(#63) Allow invoking other templates

Closes #63

src/main/controllers.zig

@@ -227,7 +227,7 @@ pub const Response = struct {
         defer stream.close();
 
         const writer = stream.writer();
-        try @import("template").execute(writer, templ, data);
+        try @import("template").execute(writer, .{}, templ, data);
 
         try stream.finish();
     }

src/template/lib.zig

@@ -1,7 +1,11 @@
 const std = @import("std");
 
 pub fn main() !void {
-    try execute(std.io.getStdOut().writer(), @embedFile("./test.tmp.html"), .{
+    try execute(
+        std.io.getStdOut().writer(),
+        .{ .test_tmpl = "{.x}" },
+        @embedFile("./test.tmp.html"),
+        .{
             .community = .{ .name = "abcd" },
             .foo = [_][]const u8{ "5", "4", "3", "2", "1" },
             .baz = [_][]const []const u8{
@@ -11,27 +15,28 @@ pub fn main() !void {
             .bar = .{ .x = "x" },
             .qux = false,
             .quxx = true,
-    });
+        },
+    );
 }
 
-pub fn execute(writer: anytype, comptime template: []const u8, args: anytype) !void {
+pub fn execute(writer: anytype, comptime other_templates: anytype, comptime template: []const u8, args: anytype) !void {
     @setEvalBranchQuota(@intCast(u32, template.len * 8));
 
     const tokens = comptime parseTemplateTokens(ControlTokenIter{ .text = template });
     const tmpl = comptime parseTemplate(tokens, 0, .root);
-    try executeTemplate(writer, tmpl.items, args, .{});
+    try executeTemplate(writer, other_templates, tmpl.items, args, .{});
 }
 
-fn executeTemplate(writer: anytype, comptime items: []const TemplateItem, args: anytype, captures: anytype) !void {
+fn executeTemplate(writer: anytype, comptime templates: anytype, comptime items: []const TemplateItem, args: anytype, captures: anytype) !void {
     inline for (items) |it| {
         switch (it) {
             .text => |text| try writer.writeAll(text),
-            .statement => |stmt| try executeStatement(writer, stmt, args, captures),
+            .statement => |stmt| try executeStatement(writer, templates, stmt, args, captures),
         }
     }
 }
 
-fn executeStatement(writer: anytype, comptime stmt: Statement, args: anytype, captures: anytype) !void {
+fn executeStatement(writer: anytype, comptime templates: anytype, comptime stmt: Statement, args: anytype, captures: anytype) !void {
     switch (stmt) {
         .expression => |expr| {
             const val = evaluateExpression(expr, args, captures);
@@ -44,6 +49,7 @@ fn executeStatement(writer: anytype, comptime stmt: Statement, args: anytype, ca
             for (iterable) |v| {
                 try executeTemplate(
                     writer,
+                    templates,
                     subtemplate,
                     args,
                     addCapture(captures, loop.header.capture, v),
@@ -54,16 +60,18 @@ fn executeStatement(writer: anytype, comptime stmt: Statement, args: anytype, ca
             const condition = evaluateExpression(if_stmt.header.condition, args, captures);
             const subtemplate = if_stmt.subtemplate;
             if (condition) {
-                try executeTemplate(writer, subtemplate, args, captures);
+                try executeTemplate(writer, templates, subtemplate, args, captures);
             } else {
                 if (if_stmt.else_branch) |branch| switch (branch) {
-                    .@"else" => |subtmpl| try executeTemplate(writer, subtmpl, args, captures),
-                    .elif => |elif| try executeStatement(writer, .{ .@"if" = elif.* }, args, captures),
+                    .@"else" => |subtmpl| try executeTemplate(writer, templates, subtmpl, args, captures),
+                    .elif => |elif| try executeStatement(writer, templates, .{ .@"if" = elif.* }, args, captures),
                 };
             }
         },
         .call_template => |call| {
-            std.log.debug("calling template {s} with arg {any}", .{ call.template_name, call.args });
+            const new_template = @field(templates, call.template_name);
+            try execute(writer, templates, new_template, evaluateExpression(call.args, args, captures));
+            //std.log.debug("calling template {s} with arg {any}", .{ call.template_name, call.args });
         },
         //else => @compileError("TODO"),
     }

src/template/test.tmp.html

@@ -22,7 +22,7 @@
         neither
       {=/if}
 
-      {#template test_tmpl .bar}
+      <template>{#template test_tmpl .bar}</template>
     </section>
   </body>
 </html>