mirror of
https://github.com/roc-lang/roc.git
synced 2025-09-28 14:24:45 +00:00
816 lines
25 KiB
Zig
816 lines
25 KiB
Zig
const std = @import("std");
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const mem = std.mem;
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const always_inline = std.builtin.CallOptions.Modifier.always_inline;
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const Allocator = mem.Allocator;
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const unicode = std.unicode;
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const testing = std.testing;
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const expectEqual = testing.expectEqual;
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const expect = testing.expect;
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const InPlace = packed enum(u8) {
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InPlace,
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Clone,
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};
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pub const RocStr = extern struct {
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str_bytes: ?[*]u8,
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str_len: usize,
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pub inline fn empty() RocStr {
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return RocStr{
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.str_len = 0,
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.str_bytes = null,
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};
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}
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// This clones the pointed-to bytes if they won't fit in a
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// small string, and returns a (pointer, len) tuple which points to them.
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pub fn init(allocator: *Allocator, bytes_ptr: [*]const u8, length: usize) RocStr {
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const roc_str_size = @sizeOf(RocStr);
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if (length < roc_str_size) {
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var ret_small_str = RocStr.empty();
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const target_ptr = @ptrToInt(&ret_small_str);
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var index: u8 = 0;
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// TODO isn't there a way to bulk-zero data in Zig?
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// Zero out the data, just to be safe
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while (index < roc_str_size) {
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var offset_ptr = @intToPtr(*u8, target_ptr + index);
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offset_ptr.* = 0;
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index += 1;
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}
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// TODO rewrite this into a for loop
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index = 0;
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while (index < length) {
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var offset_ptr = @intToPtr(*u8, target_ptr + index);
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offset_ptr.* = bytes_ptr[index];
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index += 1;
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}
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// set the final byte to be the length
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const final_byte_ptr = @intToPtr(*u8, target_ptr + roc_str_size - 1);
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final_byte_ptr.* = @truncate(u8, length) ^ 0b10000000;
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return ret_small_str;
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} else {
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var result = RocStr.initBig(allocator, u64, InPlace.Clone, length);
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@memcpy(@ptrCast([*]u8, result.str_bytes), bytes_ptr, length);
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return result;
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}
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}
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pub fn initBig(allocator: *Allocator, comptime T: type, in_place: InPlace, number_of_chars: u64) RocStr {
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const length = @sizeOf(T) + number_of_chars;
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var new_bytes: []T = allocator.alloc(T, length) catch unreachable;
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if (in_place == InPlace.InPlace) {
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new_bytes[0] = @intCast(T, number_of_chars);
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} else {
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new_bytes[0] = std.math.minInt(T);
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}
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var first_element = @ptrCast([*]align(@alignOf(T)) u8, new_bytes);
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first_element += @sizeOf(usize);
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return RocStr{
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.str_bytes = first_element,
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.str_len = number_of_chars,
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};
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}
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pub fn deinit(self: RocStr, allocator: *Allocator) void {
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if (!self.isSmallStr() and !self.isEmpty()) {
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const str_bytes_ptr: [*]u8 = self.str_bytes orelse unreachable;
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const str_bytes: []u8 = str_bytes_ptr[0..self.str_len];
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allocator.free(str_bytes);
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}
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}
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// This takes ownership of the pointed-to bytes if they won't fit in a
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// small string, and returns a (pointer, len) tuple which points to them.
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pub fn withCapacity(length: usize) RocStr {
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const roc_str_size = @sizeOf(RocStr);
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if (length < roc_str_size) {
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return RocStr.empty();
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} else {
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var new_bytes: []T = allocator.alloc(u8, length) catch unreachable;
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var new_bytes_ptr: [*]u8 = @ptrCast([*]u8, &new_bytes);
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return RocStr{
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.str_bytes = new_bytes_ptr,
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.str_len = length,
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};
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}
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}
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pub fn eq(self: RocStr, other: RocStr) bool {
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const self_bytes_ptr: ?[*]const u8 = self.str_bytes;
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const other_bytes_ptr: ?[*]const u8 = other.str_bytes;
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// If they are byte-for-byte equal, they're definitely equal!
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if (self_bytes_ptr == other_bytes_ptr and self.str_len == other.str_len) {
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return true;
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}
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const self_len = self.len();
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const other_len = other.len();
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// If their lengths are different, they're definitely unequal.
