Merge branch 'partial' into render

js/test_cases/partial_jump_around_one/input1.json

@@ -0,0 +1,28 @@
+{
+  "v0": "0",
+  "level3": {
+    "v3": "3",
+    "v4": "3",
+    "v5": "3",
+    "level4": {
+      "v4": "4",
+      "v5": "4",
+      "level5": {
+        "v5": "5"
+      }
+    }
+  },
+  "level1": {
+    "v1": "1",
+    "v2": "1",
+    "v3": "1",
+    "v4": "1",
+    "v5": "1",
+    "level2": {
+      "v2": "2",
+      "v3": "2",
+      "v4": "2",
+      "v5": "2"
+    }
+  }
+}

js/test_cases/partial_jump_around_one/main.dust

@@ -0,0 +1,3 @@
+{#level1.level2}
+{>partialone v0="a" v1="a" v2="a" v3="a" v4="a" v5="a"/}
+{/level1.level2}

js/test_cases/partial_jump_around_one/partialone.dust

@@ -0,0 +1,3 @@
+{#level3.level4}
+    {>partialtwo/}
+{/level3.level4}

js/test_cases/partial_jump_around_one/partialtwo.dust

@@ -0,0 +1,8 @@
+{#level5}
+    {v0}{~n}
+    {v1}{~n}
+    {v2}{~n}
+    {v3}{~n}
+    {v4}{~n}
+    {v5}{~n}
+{/level5}

js/test_cases/partial_jump_around_two/input1.json

@@ -0,0 +1,27 @@
+{
+  "level3": {
+    "v3": "3",
+    "v4": "3",
+    "v5": "3",
+    "level4": {
+      "v4": "4",
+      "v5": "4",
+      "level5": {
+        "v5": "5"
+      }
+    }
+  },
+  "level1": {
+    "v1": "1",
+    "v2": "1",
+    "v3": "1",
+    "v4": "1",
+    "v5": "1",
+    "level2": {
+      "v2": "2",
+      "v3": "2",
+      "v4": "2",
+      "v5": "2"
+    }
+  }
+}

js/test_cases/partial_jump_around_two/main.dust

@@ -0,0 +1,3 @@
+{#level1.level2}
+{>partialone v1="a" v2="a" v3="a" v4="a" v5="a"/}
+{/level1.level2}

js/test_cases/partial_jump_around_two/partialone.dust

@@ -0,0 +1,3 @@
+{#level3.level4}
+    {>partialtwo v1="b" v2="b" v3="b" v4="b" v5="b" /}
+{/level3.level4}

js/test_cases/partial_jump_around_two/partialtwo.dust

@@ -0,0 +1,7 @@
+{#level5}
+    {v1}{~n}
+    {v2}{~n}
+    {v3}{~n}
+    {v4}{~n}
+    {v5}{~n}
+{/level5}

js/test_cases/partial_path/greeting.dust

@@ -0,0 +1 @@
+Hello {name}{?item}, nice {item}{/item}!{~n}

js/test_cases/partial_path/input1.json

@@ -0,0 +1,14 @@
+{
+  "people": [
+    {
+      "name": "Alice",
+      "item": "cat"
+    },
+    {
+      "name": "Bob"
+    }
+  ],
+  "globals": {
+    "item": "couch"
+  }
+}

js/test_cases/partial_path/main.dust

@@ -0,0 +1,3 @@
+{#people}
+{>greeting item=globals.item/}
+{/people}

js/test_cases/partial_simple/README.md

@@ -0,0 +1 @@
+Partial parameters do not take highest priority but also do not seem to take lowest priority. Current theory is parameters are inserted 1 level above the current context (so parameters would be references before walking up).

