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Diffstat (limited to 'v_windows/v/vlib/builtin/string.v')
| -rw-r--r-- | v_windows/v/vlib/builtin/string.v | 1604 |
1 files changed, 1604 insertions, 0 deletions
diff --git a/v_windows/v/vlib/builtin/string.v b/v_windows/v/vlib/builtin/string.v new file mode 100644 index 0000000..1a4815d --- /dev/null +++ b/v_windows/v/vlib/builtin/string.v @@ -0,0 +1,1604 @@ +// Copyright (c) 2019-2021 Alexander Medvednikov. All rights reserved. +// Use of this source code is governed by an MIT license +// that can be found in the LICENSE file. +module builtin + +import strconv + +/* +NB: A V string should be/is immutable from the point of view of + V user programs after it is first created. A V string is + also slightly larger than the equivalent C string because + the V string also has an integer length attached. + + This tradeoff is made, since V strings are created just *once*, + but potentially used *many times* over their lifetime. + + The V string implementation uses a struct, that has a .str field, + which points to a C style 0 terminated memory block. Although not + strictly necessary from the V point of view, that additional 0 + is *very useful for C interoperability*. + + The V string implementation also has an integer .len field, + containing the length of the .str field, excluding the + terminating 0 (just like the C's strlen(s) would do). + + The 0 ending of .str, and the .len field, mean that in practice: + a) a V string s can be used very easily, wherever a + C string is needed, just by passing s.str, + without a need for further conversion/copying. + + b) where strlen(s) is needed, you can just pass s.len, + without having to constantly recompute the length of s + *over and over again* like some C programs do. This is because + V strings are immutable and so their length does not change. + + Ordinary V code *does not need* to be concerned with the + additional 0 in the .str field. The 0 *must* be put there by the + low level string creating functions inside this module. + + Failing to do this will lead to programs that work most of the + time, when used with pure V functions, but fail in strange ways, + when used with modules using C functions (for example os and so on). +*/ +pub struct string { +pub: + str &byte = 0 // points to a C style 0 terminated string of bytes. + len int // the length of the .str field, excluding the ending 0 byte. It is always equal to strlen(.str). + // NB string.is_lit is an enumeration of the following: + // .is_lit == 0 => a fresh string, should be freed by autofree + // .is_lit == 1 => a literal string from .rodata, should NOT be freed + // .is_lit == -98761234 => already freed string, protects against double frees. + // ---------> ^^^^^^^^^ calling free on these is a bug. + // Any other value means that the string has been corrupted. +mut: + is_lit int +} + +pub fn (s string) runes() []rune { + mut runes := []rune{cap: s.len} + for i := 0; i < s.len; i++ { + char_len := utf8_char_len(unsafe { s.str[i] }) + if char_len > 1 { + end := if s.len - 1 >= i + char_len { i + char_len } else { s.len } + mut r := unsafe { s[i..end] } + runes << r.utf32_code() + i += char_len - 1 + } else { + runes << unsafe { s.str[i] } + } + } + return runes +} + +// tos converts a C string to a V string. +// String data is reused, not copied. +[unsafe] +pub fn tos(s &byte, len int) string { + // This should never happen. + if s == 0 { + panic('tos(): nil string') + } + return string{ + str: unsafe { s } + len: len + } +} + +// tos_clone returns a copy of `s`. +[unsafe] +pub fn tos_clone(s &byte) string { + return unsafe { tos2(s) }.clone() +} + +// tos2 does the same as `tos`, but also calculates the length. Called by `string(bytes)` casts. +// Used only internally. +[unsafe] +pub fn tos2(s &byte) string { + if s == 0 { + panic('tos2: nil string') + } + return string{ + str: unsafe { s } + len: unsafe { vstrlen(s) } + } +} + +// tos3 does the same as `tos2`, but for char*, to avoid warnings. +[unsafe] +pub fn tos3(s &char) string { + if s == 0 { + panic('tos3: nil string') + } + return string{ + str: &byte(s) + len: unsafe { vstrlen_char(s) } + } +} + +// tos4 does the same as `tos2`, but returns an empty string on nil ptr. +[unsafe] +pub fn tos4(s &byte) string { + if s == 0 { + return '' + } + return unsafe { tos2(s) } +} + +// tos5 does the same as `tos4`, but for char*, to avoid warnings. +[unsafe] +pub fn tos5(s &char) string { + if s == 0 { + return '' + } + return unsafe { tos3(s) } +} + +// vstring converts a C style string to a V string. NB: the string data is reused, NOT copied. +// strings returned from this function will be normal V strings beside that (i.e. they would be +// freed by V's -autofree mechanism, when they are no longer used). +[unsafe] +pub fn (bp &byte) vstring() string { + return string{ + str: unsafe { bp } + len: unsafe { vstrlen(bp) } + } +} + +// vstring_with_len