feat: skip attribute for for function

README.md

@@ -221,7 +221,7 @@ Stuart currently supports the following functions:
 | `end` | Ends a section or another function. | `end("section_name")`, `end(function_name)` |
 | `insert` | Inserts a section into the template, only used in `root.html`. | `insert("section_name")` |
 | `import` | Imports a JSON file as a variable. | `import($data, "data.json")` |
-| `for` | Iterates over a JSON array or a directory of markdown files. The loop is ended with `end(for)`. | `for($tag, "tags.json")`, `for($post, "posts/", limit=3, order="desc", sortby="date")`, `for($item, $array)` |
+| `for` | Iterates over a JSON array or a directory of markdown files. The loop is ended with `end(for)`. | `for($tag, "tags.json")`, `for($post, "posts/", skip=3, limit=3, order="desc", sortby="date")`, `for($item, $array)` |
 | `dateformat` | Formats a date using the [chrono](https://docs.rs/chrono/0.4.19/chrono/format/strftime/index.html) format string. The date input can be any kind of formatted date or timestamp. | `dateformat($date, "%Y-%m-%d")` |
 | `if[eq,ne,gt,ge,lt,le]` | Performs a comparison between two values. The block is ended with `end(if[eq,ne,...])`. | `ifeq($a, $b)`, `ifge($age, 18)` |
 | `ifdefined` | Checks if a variable is defined. The block is ended with `end(ifdefined)`. | `ifdefined($variable)`, `ifdefined($variable.property)` |

stuart-core/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "stuart_core"
-version = "0.2.4"
+version = "0.2.5"
 edition = "2021"
 license = "MIT"
 homepage = "https://github.com/w-henderson/Stuart"

stuart-core/src/functions/parsers/for.rs

@@ -17,7 +17,8 @@ pub struct ForFunction {
     variable_name: String,
     source: String,
     source_type: ForFunctionSourceType,
-    limit: Option<u16>,
+    skip: Option<usize>,
+    limit: Option<usize>,
     sort_variable: Option<String>,
     sort_order: SortOrder,
 }
@@ -65,12 +66,24 @@ impl FunctionParser for ForParser {
             ForFunctionSourceType::JSONObject
         };
 
+        let mut skip = None;
         let mut limit = None;
         let mut sort_variable = None;
         let mut sort_order = SortOrder::Asc;
 
         for (name, arg) in &raw.named_args {
             match name.as_str() {
+                "skip" => {
+                    quiet_assert!(arg.as_integer().is_some())?;
+                    quiet_assert!(skip.is_none())?;
+
+                    skip = Some(
+                        arg.as_integer()
+                            .unwrap()
+                            .try_into()
+                            .map_err(|_| ParseError::InvalidArgument)?,
+                    );
+                }
                 "limit" => {
                     quiet_assert!(arg.as_integer().is_some())?;
                     quiet_assert!(limit.is_none())?;
@@ -103,6 +116,7 @@ impl FunctionParser for ForParser {
             variable_name: variable_name.to_string(),
             source,
             source_type,
+            skip,
             limit,
             sort_variable,
             sort_order,
@@ -201,13 +215,19 @@ impl Function for ForFunction {
             });
         }
 
-        let variable_iter: Box<dyn Iterator<Item = Value>> = match (self.limit, self.sort_order) {
-            (None, SortOrder::Asc) => Box::new(variables.into_iter()),
-            (None, SortOrder::Desc) => Box::new(variables.into_iter().rev()),
-            (Some(l), SortOrder::Asc) => Box::new(variables.into_iter().take(l as usize)),
-            (Some(l), SortOrder::Desc) => Box::new(variables.into_iter().rev().take(l as usize)),
+        let mut variable_iter: Box<dyn Iterator<Item = Value>> = match self.sort_order {
+            SortOrder::Asc => Box::new(variables.into_iter()),
+            SortOrder::Desc => Box::new(variables.into_iter().rev()),
         };
 
+        if let Some(s) = self.skip {
+            variable_iter = Box::new(variable_iter.skip(s));
+        }
+
+        if let Some(l) = self.limit {
+            variable_iter = Box::new(variable_iter.take(l));
+        }
+
         for variable in variable_iter {
             scope.tokens.rewind_to(waypoint);
 

stuart-core/src/tests/mod.rs

@@ -11,6 +11,7 @@ define_testcases![
     for_loop_json_file,
     for_loop_json_object,
     for_loop_nested,
+    for_loop_skip_limit,
     dateformat,
     excerpt,
     ifdefined,

stuart-core/src/tests/testcases/for_loop_skip_limit/in.html

@@ -0,0 +1,7 @@
+{{ begin("main") }}
+<ul>
+{{ for($country, "data.json", skip=1, limit=1) }}
+<li>{{ $country.name }}</li>
+{{ end(for) }}
+</ul>
+{{ end("main") }}

stuart-core/src/tests/testcases/for_loop_skip_limit/out.html

@@ -0,0 +1,7 @@
+<html>
+<body>
+<ul>
+<li>United States</li>
+</ul>
+</body>
+</html>

stuart/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "stuart"
-version = "0.2.4"
+version = "0.2.5"
 edition = "2021"
 license = "MIT"
 homepage = "https://github.com/w-henderson/Stuart"
@@ -15,7 +15,7 @@ name = "stuart"
 path = "src/main.rs"
 
 [dependencies]
-stuart_core = { version = "^0.2.4", path = "../stuart-core" }
+stuart_core = { version = "^0.2.5", path = "../stuart-core" }
 
 clap = "^3.2"
 toml = "^0.5"