js/test_cases/partial_simple/greeting.dust

@@ -0,0 +1 @@
+Hello {name}{?item}, nice {item}{/item}!{~n}

js/test_cases/partial_simple/input1.json

@@ -0,0 +1,4 @@
+{"people": [
+  {"name": "Alice", "item": "cat"},
+  {"name": "Bob"}
+]}

js/test_cases/partial_simple/input2.json

@@ -0,0 +1,5 @@
+{"people": [
+  {"name": "Alice"},
+  {"name": "Bob"}
+],
+ "item": "cat"}

js/test_cases/partial_simple/main.dust

@@ -0,0 +1,3 @@
+{#people}
+{>greeting item="shoes"/}
+{/people}

src/bin.rs

@@ -8,6 +8,7 @@ use renderer::DustRenderer;
 use renderer::Loopable;
 use renderer::RenderError;
 use renderer::Renderable;
+use renderer::WalkError;
 use renderer::Walkable;
 use std::env;
 use std::fs;
@@ -91,67 +92,48 @@ impl Renderable for serde_json::Value {
 }
 
 impl Walkable for serde_json::Value {
-    fn walk(&self, segment: &str) -> Result<&dyn ContextElement, RenderError> {
+    fn walk(&self, segment: &str) -> Result<&dyn ContextElement, WalkError> {
         match self {
-            serde_json::Value::Null => Err(RenderError::CantWalk {
+            serde_json::Value::Null => Err(WalkError::CantWalk),
-                segment: segment.to_string(),
+            serde_json::Value::Bool(_boolean) => Err(WalkError::CantWalk),
-                elem: self,
+            serde_json::Value::Number(_num) => Err(WalkError::CantWalk),
-            }),
+            serde_json::Value::String(_string) => Err(WalkError::CantWalk),
-            serde_json::Value::Bool(_boolean) => Err(RenderError::CantWalk {
+            serde_json::Value::Array(_arr) => Err(WalkError::CantWalk),
-                segment: segment.to_string(),
+            serde_json::Value::Object(obj) => obj
-                elem: self,
+                .get(segment)
-            }),
-            serde_json::Value::Number(_num) => Err(RenderError::CantWalk {
-                segment: segment.to_string(),
-                elem: self,
-            }),
-            serde_json::Value::String(_string) => Err(RenderError::CantWalk {
-                segment: segment.to_string(),
-                elem: self,
-            }),
-            serde_json::Value::Array(_arr) => Err(RenderError::CantWalk {
-                segment: segment.to_string(),
-                elem: self,
-            }),
-            serde_json::Value::Object(obj) => {
-                obj.get(segment)
                 .map(|val| val as _)
-                    .ok_or(RenderError::WontWalk {
+                .ok_or(WalkError::CantWalk),
-                        segment: segment.to_string(),
-                        elem: self,
-                    })
-            }
         }
     }
 }
 
 impl Loopable for serde_json::Value {
-    fn get_loop_elements(&self) -> Result<Vec<&dyn ContextElement>, RenderError> {
+    fn get_loop_elements(&self) -> Vec<&dyn ContextElement> {
         match self {
-            serde_json::Value::Null => Ok(Vec::new()),
+            serde_json::Value::Null => Vec::new(),
             serde_json::Value::Bool(boolean) => {
                 if *boolean {
-                    Ok(vec![self])
+                    vec![self]
                 } else {
-                    Ok(Vec::new())
+                    Vec::new()
                 }
             }
-            serde_json::Value::Number(_num) => Ok(vec![self]),
+            serde_json::Value::Number(_num) => vec![self],
             serde_json::Value::String(string_value) => {
                 if string_value.is_empty() {
-                    Ok(Vec::new())
+                    Vec::new()
                 } else {
-                    Ok(vec![self])
+                    vec![self]
                 }
             }
             serde_json::Value::Array(array_value) => {
                 if array_value.is_empty() {
-                    Ok(Vec::new())
+                    Vec::new()
                 } else {
-                    Ok(array_value.iter().map(|x| x as _).collect())
+                    array_value.iter().map(|x| x as _).collect()
                 }
             }
-            serde_json::Value::Object(_obj) => Ok(vec![self]),
+            serde_json::Value::Object(_obj) => vec![self],
         }
     }
 }

src/parser/mod.rs

@@ -6,6 +6,8 @@ pub use parser::template;
 pub use parser::Body;
 pub use parser::DustTag;
 pub use parser::Filter;
+pub use parser::KVPair;
+pub use parser::RValue;
 pub use parser::Special;
 pub use parser::Template;
 pub use parser::TemplateElement;

