diff --git a/Cargo.toml b/Cargo.toml
index 1d6ea86..6bc70d2 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -11,11 +11,11 @@ structopt = "0.3.23"
 tera = "1.12.1"
 
 [dependencies.minify-html]
-version = "0.6.8"
+version = "0.8.0"
 features = ["js-esbuild"]
 
 [dependencies.mlua]
-version = "0.6.3"
+version = "0.7.3"
 features = ["luajit", "macros", "serialize"]
 
 [dependencies.serde]
diff --git a/assets/template.html.tera b/assets/template.html.tera
index 3b5ccb9..67a8959 100644
--- a/assets/template.html.tera
+++ b/assets/template.html.tera
@@ -1,107 +1,110 @@
 <!DOCTYPE html>
 <html>
-  <head>
+
+<head>
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width" />
     <title>Plan</title>
 
     <style type="text/css">
-      body {
-        font-family: -apple-system, BlinkMacSystemFont, Segoe UI, Helvetica,
-          Arial, sans-serif, Apple Color Emoji, Segoe UI Emoji;
-      }
+        body {
+            font-family: -apple-system, BlinkMacSystemFont, Segoe UI, Helvetica,
+                Arial, sans-serif, Apple Color Emoji, Segoe UI Emoji;
+        }
 
-      table td,
-      table th {
-        padding: 4px 10px;
-        border: 2px solid #dfe2e5;
-      }
+        table td,
+        table th {
+            padding: 4px 10px;
+            border: 2px solid #dfe2e5;
+        }
 
-      tr {
-        background-color: #fff;
-        border-top: 2px solid #c6cbd1;
-      }
+        tr {
+            background-color: #fff;
+            border-top: 2px solid #c6cbd1;
+        }
 
-      table {
-        display: block;
-        width: 100%;
-        overflow: auto;
-        border-spacing: 0;
-        border-collapse: collapse;
-      }
+        table {
+            display: block;
+            width: 100%;
+            overflow: auto;
+            border-spacing: 0;
+            border-collapse: collapse;
+        }
     </style>
-  </head>
-  <body>
+</head>
+
+<body>
     {% for i in range(end=repeat) %}
     <table>
-      <thead>
-        <tr>
-          <th>&#35;</th>
-          {% if times %}
-          <th align="left">{{ locale.time }}</th>
-          {% endif %}
-          <th align="left">{{ locale.mo }}</th>
-          <th align="left">{{ locale.tu }}</th>
-          <th align="left">{{ locale.we }}</th>
-          <th align="left">{{ locale.th }}</th>
-          <th align="left">{{ locale.fr }}</th>
-        </tr>
-      </thead>
-      <tbody>
-        {% for r in rows %}
-        <tr>
-          <td>{{ r.idx }}</td>
+        <thead>
+            <tr>
+                <th>&#35;</th>
+                {% if times %}
+                <th align="left">{{ locale.time }}</th>
+                {% endif %}
+                <th align="left">{{ locale.mo }}</th>
+                <th align="left">{{ locale.tu }}</th>
+                <th align="left">{{ locale.we }}</th>
+                <th align="left">{{ locale.th }}</th>
+                <th align="left">{{ locale.fr }}</th>
+            </tr>
+        </thead>
+        <tbody>
+            {% for r in rows %}
+            <tr>
+                <td>{{ r.idx }}</td>
 
-          {% if times %}
-          <td>{{ r.time }}</td>
-          {% endif %}
+                {% if times %}
+                <td>{{ r.time }}</td>
+                {% endif %}
 
-          <td>
-            {% if r.mo %} {% if r.mo.room %}
-            <b>{{ r.mo.room }}</b>
-            {% endif %}
+                <td>
+                    {% if r.mo %} {% if r.mo.room %}
+                    <b>{{ r.mo.room }}</b>
+                    {% endif %}
 
-            {{ r.mo.name }}
-            {% endif %}
-          </td>
-          <td>
-            {% if r.tu %} {% if r.tu.room %}
-            <b>{{ r.tu.room }}</b>
-            {% endif %}
+                    {{ r.mo.name }}
+                    {% endif %}
+                </td>
+                <td>
+                    {% if r.tu %} {% if r.tu.room %}
+                    <b>{{ r.tu.room }}</b>
+                    {% endif %}
 
-            {{ r.tu.name }}
-            {% endif %}
-          </td>
-          <td>
-            {% if r.we %} {% if r.we.room %}
-            <b>{{ r.we.room }}</b>
-            {% endif %}
+                    {{ r.tu.name }}
+                    {% endif %}
+                </td>
+                <td>
+                    {% if r.we %} {% if r.we.room %}
+                    <b>{{ r.we.room }}</b>
+                    {% endif %}
 
-            {{ r.we.name }}
-            {% endif %}
-          </td>
-          <td>
-            {% if r.th %} {% if r.th.room %}
-            <b>{{ r.th.room }}</b>
-            {% endif %}
+                    {{ r.we.name }}
+                    {% endif %}
+                </td>
+                <td>
+                    {% if r.th %} {% if r.th.room %}
+                    <b>{{ r.th.room }}</b>
+                    {% endif %}
 
-            {{ r.th.name }}
-            {% endif %}
-          </td>
-          <td>
-            {% if r.fr %} {% if r.fr.room %}
-            <b>{{ r.fr.room }}</b>
-            {% endif %}
+                    {{ r.th.name }}
+                    {% endif %}
+                </td>
+                <td>
+                    {% if r.fr %} {% if r.fr.room %}
+                    <b>{{ r.fr.room }}</b>
+                    {% endif %}
 
