Implement HashMap parsing

closes #9

README.md

@@ -28,6 +28,7 @@ This is a top-down LL parser that parses directly into Zig structs.
   * [x] Mapping to pointers
   * [x] Mapping to integer and floats with lower bit number than defined by TOML, i.e. `i16`, `f32`.
   * [x] Mapping to optional fields
+  * [x] Mapping to HashMaps
 
 ## Example
 See [`example1.zig`](./examples/example1.zig) for the complete code that parses [`example.toml`](./examples/example1.toml)

src/main.zig

@@ -12,6 +12,7 @@ pub const Time = datetime.Time;
 pub const DateTime = datetime.DateTime;
 pub const Value = value.Value;
 pub const ValueList = value.ValueList;
+pub const HashMap = struct_mapping.HashMap;
 
 pub const Position = parser.Position;
 pub const FieldPath = []const []const u8;

src/struct_mapping.zig

@@ -23,6 +23,10 @@ pub const Context = struct {
 };
 
 pub fn intoStruct(ctx: *Context, comptime T: type, dest: *T, table: *Table) !void {
+    if (std.meta.hasFn(T, "tomlIntoStruct")) {
+        dest.* = try T.tomlIntoStruct(ctx, table);
+        return;
+    }
     switch (@typeInfo(T)) {
         .@"struct" => |info| {
             inline for (info.fields) |field_info| {
@@ -181,3 +185,26 @@ fn setValue(ctx: *Context, comptime T: type, dest: *T, value: *const Value) !voi
         else => return error.NotSupportedFieldType,
     }
 }
+
+pub fn HashMap(comptime T: type) type {
+    return struct {
+        map: std.StringHashMap(T),
+
+        pub fn tomlIntoStruct(ctx: *Context, table: *Table) !@This() {
+            var map = std.StringHashMap(T).init(ctx.alloc);
+            errdefer map.deinit();
+
+            var it = table.iterator();
+            while (it.next()) |entry| {
+                var value: T = undefined;
+                try setValue(ctx, T, &value, entry.value_ptr);
+
+                const key: []u8 = try ctx.alloc.alloc(u8, entry.key_ptr.len);
+                @memcpy(key, entry.key_ptr.*);
+                try map.put(key, value);
+            }
+
+            return .{ .map = map };
+        }
+    };
+}

src/tests.zig

@@ -67,6 +67,8 @@ test "parse into struct" {
         e1: E1,
         tab1: Table,
         tab2: *Table,
+        hm: main.HashMap(Tt),
+        hm2: *main.HashMap(Tt),
     };
 
     var p = main.Parser(Aa).init(testing.allocator);
@@ -124,6 +126,20 @@ test "parse into struct" {
     try testing.expectEqualSlices(u8, "str1", aa.tab1.get("b").?.table.get("val").?.string);
     try testing.expectEqual(4, aa.tab2.get("a").?.table.get("val").?.integer);
     try testing.expectEqualSlices(u8, "str2", aa.tab2.get("b").?.table.get("val").?.string);
+
+    try testing.expectEqual(3, aa.hm.map.get("f1").?.aa);
+    try testing.expectEqual(4, aa.hm.map.get("f1").?.bb);
+    try testing.expectEqual(5, aa.hm.map.get("f2").?.aa);
+    try testing.expectEqual(6, aa.hm.map.get("f2").?.bb);
+    try testing.expectEqual(10, aa.hm.map.get("f3").?.aa);
+    try testing.expectEqual(11, aa.hm.map.get("f3").?.bb);
+
+    try testing.expectEqual(3, aa.hm2.map.get("f1").?.aa);
+    try testing.expectEqual(4, aa.hm2.map.get("f1").?.bb);
+    try testing.expectEqual(5, aa.hm2.map.get("f2").?.aa);
+    try testing.expectEqual(6, aa.hm2.map.get("f2").?.bb);
+    try testing.expectEqual(10, aa.hm2.map.get("f3").?.aa);
+    try testing.expectEqual(11, aa.hm2.map.get("f3").?.bb);
 }
 
 test "optionals (--release=fast)" {

test/doc1.toml.txt

@@ -46,3 +46,17 @@ val = "str1"
 val = 4
 [tab2.b]
 val = "str2"
+
+[hm]
+f1 = {aa= 3, bb = 4}
+f2 = {aa = 5, bb = 6}
+[hm.f3]
+aa = 10
+bb = 11
+
+[hm2]
+f1 = {aa= 3, bb = 4}
+f2 = {aa = 5, bb = 6}
+[hm2.f3]
+aa = 10
+bb = 11