src/parser/parser.rs

@@ -6,7 +6,7 @@ use nom::bytes::complete::{tag, take_until, take_until_parser_matches};
 use nom::character::complete::line_ending;
 use nom::character::complete::multispace0;
 use nom::character::complete::one_of;
-use nom::character::complete::space1;
+use nom::character::complete::{space0, space1};
 use nom::combinator::all_consuming;
 use nom::combinator::map;
 use nom::combinator::opt;
@@ -114,20 +114,20 @@ pub struct ParameterizedBlock<'a> {
 
 #[derive(Clone, Debug, PartialEq)]
 pub struct Partial<'a> {
-    name: String,
+    pub name: String,
-    params: Vec<KVPair<'a>>,
+    pub params: Vec<KVPair<'a>>,
 }
 
 #[derive(Clone, Debug, PartialEq)]
-enum RValue<'a> {
+pub enum RValue<'a> {
     RVPath(Path<'a>),
     RVString(String),
 }
 
 #[derive(Clone, Debug, PartialEq)]
-struct KVPair<'a> {
+pub struct KVPair<'a> {
-    key: &'a str,
+    pub key: &'a str,
-    value: RValue<'a>,
+    pub value: RValue<'a>,
 }
 
 #[derive(Clone, Debug, PartialEq)]
@@ -387,7 +387,11 @@ where
         let (i, (name, params, inner, maybe_else, _closing_name)) = tuple((
             preceded(tag(open_matcher), tag(tag_name)),
             terminated(
-                opt(preceded(space1, separated_list1(space1, key_value_pair))),
+                opt(delimited(
+                    space1,
+                    separated_list1(space1, key_value_pair),
+                    space0,
+                )),
                 tag("}"),
             ),
             opt(body),
@@ -420,7 +424,11 @@ where
             tag(open_matcher),
             tuple((
                 tag(tag_name),
-                opt(preceded(space1, separated_list1(space1, key_value_pair))),
+                opt(delimited(
+                    space1,
+                    separated_list1(space1, key_value_pair),
+                    space0,
+                )),
             )),
             tag("/}"),
         )(i)?;
@@ -449,7 +457,11 @@ where
             tag(open_matcher),
             tuple((
                 alt((map(key, String::from), quoted_string)),
-                opt(preceded(space1, separated_list1(space1, key_value_pair))),
+                opt(delimited(
+                    space1,
+                    separated_list1(space1, key_value_pair),
+                    space0,
+                )),
             )),
             tag("/}"),
         )(i)?;
@@ -1052,4 +1064,55 @@ mod tests {
             ))
         );
     }
+
+    #[test]
+    fn test_full_document_parameterized_partial() {
+        assert_eq!(
+            super::template(
+                r#"{#level3.level4}{>partialtwo v1="b" v2="b" v3="b" v4="b" v5="b" /}{/level3.level4}"#
+            ),
+            Ok::<_, nom::Err<(&str, ErrorKind)>>((
+                "",
+                Template {
+                    contents: Body {
+                        elements: vec![TemplateElement::TETag(DustTag::DTSection(Container {
+                            path: Path {
+                                keys: vec!["level3", "level4"]
+                            },
+                            contents: Some(Body {
+                                elements: vec![TemplateElement::TETag(DustTag::DTPartial(
+                                    Partial {
+                                        name: "partialtwo".to_owned(),
+                                        params: vec![
+                                            KVPair {
+                                                key: "v1",
+                                                value: RValue::RVString("b".to_owned())
+                                            },
+                                            KVPair {
+                                                key: "v2",
+                                                value: RValue::RVString("b".to_owned())
+                                            },
+                                            KVPair {
+                                                key: "v3",
+                                                value: RValue::RVString("b".to_owned())
+                                            },
+                                            KVPair {
+                                                key: "v4",
+                                                value: RValue::RVString("b".to_owned())
+                                            },
+                                            KVPair {
+                                                key: "v5",
+                                                value: RValue::RVString("b".to_owned())
+                                            }
+                                        ]
+                                    }
+                                ))]
+                            }),
+                            else_contents: None
+                        }))]
+                    }
+                }
+            ))
+        );
+    }
 }

