DzLox

commit d029753740ee504e49ac581cf101ea57c3a1534c
parent 894c642b4d9c59a602305306f9ac8800d4108871
Author: Szymon Mikulicz <szymon.mikulicz@posteo.net>
Date:   Sat, 22 Oct 2022 03:03:55 +0200

First instruction

Diffstat:
A
zlox/src/chunk.zig
 | 
35
+++++++++++++++++++++++++++++++++++
A
zlox/src/debug.zig
 | 
29
+++++++++++++++++++++++++++++
M
zlox/src/main.zig
 | 
16
++++++++++------

3 files changed, 74 insertions(+), 6 deletions(-)
diff --git a/zlox/src/chunk.zig b/zlox/src/chunk.zig
@@ -0,0 +1,35 @@
+const std = @import("std");
+
+pub const OP = enum(u8) { RETURN };
+
+fn grow_capacity(capacity: usize) usize {
+    return if (capacity < 8) 8 else capacity * 2;
+}
+
+fn grow_array(comptime T: type, allocator: std.mem.Allocator, ptr: ?[]T, new_count: usize) ![]T {
+    return if (ptr == null)
+        try allocator.alloc(T, new_count)
+    else
+        try allocator.reallocAtLeast(ptr.?, new_count);
+}
+
+pub const Chunk = struct {
+    pub fn init(allocator: std.mem.Allocator) Chunk {
+        return Chunk{ .count = 0, .capacity = 0, .code = null, .allocator = allocator };
+    }
+    pub fn write(self: *Chunk, byte: u8) !void {
+        if (self.capacity < self.count + 1) {
+            self.capacity = grow_capacity(self.capacity);
+            self.code = try grow_array(u8, self.allocator, self.code, self.capacity);
+        }
+        self.code.?[self.count] = byte;
+        self.count += 1;
+    }
+    pub fn free(self: *Chunk) void {
+        self.allocator.free(self.code.?);
+    }
+    count: usize,
+    capacity: usize,
+    code: ?[]u8,
+    allocator: std.mem.Allocator,
+};
diff --git a/zlox/src/debug.zig b/zlox/src/debug.zig
@@ -0,0 +1,29 @@
+const std = @import("std");
+const chunk = @import("chunk.zig");
+const OP = chunk.OP;
+
+pub fn disassembleChunk(ch: chunk.Chunk, name: []const u8) !void {
+    std.debug.print("== {s} ==\n", .{name});
+
+    var offset: usize = 0;
+    while (offset < ch.count) {
+        offset = disassembleInstruction(ch.code.?, offset);
+    }
+}
+
+pub fn disassembleInstruction(code: []u8, offset: usize) usize {
+    std.debug.print("{d:0>4} ", .{offset});
+
+    return switch (code[offset]) {
+        @enumToInt(OP.RETURN) => simpleInstruction("OP_RETURN", offset),
+        else => blk: {
+            std.debug.print("Unknown opcode {}\n", .{code[offset]});
+            break :blk offset + 1;
+        },
+    };
+}
+
+pub fn simpleInstruction(name: []const u8, offset: usize) usize {
+    std.debug.print("{s}\n", .{name});
+    return offset + 1;
+}
diff --git a/zlox/src/main.zig b/zlox/src/main.zig
@@ -1,9 +1,13 @@
 const std = @import("std");
+const chunk = @import("chunk.zig");
+const debug = @import("debug.zig");
 
-pub fn main() anyerror!void {
-    std.log.info("All your codebase are belong to us.", .{});
-}
-
-test "basic test" {
-    try std.testing.expectEqual(10, 3 + 7);
+pub fn main() anyerror!u8 {
+    var allocator = std.heap.GeneralPurposeAllocator(.{}){};
+    defer std.debug.assert(!allocator.deinit());
+    var ch = chunk.Chunk.init(allocator.allocator());
+    try ch.write(@enumToInt(chunk.OP.RETURN));
+    try debug.disassembleChunk(ch, "test chunk");
+    ch.free();
+    return 0;
 }