Properly join MacroFor body expressions and remove hack

README.md

@@ -175,6 +175,57 @@ end
 puts ClassView.to_html
 ```
 
+### Compile-time Control Flow (MacroIf / MacroFor)
+
+In addition to runtime `if`/`#each`, you can also use Crystal's macro control flow (`{% if %}` / `{% for %}`) inside templates. This runs at compile-time and can be used to generate markup based on compile-time information such as compiler flags or `@type`.
+
+#### `MacroIf` (`{% if %}`)
+
+```crystal
+require "to_html"
+
+class BuildVariantView
+  ToHtml.class_template do
+    head do
+      {% if flag?(:release) %}
+        script src: "/assets/app.min.js"
+      {% else %}
+        script src: "/assets/app.js"
+      {% end %}
+    end
+  end
+end
+
+puts BuildVariantView.to_html
+```
+
+#### `MacroFor` (`{% for %}`)
+
+```crystal
+require "to_html"
+
+class AutoFormView
+  getter first_name : String
+  getter last_name : String
+
+  def initialize(@first_name, @last_name); end
+
+  ToHtml.instance_template do
+    form do
+      {% for ivar in @type.instance_vars %}
+        label for: {{ivar.name.stringify}} do
+          {{ivar.name.stringify}}
+        end
+
+        input type: :text, name: {{ivar.name.stringify}}, value: {{ivar.name.id}}
+      {% end %}
+    end
+  end
+end
+
+puts AutoFormView.new(first_name: "Ada", last_name: "Lovelace").to_html
+```
+
 ### Attributes
 
 #### Named Arguments
@@ -262,12 +313,12 @@ Have a look into the `benchmark/` folder to find out how these numbers were dete
 Execute `crystal run --release benchmark/benchmark.cr` to reproduce.
 
 ```
-         ecr   1.55M (643.71ns) (± 3.02%)  4.27kB/op        fastest
-     to_html 884.07k (  1.13µs) (± 3.45%)  5.52kB/op   1.76× slower
-   blueprint 457.54k (  2.19µs) (± 3.70%)   4.9kB/op   3.40× slower
-     markout 191.89k (  5.21µs) (± 3.37%)  8.08kB/op   8.10× slower
-html_builder  59.03k ( 16.94µs) (± 3.86%)  10.4kB/op  26.32× slower
-       water  57.48k ( 17.40µs) (± 4.22%)  11.2kB/op  27.03× slower
+         ecr 999.84k (  1.00µs) (± 6.97%)  4.27kB/op        fastest
+     to_html 576.96k (  1.73µs) (± 7.51%)  5.52kB/op   1.73× slower
+   blueprint 377.61k (  2.65µs) (± 8.35%)   4.9kB/op   2.65× slower
+     markout 120.59k (  8.29µs) (± 8.54%)  8.08kB/op   8.29× slower
+html_builder  49.94k ( 20.02µs) (± 7.38%)  10.4kB/op  20.02× slower
+       water  46.83k ( 21.35µs) (± 8.31%)  11.2kB/op  21.35× slower
 ```
 
 Compared shards taken from [awesome-crystal](https://github.com/veelenga/awesome-crystal#html-builders)

shard.lock

@@ -2,7 +2,7 @@ version: 2.0
 shards:
   blueprint:
     git: https://github.com/stephannv/blueprint.git
-    version: 1.0.0
+    version: 1.1.0
 
   html_builder:
     git: https://github.com/crystal-lang/html_builder.git

src/instance_template.cr

@@ -125,20 +125,7 @@ module ToHtml
     {% elsif blk.body.is_a?(MacroFor) %}
       \{% for {{blk.body.vars.splat}} in {{blk.body.exp}} %}
         ToHtml.to_html_eval_exps({{io}}, {{indent_level}}) do
-          # Crystal can turn inline macro expressions (`{{...}}`) inside a macro-for body into
-          # "line-based" output (newlines around the expansion), which breaks calls without
-          # parentheses (e.g. `name:\n"value"\n, value:`). We keep real statement newlines, but
-          # collapse the ones that can't be statement separators.
-          #
-          # Upstream: https://github.com/crystal-lang/crystal/issues/16544
-          {%
-            body = blk.body.body.stringify
-              .gsub(/\s*\n\s*,\s*/, ", ")
-              .gsub(/\s*\n\s*\./, ".")
-              .gsub(/\s*\n\s*do\b/, " do")
-              .gsub(/([:,(\[{=])\s*\n\s*/, "\\1 ")
-          %}
-          {{body.id}}
+          {{blk.body.body.expressions.join("").id}}
         end
       \{% end %}
     {% elsif blk.body.is_a?(MacroExpression) || blk.body.is_a?(MacroLiteral) %}