converts a C style string to a V string. +// NB: the string data is reused, NOT copied. +[unsafe] +pub fn (bp &byte) vstring_with_len(len int) string { + return string{ + str: unsafe { bp } + len: len + is_lit: 0 + } +} + +// vstring converts C char* to V string. +// NB: the string data is reused, NOT copied. +[unsafe] +pub fn (cp &char) vstring() string { + return string{ + str: &byte(cp) + len: unsafe { vstrlen_char(cp) } + is_lit: 0 + } +} + +// vstring_with_len converts C char* to V string. +// NB: the string data is reused, NOT copied. +[unsafe] +pub fn (cp &char) vstring_with_len(len int) string { + return string{ + str: &byte(cp) + len: len + is_lit: 0 + } +} + +// vstring_literal converts a C style string to a V string. +// NB: the string data is reused, NOT copied. +// NB2: unlike vstring, vstring_literal will mark the string +// as a literal, so it will not be freed by autofree. +// This is suitable for readonly strings, C string literals etc, +// that can be read by the V program, but that should not be +// managed by it, for example `os.args` is implemented using it. +[unsafe] +pub fn (bp &byte) vstring_literal() string { + return string{ + str: unsafe { bp } + len: unsafe { vstrlen(bp) } + is_lit: 1 + } +} + +// vstring_with_len converts a C style string to a V string. +// NB: the string data is reused, NOT copied. +[unsafe] +pub fn (bp &byte) vstring_literal_with_len(len int) string { + return string{ + str: unsafe { bp } + len: len + is_lit: 1 + } +} + +// vstring_literal converts C char* to V string. +// See also vstring_literal defined on byteptr for more details. +// NB: the string data is reused, NOT copied. +[unsafe] +pub fn (cp &char) vstring_literal() string { + return string{ + str: &byte(cp) + len: unsafe { vstrlen_char(cp) } + is_lit: 1 + } +} + +// vstring_literal_with_len converts C char* to V string. +// See also vstring_literal_with_len defined on byteptr. +// NB: the string data is reused, NOT copied. +[unsafe] +pub fn (cp &char) vstring_literal_with_len(len int) string { + return string{ + str: &byte(cp) + len: len + is_lit: 1 + } +} + +// clone_static returns an independent copy of a given array. +// It should be used only in -autofree generated code. +fn (a string) clone_static() string { + return a.clone() +} + +// clone returns a copy of the V string `a`. +pub fn (a string) clone() string { + if a.len == 0 { + return '' + } + mut b := string{ + str: unsafe { malloc_noscan(a.len + 1) } + len: a.len + } + unsafe { + vmemcpy(b.str, a.str, a.len) + b.str[a.len] = 0 + } + return b +} + +// cstring_to_vstring creates a copy of cstr and turns it into a v string. +[unsafe] +pub fn cstring_to_vstring(cstr &char) string { + return unsafe { tos_clone(&byte(cstr)) } +} + +// replace_once replaces the first occurence of `rep` with the string passed in `with`. +pub fn (s string) replace_once(rep string, with string) string { + idx := s.index_(rep) + if idx == -1 { + return s.clone() + } + return s.substr(0, idx) + with + s.substr(idx + rep.len, s.len) +} + +// replace replaces all occurences of `rep` with the string passed in `with`. +[direct_array_access] +pub fn (s string) replace(rep string, with string) string { + if s.len == 0 || rep.len == 0 || rep.len > s.len { + return s.clone() + } + if !s.contains(rep) { + return s.clone() + } + // TODO PERF Allocating ints is expensive. Should be a stack array + // Get locations of all reps within this string + mut idxs := []int{cap: s.len / rep.len} + defer { + unsafe { idxs.free() } + } + mut idx := 0 + for { + idx = s.index_after(rep, idx) + if idx == -1 { + break + } + idxs << idx + idx += rep.len + } + // Dont change the string if there's nothing to replace + if idxs.len == 0 { + return s.clone() + } + // Now we know the number of replacements we need to do and we can calc the len of the new string + new_len := s.len + idxs.len * (with.len - rep.len) + mut b := unsafe { malloc_noscan(new_len + 1) } // add space for the null byte at the end + // Fill the new string + mut b_i := 0 + mut s_idx := 0 + for _, rep_pos in idxs { + for i in s_idx .. rep_pos { // copy everything up to piece being replaced + unsafe { + b[b_i] = s[i] + } + b_i++ + } + s_idx = rep_pos + rep.len // move string index past replacement + for i in 0 .. with.len { // copy replacement piece + unsafe { + b[b_i] = with[i] + } + b_i++ + } + } + if s_idx < s.len { // if any original after last replacement, copy it + for i in s_idx .. s.len { + unsafe { + b[b_i] = s[i] + } + b_i++ + } + } + unsafe { + b[new_len] = 0 + return tos(b, new_len) + } +} + +struct RepIndex { + idx int + val_idx int +} + +// replace_each replaces all occurences of the string pairs given in `vals`. +// Example: assert 'ABCD'.replace_each(['B','C/','C','D','D','C']) == 'AC/DC' +[direct_array_access] +pub fn (s string) replace_each(vals []string) string { + if s.len == 0 || vals.len == 0 { + return s.clone() + } + if vals.len % 2 != 0 { + eprintln('string.replace_each(): odd