src/renderer/context_element.rs

@@ -1,11 +1,12 @@
 use crate::parser::Filter;
 use crate::renderer::errors::RenderError;
+use crate::renderer::errors::WalkError;
 use std::fmt::Debug;
 
 pub trait ContextElement: Debug + Walkable + Renderable + Loopable {}
 
 pub trait Walkable {
-    fn walk(&self, segment: &str) -> Result<&dyn ContextElement, RenderError>;
+    fn walk(&self, segment: &str) -> Result<&dyn ContextElement, WalkError>;
 }
 
 pub trait Renderable {
@@ -22,5 +23,5 @@ pub trait Loopable {
     /// once with the context being the element at that path. Finally,
     /// if its an array-like value then it will render n-times, once
     /// for each element of the array.
-    fn get_loop_elements(&self) -> Result<Vec<&dyn ContextElement>, RenderError>;
+    fn get_loop_elements(&self) -> Vec<&dyn ContextElement>;
 }

src/renderer/errors.rs

@@ -1,27 +1,16 @@
-use crate::renderer::context_element::ContextElement;
 use std::error;
 use std::fmt;
 
-pub enum RenderError<'a> {
+/// Fatal errors while rendering.
+///
+/// A RenderError will halt rendering.
+pub enum RenderError {
     Generic(String),
-    /// For when walking is absolutely impossible
+    TemplateNotFound(String),
-    CantWalk {
+}
-        segment: String,
+
-        elem: &'a dyn ContextElement,
+pub enum WalkError {
-    },
+    CantWalk,
-    /// For when walking fails (example, a missing key on a map)
-    WontWalk {
-        segment: String,
-        elem: &'a dyn ContextElement,
-    },
-    NotFound {
-        path: &'a Vec<&'a str>,
-        breadcrumbs: Vec<&'a dyn ContextElement>,
-    },
-    /// Attempting to render and unrenderable type (for example, an object without any filters)
-    CantRender {
-        elem: &'a dyn ContextElement,
-    },
 }
 
 #[derive(Clone)]
@@ -29,43 +18,51 @@ pub struct CompileError {
     pub message: String,
 }
 
-impl fmt::Display for RenderError<'_> {
+impl fmt::Display for RenderError {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match self {
             RenderError::Generic(msg) => write!(f, "{}", msg),
-            RenderError::CantWalk { segment, elem } => {
+            RenderError::TemplateNotFound(name) => {
-                write!(f, "Tried to walk to {} from {:?}", segment, elem)
+                write!(f, "No template named {} in context", name)
-            }
-            RenderError::WontWalk { segment, elem } => {
-                write!(f, "Failed to walk to {} from {:?}", segment, elem)
-            }
-            RenderError::CantRender { elem } => write!(f, "Cant render {:?}", elem),
-            RenderError::NotFound { path, breadcrumbs } => {
-                write!(f, "Could not find {:?} in {:?}", path, breadcrumbs)
             }
         }
     }
 }
 
-impl fmt::Debug for RenderError<'_> {
+impl fmt::Debug for RenderError {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match self {
             RenderError::Generic(msg) => write!(f, "{}", msg),
-            RenderError::CantWalk { segment, elem } => {
+            RenderError::TemplateNotFound(name) => {
-                write!(f, "Tried to walk to {} from {:?}", segment, elem)
+                write!(f, "No template named {} in context", name)
-            }
-            RenderError::WontWalk { segment, elem } => {
-                write!(f, "Failed to walk to {} from {:?}", segment, elem)
-            }
-            RenderError::CantRender { elem } => write!(f, "Cant render {:?}", elem),
-            RenderError::NotFound { path, breadcrumbs } => {
-                write!(f, "Could not find {:?} in {:?}", path, breadcrumbs)
             }
         }
     }
 }
 
