmt, ArrayView<const StringView>{detail::format_param(std::forward<Types>(params))...});
+}
+
+}
+
+#endif // string_utils_hh_INCLUDED