-            {{ r.fr.name }}
-            {% endif %}
-          </td>
-        </tr>
-        {% endfor %}
-      </tbody>
+                    {{ r.fr.name }}
+                    {% endif %}
+                </td>
+            </tr>
+            {% endfor %}
+        </tbody>
     </table>
     {% if i != repeat - 1 %}
     <hr />
     {% endif %}{% endfor %}
-  </body>
+</body>
+
 </html>
diff --git a/src/main.rs b/src/main.rs
index fbea62a..c3971e0 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,4 +1,3 @@
-use anyhow::Context;
 use std::path::PathBuf;
 use structopt::StructOpt;
 
@@ -13,12 +12,7 @@ struct Opt {
 fn main() -> anyhow::Result<()> {
     let opt = Opt::from_args();
 
-    let s_data = script::run_buildscript(opt.infile)?;
-    let path = s_data.outfile.clone();
-    let rendered = renderer::render(s_data)?;
-
-    std::fs::write(path, rendered)
-        .context("failed to write outfile")?;
+    script::run_buildscript(opt.infile)?;
 
     Ok(())
 }
diff --git a/src/script.rs b/src/script.rs
index 876cf6e..ac32fd7 100644
--- a/src/script.rs
+++ b/src/script.rs
@@ -1,34 +1,51 @@
-use mlua::{Lua, LuaSerdeExt};
+use mlua::{DeserializeOptions, Lua, LuaSerdeExt, Table, Value};
 use serde::{Deserialize, Serialize};
-use std::path::PathBuf;
+use std::{fs, path::PathBuf, sync::Arc};
 
-pub fn run_buildscript(infile: PathBuf) -> anyhow::Result<ScriptData> {
+use crate::renderer;
+
+pub fn run_buildscript(infile: PathBuf) -> anyhow::Result<()> {
     let script = std::fs::read(infile)?;
 
     // required to allow C lua libs
     let lua = unsafe { Lua::unsafe_new() };
+
+    lua.globals()
+        .set("render", lua.create_function(lua_render)?)?;
+
     lua.load(&script).exec()?;
 
-    let sdata = lua.from_value_with(
-        mlua::Value::Table(lua.globals()),
-        mlua::DeserializeOptions::default()
-            .deny_recursive_tables(false)
-            .deny_unsupported_types(false),
-    )?;
+    Ok(())
+}
 
-    Ok(sdata)
+fn lua_render<'lua>(lua: &'lua Lua, args: Table<'lua>) -> Result<(), mlua::Error> {
+    let args =
+        lua.from_value_with::<ScriptData>(Value::Table(args), DeserializeOptions::default())?;
+    let path = args.outfile.clone();
+
+    let rendered =
+        renderer::render(args).map_err(|e| mlua::Error::ExternalError(Arc::from(Box::from(e))))?;
+
+    fs::write(path, rendered)?;
+
+    Ok(())
 }
 
 #[derive(Debug, Deserialize)]
-#[serde(rename_all = "PascalCase")]
 pub struct ScriptData {
     pub days: Days,
     pub outfile: PathBuf,
+    #[serde(default)]
     pub locale: Locale,
+    #[serde(default = "default_repeat_count")]
     pub repeat_count: usize,
     pub times: Vec<String>,
 }
 
+fn default_repeat_count() -> usize {
+    1
+}
+
 #[derive(Debug, Deserialize)]
 pub struct Days {
     pub mo: Vec<Class>,

#	{{ locale.time }}	{{ locale.mo }}	{{ locale.tu }}	{{ locale.we }}	{{ locale.th }}	{{ locale.fr }}
{{ r.idx }}
#	{{ locale.time }}	{{ locale.mo }}	{{ locale.tu }}	{{ locale.we }}	{{ locale.th }}	{{ locale.fr }}
{{ r.idx }}	{{ r.time }}	{{ r.time }}	- {% if r.mo %} {% if r.mo.room %} - {{ r.mo.room }} - {% endif %} +	+ {% if r.mo %} {% if r.mo.room %} + {{ r.mo.room }} + {% endif %} - {{ r.mo.name }} - {% endif %} -	- {% if r.tu %} {% if r.tu.room %} - {{ r.tu.room }} - {% endif %} + {{ r.mo.name }} + {% endif %} +	+ {% if r.tu %} {% if r.tu.room %} + {{ r.tu.room }} + {% endif %} - {{ r.tu.name }} - {% endif %} -	- {% if r.we %} {% if r.we.room %} - {{ r.we.room }} - {% endif %} + {{ r.tu.name }} + {% endif %} +	+ {% if r.we %} {% if r.we.room %} + {{ r.we.room }} + {% endif %} - {{ r.we.name }} - {% endif %} -	- {% if r.th %} {% if r.th.room %} - {{ r.th.room }} - {% endif %} + {{ r.we.name }} + {% endif %} +	+ {% if r.th %} {% if r.th.room %} + {{ r.th.room }} + {% endif %} - {{ r.th.name }} - {% endif %} -	- {% if r.fr %} {% if r.fr.room %} - {{ r.fr.room }} - {% endif %} + {{ r.th.name }} + {% endif %} +	+ {% if r.fr %} {% if r.fr.room %} + {{ r.fr.room }} + {% endif %} - {{ r.fr.name }} - {% endif %} -