-impl error::Error for RenderError<'_> {
+impl error::Error for RenderError {
+    fn source(&self) -> Option<&(dyn error::Error + 'static)> {
+        None
+    }
+}
+
+impl fmt::Display for WalkError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            WalkError::CantWalk => write!(f, "Failed to walk"),
+        }
+    }
+}
+
+impl fmt::Debug for WalkError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            WalkError::CantWalk => write!(f, "Failed to walk"),
+        }
+    }
+}
+
+impl error::Error for WalkError {
     fn source(&self) -> Option<&(dyn error::Error + 'static)> {
         None
     }

src/renderer/mod.rs

@@ -2,7 +2,9 @@
 
 mod context_element;
 mod errors;
+mod parameters_context;
 mod renderer;
+mod walking;
 
 pub use context_element::ContextElement;
 pub use context_element::Loopable;
@@ -10,6 +12,7 @@ pub use context_element::Renderable;
 pub use context_element::Walkable;
 pub use errors::CompileError;
 pub use errors::RenderError;
+pub use errors::WalkError;
 pub use renderer::compile_template;
 pub use renderer::CompiledTemplate;
 pub use renderer::DustRenderer;

src/renderer/parameters_context.rs

@@ -0,0 +1,86 @@
+use crate::parser::KVPair;
+use crate::parser::{Filter, RValue};
+use crate::renderer::context_element::ContextElement;
+use crate::renderer::walking::walk_path;
+use crate::renderer::Loopable;
+use crate::renderer::RenderError;
+use crate::renderer::Renderable;
+use crate::renderer::WalkError;
+use crate::renderer::Walkable;
+use std::collections::HashMap;
+
+#[derive(Clone, Debug)]
+pub struct ParametersContext<'a> {
+    params: HashMap<&'a str, &'a RValue<'a>>,
+    breadcrumbs: &'a Vec<&'a dyn ContextElement>,
+}
+
+impl<'a> ParametersContext<'a> {
+    pub fn new(
+        breadcrumbs: &'a Vec<&'a dyn ContextElement>,
+        params: &'a Vec<KVPair<'a>>,
+    ) -> ParametersContext<'a> {
+        let param_map = params
+            .iter()
+            .map(|pair: &KVPair<'a>| (pair.key, &pair.value))
+            .collect();
+        ParametersContext {
+            params: param_map,
+            breadcrumbs: breadcrumbs,
+        }
+    }
+}
+
+impl<'a> ContextElement for ParametersContext<'a> {}
+
+impl<'a> Renderable for ParametersContext<'a> {
+    fn render(&self, _filters: &Vec<Filter>) -> Result<String, RenderError> {
+        // TODO: Would this even ever be called? Won't matter, but I'd
+        // like to know. Since it is injected 1 above the current
+        // context, we wouldn't be able to access it with `{.}`.
+        Ok("[object Object]".to_owned())
+    }
+}
+
+impl<'a> Loopable for ParametersContext<'a> {
+    fn get_loop_elements(&self) -> Vec<&dyn ContextElement> {
+        // TODO: Would this even ever be called? Won't matter, but I'd
+        // like to know. Since it is injected 1 above the current
+        // context, we wouldn't be able to access it with `{.}`.
+        vec![self]
+    }
+}
+
+impl<'a> Walkable for ParametersContext<'a> {
+    fn walk(&self, segment: &str) -> Result<&dyn ContextElement, WalkError> {
+        let rval = self.params.get(segment).ok_or(WalkError::CantWalk)?;
+        match rval {
+            RValue::RVPath(path) => walk_path(self.breadcrumbs, &path.keys),
+            RValue::RVString(text) => Ok(text),
+        }
+    }
+}
+
+impl ContextElement for String {}
+
+impl Renderable for String {
+    fn render(&self, _filters: &Vec<Filter>) -> Result<String, RenderError> {
+        Ok(self.clone())
+    }
+}
+
+impl Loopable for String {
+    fn get_loop_elements(&self) -> Vec<&dyn ContextElement> {
+        if self.is_empty() {
+            Vec::new()
+        } else {
+            vec![self]
+        }
+    }
+}
+
+impl Walkable for String {
+    fn walk(&self, segment: &str) -> Result<&dyn ContextElement, WalkError> {
+        Err(WalkError::CantWalk)
+    }
+}

src/renderer/renderer.rs

@@ -7,6 +7,9 @@ use crate::parser::TemplateElement;
 use crate::renderer::context_element::ContextElement;
 use crate::renderer::errors::CompileError;
 use crate::renderer::errors::RenderError;
+use crate::renderer::errors::WalkError;
+use crate::renderer::parameters_context::ParametersContext;
+use crate::renderer::walking::walk_path;
 use std::collections::HashMap;
 