number of strings') + return s.clone() + } + // `rep` - string to replace + // `with` - string to replace with + // Remember positions of all rep strings, and calculate the length + // of the new string to do just one allocation. + mut new_len := s.len + mut idxs := []RepIndex{} + mut idx := 0 + s_ := s.clone() + for rep_i := 0; rep_i < vals.len; rep_i += 2 { + // vals: ['rep1, 'with1', 'rep2', 'with2'] + rep := vals[rep_i] + with := vals[rep_i + 1] + + for { + idx = s_.index_after(rep, idx) + if idx == -1 { + break + } + // The string already found is set to `/del`, to avoid duplicate searches. + for i in 0 .. rep.len { + unsafe { + s_.str[idx + i] = 127 + } + } + // We need to remember both the position in the string, + // and which rep/with pair it refers to. + + idxs << RepIndex{ + idx: idx + val_idx: rep_i + } + + idx += rep.len + new_len += with.len - rep.len + } + } + + // Dont change the string if there's nothing to replace + if idxs.len == 0 { + return s.clone() + } + idxs.sort(a.idx < b.idx) + mut b := unsafe { malloc_noscan(new_len + 1) } // add space for 0 terminator + // Fill the new string + mut idx_pos := 0 + mut cur_idx := idxs[idx_pos] + mut b_i := 0 + for i := 0; i < s.len; i++ { + if i == cur_idx.idx { + // Reached the location of rep, replace it with "with" + rep := vals[cur_idx.val_idx] + with := vals[cur_idx.val_idx + 1] + for j in 0 .. with.len { + unsafe { + b[b_i] = with[j] + } + b_i++ + } + // Skip the length of rep, since we just replaced it with "with" + i += rep.len - 1 + // Go to the next index + idx_pos++ + if idx_pos < idxs.len { + cur_idx = idxs[idx_pos] + } + } else { + // Rep doesnt start here, just copy + unsafe { + b[b_i] = s.str[i] + } + b_i++ + } + } + unsafe { + b[new_len] = 0 + return tos(b, new_len) + } +} + +// bool returns `true` if the string equals the word "true" it will return `false` otherwise. +pub fn (s string) bool() bool { + return s == 'true' || s == 't' // TODO t for pg, remove +} + +// int returns the value of the string as an integer `'1'.int() == 1`. +pub fn (s string) int() int { + return int(strconv.common_parse_int(s, 0, 32, false, false) or { 0 }) +} + +// i64 returns the value of the string as i64 `'1'.i64() == i64(1)`. +pub fn (s string) i64() i64 { + return strconv.common_parse_int(s, 0, 64, false, false) or { 0 } +} + +// i8 returns the value of the string as i8 `'1'.i8() == i8(1)`. +pub fn (s string) i8() i8 { + return i8(strconv.common_parse_int(s, 0, 8, false, false) or { 0 }) +} + +// i16 returns the value of the string as i16 `'1'.i16() == i16(1)`. +pub fn (s string) i16() i16 { + return i16(strconv.common_parse_int(s, 0, 16, false, false) or { 0 }) +} + +// f32 returns the value of the string as f32 `'1.0'.f32() == f32(1)`. +pub fn (s string) f32() f32 { + return f32(strconv.atof64(s)) +} + +// f64 returns the value of the string as f64 `'1.0'.f64() == f64(1)`. +pub fn (s string) f64() f64 { + return strconv.atof64(s) +} + +// u16 returns the value of the string as u16 `'1'.u16() == u16(1)`. +pub fn (s string) u16() u16 { + return u16(strconv.common_parse_uint(s, 0, 16, false, false) or { 0 }) +} + +// u32 returns the value of the string as u32 `'1'.u32() == u32(1)`. +pub fn (s string) u32() u32 { + return u32(strconv.common_parse_uint(s, 0, 32, false, false) or { 0 }) +} + +// u64 returns the value of the string as u64 `'1'.u64() == u64(1)`. +pub fn (s string) u64() u64 { + return strconv.common_parse_uint(s, 0, 64, false, false) or { 0 } +} + +[direct_array_access] +fn (s string) == (a string) bool { + if s.str == 0 { + // should never happen + panic('string.eq(): nil string') + } + if s.len != a.len { + return false + } + if s.len > 0 { + last_idx := s.len - 1 + if s[last_idx] != a[last_idx] { + return false + } + } + unsafe { + return vmemcmp(s.str, a.str, a.len) == 0 + } +} + +fn (s string) < (a string) bool { + for i in 0 .. s.len { + if i >= a.len || s[i] > a[i] { + return false + } else if s[i] < a[i] { + return true + } + } + if s.len < a.len { + return true + } + return false +} + +fn (s string) + (a string) string { + new_len := a.len + s.len + mut res := string{ + str: unsafe { malloc_noscan(new_len + 1) } + len: new_len + } + for j in 0 .. s.len { + unsafe { + res.str[j] = s.str[j] + } + } + for j in 0 .. a.len { + unsafe { + res.str[s.len + j] = a.str[j] + } + } + unsafe { + res.str[new_len] = 0 // V strings are not null terminated, but just in case + } + return res +} + +// split splits the string to an array by `delim`. +// Example: assert 'A B C'.split(' ') == ['A','B','C'] +// If `delim` is empty the string is split by it's characters. +// Example: assert 'DEF'.split('') == ['D','E','F'] +pub fn (s string) split(delim string) []string { + return s.split_nth(delim, 0) +} + +// split_nth splits the string based on the passed `delim` substring. +// It returns the first Nth parts. When N=0, return all the splits. +// The last returned element has the remainder