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if (self_len != other_len) {
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return false;
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}
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const self_u8_ptr: [*]const u8 = @ptrCast([*]const u8, &self);
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const other_u8_ptr: [*]const u8 = @ptrCast([*]const u8, &other);
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const self_bytes: [*]const u8 = if (self.isSmallStr() or self.isEmpty()) self_u8_ptr else self_bytes_ptr orelse unreachable;
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const other_bytes: [*]const u8 = if (other.isSmallStr() or other.isEmpty()) other_u8_ptr else other_bytes_ptr orelse unreachable;
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var index: usize = 0;
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// TODO rewrite this into a for loop
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const length = self.len();
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while (index < length) {
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if (self_bytes[index] != other_bytes[index]) {
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return false;
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}
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index = index + 1;
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}
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return true;
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}
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pub fn clone(allocator: *Allocator, comptime T: type, in_place: InPlace, str: RocStr) RocStr {
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if (str.isSmallStr() or str.isEmpty()) {
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// just return the bytes
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return str;
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} else {
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var new_str = RocStr.initBig(allocator, T, in_place, str.str_len);
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var old_bytes: [*]u8 = @ptrCast([*]u8, str.str_bytes);
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var new_bytes: [*]u8 = @ptrCast([*]u8, new_str.str_bytes);
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@memcpy(new_bytes, old_bytes, str.str_len);
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return new_str;
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}
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}
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pub fn isSmallStr(self: RocStr) bool {
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return @bitCast(isize, self.str_len) < 0;
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}
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pub fn len(self: RocStr) usize {
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const bytes: [*]const u8 = @ptrCast([*]const u8, &self);
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const last_byte = bytes[@sizeOf(RocStr) - 1];
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const small_len = @as(usize, last_byte ^ 0b1000_0000);
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const big_len = self.str_len;
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// Since this conditional would be prone to branch misprediction,
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// make sure it will compile to a cmov.
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return if (self.isSmallStr()) small_len else big_len;
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}
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pub fn isEmpty(self: RocStr) bool {
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return self.len() == 0;
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}
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pub fn asSlice(self: RocStr) []u8 {
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// Since this conditional would be prone to branch misprediction,
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// make sure it will compile to a cmov.
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return self.asU8ptr()[0..self.len()];
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}
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pub fn asU8ptr(self: RocStr) [*]u8 {
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// Since this conditional would be prone to branch misprediction,
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// make sure it will compile to a cmov.
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return if (self.isSmallStr() or self.isEmpty()) (&@bitCast([16]u8, self)) else (@ptrCast([*]u8, self.str_bytes));
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}
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// Given a pointer to some bytes, write the first (len) bytes of this
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// RocStr's contents into it.
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//
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// One use for this function is writing into an `alloca` for a C string that
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// only needs to live long enough to be passed as an argument to
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// a C function - like the file path argument to `fopen`.
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pub fn memcpy(self: RocStr, dest: [*]u8, length: usize) void {
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const src = self.asU8ptr();
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@memcpy(dest, src, length);
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}
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test "RocStr.eq: equal" {
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const str1_len = 3;
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var str1: [str1_len]u8 = "abc".*;
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const str1_ptr: [*]u8 = &str1;
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var roc_str1 = RocStr.init(testing.allocator, str1_ptr, str1_len);
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const str2_len = 3;
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var str2: [str2_len]u8 = "abc".*;
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const str2_ptr: [*]u8 = &str2;
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var roc_str2 = RocStr.init(testing.allocator, str2_ptr, str2_len);
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expect(roc_str1.eq(roc_str2));
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roc_str1.deinit(testing.allocator);
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roc_str2.deinit(testing.allocator);
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}
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test "RocStr.eq: not equal different length" {
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const str1_len = 4;
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var str1: [str1_len]u8 = "abcd".*;
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const str1_ptr: [*]u8 = &str1;
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var roc_str1 = RocStr.init(testing.allocator, str1_ptr, str1_len);
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const str2_len = 3;
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var str2: [str2_len]u8 = "abc".*;
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const str2_ptr: [*]u8 = &str2;
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var roc_str2 = RocStr.init(testing.allocator, str2_ptr, str2_len);
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defer {
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roc_str1.deinit(testing.allocator);
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roc_str2.deinit(testing.allocator);
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}
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expect(!roc_str1.eq(roc_str2));
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}
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test "RocStr.eq: not equal same length" {
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const str1_len = 3;
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var str1: [str1_len]u8 = "acb".*;
