build: add oneshot parsing example

build.zig

@@ -1,7 +1,45 @@
 const std = @import("std");
 
 pub fn build(b: *std.Build) void {
+    const target = b.standardTargetOptions(.{});
+
     const nice = b.addModule("nice", .{
         .source_file = .{ .path = "src/config.zig" },
     });
+
+    add_examples(b, .{
+        .target = target,
+        .nice_mod = nice,
+    });
+}
+
+const ExampleOptions = struct {
+    target: std.zig.CrossTarget,
+    nice_mod: *std.Build.Module,
+};
+
+const Example = struct {
+    name: []const u8,
+    file: []const u8,
+};
+
+const examples = [_]Example{
+    .{ .name = "parse", .file = "examples/parse.zig" },
+};
+
+pub fn add_examples(b: *std.build, options: ExampleOptions) void {
+    const example_step = b.step("examples", "build examples");
+
+    inline for (examples) |example| {
+        const ex_exe = b.addExecutable(.{
+            .name = example.name,
+            .root_source_file = .{ .path = example.file },
+            .target = options.target,
+            .optimize = .Debug,
+        });
+
+        ex_exe.addModule("nice", options.nice_mod);
+        const install = b.addInstallArtifact(ex_exe, .{});
+        example_step.dependOn(&install.step);
+    }
 }

examples/parse.zig

@@ -0,0 +1,29 @@
+const std = @import("std");
+
+const nice = @import("nice");
+
+pub fn main() !void {
+    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
+    defer _ = gpa.deinit();
+    const allocator = gpa.allocator();
+
+    const args = try std.process.argsAlloc(allocator);
+    defer std.process.argsFree(allocator, args);
+    if (args.len < 2) return;
+
+    const data = try std.fs.cwd().readFileAlloc(allocator, args[1], 4_294_967_295);
+    var needfree = true;
+    defer if (needfree) allocator.free(data);
+
+    var parser = nice.Parser{ .allocator = allocator };
+
+    const document = try parser.parseBuffer(data);
+    defer document.deinit();
+
+    // free data memory to ensure that the parsed document is not holding
+    // references to it.
+    allocator.free(data);
+    needfree = false;
+
+    document.printDebug();
+}