Add common Expand trait

src/template/mod.rs

@@ -1,4 +1,5 @@
 use crate::error::{ExpandError, ParseError};
+pub use crate::template::raw::Expand;
 use crate::VariableMap;
 
 mod raw;
@@ -252,7 +253,7 @@ impl<'a> ByteTemplate<'a> {
 	///
 	/// This will substitute all variables in the template with the values from the given map.
 	///
-	/// You can pass either a [`HashMap`][std::collections::HashMap], [`BTreeMap`][std::collections::BTreeMap] or [`Env`][crate::Env] as the `variables` parameter.
+	/// You can pass either a [`HashMap`][std::collections::HashMap], [`BTreeMap`][std::collections::BTreeMap], [`IndexMap`][indexmap::IndexMap] or [`Env`][crate::Env] as the `variables` parameter.
 	/// The maps must have [`&str`] or [`String`] keys, and the values must be [`AsRef<[u8]>`].
 	pub fn expand<'b, M>(&self, variables: &'b M) -> Result<Vec<u8>, ExpandError>
 	where

src/template/raw/expand.rs

@@ -2,9 +2,24 @@ use super::{Part, Template, Variable};
 use crate::error::{self, ExpandError};
 use crate::VariableMap;
 
-impl Template {
+/// Common `expand` prototype, e.g., for variables and templates
+pub trait Expand {
+	/// Expand into the output vector.
+	fn expand<'a, M, F>(
+		&self,
+		output: &mut Vec<u8>,
+		source: &[u8],
+		variables: &'a M,
+		to_bytes: &F,
+	) -> Result<(), ExpandError>
+	where
+		M: VariableMap<'a> + ?Sized,
+		F: Fn(&M::Value) -> &[u8];
+}
+
+impl Expand for Template {
 	/// Expand the template into the output vector.
-	pub fn expand<'a, M, F>(
+	fn expand<'a, M, F>(
 		&self,
 		output: &mut Vec<u8>,
 		source: &[u8],
@@ -27,7 +42,7 @@ impl Template {
 	}
 }
 
-impl Variable {
+impl Expand for Variable {
 	/// Expand the variable into the output vector.
 	fn expand<'a, M, F>(
 		&self,

src/template/raw/mod.rs

@@ -1,6 +1,8 @@
 mod expand;
 mod parse;
 
+pub use expand::Expand;
+
 /// Raw template that doesn't know track the original source.
 ///
 /// Internally, this keeps a bunch of offsets into the original source.

src/template/raw/parse.rs

@@ -140,8 +140,8 @@ impl Variable {
 		}
 
 		// If there is no matching un-escaped closing brace, it's missing.
-		let end = finger + find_closing_brace(&source[finger..])
-			.ok_or(error::MissingClosingBrace { position: finger + 1 })?;
+		let end = finger
+			+ find_closing_brace(&source[finger..]).ok_or(error::MissingClosingBrace { position: finger + 1 })?;
 
 		let variable = Variable {
 			name: name_start..name_end,