Refactor and shorten debug output

src/config/mod.rs

@@ -178,9 +178,7 @@ impl EwwConfig {
 }
 
 #[repr(transparent)]
-#[derive(
-    Debug, Clone, Hash, PartialEq, Eq, derive_more::AsRef, derive_more::From, derive_more::FromStr, Serialize, Deserialize,
-)]
+#[derive(Clone, Hash, PartialEq, Eq, derive_more::AsRef, derive_more::From, derive_more::FromStr, Serialize, Deserialize)]
 pub struct WindowName(String);
 
 impl std::borrow::Borrow<str> for WindowName {
@@ -195,6 +193,12 @@ impl fmt::Display for WindowName {
     }
 }
 
+impl fmt::Debug for WindowName {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "WindowName(\"{}\")", self.0)
+    }
+}
+
 #[derive(Debug, Clone, PartialEq)]
 pub struct EwwWindowDefinition {
     pub position: Coords,

src/eww_state.rs

@@ -1,7 +1,7 @@
 use crate::{
     config::WindowName,
     util,
-    value::{AttrName, StringOrVarRef, VarName},
+    value::{AttrName, AttrValueElement, VarName},
 };
 use anyhow::*;
 use std::{collections::HashMap, process::Command, sync::Arc};
@@ -51,7 +51,7 @@ pub struct EwwWindowState {
 }
 
 impl EwwWindowState {
-    /// register a new [StateChangeHandler]
+    /// register a new [`StateChangeHandler`]
     fn put_handler(&mut self, handler: StateChangeHandler) {
         let handler = Arc::new(handler);
         for var_name in handler.used_variables() {
@@ -128,8 +128,8 @@ impl EwwState {
         value
             .iter()
             .map(|element| match element {
-                StringOrVarRef::Primitive(primitive) => Ok(primitive.clone()),
-                StringOrVarRef::VarRef(var_name) => self
+                AttrValueElement::Primitive(primitive) => Ok(primitive.clone()),
+                AttrValueElement::VarRef(var_name) => self
                     .variables_state
                     .get(var_name)
                     .cloned()
@@ -148,26 +148,27 @@ impl EwwState {
         &mut self,
         window_name: &WindowName,
         local_env: &HashMap<VarName, AttrValue>,
-        mut attributes: HashMap<AttrName, AttrValue>,
+        attributes: HashMap<AttrName, AttrValue>,
         set_value: F,
     ) {
-        let window_state = self
-            .windows
-            .entry(window_name.clone())
-            .or_insert_with(EwwWindowState::default);
-
-        let resolved_attributes: Vec<(AttrName, AttrValue)> = attributes
-            .drain()
-            .map(|(attr_name, attr_value)| (attr_name, attr_value.resolve_one_level(local_env)))
-            .collect();
-
         let handler = StateChangeHandler {
             func: Box::new(set_value),
-            unresolved_values: resolved_attributes,
+            unresolved_values: attributes
+                .into_iter()
+                .map(|(attr_name, attr_value)| (attr_name, attr_value.resolve_one_level(local_env)))
+                .collect(),
         };
 
         handler.run_with_state(&self.variables_state);
-        window_state.put_handler(handler);
+
+        // only store the handler if at least one variable is being used
+        if handler.used_variables().next().is_some() {
+            let window_state = self
+                .windows
+                .entry(window_name.clone())
+                .or_insert_with(EwwWindowState::default);
+            window_state.put_handler(handler);
+        }
     }
 }
 

src/value/attr_value.rs

@@ -3,32 +3,39 @@ use std::{collections::HashMap, iter::FromIterator};
 
 use super::*;
 
-#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, derive_more::Into, derive_more::From)]
-pub struct AttrValue(Vec<StringOrVarRef>);
+/// A value assigned to an attribute in a widget.
+/// This can be a primitive String that contains any amount of variable
+/// references, as would be generated by the string "foo {{var}} bar".
+#[derive(Serialize, Deserialize, Clone, PartialEq, derive_more::Into, derive_more::From)]
+pub struct AttrValue(Vec<AttrValueElement>);
+
+impl fmt::Debug for AttrValue {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "AttrValue({:?})", self.0)
+    }
+}
 
 impl IntoIterator for AttrValue {
     type IntoIter = std::vec::IntoIter<Self::Item>;
-    type Item = StringOrVarRef;
+    type Item = AttrValueElement;
 
     fn into_iter(self) -> Self::IntoIter {
         self.0.into_iter()
     }
 }
 
-impl FromIterator<StringOrVarRef> for AttrValue {
-    fn from_iter<T: IntoIterator<Item = StringOrVarRef>>(iter: T) -> Self {
-        let mut result = AttrValue(Vec::new());
-        result.0.extend(iter);
-        result
+impl FromIterator<AttrValueElement> for AttrValue {
+    fn from_iter<T: IntoIterator<Item = AttrValueElement>>(iter: T) -> Self {
+        AttrValue(iter.into_iter().collect())
     }
 }
 
 impl AttrValue {
     pub fn from_primitive<T: Into<PrimitiveValue>>(v: T) -> Self {
-        AttrValue(vec![StringOrVarRef::Primitive(v.into())])
+        AttrValue(vec![AttrValueElement::Primitive(v.into())])
     }
 
