4 files changed, 52 insertions, 20 deletions

diff --git a/src/eval/Title.zig b/src/eval/Title.zig
index 56524ad..730d512 100644
--- a/src/eval/Title.zig
+++ b/src/eval/Title.zig
@@ -38,7 +38,7 @@ fn html(context: *anyopaque, alloc: Allocator) HTML.Error!HTML {
         5 => "h5",
         6 => "h6",
         else => unreachable,
-        });
+    });
     errdefer el.deinit();
     try el.appendContent(try self.content.html(alloc));
     return el;
diff --git a/src/eval/paragraph.zig b/src/eval/paragraph.zig
index e56b7ff..468b92e 100644
--- a/src/eval/paragraph.zig
+++ b/src/eval/paragraph.zig
@@ -9,7 +9,6 @@ pub const Bold = Element.Simple("b");
 pub const Italic = Element.Simple("em");
 pub const Code = Element.Simple("code");
 
-
 pub const Link = struct {
     link: []const u8,
     content: Element,
diff --git a/src/parser.zig b/src/parser.zig
index 163c5a8..b2c0f95 100644
--- a/src/parser.zig
+++ b/src/parser.zig
@@ -11,24 +11,43 @@ pub const Error = error{
     FeatureNotSupported,
 } || Lexer.Error || paragraph.Error || title.Error || link.Error || Allocator.Error;
 
-pub fn parseReader(parent: Allocator, r: *std.io.Reader) ![]const u8 {
+pub const Document = struct {
+    arena: std.heap.ArenaAllocator,
+    root: []Element,
+
+    pub fn renderHTML(self: @This(), alloc: Allocator) Element.HTML.Error![]const u8 {
+        var content = try std.ArrayList(u8).initCapacity(alloc, self.root.len * 6);
+        errdefer content.deinit(alloc);
+        for (self.root) |it| {
+            const v = try it.renderHTML(alloc);
+            defer alloc.free(v);
+            try content.appendSlice(alloc, v);
+        }
+        return content.toOwnedSlice(alloc);
+    }
+
+    pub fn deinit(self: @This()) void {
+        self.arena.deinit();
+    }
+};
+
+pub fn parseReader(parent: Allocator, r: *std.io.Reader) !Document {
     var l = try Lexer.initReader(parent, r);
     defer parent.free(l.iter.bytes);
     return gen(parent, &l);
 }
 
-pub fn parse(parent: Allocator, content: []const u8) Error![]const u8 {
+pub fn parse(parent: Allocator, content: []const u8) Error!Document {
     var l = try Lexer.init(content);
     return gen(parent, &l);
 }
 
-fn gen(parent: Allocator, l: *Lexer) Error![]const u8 {
+fn gen(parent: Allocator, l: *Lexer) Error!Document {
     var arena = std.heap.ArenaAllocator.init(parent);
-    defer arena.deinit();
     const alloc = arena.allocator();
+    errdefer arena.deinit();
 
     var elements = try std.ArrayList(Element).initCapacity(alloc, 2);
-
     base: while (l.peek()) |it| {
         try elements.append(alloc, switch (it.kind) {
             // block paragraph
@@ -42,20 +61,16 @@ fn gen(parent: Allocator, l: *Lexer) Error![]const u8 {
             else => return Error.FeatureNotSupported,
         });
     }
-
-    var res = try std.ArrayList(u8).initCapacity(parent, elements.items.len);
-    errdefer res.deinit(parent);
-    for (elements.items) |it| {
-        try res.appendSlice(parent, try it.renderHTML(alloc));
-    }
-    return res.toOwnedSlice(parent);
+    return .{ .root = try elements.toOwnedSlice(alloc), .arena = arena };
 }
 
 fn doTest(alloc: Allocator, t: []const u8, v: []const u8) !void {
     const g = try parse(alloc, t);
-    defer alloc.free(g);
-    std.testing.expect(std.mem.eql(u8, g, v)) catch |err| {
-        std.debug.print("{s}\n", .{g});
+    defer g.deinit();
+    const res = try g.renderHTML(alloc);
+    defer alloc.free(res);
+    std.testing.expect(std.mem.eql(u8, res, v)) catch |err| {
+        std.debug.print("{s}\n", .{res});
         return err;
     };
 }
@@ -78,3 +93,14 @@ test "parse multilines" {
         \\hehe
     , "<h1>title</h1><p>hello world ;3</p><h2>subtitle</h2><p>hehe</p>");
 }
+
+test "multiple render doc" {
+    var arena = std.heap.ArenaAllocator.init(std.testing.allocator);
+    defer arena.deinit();
+    const alloc = arena.allocator();
+
+    const g = try parse(alloc, "hello *world*");
+    const a = try g.renderHTML(alloc);
+    const b = try g.renderHTML(alloc);
+    try std.testing.expect(std.mem.eql(u8, a, b));
+}
diff --git a/src/root.zig b/src/root.zig
index 32f48ef..185e6b6 100644
--- a/src/root.zig
+++ b/src/root.zig
@@ -1,6 +1,8 @@
 const std = @import("std");
 const builtin = @import("builtin");
+const Allocator = std.mem.Allocator;
 const parser = @import("parser.zig");
+pub const Document = parser.Document;
 pub const Error = parser.Error;
 
 inline fn getErrorCode(err: Error) u8 {
@@ -45,7 +47,12 @@ var default_alloc: std.mem.Allocator =
 /// Use typdown_getErrorString to retrieve the string linked with the error code.
 /// Use parse if you are in Zig.
 export fn typdown_parse(content: [*:0]const u8, code: *u8) ?[*:0]const u8 {
-    const res = parse(default_alloc, std.mem.span(content)) catch |err| {
+    const doc = parse(default_alloc, std.mem.span(content)) catch |err| {
+        code.* = getErrorCode(err);
+        return null;
+    };
+    defer doc.deinit();
+    const res = doc.renderHTML(default_alloc) catch |err| {
         code.* = getErrorCode(err);
         return null;
     };
@@ -60,11 +67,11 @@ export fn typdown_parse(content: [*:0]const u8, code: *u8) ?[*:0]const u8 {
 /// Parse the content.
 ///
 /// Use parse if you are not in Zig.
-pub fn parse(alloc: std.mem.Allocator, content: []const u8) Error![]const u8 {
+pub fn parse(alloc: std.mem.Allocator, content: []const u8) Error!Document {
     return parser.parse(alloc, content);
 }
 
-pub fn parseReader(alloc: std.mem.Allocator, r: *std.io.Reader) (Error || std.io.Reader.Error)![]const u8 {
+pub fn parseReader(alloc: std.mem.Allocator, r: *std.io.Reader) (Error || std.io.Reader.Error)!Document {
     return parser.parseReader(alloc, r);
 }