headers plugin

Cargo.lock

@@ -2500,6 +2500,16 @@ dependencies = [
  "url",
 ]
 
+[[package]]
+name = "nu_plugin_headers"
+version = "0.1.0"
+dependencies = [
+ "nu-errors",
+ "nu-plugin",
+ "nu-protocol",
+ "nu-source",
+]
+
 [[package]]
 name = "nu_plugin_inc"
 version = "0.11.0"

crates/nu-cli/src/commands/headers.rs

@@ -0,0 +1,39 @@
+use crate::commands::WholeStreamCommand;
+use crate::context::CommandRegistry;
+use crate::prelude::*;
+use futures::stream::StreamExt;
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, Signature, UntaggedValue, Value};
+
+pub struct Headers;
+
+impl WholeStreamCommand for Headers {
+    fn name(&self) -> &str {
+        "headers"
+    }
+    fn signature(&self) -> Signature {
+        Signature::build("headers")
+    }
+    fn usage(&self) -> &str {
+        "Use the first row of the table as headers"
+    }
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        args.process(registry, count)?.run()
+    }
+}
+pub fn count(
+    CountArgs {}: CountArgs,
+    RunnableContext { input, name, .. }: RunnableContext,
+) -> Result<OutputStream, ShellError> {
+    let stream = async_stream! {
+        let rows: Vec<Value> = input.values.collect().await;
+
+        yield ReturnSuccess::value(UntaggedValue::int(rows.len()).into_value(name))
+    };
+
+    Ok(stream.to_output_stream())
+}

crates/nu_plugin_headers/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "nu_plugin_headers"
+version = "0.1.0"
+authors = ["Sam Hedin <sam.hedin@gmail.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+nu-plugin = { path = "../nu-plugin", version = "0.11.0" }
+nu-protocol = { path = "../nu-protocol", version = "0.11.0" }
+nu-source = { path = "../nu-source", version = "0.11.0" }
+nu-errors = { path = "../nu-errors", version = "0.11.0" }

crates/nu_plugin_headers/Makefile

@@ -0,0 +1,2 @@
+out:
+	cargo install --path . --force

crates/nu_plugin_headers/src/headers.rs

@@ -0,0 +1,18 @@
+pub struct Headers;
+impl Headers {
+    pub fn new() -> Headers {
+        Headers
+    }
+}
+
+impl WholeStreamCommand for Headers {
+    fn name(&self) -> &str{
+        "headers"
+    }
+    fn signature(&self) -> Signature {
+        Signature::build("headers")
+    }
+    fn usage(&self) -> &str {
+        "Use the first row of the table as headers"
+    }
+}

crates/nu_plugin_headers/src/lib.rs

@@ -0,0 +1,3 @@
+mod nu;
+mod headers;
+pub use headers::Headers;

crates/nu_plugin_headers/src/main.rs

@@ -0,0 +1,7 @@
+use nu_plugin::serve_plugin;
+use nu_plugin_headers::Headers;
+
+//https://github.com/nushell/nushell/issues/1486
+fn main() {
+    serve_plugin(&mut Headers::new())
+}

crates/nu_plugin_headers/src/nu/mod.rs

@@ -0,0 +1,16 @@
+use crate::headers::Headers;
+use nu_errors::ShellError;
+use nu_plugin::Plugin;
+use nu_protocol::{CallInfo, ReturnSuccess, ReturnValue, Signature, Value};
+
+impl Plugin for Headers {
+    fn config(&mut self) -> Result<Signature, ShellError> {
+        Ok(Signature::build("headers")
+           .desc("Use the first row of the table as headers")
+            .filter())
+    }
+
+    fn begin_filter(&mut self, call_info: CallInfo) -> Result<Vec<ReturnValue>, ShellError> {
+        Ok(vec![])
+    }
+}