Starting the rust-based parser of dust templates

src/duster/mod.rs

@@ -1,6 +1,7 @@
 //! This module contains a rust implementation of LinkedIn Dust
 
 mod node_invoker;
+mod parser;
 
 pub use node_invoker::run_node_dust;
 pub use node_invoker::NodeError;

src/duster/parser.rs

@@ -0,0 +1,54 @@
+use nom::branch::alt;
+use nom::bytes::complete::tag;
+use nom::bytes::complete::take_until;
+use nom::combinator::map;
+use nom::combinator::value;
+use nom::sequence::delimited;
+use nom::IResult;
+
+#[derive(Clone, Debug)]
+enum DustTag<'a> {
+    DTSpecial(Special),
+    DTComment(Comment<'a>),
+}
+
+#[derive(Clone, Debug)]
+enum Special {
+    Space,
+    NewLine,
+    CarriageReturn,
+    LeftCurlyBrace,
+    RightCurlyBrace,
+}
+
+#[derive(Clone, Debug)]
+struct Comment<'a> {
+    value: &'a str,
+}
+
+fn dust_tag(i: &str) -> IResult<&str, DustTag> {
+    alt((
+        map(special, DustTag::DTSpecial),
+        map(comment, DustTag::DTComment),
+    ))(i)
+}
+
+fn special(i: &str) -> IResult<&str, Special> {
+    delimited(
+        tag("{~"),
+        alt((
+            value(Special::Space, tag("s")),
+            value(Special::NewLine, tag("s")),
+            value(Special::CarriageReturn, tag("s")),
+            value(Special::LeftCurlyBrace, tag("s")),
+            value(Special::RightCurlyBrace, tag("s")),
+        )),
+        tag("}"),
+    )(i)
+}
+
+fn comment(i: &str) -> IResult<&str, Comment> {
+    map(delimited(tag("{!"), take_until("!}"), tag("!}")), |body| {
+        Comment { value: body }
+    })(i)
+}