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const str1_ptr: [*]u8 = &str1;
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var roc_str1 = RocStr.init(testing.allocator, str1_ptr, str1_len);
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const str2_len = 3;
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var str2: [str2_len]u8 = "abc".*;
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const str2_ptr: [*]u8 = &str2;
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var roc_str2 = RocStr.init(testing.allocator, str2_ptr, str2_len);
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defer {
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roc_str1.deinit(testing.allocator);
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roc_str2.deinit(testing.allocator);
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}
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expect(!roc_str1.eq(roc_str2));
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}
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};
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// Str.equal
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pub fn strEqual(self: RocStr, other: RocStr) callconv(.C) bool {
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return self.eq(other);
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}
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// Str.numberOfBytes
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pub fn strNumberOfBytes(string: RocStr) callconv(.C) usize {
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return string.len();
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}
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// Str.fromInt
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// When we actually use this in Roc, libc will be linked so we have access to std.heap.c_allocator
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pub fn strFromIntC(int: i64) callconv(.C) RocStr {
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return strFromInt(std.heap.c_allocator, int);
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}
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fn strFromInt(allocator: *Allocator, int: i64) RocStr {
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// prepare for having multiple integer types in the future
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return @call(.{ .modifier = always_inline }, strFromIntHelp, .{ allocator, i64, int });
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}
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fn strFromIntHelp(allocator: *Allocator, comptime T: type, int: T) RocStr {
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// determine maximum size for this T
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comptime const size = comptime blk: {
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// the string representation of the minimum i128 value uses at most 40 characters
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var buf: [40]u8 = undefined;
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var result = std.fmt.bufPrint(&buf, "{}", .{std.math.minInt(T)}) catch unreachable;
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break :blk result.len;
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};
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var buf: [size]u8 = undefined;
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const result = std.fmt.bufPrint(&buf, "{}", .{int}) catch unreachable;
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return RocStr.init(allocator, &buf, result.len);
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}
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// Str.split
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// When we actually use this in Roc, libc will be linked so we have access to std.heap.c_allocator
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pub fn strSplitInPlaceC(array: [*]RocStr, string: RocStr, delimiter: RocStr) callconv(.C) void {
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return @call(.{ .modifier = always_inline }, strSplitInPlace, .{ std.heap.c_allocator, array, string, delimiter });
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}
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fn strSplitInPlace(allocator: *Allocator, array: [*]RocStr, string: RocStr, delimiter: RocStr) void {
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var ret_array_index: usize = 0;
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var slice_start_index: usize = 0;
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var str_index: usize = 0;
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const str_bytes = string.asU8ptr();
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const str_len = string.len();
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const delimiter_bytes_ptrs = delimiter.asU8ptr();
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const delimiter_len = delimiter.len();
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if (str_len > delimiter_len) {
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const end_index: usize = str_len - delimiter_len + 1;
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while (str_index <= end_index) {
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var delimiter_index: usize = 0;
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var matches_delimiter = true;
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while (delimiter_index < delimiter_len) {
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var delimiterChar = delimiter_bytes_ptrs[delimiter_index];
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var strChar = str_bytes[str_index + delimiter_index];
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if (delimiterChar != strChar) {
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matches_delimiter = false;
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break;
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}
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delimiter_index += 1;
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}
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if (matches_delimiter) {
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const segment_len: usize = str_index - slice_start_index;
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array[ret_array_index] = RocStr.init(allocator, str_bytes + slice_start_index, segment_len);
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slice_start_index = str_index + delimiter_len;
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ret_array_index += 1;
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str_index += delimiter_len;
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} else {
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str_index += 1;
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}
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}
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}
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array[ret_array_index] = RocStr.init(allocator, str_bytes + slice_start_index, str_len - slice_start_index);
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}
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test "strSplitInPlace: no delimiter" {
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// Str.split "abc" "!" == [ "abc" ]
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const str_arr = "abc";
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const str = RocStr.init(testing.allocator, str_arr, str_arr.len);
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const delimiter_arr = "!";
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const delimiter = RocStr.init(testing.allocator, delimiter_arr, delimiter_arr.len);
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var array: [1]RocStr = undefined;
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const array_ptr: [*]RocStr = &array;
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strSplitInPlace(testing.allocator, array_ptr, str, delimiter);
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var expected = [1]RocStr{
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str,
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};
