Add from csv and from tsv (#320)

crates/nu-protocol/src/pipeline_data.rs

@@ -51,10 +51,10 @@ impl PipelineData {
         }
     }
 
-    pub fn collect_string(self) -> String {
+    pub fn collect_string(self, separator: &str) -> String {
         match self {
-            PipelineData::Value(v) => v.into_string("\n"),
-            PipelineData::Stream(s) => s.into_string("\n"),
+            PipelineData::Value(v) => v.into_string(separator),
+            PipelineData::Stream(s) => s.into_string(separator),
         }
     }
 

crates/nu-protocol/src/shell_error.rs

@@ -60,6 +60,10 @@ pub enum ShellError {
         right_span: Span,
     },
 
+    #[error("Delimiter error")]
+    #[diagnostic(code(nu::shell::delimiter_error), url(docsrs))]
+    DelimiterError(String, #[label("{0}")] Span),
+
     #[error("Incompatible parameters.")]
     #[diagnostic(code(nu::shell::incompatible_parameters), url(docsrs))]
     IncompatibleParametersSingle(String, #[label = "{0}"] Span),

crates/nu-protocol/src/value/stream.rs

@@ -20,12 +20,9 @@ pub struct ValueStream {
 
 impl ValueStream {
     pub fn into_string(self, separator: &str) -> String {
-        format!(
-            "[{}]",
-            self.map(|x: Value| x.into_string(", "))
-                .collect::<Vec<String>>()
-                .join(separator)
-        )
+        self.map(|x: Value| x.into_string(", "))
+            .collect::<Vec<String>>()
+            .join(separator)
     }
 
     pub fn from_stream(