add initialisation method from embedde file

src/lib.zig

@@ -1,6 +1,8 @@
 const std = @import("std");
 const rand = std.crypto.random;
 
+const markov_data = @embedFile("markov.bin");
+
 pub const DataPoint = struct {
     char: u8,
     prob: f32,
@@ -15,23 +17,31 @@ pub const MarkovChain = struct {
     allocator: std.mem.Allocator,
     map: std.AutoHashMap(u8, []DataPoint),
 
-    pub fn init(path: []const u8, allocator: std.mem.Allocator) !MarkovChain {
+    pub fn fromFile(path: []const u8, allocator: std.mem.Allocator) !MarkovChain {
+        var markovBinFile = try std.fs.cwd().openFile(path, .{ .mode = .read_only });
+        const reader = markovBinFile.reader();
+
+        return try fromReader(&reader, allocator);
+    }
+
+    pub fn fromMemory(data: []const u8, allocator: std.mem.Allocator) !MarkovChain {
+        var stream = std.io.fixedBufferStream(data);
+        const reader = stream.reader();
+
+        return try fromReader(reader, allocator);
+    }
+
+    fn fromReader(reader: anytype, allocator: std.mem.Allocator) !MarkovChain {
         var self = MarkovChain{
             .allocator = allocator,
             .map = std.AutoHashMap(u8, []DataPoint).init(allocator),
         };
 
-        var markovBinFile = try std.fs.cwd().openFile(path, .{ .mode = .read_only });
-
-        var reader = markovBinFile.reader();
-
         for (0..256) |prevChar| {
             const cnt = try reader.readInt(u8, .little);
-            //std.debug.print("previous : {c} - cnt : {d}\n", .{ @as(u8, @intCast(prevChar)), cnt });
             var nextChars: []DataPoint = try self.allocator.alloc(DataPoint, cnt);
             for (0..cnt) |i| {
                 const nextByte = try reader.readByte();
-                //std.debug.print("next : {c}\n", .{nextByte});
                 const prob: f32 = @bitCast(try reader.readInt(u32, .little));
                 nextChars[i] = DataPoint{
                     .char = nextByte,
@@ -41,8 +51,6 @@ pub const MarkovChain = struct {
             try self.map.put(@as(u8, @intCast(prevChar)), nextChars);
         }
 
-        //std.debug.print("choices for A : {any}\n", .{self.map.get(97).?});
-
         return self;
     }
 
@@ -74,19 +82,36 @@ pub const MarkovChain = struct {
     }
 };
 
-test "basic test" {
+test "basic test from file" {
     var gpa = std.heap.GeneralPurposeAllocator(.{}){};
     const allocator = gpa.allocator();
     defer {
         _ = gpa.deinit();
     }
 
-    var markov = try MarkovChain.init("markov.bin", allocator);
+    var markov = try MarkovChain.fromFile("markov.bin", allocator);
     defer markov.deinit();
 
-    for (0..24) |_| {
+    for (0..6) |_| {
         const randName = try markov.generate(8, allocator);
         defer allocator.free(randName);
-        std.debug.print("generated : {s}\n", .{randName});
+        std.debug.print("generated from file: {s}\n", .{randName});
+    }
+}
+
+test "basic test from embedded file" {
+    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
+    const allocator = gpa.allocator();
+    defer {
+        _ = gpa.deinit();
+    }
+
+    var markov = try MarkovChain.fromMemory(markov_data, allocator);
+    defer markov.deinit();
+
+    for (0..6) |_| {
+        const randName = try markov.generate(8, allocator);
+        defer allocator.free(randName);
+        std.debug.print("generated from memory: {s}\n", .{randName});
     }
 }