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defer {
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for (array) |roc_str| {
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roc_str.deinit(testing.allocator);
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}
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for (expected) |roc_str| {
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roc_str.deinit(testing.allocator);
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}
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str.deinit(testing.allocator);
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delimiter.deinit(testing.allocator);
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}
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expectEqual(array.len, expected.len);
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expect(array[0].eq(expected[0]));
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}
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test "strSplitInPlace: empty end" {
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const str_arr = "1---- ---- ---- ---- ----2---- ---- ---- ---- ----";
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const str = RocStr.init(testing.allocator, str_arr, str_arr.len);
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const delimiter_arr = "---- ---- ---- ---- ----";
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const delimiter = RocStr.init(testing.allocator, delimiter_arr, delimiter_arr.len);
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const array_len: usize = 3;
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var array: [array_len]RocStr = [_]RocStr{
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undefined,
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undefined,
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undefined,
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};
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const array_ptr: [*]RocStr = &array;
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strSplitInPlace(testing.allocator, array_ptr, str, delimiter);
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const one = RocStr.init(testing.allocator, "1", 1);
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const two = RocStr.init(testing.allocator, "2", 1);
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var expected = [3]RocStr{
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one, two, RocStr.empty(),
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};
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defer {
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for (array) |rocStr| {
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rocStr.deinit(testing.allocator);
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}
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for (expected) |rocStr| {
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rocStr.deinit(testing.allocator);
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}
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str.deinit(testing.allocator);
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delimiter.deinit(testing.allocator);
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}
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expectEqual(array.len, expected.len);
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expect(array[0].eq(expected[0]));
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expect(array[1].eq(expected[1]));
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expect(array[2].eq(expected[2]));
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}
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test "strSplitInPlace: delimiter on sides" {
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const str_arr = "tttghittt";
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const str = RocStr.init(testing.allocator, str_arr, str_arr.len);
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const delimiter_arr = "ttt";
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const delimiter = RocStr.init(testing.allocator, delimiter_arr, delimiter_arr.len);
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const array_len: usize = 3;
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var array: [array_len]RocStr = [_]RocStr{
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undefined,
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undefined,
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undefined,
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};
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const array_ptr: [*]RocStr = &array;
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strSplitInPlace(testing.allocator, array_ptr, str, delimiter);
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const ghi_arr = "ghi";
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const ghi = RocStr.init(testing.allocator, ghi_arr, ghi_arr.len);
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var expected = [3]RocStr{
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RocStr.empty(), ghi, RocStr.empty(),
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};
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defer {
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for (array) |rocStr| {
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rocStr.deinit(testing.allocator);
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}
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for (expected) |rocStr| {
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rocStr.deinit(testing.allocator);
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}
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str.deinit(testing.allocator);
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delimiter.deinit(testing.allocator);
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}
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expectEqual(array.len, expected.len);
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expect(array[0].eq(expected[0]));
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expect(array[1].eq(expected[1]));
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expect(array[2].eq(expected[2]));
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}
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test "strSplitInPlace: three pieces" {
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// Str.split "a!b!c" "!" == [ "a", "b", "c" ]
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const str_arr = "a!b!c";
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const str = RocStr.init(testing.allocator, str_arr, str_arr.len);
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const delimiter_arr = "!";
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const delimiter = RocStr.init(testing.allocator, delimiter_arr, delimiter_arr.len);
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const array_len: usize = 3;
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var array: [array_len]RocStr = undefined;
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const array_ptr: [*]RocStr = &array;
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strSplitInPlace(testing.allocator, array_ptr, str, delimiter);
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const a = RocStr.init(testing.allocator, "a", 1);
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const b = RocStr.init(testing.allocator, "b", 1);
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const c = RocStr.init(testing.allocator, "c", 1);
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var expected_array = [array_len]RocStr{
|
|
a, b, c,
|
|
};
|
|
|
|
defer {
|
|
for (array) |roc_str| {
|
|
roc_str.deinit(testing.allocator);
|
|
}
|
|
|
|
for (expected_array) |roc_str| {
|
|
roc_str.deinit(testing.allocator);
|
|
}
|
|
|
|
str.deinit(testing.allocator);
|
|
delimiter.deinit(testing.allocator);
|
|
}
|
|
|
|
expectEqual(expected_array.len, array.len);
|
|
expect(array[0].eq(expected_array[0]));
|
|
expect(array[1].eq(expected_array[1]));
|
|
expect(array[2].eq(expected_array[2]));
|
|
}
|
|
|
|
// This is used for `Str.split : Str, Str -> Array Str
|
|
// It is used to count how many segments the input `_str`
|
|
// needs to be broken into, so that we can allocate a array
|
|
// of that size. It always returns at least 1.