 #[derive(Clone, Debug)]
@@ -49,14 +52,11 @@ impl<'a> DustRenderer<'a> {
         &'a self,
         name: &str,
         breadcrumbs: &Vec<&'a dyn ContextElement>,
-    ) -> Result<String, RenderError<'a>> {
+    ) -> Result<String, RenderError> {
         let main_template = match self.templates.get(name) {
             Some(tmpl) => tmpl,
             None => {
-                return Err(RenderError::Generic(format!(
+                return Err(RenderError::TemplateNotFound(name.to_owned()));
-                    "No template named {} in context",
-                    name
-                )));
             }
         };
         self.render_body(&main_template.contents, breadcrumbs)
@@ -66,7 +66,7 @@ impl<'a> DustRenderer<'a> {
         &'a self,
         body: &'a Body,
         breadcrumbs: &Vec<&'a dyn ContextElement>,
-    ) -> Result<String, RenderError<'a>> {
+    ) -> Result<String, RenderError> {
         let mut output = String::new();
         for elem in &body.elements {
             match elem {
@@ -84,7 +84,7 @@ impl<'a> DustRenderer<'a> {
         &'a self,
         tag: &'a DustTag,
         breadcrumbs: &Vec<&'a dyn ContextElement>,
-    ) -> Result<String, RenderError<'a>> {
+    ) -> Result<String, RenderError> {
         match tag {
             DustTag::DTComment(_comment) => (),
             DustTag::DTSpecial(special) => {
@@ -100,21 +100,20 @@ impl<'a> DustRenderer<'a> {
             DustTag::DTReference(reference) => {
                 let val = walk_path(breadcrumbs, &reference.path.keys);
                 match val {
-                    Err(RenderError::NotFound { .. }) => return Ok("".to_owned()),
+                    Err(WalkError::CantWalk) => return Ok("".to_owned()),
                     Ok(final_val) => {
-                        let loop_elements = final_val.get_loop_elements()?;
+                        let loop_elements = final_val.get_loop_elements();
                         if loop_elements.is_empty() {
                             return Ok("".to_owned());
                         } else {
                             return final_val.render(&reference.filters);
                         }
                     }
-                    Err(render_error) => return Err(render_error),
                 }
             }
             DustTag::DTSection(container) => {
                 let val = walk_path(breadcrumbs, &container.path.keys);
-                let loop_elements: Vec<&dyn ContextElement> = self.get_loop_elements(val)?;
+                let loop_elements: Vec<&dyn ContextElement> = self.get_loop_elements(val);
                 if loop_elements.is_empty() {
                     // Oddly enough if the value is falsey (like
                     // an empty array or null), Dust uses the
@@ -144,7 +143,7 @@ impl<'a> DustRenderer<'a> {
             }
             DustTag::DTExists(container) => {
                 let val = walk_path(breadcrumbs, &container.path.keys);
-                let loop_elements: Vec<&dyn ContextElement> = self.get_loop_elements(val)?;
+                let loop_elements: Vec<&dyn ContextElement> = self.get_loop_elements(val);
                 if loop_elements.is_empty() {
                     return match &container.else_contents {
                         Some(body) => self.render_body(&body, breadcrumbs),
@@ -159,7 +158,7 @@ impl<'a> DustRenderer<'a> {
             }
             DustTag::DTNotExists(container) => {
                 let val = walk_path(breadcrumbs, &container.path.keys);
-                let loop_elements: Vec<&dyn ContextElement> = self.get_loop_elements(val)?;
+                let loop_elements: Vec<&dyn ContextElement> = self.get_loop_elements(val);
                 if !loop_elements.is_empty() {
                     return match &container.else_contents {
                         Some(body) => self.render_body(&body, breadcrumbs),
@@ -172,6 +171,18 @@ impl<'a> DustRenderer<'a> {
                     };
                 }
             }
+            DustTag::DTPartial(partial) => {
+                if partial.params.is_empty() {
+                    let rendered_content = self.render(&partial.name, breadcrumbs)?;
+                    return Ok(rendered_content);
+                } else {
+                    let injected_context = ParametersContext::new(breadcrumbs, &partial.params);
+                    let mut new_breadcrumbs = breadcrumbs.clone();
+                    new_breadcrumbs.insert(new_breadcrumbs.len() - 1, &injected_context);
+                    let rendered_content = self.render(&partial.name, &new_breadcrumbs)?;
+                    return Ok(rendered_content);
+                }
+            }
             _ => (), // TODO: Implement the rest
         }
         Ok("".to_owned())
@@ -183,72 +194,15 @@ impl<'a> DustRenderer<'a> {
     /// block, this will return an empty vector.
     fn get_loop_elements<'b>(
         &'a self,
-        walk_result: Result<&'b dyn ContextElement, RenderError<'b>>,
+        walk_result: Result<&'b dyn ContextElement, WalkError>,
-    ) -> Result<Vec<&'b dyn ContextElement>, RenderError<'b>> {
+    ) -> Vec<&'b dyn ContextElement> {
-        if let Err(RenderError::NotFound { .. }) = walk_result {
+        match walk_result {
-            // If reference does not exist in the context, render the else block
+            Err(WalkError::CantWalk) => Vec::new(),
-            Ok(vec![])
+            Ok(walk_target) => walk_target.get_loop_elements(),
-        } else {
-            Ok(walk_result?.get_loop_elements()?)
         }
     }
 }
 