of the string, even if +// the remainder contains more `delim` substrings. +[direct_array_access] +pub fn (s string) split_nth(delim string, nth int) []string { + mut res := []string{} + mut i := 0 + + match delim.len { + 0 { + i = 1 + for ch in s { + if nth > 0 && i >= nth { + res << s[i..] + break + } + res << ch.ascii_str() + i++ + } + return res + } + 1 { + mut start := 0 + delim_byte := delim[0] + + for i < s.len { + if s[i] == delim_byte { + was_last := nth > 0 && res.len == nth - 1 + if was_last { + break + } + val := s.substr(start, i) + res << val + start = i + delim.len + i = start + } else { + i++ + } + } + + // Then the remaining right part of the string + if nth < 1 || res.len < nth { + res << s[start..] + } + return res + } + else { + mut start := 0 + // Take the left part for each delimiter occurence + for i <= s.len { + is_delim := i + delim.len <= s.len && s.substr(i, i + delim.len) == delim + if is_delim { + was_last := nth > 0 && res.len == nth - 1 + if was_last { + break + } + val := s.substr(start, i) + res << val + start = i + delim.len + i = start + } else { + i++ + } + } + // Then the remaining right part of the string + if nth < 1 || res.len < nth { + res << s[start..] + } + return res + } + } +} + +// split_into_lines splits the string by newline characters. +// newlines are stripped. +// Both `\n` and `\r\n` newline endings are supported. +[direct_array_access] +pub fn (s string) split_into_lines() []string { + mut res := []string{} + if s.len == 0 { + return res + } + mut start := 0 + mut end := 0 + for i := 0; i < s.len; i++ { + if s[i] == 10 { + end = if i > 0 && s[i - 1] == 13 { i - 1 } else { i } + res << if start == end { '' } else { s[start..end] } + start = i + 1 + } + } + if start < s.len { + res << s[start..] + } + return res +} + +// used internally for [2..4] +fn (s string) substr2(start int, _end int, end_max bool) string { + end := if end_max { s.len } else { _end } + return s.substr(start, end) +} + +// substr returns the string between index positions `start` and `end`. +// Example: assert 'ABCD'.substr(1,3) == 'BC' +pub fn (s string) substr(start int, end int) string { + $if !no_bounds_checking ? { + if start > end || start > s.len || end > s.len || start < 0 || end < 0 { + panic('substr($start, $end) out of bounds (len=$s.len)') + } + } + len := end - start + if len == s.len { + return s.clone() + } + mut res := string{ + str: unsafe { malloc_noscan(len + 1) } + len: len + } + for i in 0 .. len { + unsafe { + res.str[i] = s.str[start + i] + } + } + unsafe { + res.str[len] = 0 + } + return res +} + +// index returns the position of the first character of the input string. +// It will return `-1` if the input string can't be found. +fn (s string) index_(p string) int { + if p.len > s.len || p.len == 0 { + return -1 + } + if p.len > 2 { + return s.index_kmp(p) + } + mut i := 0 + for i < s.len { + mut j := 0 + for j < p.len && unsafe { s.str[i + j] == p.str[j] } { + j++ + } + if j == p.len { + return i + } + i++ + } + return -1 +} + +// index returns the position of the first character of the input string. +// It will return `none` if the input string can't be found. +pub fn (s string) index(p string) ?int { + idx := s.index_(p) + if idx == -1 { + return none + } + return idx +} + +// index_kmp does KMP search. +[direct_array_access; manualfree] +fn (s string) index_kmp(p string) int { + if p.len > s.len { + return -1 + } + mut prefix := []int{len: p.len} + defer { + unsafe { prefix.free() } + } + mut j := 0 + for i := 1; i < p.len; i++ { + for unsafe { p.str[j] != p.str[i] } && j > 0 { + j = prefix[j - 1] + } + if unsafe { p.str[j] == p.str[i] } { + j++ + } + prefix[i] = j + } + j = 0 + for i in 0 .. s.len { + for unsafe { p.str[j] != s.str[i] } && j > 0 { + j = prefix[j - 1] + } + if unsafe { p.str[j] == s.str[i] } { + j++ + } + if j == p.len { + return i - p.len + 1 + } + } + return -1 +} + +// index_any returns the position of any of the characters in the input string - if found. +pub fn (s string) index_any(chars string) int { + for c in chars { + idx := s.index_(c.ascii_str()) + if idx == -1 { + continue + } + return idx + } + return -1 +} + +// last_index returns the position of the last occurence of the input string. +fn (s string) last_index_(p string) int { + if p.len > s.len || p.len == 0 { + return -1 + } + mut i := s.len - p.len + for i >= 0 { + mut j := 0 + for j < p.len && unsafe { s.str[i + j] == p.str[j] } { + j++ + } + if j == p.len { + return i + } + i-- + } + return -1 +} + +// last_index returns the position of the last occurence of the input string. +pub fn (s string) last_index(p string) ?int { + idx := s.last_index_(p) + if idx == -1 { + return none + } + return idx +} + +// index_after returns the position of the input string, starting search from `start` position. +pub fn (s string) index_after(p string, start int) int { + if p.len > s.len { + return -1 + } + mut strt := start + if start < 