|
|
pub fn countSegments(string: RocStr, delimiter: RocStr) callconv(.C) usize {
|
|
const str_bytes = string.asU8ptr();
|
|
const str_len = string.len();
|
|
|
|
const delimiter_bytes_ptrs = delimiter.asU8ptr();
|
|
const delimiter_len = delimiter.len();
|
|
|
|
var count: usize = 1;
|
|
|
|
if (str_len > delimiter_len) {
|
|
var str_index: usize = 0;
|
|
const end_cond: usize = str_len - delimiter_len + 1;
|
|
|
|
while (str_index < end_cond) {
|
|
var delimiter_index: usize = 0;
|
|
|
|
var matches_delimiter = true;
|
|
|
|
while (delimiter_index < delimiter_len) {
|
|
const delimiterChar = delimiter_bytes_ptrs[delimiter_index];
|
|
const strChar = str_bytes[str_index + delimiter_index];
|
|
|
|
if (delimiterChar != strChar) {
|
|
matches_delimiter = false;
|
|
break;
|
|
}
|
|
|
|
delimiter_index += 1;
|
|
}
|
|
|
|
if (matches_delimiter) {
|
|
count += 1;
|
|
}
|
|
|
|
str_index += 1;
|
|
}
|
|
}
|
|
|
|
return count;
|
|
}
|
|
|
|
test "countSegments: long delimiter" {
|
|
// Str.split "str" "delimiter" == [ "str" ]
|
|
// 1 segment
|
|
const str_arr = "str";
|
|
const str = RocStr.init(testing.allocator, str_arr, str_arr.len);
|
|
|
|
const delimiter_arr = "delimiter";
|
|
const delimiter = RocStr.init(testing.allocator, delimiter_arr, delimiter_arr.len);
|
|
|
|
defer {
|
|
str.deinit(testing.allocator);
|
|
delimiter.deinit(testing.allocator);
|
|
}
|
|
|
|
const segments_count = countSegments(str, delimiter);
|
|
expectEqual(segments_count, 1);
|
|
}
|
|
|
|
test "countSegments: delimiter at start" {
|
|
// Str.split "hello there" "hello" == [ "", " there" ]
|
|
// 2 segments
|
|
const str_arr = "hello there";
|
|
const str = RocStr.init(testing.allocator, str_arr, str_arr.len);
|
|
|
|
const delimiter_arr = "hello";
|
|
const delimiter = RocStr.init(testing.allocator, delimiter_arr, delimiter_arr.len);
|
|
|
|
defer {
|
|
str.deinit(testing.allocator);
|
|
delimiter.deinit(testing.allocator);
|
|
}
|
|
|
|
const segments_count = countSegments(str, delimiter);
|
|
|
|
expectEqual(segments_count, 2);
|
|
}
|
|
|
|
test "countSegments: delimiter interspered" {
|
|
// Str.split "a!b!c" "!" == [ "a", "b", "c" ]
|
|
// 3 segments
|
|
const str_arr = "a!b!c";
|
|
const str = RocStr.init(testing.allocator, str_arr, str_arr.len);
|
|
|
|
const delimiter_arr = "!";
|
|
const delimiter = RocStr.init(testing.allocator, delimiter_arr, delimiter_arr.len);
|
|
|
|
defer {
|
|
str.deinit(testing.allocator);
|
|
delimiter.deinit(testing.allocator);
|
|
}
|
|
|
|
const segments_count = countSegments(str, delimiter);
|
|
|
|
expectEqual(segments_count, 3);
|
|
}
|
|
|
|
fn rocStrFromLiteral(bytes_arr: *const []u8) RocStr {}
|
|
|
|
// Str.startsWith
|
|
pub fn startsWith(string: RocStr, prefix: RocStr) callconv(.C) bool {
|
|
const bytes_len = string.len();
|
|
const bytes_ptr = string.asU8ptr();
|
|
|
|
const prefix_len = prefix.len();
|
|
const prefix_ptr = prefix.asU8ptr();
|
|
|
|
if (prefix_len > bytes_len) {
|
|
return false;
|
|
}
|
|
|
|
// we won't exceed bytes_len due to the previous check
