Tidy up IO code

This commit is contained in:
kayomn 2022-11-01 22:57:25 +00:00
parent 14e5e18228
commit cfd3e85021
1 changed files with 82 additions and 76 deletions

View File

@ -32,26 +32,6 @@ pub fn Spliterator(comptime Element: type) type {
return (self.source.len != 0); return (self.source.len != 0);
} }
test "Check has data" {
var empty_spliterator = Spliterator(u8){
.source = "",
.delimiter = "/",
};
try testing.expect(!empty_spliterator.hasNext());
var stateful_spliterator = Spliterator(u8){
.source = "data",
.delimiter = "/",
};
try testing.expect(stateful_spliterator.hasNext());
_ = try stateful_spliterator.next();
try testing.expect(!stateful_spliterator.hasNext());
}
/// ///
/// Iterates on `self` and returns the next view of [Spliterator.source] that matches /// Iterates on `self` and returns the next view of [Spliterator.source] that matches
/// [Spliterator.delimiter], or `null` if there is no more data to be processed. /// [Spliterator.delimiter], or `null` if there is no more data to be processed.
@ -59,81 +39,99 @@ pub fn Spliterator(comptime Element: type) type {
pub fn next(self: *Self) ?[]const Element { pub fn next(self: *Self) ?[]const Element {
if (!self.hasNext()) return null; if (!self.hasNext()) return null;
if (self.delimiter.len == 0) {
defer self.source = self.source[self.source.len .. self.source.len];
return self.source[0 .. self.source.len];
}
if (findFirstOf(Element, self.source, self.delimiter, struct { if (findFirstOf(Element, self.source, self.delimiter, struct {
fn testEquality(this: Element, that: Element) bool { fn testEquality(this: Element, that: Element) bool {
return this == that; return this == that;
} }
}.testEquality)) |head| { }.testEquality)) |head| {
const tail = (head + self.delimiter.len); defer self.source = self.source[(head + self.delimiter.len) .. self.source.len];
defer self.source = self.source[tail .. self.source.len]; return self.source[0 .. head];
return self.source[0 .. (tail - 1)];
} }
defer self.source = self.source[self.source.len .. self.source.len]; defer self.source = self.source[self.source.len .. self.source.len];
return self.source; return self.source;
} }
test "Iterate through data" {
// Single-character delimiter.
{
var spliterator = Spliterator(u8){
.source = "single.character.separated.hello.world",
.delimiter = ".",
};
const components = [_][]const u8{"single",
"character", "separated", "hello", "world"};
var index = @as(usize, 0);
while (spliterator.next()) |split| : (index += 1) {
try testing.expect(equals(u8, split, components[index]));
}
}
// Multi-character delimiter.
{
var spliterator = Spliterator(u8){
.source = "finding a needle in a needle stack",
.delimiter = "needle",
};
const components = [_][]const u8{"finding a ", " in a ", " stack"};
var index = @as(usize, 0);
while (spliterator.next()) |split| : (index += 1) {
try testing.expect(equals(u8, split, components[index]));
}
}
}
}; };
} }
test "Spliterator of string literals" {
// Empty source.
{
var spliterator = Spliterator(u8){
.source = "",
.delimiter = " ",
};
try testing.expect(!spliterator.hasNext());
}
// Empty delimiter.
{
var spliterator = Spliterator(u8){
.source = "aaa",
.delimiter = "",
};
try testing.expect(spliterator.hasNext());
try testing.expect(equals(u8, spliterator.next().?, "aaa"));
try testing.expect(!spliterator.hasNext());
}
// Single-character delimiter.
{
var spliterator = Spliterator(u8){
.source = "single.character.separated.hello.world",
.delimiter = ".",
};
const components = [_][]const u8{"single",
"character", "separated", "hello", "world"};
var index = @as(usize, 0);
const components_tail = components.len - 1;
while (spliterator.next()) |split| : (index += 1) {
try testing.expect(spliterator.hasNext() == (index < components_tail));
try testing.expect(equals(u8, split, components[index]));
}
try testing.expect(!spliterator.hasNext());
}
// Multi-character delimiter.
{
var spliterator = Spliterator(u8){
.source = "finding a needle in a needle stack",
.delimiter = "needle",
};
const components = [_][]const u8{"finding a ", " in a ", " stack"};
var index = @as(usize, 0);
const components_tail = components.len - 1;
while (spliterator.next()) |split| : (index += 1) {
try testing.expect(spliterator.hasNext() == (index < components_tail));
try testing.expect(equals(u8, split, components[index]));
}
try testing.expect(!spliterator.hasNext());
}
}
/// ///
/// Closure that captures a reference to writable resources like block devices, memory buffers, /// Closure that captures a reference to writable resources like block devices, memory buffers,
/// network sockets, and more. /// network sockets, and more.
/// ///
pub const Writer = meta.Function(@sizeOf(usize), []const u8, usize); pub const Writer = meta.Function(@sizeOf(usize), []const u8, usize);
///
/// Returns `true` if `elements` starts with the characters in `with`, otherwise `false`.
///
pub fn begins(comptime Element: type, elements: []const Element, with: []const Element) bool {
if (elements.len < with.len) return false;
return equals(Element, elements[0 .. with.len], with);
}
test "Check memory begins with" {
const bytes_sequence = &.{69, 42};
try testing.expect(begins(u8, &.{69, 42, 0, 89}, bytes_sequence));
try testing.expect(!begins(u8, &.{69, 89, 42, 0}, bytes_sequence));
}
/// ///
/// Returns a sliced reference of the raw bytes in `pointer`. /// Returns a sliced reference of the raw bytes in `pointer`.
/// ///
@ -260,9 +258,8 @@ pub fn findFirstOf(comptime Element: type, haystack: []const Element,
const tail = (haystack.len - needle.len); const tail = (haystack.len - needle.len);
walk_haystack: while (head <= tail) : (head += 1) { walk_haystack: while (head <= tail) : (head += 1) {
for (needle) |element, index| { for (needle) |element, index|
if (!testEquality(haystack[head + index], element)) continue: walk_haystack; if (!testEquality(haystack[head + index], element)) continue: walk_haystack;
}
return head; return head;
} }
@ -271,7 +268,16 @@ pub fn findFirstOf(comptime Element: type, haystack: []const Element,
} }
test "Find first of sequence" { test "Find first of sequence" {
const haystack = &.{"foo", "bar", "baz"};
const testEquality = struct {
fn testEquality(this: []const u8, that: []const u8) bool {
return equals(u8, this, that);
}
}.testEquality;
try testing.expect(findFirstOf([]const u8, haystack, &.{"bar", "baz"}, testEquality).? == 1);
try testing.expect(findFirstOf([]const u8, haystack, &.{"baz", "bar"}, testEquality) == null);
} }
/// ///