0 { + strt = 0 + } + if start >= s.len { + return -1 + } + mut i := strt + for i < s.len { + mut j := 0 + mut ii := i + for j < p.len && unsafe { s.str[ii] == p.str[j] } { + j++ + ii++ + } + if j == p.len { + return i + } + i++ + } + return -1 +} + +// index_byte returns the index of byte `c` if found in the string. +// index_byte returns -1 if the byte can not be found. +pub fn (s string) index_byte(c byte) int { + for i in 0 .. s.len { + if unsafe { s.str[i] } == c { + return i + } + } + return -1 +} + +// last_index_byte returns the index of the last occurence of byte `c` if found in the string. +// last_index_byte returns -1 if the byte is not found. +pub fn (s string) last_index_byte(c byte) int { + for i := s.len - 1; i >= 0; i-- { + if unsafe { s.str[i] == c } { + return i + } + } + return -1 +} + +// count returns the number of occurrences of `substr` in the string. +// count returns -1 if no `substr` could be found. +pub fn (s string) count(substr string) int { + if s.len == 0 || substr.len == 0 { + return 0 + } + if substr.len > s.len { + return 0 + } + + mut n := 0 + + if substr.len == 1 { + target := substr[0] + + for letter in s { + if letter == target { + n++ + } + } + + return n + } + + mut i := 0 + for { + i = s.index_after(substr, i) + if i == -1 { + return n + } + i += substr.len + n++ + } + return 0 // TODO can never get here - v doesn't know that +} + +// contains returns `true` if the string contains `substr`. +pub fn (s string) contains(substr string) bool { + if substr.len == 0 { + return true + } + if s.index_(substr) == -1 { + return false + } + return true +} + +// contains_any returns `true` if the string contains any chars in `chars`. +pub fn (s string) contains_any(chars string) bool { + for c in chars { + if s.contains(c.ascii_str()) { + return true + } + } + return false +} + +// contains_any_substr returns `true` if the string contains any of the strings in `substrs`. +pub fn (s string) contains_any_substr(substrs []string) bool { + if substrs.len == 0 { + return true + } + for sub in substrs { + if s.contains(sub) { + return true + } + } + return false +} + +// starts_with returns `true` if the string starts with `p`. +pub fn (s string) starts_with(p string) bool { + if p.len > s.len { + return false + } + for i in 0 .. p.len { + if unsafe { s.str[i] != p.str[i] } { + return false + } + } + return true +} + +// ends_with returns `true` if the string ends with `p`. +pub fn (s string) ends_with(p string) bool { + if p.len > s.len { + return false + } + for i in 0 .. p.len { + if unsafe { p.str[i] != s.str[s.len - p.len + i] } { + return false + } + } + return true +} + +// to_lower returns the string in all lowercase characters. +// TODO only works with ASCII +pub fn (s string) to_lower() string { + unsafe { + mut b := malloc_noscan(s.len + 1) + for i in 0 .. s.len { + if s.str[i] >= `A` && s.str[i] <= `Z` { + b[i] = s.str[i] + 32 + } else { + b[i] = s.str[i] + } + } + b[s.len] = 0 + return tos(b, s.len) + } +} + +// is_lower returns `true` if all characters in the string is lowercase. +// Example: assert 'hello developer'.is_lower() == true +[direct_array_access] +pub fn (s string) is_lower() bool { + for i in 0 .. s.len { + if s[i] >= `A` && s[i] <= `Z` { + return false + } + } + return true +} + +// to_upper returns the string in all uppercase characters. +// Example: assert 'Hello V'.to_upper() == 'HELLO V' +pub fn (s string) to_upper() string { + unsafe { + mut b := malloc_noscan(s.len + 1) + for i in 0 .. s.len { + if s.str[i] >= `a` && s.str[i] <= `z` { + b[i] = s.str[i] - 32 + } else { + b[i] = s.str[i] + } + } + b[s.len] = 0 + return tos(b, s.len) + } +} + +// is_upper returns `true` if all characters in the string is uppercase. +// Example: assert 'HELLO V'.is_upper() == true +[direct_array_access] +pub fn (s string) is_upper() bool { + for i in 0 .. s.len { + if s[i] >= `a` && s[i] <= `z` { + return false + } + } + return true +} + +// capitalize returns the string with the first character capitalized. +// Example: assert 'hello'.capitalize() == 'Hello' +[direct_array_access] +pub fn (s string) capitalize() string { + if s.len == 0 { + return '' + } + s0 := s[0] + letter := s0.ascii_str() + uletter := letter.to_upper() + if s.len == 1 { + return uletter + } + srest := s[1..] + res := uletter + srest + return res +} + +// is_capital returns `true` if the first character in the string is a capital letter. +// Example: assert 'Hello'.is_capital() == true +[direct_array_access] +pub fn (s string) is_capital() bool { + if s.len == 0 || !