|
|
var i: usize = 0;
|
|
while (i < prefix_len) {
|
|
if (bytes_ptr[i] != prefix_ptr[i]) {
|
|
return false;
|
|
}
|
|
i += 1;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
test "startsWith: foo starts with fo" {
|
|
const foo = RocStr.init(testing.allocator, "foo", 3);
|
|
const fo = RocStr.init(testing.allocator, "fo", 2);
|
|
expect(startsWith(foo, fo));
|
|
}
|
|
|
|
test "startsWith: 123456789123456789 starts with 123456789123456789" {
|
|
const str = RocStr.init(testing.allocator, "123456789123456789", 18);
|
|
defer str.deinit(testing.allocator);
|
|
expect(startsWith(str, str));
|
|
}
|
|
|
|
test "startsWith: 12345678912345678910 starts with 123456789123456789" {
|
|
const str = RocStr.init(testing.allocator, "12345678912345678910", 20);
|
|
defer str.deinit(testing.allocator);
|
|
const prefix = RocStr.init(testing.allocator, "123456789123456789", 18);
|
|
defer prefix.deinit(testing.allocator);
|
|
|
|
expect(startsWith(str, prefix));
|
|
}
|
|
|
|
// Str.endsWith
|
|
pub fn endsWith(string: RocStr, suffix: RocStr) callconv(.C) bool {
|
|
const bytes_len = string.len();
|
|
const bytes_ptr = string.asU8ptr();
|
|
|
|
const suffix_len = suffix.len();
|
|
const suffix_ptr = suffix.asU8ptr();
|
|
|
|
if (suffix_len > bytes_len) {
|
|
return false;
|
|
}
|
|
|
|
const offset: usize = bytes_len - suffix_len;
|
|
var i: usize = 0;
|
|
while (i < suffix_len) {
|
|
if (bytes_ptr[i + offset] != suffix_ptr[i]) {
|
|
return false;
|
|
}
|
|
i += 1;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
test "endsWith: foo ends with oo" {
|
|
const foo = RocStr.init(testing.allocator, "foo", 3);
|
|
const oo = RocStr.init(testing.allocator, "oo", 2);
|
|
defer foo.deinit(testing.allocator);
|
|
defer oo.deinit(testing.allocator);
|
|
|
|
expect(endsWith(foo, oo));
|
|
}
|
|
|
|
test "endsWith: 123456789123456789 ends with 123456789123456789" {
|
|
const str = RocStr.init(testing.allocator, "123456789123456789", 18);
|
|
defer str.deinit(testing.allocator);
|
|
expect(endsWith(str, str));
|
|
}
|
|
|
|
test "endsWith: 12345678912345678910 ends with 345678912345678910" {
|
|
const str = RocStr.init(testing.allocator, "12345678912345678910", 20);
|
|
const suffix = RocStr.init(testing.allocator, "345678912345678910", 18);
|
|
defer str.deinit(testing.allocator);
|
|
defer suffix.deinit(testing.allocator);
|
|
|
|
expect(endsWith(str, suffix));
|
|
}
|
|
|
|
test "endsWith: hello world ends with world" {
|
|
const str = RocStr.init(testing.allocator, "hello world", 11);
|
|
const suffix = RocStr.init(testing.allocator, "world", 5);
|
|
defer str.deinit(testing.allocator);
|
|
defer suffix.deinit(testing.allocator);
|
|
|
|
expect(endsWith(str, suffix));
|
|
}
|
|
|
|
// Str.concat
|
|
// When we actually use this in Roc, libc will be linked so we have access to std.heap.c_allocator
|
|
pub fn strConcatC(ptr_size: u32, result_in_place: InPlace, arg1: RocStr, arg2: RocStr) callconv(.C) RocStr {
|
|
return @call(.{ .modifier = always_inline }, strConcat, .{ std.heap.c_allocator, ptr_size, result_in_place, arg1, arg2 });
