better parsing

1 files changed, 43 insertions, 3 deletions

diff --git a/src/parse/mod.rs b/src/parse/mod.rs
index 006fce2..9d3164e 100644
--- a/src/parse/mod.rs
+++ b/src/parse/mod.rs
@@ -912,6 +912,20 @@ struct Cursor<'a> {
     backtrace: bool,
 }
 
+#[derive(Default)]
+struct SpaceStats {
+    space: u32,
+    tab: u32,
+    lf: u32,
+    cr: u32,
+}
+
+impl SpaceStats {
+    fn is_empty(&self) -> bool {
+        self.space == 0 && self.tab == 0 && self.lf == 0 && self.cr == 0
+    }
+}
+
 impl<'a> Cursor<'a> {
     fn new(buf: &'a [u8], mode: ParseMode) -> Self {
         Self {
@@ -978,6 +992,31 @@ impl<'a> Cursor<'a> {
         }
     }
 
+    fn spaces_stats(&mut self) -> SpaceStats {
+        let mut stats = SpaceStats::default();
+        while self.has() && b" \t\n\r".contains(&self.buf[0]) {
+            match self.buf[0] {
+                b' ' => stats.space += 1,
+                b'\t' => stats.tab += 1,
+                b'\n' => stats.lf += 1,
+                b'\r' => stats.cr += 1,
+                _ => unreachable!(),
+            }
+            self.adv();
+        }
+        stats
+    }
+
+    /// returns true if the next thing in the buffer is whitespace (including at least one newline)
+    /// 
+    /// does not modify the buffer
+    fn whitespace_newline(&mut self) -> bool {
+        let x = self.buf;
+        let s = self.spaces_stats();
+        self.buf = x;
+        s.lf > 0
+    }
+
     fn is_completion(&self) -> bool {
         matches!(self.mode, ParseMode::Completion)
     }
@@ -1015,7 +1054,7 @@ impl Parse for Command<PreExpansion> {
     fn parse(b: &mut Cursor<'_>) -> Result<Self> {
         let path: ExpString = b.parse()?;
         let mut args = Vec::new();
-        loop {
+        while !b.whitespace_newline() {
             match ExpString::parse(b) {
                 Ok(arg) => args.push(arg),
                 Err(ParseError::NotAString) => break,
@@ -1031,7 +1070,8 @@ impl Parse for Pipes<PreExpansion> {
         let mut cmds: Vec<Command<PreExpansion>> = vec![b.parse()?];
 
         loop {
-            b.spaces();
+            let space_stats = b.spaces_stats();
+
             if b.is_empty() {
                 return Ok(Pipes { cmds });
             }
@@ -1040,7 +1080,7 @@ impl Parse for Pipes<PreExpansion> {
             if c == b'|' {
                 b.adv();
                 cmds.push(b.parse()?);
-            } else if is_symbol(c) {
+            } else if space_stats.lf > 0 || is_symbol(c) {
                 return Ok(Pipes { cmds });
             } else {
                 Err(ParseError::Unknown(c))?;