(s[0] >= `A` && s[0] <= `Z`) { + return false + } + for i in 1 .. s.len { + if s[i] >= `A` && s[i] <= `Z` { + return false + } + } + return true +} + +// title returns the string with each word capitalized. +// Example: assert 'hello v developer'.title() == 'Hello V Developer' +pub fn (s string) title() string { + words := s.split(' ') + mut tit := []string{} + for word in words { + tit << word.capitalize() + } + title := tit.join(' ') + return title +} + +// is_title returns true if all words of the string is capitalized. +// Example: assert 'Hello V Developer'.is_title() == true +pub fn (s string) is_title() bool { + words := s.split(' ') + for word in words { + if !word.is_capital() { + return false + } + } + return true +} + +// find_between returns the string found between `start` string and `end` string. +// Example: assert 'hey [man] how you doin'.find_between('[', ']') == 'man' +pub fn (s string) find_between(start string, end string) string { + start_pos := s.index_(start) + if start_pos == -1 { + return '' + } + // First get everything to the right of 'start' + val := s[start_pos + start.len..] + end_pos := val.index_(end) + if end_pos == -1 { + return val + } + return val[..end_pos] +} + +// trim_space strips any of ` `, `\n`, `\t`, `\v`, `\f`, `\r` from the start and end of the string. +// Example: assert ' Hello V '.trim_space() == 'Hello V' +pub fn (s string) trim_space() string { + return s.trim(' \n\t\v\f\r') +} + +// trim strips any of the characters given in `cutset` from the start and end of the string. +// Example: assert ' ffHello V ffff'.trim(' f') == 'Hello V' +[direct_array_access] +pub fn (s string) trim(cutset string) string { + if s.len < 1 || cutset.len < 1 { + return s.clone() + } + mut pos_left := 0 + mut pos_right := s.len - 1 + mut cs_match := true + for pos_left <= s.len && pos_right >= -1 && cs_match { + cs_match = false + for cs in cutset { + if s[pos_left] == cs { + pos_left++ + cs_match = true + break + } + } + for cs in cutset { + if s[pos_right] == cs { + pos_right-- + cs_match = true + break + } + } + if pos_left > pos_right { + return '' + } + } + return s.substr(pos_left, pos_right + 1) +} + +// trim_left strips any of the characters given in `cutset` from the left of the string. +// Example: assert 'd Hello V developer'.trim_left(' d') == 'Hello V developer' +[direct_array_access] +pub fn (s string) trim_left(cutset string) string { + if s.len < 1 || cutset.len < 1 { + return s.clone() + } + mut pos := 0 + for pos < s.len { + mut found := false + for cs in cutset { + if s[pos] == cs { + found = true + break + } + } + if !found { + break + } + pos++ + } + return s[pos..] +} + +// trim_right strips any of the characters given in `cutset` from the right of the string. +// Example: assert ' Hello V d'.trim_right(' d') == ' Hello V' +[direct_array_access] +pub fn (s string) trim_right(cutset string) string { + if s.len < 1 || cutset.len < 1 { + return s.clone() + } + mut pos := s.len - 1 + for pos >= 0 { + mut found := false + for cs in cutset { + if s[pos] == cs { + found = true + } + } + if !found { + break + } + pos-- + } + if pos < 0 { + return '' + } + return s[..pos + 1] +} + +// trim_prefix strips `str` from the start of the string. +// Example: assert 'WorldHello V'.trim_prefix('World') == 'Hello V' +pub fn (s string) trim_prefix(str string) string { + if s.starts_with(str) { + return s[str.len..] + } + return s.clone() +} + +// trim_suffix strips `str` from the end of the string. +// Example: assert 'Hello VWorld'.trim_suffix('World') == 'Hello V' +pub fn (s string) trim_suffix(str string) string { + if s.ends_with(str) { + return s[..s.len - str.len] + } + return s.clone() +} + +// compare_strings returns `-1` if `a < b`, `1` if `a > b` else `0`. +pub fn compare_strings(a &string, b &string) int { + if a < b { + return -1 + } + if a > b { + return 1 + } + return 0 +} + +// compare_strings_by_len returns `-1` if `a.len < b.len`, `1` if `a.len > b.len` else `0`. +fn compare_strings_by_len(a &string, b &string) int { + if a.len < b.len { + return -1 + } + if a.len > b.len { + return 1 + } + return 0 +} + +// compare_lower_strings returns the same as compare_strings but converts `a` and `b` to lower case before comparing. +fn compare_lower_strings(a &string, b &string) int { + aa := a.to_lower() + bb := b.to_lower() + return compare_strings(&aa, &bb) +} + +// sort_ignore_case sorts the string array using case insesitive comparing. +pub fn (mut s []string) sort_ignore_case() { + s.sort_with_compare(compare_lower_strings) +} + +// sort_by_len sorts the the string array by each string's `.len` length. +pub fn (mut s []string) sort_by_len() { + s.sort_with_compare(compare_strings_by_len) +} + +// str returns a copy of the string +pub fn (s string) str() string { + return s.clone() +} + +// at returns the byte at index `idx`. +// Example: assert 'ABC'.at(1) == byte(`B`) +fn (s string) at(idx int) byte { + $if !no_bounds_checking ? { + if idx < 0 || idx >= s.len { + panic('string index out of range: $idx / $s.len') + } + } + unsafe { + return s.str[idx] + } +} + +// version of `at()` that is used in `a[i] or {` +// return an error when the index is out of range +fn (s string) at_with_check(idx int) ?byte { + if idx < 0 || idx >= s.len { + return error('string index out of range') + } + unsafe { + return