Add a definition of span and the parser for a full document

src/duster/mod.rs

@@ -6,3 +6,5 @@ mod parser;
 pub use node_invoker::run_node_dust;
 pub use node_invoker::NodeError;
 pub use node_invoker::Result;
+pub use parser::template;
+pub use parser::Template;

src/duster/parser.rs

@@ -4,6 +4,7 @@ use nom::bytes::complete::tag;
 use nom::bytes::complete::take_until;
 use nom::combinator::map;
 use nom::combinator::recognize;
+use nom::combinator::rest;
 use nom::combinator::value;
 use nom::multi::many0;
 use nom::multi::separated_list;
@@ -55,6 +56,19 @@ enum Filter {
     JsonParse,
 }
 
+struct Span<'a> {
+    contents: &'a str,
+}
+
+pub struct Template<'a> {
+    elements: Vec<TemplateElement<'a>>,
+}
+
+enum TemplateElement<'a> {
+    TESpan(Span<'a>),
+    TETag(DustTag<'a>),
+}
+
 fn dust_tag(i: &str) -> IResult<&str, DustTag> {
     alt((
         map(special, DustTag::DTSpecial),
@@ -121,3 +135,22 @@ fn filter(i: &str) -> IResult<&str, Filter> {
         )),
     )(i)
 }
+
+/// Any text that is not a Dust element
+fn span(i: &str) -> IResult<&str, Span> {
+    let (remaining, body) = alt((take_until("{"), rest))(i)?;
+    Ok((remaining, Span { contents: body }))
+}
+
+pub fn template(i: &str) -> IResult<&str, Template> {
+    let (remaining, template_elements) = many0(alt((
+        map(span, TemplateElement::TESpan),
+        map(dust_tag, TemplateElement::TETag),
+    )))(i)?;
+    Ok((
+        remaining,
+        Template {
+            elements: template_elements,
+        },
+    ))
+}