implement basic namespacing for types, traits and commands

src/syntax/check.rs

@@ -20,6 +20,10 @@ pub fn check(
         ))
     }
 
+    if let Err(e_span) = check_missing_sink(&syntax) {
+        errs.push(SyntaxError::MissingSink(vec![(file_id, e_span)]));
+    }
+
     if errs.is_empty() {
         Ok(syntax)
     } else {
@@ -44,11 +48,11 @@ fn check_missing_filters(syntax: &Vec<PipelineElement>) -> Result<(), Vec<logos:
 
     for i in 0..syntax.len() {
         if let (
-            Some(PipelineElement {
+            Some(&PipelineElement {
                 kind: PipelineElementKind::Pipe,
                 ref span,
             }),
-            Some(PipelineElement {
+            Some(&PipelineElement {
                 kind: PipelineElementKind::Pipe,
                 span: ref span1,
             }),
@@ -64,3 +68,15 @@ fn check_missing_filters(syntax: &Vec<PipelineElement>) -> Result<(), Vec<logos:
         Err(missing_filter_locs)
     }
 }
+
+fn check_missing_sink(syntax: &Vec<PipelineElement>) -> Result<(), logos::Span> {
+    if let Some(&PipelineElement {
+        kind: PipelineElementKind::Pipe,
+        ref span,
+    }) = syntax.last()
+    {
+        Err(span.clone())
+    } else {
+        Ok(())
+    }
+}

src/syntax/error.rs

@@ -13,11 +13,11 @@ pub enum SyntaxError {
     MissingSink(Vec<(FileId, logos::Span)>),
     /// This indicates a missing filter somewhere in the pipeline, meaning that there's 2 pipes after one another
     MissingFilter(Vec<(FileId, logos::Span)>),
-    /// A literal cannot be a sink
+    /// A literal cannot be a sink, TODO
     LiteralAsSink,
-    /// A literal can't be a filter either
+    /// A literal can't be a filter either, TODO
     LiteralAsFilter,
-    /// A literal acting as streamer cannot take arguments
+    /// A literal acting as streamer cannot take arguments, TODO
     LiteralWithArgs,
 }
 
@@ -51,7 +51,16 @@ impl SyntaxError {
                         })
                         .collect(),
                 ),
-            _ => todo!(),
+            Self::MissingSink(locs) => Diagnostic::error()
+                .with_message("pipelines cannot end on a pipe")
+                .with_labels(
+                    locs.into_iter()
+                        .map(|(file_id, span)| {
+                            Label::primary(*file_id, span.clone()).with_message("no sink")
+                        })
+                        .collect(),
+                ),
+            _ => unimplemented!(),
         }
     }
 }