s.str[idx] + } +} + +// is_space returns `true` if the byte is a white space character. +// The following list is considered white space characters: ` `, `\t`, `\n`, `\v`, `\f`, `\r`, 0x85, 0xa0 +// Example: assert byte(` `).is_space() == true +[inline] +pub fn (c byte) is_space() bool { + // 0x85 is NEXT LINE (NEL) + // 0xa0 is NO-BREAK SPACE + return c == 32 || (c > 8 && c < 14) || (c == 0x85) || (c == 0xa0) +} + +// is_digit returns `true` if the byte is in range 0-9 and `false` otherwise. +// Example: assert byte(`9`) == true +[inline] +pub fn (c byte) is_digit() bool { + return c >= `0` && c <= `9` +} + +// is_hex_digit returns `true` if the byte is either in range 0-9, a-f or A-F and `false` otherwise. +// Example: assert byte(`F`) == true +[inline] +pub fn (c byte) is_hex_digit() bool { + return c.is_digit() || (c >= `a` && c <= `f`) || (c >= `A` && c <= `F`) +} + +// is_oct_digit returns `true` if the byte is in range 0-7 and `false` otherwise. +// Example: assert byte(`7`) == true +[inline] +pub fn (c byte) is_oct_digit() bool { + return c >= `0` && c <= `7` +} + +// is_bin_digit returns `true` if the byte is a binary digit (0 or 1) and `false` otherwise. +// Example: assert byte(`0`) == true +[inline] +pub fn (c byte) is_bin_digit() bool { + return c == `0` || c == `1` +} + +// is_letter returns `true` if the byte is in range a-z or A-Z and `false` otherwise. +// Example: assert byte(`V`) == true +[inline] +pub fn (c byte) is_letter() bool { + return (c >= `a` && c <= `z`) || (c >= `A` && c <= `Z`) +} + +// free allows for manually freeing the memory occupied by the string +[manualfree; unsafe] +pub fn (s &string) free() { + $if prealloc { + return + } + if s.is_lit == -98761234 { + double_free_msg := unsafe { &byte(c'double string.free() detected\n') } + double_free_msg_len := unsafe { vstrlen(double_free_msg) } + $if freestanding { + bare_eprint(double_free_msg, u64(double_free_msg_len)) + } $else { + _write_buf_to_fd(1, double_free_msg, double_free_msg_len) + } + return + } + if s.is_lit == 1 || s.str == 0 { + return + } + unsafe { + free(s.str) + } + s.is_lit = -98761234 +} + +// before returns the contents before `sub` in the string. +// If the substring is not found, it returns the full input string. +// Example: assert '23:34:45.234'.before('.') == '23:34:45' +// Example: assert 'abcd'.before('.') == 'abcd' +// TODO: deprecate and remove either .before or .all_before +pub fn (s string) before(sub string) string { + pos := s.index_(sub) + if pos == -1 { + return s.clone() + } + return s[..pos] +} + +// all_before returns the contents before `sub` in the string. +// If the substring is not found, it returns the full input string. +// Example: assert '23:34:45.234'.all_before('.') == '23:34:45' +// Example: assert 'abcd'.all_before('.') == 'abcd' +pub fn (s string) all_before(sub string) string { + // TODO remove dup method + pos := s.index_(sub) + if pos == -1 { + return s.clone() + } + return s[..pos] +} + +// all_before_last returns the contents before the last occurence of `sub` in the string. +// If the substring is not found, it returns the full input string. +// Example: assert '23:34:45.234'.all_before_last(':') == '23:34' +// Example: assert 'abcd'.all_before_last('.') == 'abcd' +pub fn (s string) all_before_last(sub string) string { + pos := s.last_index_(sub) + if pos == -1 { + return s.clone() + } + return s[..pos] +} + +// all_after returns the contents after `sub` in the string. +// If the substring is not found, it returns the full input string. +// Example: assert '23:34:45.234'.all_after('.') == '234' +// Example: assert 'abcd'.all_after('z') == 'abcd' +pub fn (s string) all_after(sub string) string { + pos := s.index_(sub) + if pos == -1 { + return s.clone() + } + return s[pos + sub.len..] +} + +// all_after_last returns the contents after the last occurence of `sub` in the string. +// If the substring is not found, it returns the full input string. +// Example: assert '23:34:45.234'.all_after_last(':') == '45.234' +// Example: assert 'abcd'.all_after_last('z') == 'abcd' +pub fn (s string) all_after_last(sub string) string { + pos := s.last_index_(sub) + if pos == -1 { + return s.clone() + } + return s[pos + sub.len..] +} + +// after returns the contents after the last occurence of `sub` in the string. +// If the substring is not found, it returns the full input string. +// Example: assert '23:34:45.234'.after(':') == '45.234' +// Example: assert 'abcd'.after('z') == 'abcd' +// TODO: deprecate either .all_after_last or .after +pub fn (s string) after(sub string) string { + return s.all_after_last(sub) +} + +// after_char returns the contents after the first occurence of `sub` character in the string. +// If the substring is not found, it returns the full input string. +// Example: assert '23:34:45.234'.after_char(`:`) == '34:45.234' +// Example: assert 'abcd'.after_char(`:`) == 'abcd' +pub fn (s string) after_char(sub byte) string { + mut pos := -1 + for i, c in s { + if c == sub { + pos = i + break + } + } + if pos == -1 { + return s.clone() + } + return s[pos + 1..] +} + +// join joins a string array into a string using `sep` separator. +// Example: assert ['Hello','V'].join(' ') == 'Hello V' +pub fn (a []string) join(sep string) string { + if a.len == 0 { + return '' + } + mut len := 0 + for val in a { + len += val.len + sep.len + } + len -= sep.len + // Allocate enough memory + mut res := string{ + str: unsafe { malloc_noscan(len + 1) } + len: len + } + mut idx := 0 + for i, val in a { + unsafe { + vmemcpy(res.str + idx, val.str, val.len) + idx += val.len + } + // Add sep if it's not last + if i != a.len - 1 { + unsafe { + vmemcpy(res.str + idx, sep.str, sep.len) + idx += sep.len + } + } + } + unsafe { + res.str[res.len] = 0 + } + return res +} + +// join joins a string array into a string using a `\n` newline delimiter. +pub fn (s []string) join_lines() string { + return s.join('\n') +} + +// reverse returns a reversed string. +// Example: assert 'Hello V'.reverse() == 'V olleH' +pub fn (s string) reverse() string { + if s.len == 0 || s.len == 1 { + return s.clone() + } + mut res := string{ + str: unsafe { malloc_noscan(s.len + 1) } + len: s.len + } + for i := s.len - 1; i >= 0; i-- { + unsafe { + res.str[s.len - i - 1] = s[i] + } + } + unsafe { + res.str[res.len] = 0 + } + return res +} + +// limit returns a portion of the string, starting at `0` and extending for a given number of characters afterward. +// 'hello'.limit(2) => 'he' +// 'hi'.limit(10) => 'hi' +pub fn (s string) limit(max int) string { + u := s.runes() + if u.len <= max { + return s.clone() + } + return u[0..max].string() +} + +// hash returns an integer hash of the string. +pub fn (s string) hash() int { + mut h := u32(0) + if h == 0 && s.len > 0 { + for c in s { + h = h * 31 + u32(c) + } + } + return int(h) +} + +// bytes returns the string converted to a byte array. +pub fn (s string) bytes() []byte { + if s.len == 0 { + return [] + } + mut buf := []byte{len: s.len} + unsafe { vmemcpy(buf.data, s.str, s.len) } + return buf +} + +// repeat returns a new string with `count` number of copies of the string it was called on. +pub fn (s string) repeat(count int) string { + if count < 0 { + panic('string.repeat: count is negative: $count') + } else if count == 0 { + return '' + } else if count == 1 { + return s.clone() + } + mut ret := unsafe { malloc_noscan(s.len * count + 1) } + for i in 0 .. count { + for j in 0 .. s.len { + unsafe { + ret[i * s.len + j] = s[j] + } + } + } + new_len := s.len * count + unsafe { + ret[new_len] = 0 + } + return unsafe { ret.vstring_with_len(new_len) } +} + +// fields returns a string array of the string split by `\t` and ` ` +// Example: assert '\t\tv = v'.fields() == ['v', '=', 'v'] +// Example: assert ' sss ssss'.fields() == ['sss', 'ssss'] +pub fn (s string) fields() []string { + mut res := []string{} + mut word_start := 0 + mut word_len := 0 + mut is_in_word := false + mut is_space := false + for i, c in s { + is_space = c in [32, 9, 10] + if !is_space { + word_len++ + } + if !is_in_word && !is_space { + word_start = i + is_in_word = true + continue + } + if is_space && is_in_word { + res << s[word_start..word_start + word_len] + is_in_word = false + word_len = 0 + word_start = 0 + continue + } + } + if is_in_word && word_len > 0 { + // collect the remainder word at the end + res << s[word_start..s.len] + } + return res +} + +// strip_margin allows multi-line strings to be formatted in a way that removes white-space +// before a delimeter. by default `|` is used. +// Note: the delimiter has to be a byte at this time. That means surrounding +// the value in ``. +// +// Example: +// st := 'Hello there, +// |this is a string, +// | Everything before the first | is removed'.strip_margin() +// Returns: +// Hello there, +// this is a string, +// Everything before the first | is removed +pub fn (s string) strip_margin() string { + return s.strip_margin_custom(`|`) +} + +// strip_margin_custom does the same as `strip_margin` but will use `del` as delimiter instead of `|` +[direct_array_access] +pub fn (s string) strip_margin_custom(del byte) string { + mut sep := del + if sep.is_space() { + eprintln('Warning: `strip_margin` cannot use white-space as a delimiter') + eprintln(' Defaulting to `|`') + sep = `|` + } + // don't know how much space the resulting string will be, but the max it + // can be is this big + mut ret := unsafe { malloc_noscan(s.len + 1) } + mut count := 0 + for i := 0; i < s.len; i++ { + if s[i] in [10, 13] { + unsafe { + ret[count] = s[i] + } + count++ + // CRLF + if s[i] == 13 && i < s.len - 1 && s[i + 1] == 10 { + unsafe { + ret[count] = s[i + 1] + } + count++ + i++ + } + for s[i] != sep { + i++ + if i >= s.len { + break + } + } + } else { + unsafe { + ret[count] = s[i] + } + count++ + } + } + unsafe { + ret[count] = 0 + return ret.vstring_with_len(count) + } +} |