-enum WalkResult<'a> {
-    NoWalk,
-    PartialWalk,
-    FullyWalked(&'a dyn ContextElement),
-}
-
-fn walk_path_from_single_level<'a>(
-    context: &'a dyn ContextElement,
-    path: &Vec<&str>,
-) -> Result<WalkResult<'a>, RenderError<'a>> {
-    if path.is_empty() {
-        return Ok(WalkResult::FullyWalked(context));
-    }
-
-    let mut walk_failure = WalkResult::NoWalk;
-    let mut output = context;
-    for elem in path.iter() {
-        let new_val = output.walk(elem);
-        if let Err(RenderError::WontWalk { .. }) = new_val {
-            return Ok(walk_failure);
-        } else if let Err(RenderError::CantWalk { .. }) = new_val {
-            return Ok(walk_failure);
-        }
-        walk_failure = WalkResult::PartialWalk;
-        output = new_val?;
-    }
-
-    Ok(WalkResult::FullyWalked(output))
-}
-
-fn walk_path<'a>(
-    breadcrumbs: &Vec<&'a dyn ContextElement>,
-    path: &'a Vec<&str>,
-) -> Result<&'a dyn ContextElement, RenderError<'a>> {
-    for context in breadcrumbs.iter().rev() {
-        match walk_path_from_single_level(*context, path)? {
-            // If no walking was done at all, keep looping
-            WalkResult::NoWalk => {}
-            // If we partially walked then stop trying to find
-            // anything
-            WalkResult::PartialWalk => {
-                return Err(RenderError::NotFound {
-                    path: path,
-                    breadcrumbs: breadcrumbs.clone(),
-                });
-            }
-            WalkResult::FullyWalked(new_context) => return Ok(new_context),
-        }
-    }
-    Err(RenderError::NotFound {
-        path: path,
-        breadcrumbs: breadcrumbs.clone(),
-    })
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -278,57 +232,48 @@ mod tests {
     impl<I: ContextElement> Renderable for HashMap<&str, I> {
         fn render(&self, _filters: &Vec<Filter>) -> Result<String, RenderError> {
             // TODO: handle the filters
-            Err(RenderError::CantRender { elem: self })
+            Ok("[object Object]".to_owned())
         }
     }
 