-    pub fn iter(&self) -> std::slice::Iter<StringOrVarRef> {
+    pub fn iter(&self) -> std::slice::Iter<AttrValueElement> {
         self.0.iter()
     }
 
@@ -39,9 +46,9 @@ impl AttrValue {
     pub fn resolve_one_level(self, variables: &HashMap<VarName, AttrValue>) -> AttrValue {
         self.into_iter()
             .flat_map(|entry| match entry {
-                StringOrVarRef::VarRef(var_name) => match variables.get(&var_name) {
+                AttrValueElement::VarRef(var_name) => match variables.get(&var_name) {
                     Some(value) => value.0.clone(),
-                    _ => vec![StringOrVarRef::VarRef(var_name)],
+                    _ => vec![AttrValueElement::VarRef(var_name)],
                 },
                 _ => vec![entry],
             })
@@ -51,8 +58,8 @@ impl AttrValue {
     pub fn resolve_fully(self, variables: &HashMap<VarName, PrimitiveValue>) -> Result<PrimitiveValue> {
         self.into_iter()
             .map(|element| match element {
-                StringOrVarRef::Primitive(x) => Ok(x),
-                StringOrVarRef::VarRef(var_name) => variables
+                AttrValueElement::Primitive(x) => Ok(x),
+                AttrValueElement::VarRef(var_name) => variables
                     .get(&var_name)
                     .cloned()
                     .with_context(|| format!("Unknown variable '{}' referenced", var_name)),
@@ -72,7 +79,7 @@ impl AttrValue {
                 if c == '}' {
                     curly_count -= 1;
                     if curly_count == 0 {
-                        elements.push(StringOrVarRef::VarRef(VarName(std::mem::take(varref))));
+                        elements.push(AttrValueElement::VarRef(VarName(std::mem::take(varref))));
                         cur_varref = None
                     }
                 } else {
@@ -84,7 +91,7 @@ impl AttrValue {
                     curly_count += 1;
                     if curly_count == 2 {
                         if !cur_word.is_empty() {
-                            elements.push(StringOrVarRef::primitive(std::mem::take(&mut cur_word)));
+                            elements.push(AttrValueElement::primitive(std::mem::take(&mut cur_word)));
                         }
                         cur_varref = Some(String::new())
                     }
@@ -94,35 +101,44 @@ impl AttrValue {
             }
         }
         if let Some(unfinished_varref) = cur_varref.take() {
-            elements.push(StringOrVarRef::primitive(unfinished_varref));
+            elements.push(AttrValueElement::primitive(unfinished_varref));
         } else if !cur_word.is_empty() {
-            elements.push(StringOrVarRef::primitive(cur_word.to_owned()));
+            elements.push(AttrValueElement::primitive(cur_word.to_owned()));
         }
         AttrValue(elements)
     }
 }
 
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
-pub enum StringOrVarRef {
+#[derive(Clone, PartialEq, Serialize, Deserialize)]
+pub enum AttrValueElement {
     Primitive(PrimitiveValue),
     VarRef(VarName),
 }
 
-impl StringOrVarRef {
+impl fmt::Debug for AttrValueElement {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            AttrValueElement::Primitive(x) => write!(f, "Primitive({:?})", x),
+            AttrValueElement::VarRef(x) => write!(f, "VarRef({:?})", x),
+        }
+    }
+}
+
+impl AttrValueElement {
     pub fn primitive(s: String) -> Self {
-        StringOrVarRef::Primitive(PrimitiveValue::from_string(s))
+        AttrValueElement::Primitive(PrimitiveValue::from_string(s))
     }
 
     pub fn as_var_ref(&self) -> Option<&VarName> {
         match self {
-            StringOrVarRef::VarRef(x) => Some(&x),
+            AttrValueElement::VarRef(x) => Some(&x),
             _ => None,
         }
     }
 
     pub fn as_primitive(&self) -> Option<&PrimitiveValue> {
         match self {
-            StringOrVarRef::Primitive(x) => Some(&x),
+            AttrValueElement::Primitive(x) => Some(&x),
             _ => None,
         }
     }

src/value/mod.rs

@@ -5,11 +5,10 @@ use std::fmt;
 
 pub mod attr_value;
 pub mod primitive;
-pub mod string_with_varrefs;
 pub use attr_value::*;
 pub use primitive::*;
-pub use string_with_varrefs::*;
 
+/// The name of a variable
 #[repr(transparent)]
 #[derive(
     Clone, Hash, PartialEq, Eq, derive_more::AsRef, derive_more::From, derive_more::FromStr, Serialize, Deserialize, RefCast,
@@ -34,6 +33,7 @@ impl fmt::Debug for VarName {
     }
 }
 
+/// The name of an attribute
 #[repr(transparent)]
 #[derive(
     Clone, Hash, PartialEq, Eq, derive_more::AsRef, derive_more::From, derive_more::FromStr, Serialize, Deserialize, RefCast,
@@ -54,6 +54,6 @@ impl fmt::Display for AttrName {
 
 impl fmt::Debug for AttrName {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "AttrName({})", self.0)
+        write!(f, "AttrName(\"{}\")", self.0)
     }
 }

src/value/primitive.rs

@@ -16,7 +16,7 @@ impl fmt::Display for PrimitiveValue {
 }
 impl fmt::Debug for PrimitiveValue {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "\"{}\"", self)
+        write!(f, "\"{}\"", self.0)
     }
 }