|
|
}
|
|
|
|
fn strConcat(allocator: *Allocator, ptr_size: u32, result_in_place: InPlace, arg1: RocStr, arg2: RocStr) RocStr {
|
|
return switch (ptr_size) {
|
|
4 => strConcatHelp(allocator, i32, result_in_place, arg1, arg2),
|
|
8 => strConcatHelp(allocator, i64, result_in_place, arg1, arg2),
|
|
else => unreachable,
|
|
};
|
|
}
|
|
|
|
fn strConcatHelp(allocator: *Allocator, comptime T: type, result_in_place: InPlace, arg1: RocStr, arg2: RocStr) RocStr {
|
|
if (arg1.isEmpty()) {
|
|
return RocStr.clone(allocator, T, result_in_place, arg2);
|
|
} else if (arg2.isEmpty()) {
|
|
return RocStr.clone(allocator, T, result_in_place, arg1);
|
|
} else {
|
|
const combined_length = arg1.len() + arg2.len();
|
|
|
|
const small_str_bytes = 2 * @sizeOf(T);
|
|
const result_is_big = combined_length >= small_str_bytes;
|
|
|
|
if (result_is_big) {
|
|
var result = RocStr.initBig(allocator, T, result_in_place, combined_length);
|
|
|
|
{
|
|
const old_bytes = arg1.asU8ptr();
|
|
|
|
const new_bytes: [*]u8 = @ptrCast([*]u8, result.str_bytes);
|
|
|
|
@memcpy(new_bytes, old_bytes, arg1.len());
|
|
}
|
|
|
|
{
|
|
const old_bytes = arg2.asU8ptr();
|
|
|
|
const new_bytes = @ptrCast([*]u8, result.str_bytes) + arg1.len();
|
|
|
|
@memcpy(new_bytes, old_bytes, arg2.len());
|
|
}
|
|
|
|
return result;
|
|
} else {
|
|
var result = [16]u8{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
|
|
|
|
// if the result is small, then for sure arg1 and arg2 are also small
|
|
|
|
{
|
|
var old_bytes: [*]u8 = @ptrCast([*]u8, &@bitCast([16]u8, arg1));
|
|
var new_bytes: [*]u8 = @ptrCast([*]u8, &result);
|
|
|
|
@memcpy(new_bytes, old_bytes, arg1.len());
|
|
}
|
|
|
|
{
|
|
var old_bytes: [*]u8 = @ptrCast([*]u8, &@bitCast([16]u8, arg2));
|
|
var new_bytes = @ptrCast([*]u8, &result) + arg1.len();
|
|
|
|
@memcpy(new_bytes, old_bytes, arg2.len());
|
|
}
|
|
|
|
const mask: u8 = 0b1000_0000;
|
|
const final_byte = @truncate(u8, combined_length) | mask;
|
|
|
|
result[small_str_bytes - 1] = final_byte;
|
|
|
|
return @bitCast(RocStr, result);
|
|
}
|
|
|
|
return result;
|
|
}
|
|
}
|
|
|
|
test "RocStr.concat: small concat small" {
|
|
const str1_len = 3;
|
|
var str1: [str1_len]u8 = "foo".*;
|
|
const str1_ptr: [*]u8 = &str1;
|
|
var roc_str1 = RocStr.init(testing.allocator, str1_ptr, str1_len);
|
|
|
|
const str2_len = 3;
|
|
var str2: [str2_len]u8 = "abc".*;
|
|
const str2_ptr: [*]u8 = &str2;
|
|
var roc_str2 = RocStr.init(testing.allocator, str2_ptr, str2_len);
|
|
|
|
const str3_len = 6;
|
|
var str3: [str3_len]u8 = "fooabc".*;
|
|
const str3_ptr: [*]u8 = &str3;
|
|
var roc_str3 = RocStr.init(testing.allocator, str3_ptr, str3_len);
|
|
|
|
defer {
|
|
roc_str1.deinit(testing.allocator);
|
|
roc_str2.deinit(testing.allocator);
|
|
roc_str3.deinit(testing.allocator);
|
|
}
|
|
|
|
const result = strConcat(testing.allocator, 8, InPlace.Clone, roc_str1, roc_str2);
|
|
|
|
defer result.deinit(testing.allocator);
|
|
|
|
expect(roc_str3.eq(result));
|
|
}
|