From d578bb422e5018c7ec9d1b984232365fbdf3c784 Mon Sep 17 00:00:00 2001
From: kayomn <kayomn@kayomn.net>
Date: Mon, 24 Oct 2022 13:59:37 +0100
Subject: [PATCH] Change Allocator to use interface style

---
 src/core/io.zig    | 14 +++-----------
 src/core/table.zig | 39 +++++++++++++++++++++++++++------------
 2 files changed, 30 insertions(+), 23 deletions(-)

diff --git a/src/core/io.zig b/src/core/io.zig
index 4418c63..c04fab1 100644
--- a/src/core/io.zig
+++ b/src/core/io.zig
@@ -3,9 +3,9 @@ const stack = @import("./stack.zig");
 const std = @import("std");
 
 ///
-/// Closure for allocating, reallocating, and deallocating dynamic memory resources through itself.
 ///
-pub const Allocator = meta.BiFunction(56, ?[]u8, usize, AllocationError![]u8);
+///
+pub const Allocator = std.mem.Allocator;
 
 ///
 /// File-system agnostic abstraction for manipulating a file.
@@ -203,7 +203,7 @@ pub fn equals(comptime Element: type, this: []const Element, that: []const Eleme
     return true;
 }
 
-test "Equivalence of bytes" {
+test "Memory buffers equal" {
     const bytes_sequence = &.{69, 42, 0};
     const testing = std.testing;
 
@@ -255,11 +255,3 @@ test "Null writing" {
         try testing.expectEqual(nullWriter().apply(sequence), sequence.len);
     }
 }
-
-///
-/// Applies the singular `byte` to `writer`, returning `true` if it was successfully written,
-/// otherwise `false`.
-///
-pub fn writeByte(writer: *Writer, byte: u8) bool {
-    return (writer.apply(std.mem.asBytes(&byte)) != 0);
-}
diff --git a/src/core/table.zig b/src/core/table.zig
index b844766..ddf60b7 100644
--- a/src/core/table.zig
+++ b/src/core/table.zig
@@ -1,4 +1,4 @@
-const std = @import("std");
+const io = @import("./io.zig");
 
 ///
 /// Returns a hash-backed table type of `Value`s indexed by `Key` and using `key_context` as the key
@@ -7,7 +7,7 @@ const std = @import("std");
 pub fn Hashed(comptime Key: type, comptime Value: type,
     comptime key_context: KeyContext(Key)) type {
 
-    const Allocator = std.mem.Allocator;
+    const Allocator = io.Allocator;
 
     return struct {
         allocator: Allocator,
@@ -44,11 +44,13 @@ pub fn Hashed(comptime Key: type, comptime Value: type,
         ///
         /// Initializes a [Self] using `allocator` as the memory allocation strategy.
         ///
-        /// Returns a new [Self] value or an [Allocator.Error] if initializing failed.
+        /// Returns a new [Self] value or an [io.Allocator.Error] if initializing failed.
         ///
         pub fn init(allocator: Allocator) Allocator.Error!Self {
+            const initial_capacity = 4;
+
             return Self{
-                .buckets = try allocator.alloc(Bucket, 4),
+                .buckets = try allocator.alloc(Bucket, initial_capacity),
                 .filled = 0,
                 .allocator = allocator,
                 .load_limit = 0.75,
@@ -158,7 +160,7 @@ pub fn Hashed(comptime Key: type, comptime Value: type,
 /// [InsertError.KeyExists] occurs when an insertion was attempted on a table with a matching key
 /// already present.
 ///
-pub const InsertError = std.mem.Allocator.Error || error {
+pub const InsertError = io.Allocator.Error || error {
     KeyExists,
 };
 
@@ -173,14 +175,27 @@ pub fn KeyContext(comptime Key: type) type {
     };
 }
 
-test "Hashed table manipulation with bytes context" {
-    const testing = std.testing;
-    const io = @import("./io.zig");
+///
+/// A [KeyContext] for dealing with string literal (i.e. []const u8) values.
+///
+/// **Note** that, while lightweight, this context should only be considered safe to use with string
+/// literals or variables pointing to string literals - as the [KeyContext] does not take ownership
+/// of its keys beyond copying the reference.
+///
+pub const string_literal_context = KeyContext([]const u8){
+    .hash = io.hashBytes,
 
-    var table = try Hashed([]const u8, u32, .{
-        .equals = io.equalsBytes,
-        .hash = io.hashBytes,
-    }).init(testing.allocator);
+    .equals = struct {
+        fn stringsEqual(this: []const u8, that: []const u8) bool {
+            return io.equals(u8, this, that);
+        }
+    }.stringsEqual,
+};
+
+test "Hash table manipulation with string literal context" {
+    const testing = @import("std").testing;
+
+    var table = try Hashed([]const u8, u32, string_literal_context).init(testing.allocator);
 
     defer table.deinit();