Simple parsing

src/parser.rs

@@ -0,0 +1,52 @@
+use nom::branch::alt;
+use nom::bytes::complete::{escaped, is_not, tag};
+use nom::{ws, named, separated_list, complete};
+use nom::character::complete::one_of;
+use nom::multi::separated_list;
+use nom::sequence::{preceded, terminated};
+use nom::IResult;
+
+#[derive(Debug)]
+pub enum Item {
+    Quoted(String),
+    Bare(String),
+}
+
+impl Item {
+  crate fn name(&self) -> &str {
+    match self {
+      Item::Quoted(s) => s,
+      Item::Bare(s) => s
+    }
+  }
+}
+
+fn esc(s: &str) -> IResult<&str, &str> {
+    escaped(is_not("\\\""), '\\', one_of("\"n\\"))(s)
+}
+
+fn quoted(s: &str) -> IResult<&str, Item> {
+    terminated(preceded(tag("\""), esc), tag("\""))(s)
+        .map(|(a, b)| (a, Item::Quoted(b.to_string())))
+}
+
+fn unquoted(s: &str) -> IResult<&str, Item> {
+    is_not(" |")(s).map(|(a, b)| (a, Item::Bare(b.to_string())))
+}
+
+fn command_token(s: &str) -> IResult<&str, Item> {
+    alt((quoted, unquoted))(s)
+}
+
+fn command_args(s: &str) -> IResult<&str, Vec<Item>> {
+    separated_list(tag(" "), command_token)(s)
+}
+
+named!(
+  pub shell_parser(&str) -> Vec<Vec<Item>>,
+  complete!(
+    ws!(
+      separated_list!(tag("|"), command_args)
+    )
+  )
+);