     impl<I: ContextElement> Walkable for HashMap<&str, I> {
-        fn walk(&self, segment: &str) -> Result<&dyn ContextElement, RenderError> {
+        fn walk(&self, segment: &str) -> Result<&dyn ContextElement, WalkError> {
-            let child = self.get(segment).ok_or(RenderError::WontWalk {
+            let child = self.get(segment).ok_or(WalkError::CantWalk)?;
-                segment: segment.to_string(),
-                elem: self,
-            })?;
             Ok(child)
         }
     }
 
     impl Walkable for &str {
-        fn walk(&self, segment: &str) -> Result<&dyn ContextElement, RenderError> {
+        fn walk(&self, segment: &str) -> Result<&dyn ContextElement, WalkError> {
-            Err(RenderError::CantWalk {
+            Err(WalkError::CantWalk)
-                segment: segment.to_string(),
-                elem: self,
-            })
         }
     }
 
     impl Walkable for u32 {
-        fn walk(&self, segment: &str) -> Result<&dyn ContextElement, RenderError> {
+        fn walk(&self, segment: &str) -> Result<&dyn ContextElement, WalkError> {
-            Err(RenderError::CantWalk {
+            Err(WalkError::CantWalk)
-                segment: segment.to_string(),
-                elem: self,
-            })
         }
     }
 
     impl Loopable for &str {
-        fn get_loop_elements(&self) -> Result<Vec<&dyn ContextElement>, RenderError> {
+        fn get_loop_elements(&self) -> Vec<&dyn ContextElement> {
             if self.is_empty() {
-                Ok(Vec::new())
+                Vec::new()
             } else {
-                Ok(vec![self])
+                vec![self]
             }
         }
     }
 
     impl Loopable for u32 {
-        fn get_loop_elements(&self) -> Result<Vec<&dyn ContextElement>, RenderError> {
+        fn get_loop_elements(&self) -> Vec<&dyn ContextElement> {
-            Ok(vec![self])
+            vec![self]
         }
     }
 
     impl<I: ContextElement> Loopable for HashMap<&str, I> {
-        fn get_loop_elements(&self) -> Result<Vec<&dyn ContextElement>, RenderError> {
+        fn get_loop_elements(&self) -> Vec<&dyn ContextElement> {
-            Ok(vec![self])
+            vec![self]
         }
     }
 

src/renderer/walking.rs

@@ -0,0 +1,53 @@
+use crate::renderer::context_element::ContextElement;
+use crate::renderer::WalkError;
+
+enum WalkResult<'a> {
+    NoWalk,
+    PartialWalk,
+    FullyWalked(&'a dyn ContextElement),
+}
+
+fn walk_path_from_single_level<'a>(
+    context: &'a dyn ContextElement,
+    path: &Vec<&str>,
+) -> WalkResult<'a> {
+    if path.is_empty() {
+        return WalkResult::FullyWalked(context);
+    }
+
+    let mut walk_failure = WalkResult::NoWalk;
+    let mut output = context;
+    for elem in path.iter() {
+        let new_val = output.walk(elem);
+        match output.walk(elem) {
+            Err(WalkError::CantWalk { .. }) => {
+                return walk_failure;
+            }
+            Ok(new_val) => {
+                walk_failure = WalkResult::PartialWalk;
+                output = new_val;
+            }
+        }
+    }
+
+    WalkResult::FullyWalked(output)
+}
+
+pub fn walk_path<'a>(
+    breadcrumbs: &Vec<&'a dyn ContextElement>,
+    path: &'a Vec<&str>,
+) -> Result<&'a dyn ContextElement, WalkError> {
+    for context in breadcrumbs.iter().rev() {
+        match walk_path_from_single_level(*context, path) {
+            // If no walking was done at all, keep looping
+            WalkResult::NoWalk => {}
+            // If we partially walked then stop trying to find
+            // anything
+            WalkResult::PartialWalk => {
+                return Err(WalkError::CantWalk);
+            }
+            WalkResult::FullyWalked(new_context) => return Ok(new_context),
+        }
+    }
+    Err(WalkError::CantWalk)
+}