Pipe external to internal

Each line is a string object

Cargo.lock

@@ -143,6 +143,15 @@ name = "byteorder"
 version = "1.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "bytes"
+version = "0.4.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "byteorder 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "iovec 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "cc"
 version = "1.0.37"
@@ -285,6 +294,15 @@ dependencies = [
  "crossbeam-utils 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "crossbeam-deque"
+version = "0.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "crossbeam-epoch 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "crossbeam-utils 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "crossbeam-epoch"
 version = "0.3.1"
@@ -299,6 +317,27 @@ dependencies = [
  "scopeguard 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "crossbeam-epoch"
+version = "0.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "arrayvec 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cfg-if 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "crossbeam-utils 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "memoffset 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "scopeguard 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "crossbeam-queue"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "crossbeam-utils 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "crossbeam-utils"
 version = "0.2.2"
@@ -650,6 +689,11 @@ name = "fuchsia-cprng"
 version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "futures"
+version = "0.1.27"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "futures-channel-preview"
 version = "0.3.0-alpha.16"
@@ -710,6 +754,7 @@ name = "futures-util-preview"
 version = "0.3.0-alpha.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
+ "futures 0.1.27 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-channel-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-core-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-io-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -717,6 +762,16 @@ dependencies = [
  "memchr 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "pin-utils 0.1.0-alpha.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "slab 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tokio-io 0.1.12 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "futures_codec"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bytes 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -742,6 +797,15 @@ name = "indexmap"
 version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "iovec"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.55 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "itertools"
 version = "0.8.0"
@@ -917,6 +981,7 @@ dependencies = [
  "dunce 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-sink-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures_codec 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "indexmap 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "itertools 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "nom 5.0.0-beta1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -927,6 +992,8 @@ dependencies = [
  "rustyline 4.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "subprocess 0.1.18 (registry+https://github.com/rust-lang/crates.io-index)",
  "sysinfo 0.8.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "term 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tokio-fs 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1633,6 +1700,51 @@ dependencies = [
  "winapi 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "tokio-executor"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "crossbeam-utils 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures 0.1.27 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "tokio-fs"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "futures 0.1.27 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tokio-io 0.1.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tokio-threadpool 0.1.14 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "tokio-io"
+version = "0.1.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bytes 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures 0.1.27 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "tokio-threadpool"
+version = "0.1.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "crossbeam-deque 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "crossbeam-queue 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "crossbeam-utils 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures 0.1.27 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "num_cpus 1.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "slab 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tokio-executor 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "toml"
 version = "0.5.1"
@@ -1787,6 +1899,7 @@ dependencies = [
 "checksum build_const 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "39092a32794787acd8525ee150305ff051b0aa6cc2abaf193924f5ab05425f39"
 "checksum byte-unit 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "6754bb4703aa167bed5381f0c6842f1cc31a9ecde3b9443f726dde3ad3afb841"
 "checksum byteorder 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "a019b10a2a7cdeb292db131fc8113e57ea2a908f6e7894b0c3c671893b65dbeb"
+"checksum bytes 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)" = "206fdffcfa2df7cbe15601ef46c813fce0965eb3286db6b56c583b814b51c81c"
 "checksum cc 1.0.37 (registry+https://github.com/rust-lang/crates.io-index)" = "39f75544d7bbaf57560d2168f28fd649ff9c76153874db88bdbdfd839b1a7e7d"
 "checksum cfg-if 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)" = "b486ce3ccf7ffd79fdeb678eac06a9e6c09fc88d33836340becb8fffe87c5e33"
 "checksum chrono 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)" = "45912881121cb26fad7c38c17ba7daa18764771836b34fab7d3fbd93ed633878"
@@ -1803,7 +1916,10 @@ dependencies = [
 "checksum crc32fast 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ba125de2af0df55319f41944744ad91c71113bf74a4646efff39afe1f6842db1"
 "checksum crossbeam-channel 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)" = "0f0ed1a4de2235cabda8558ff5840bffb97fcb64c97827f354a451307df5f72b"
 "checksum crossbeam-deque 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f739f8c5363aca78cfb059edf753d8f0d36908c348f3d8d1503f03d8b75d9cf3"
+"checksum crossbeam-deque 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)" = "b18cd2e169ad86297e6bc0ad9aa679aee9daa4f19e8163860faf7c164e4f5a71"
 "checksum crossbeam-epoch 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "927121f5407de9956180ff5e936fe3cf4324279280001cd56b669d28ee7e9150"
+"checksum crossbeam-epoch 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)" = "04c9e3102cc2d69cd681412141b390abd55a362afc1540965dad0ad4d34280b4"
+"checksum crossbeam-queue 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7c979cd6cfe72335896575c6b5688da489e420d36a27a0b9eb0c73db574b4a4b"
 "checksum crossbeam-utils 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "2760899e32a1d58d5abb31129f8fae5de75220bc2176e77ff7c627ae45c918d9"
 "checksum crossbeam-utils 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "677d453a17e8bd2b913fa38e8b9cf04bcdbb5be790aa294f2389661d72036015"
 "checksum crossbeam-utils 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)" = "f8306fcef4a7b563b76b7dd949ca48f52bc1141aa067d2ea09565f3e2652aa5c"
@@ -1842,6 +1958,7 @@ dependencies = [
 "checksum flate2 1.0.7 (registry+https://github.com/rust-lang/crates.io-index)" = "f87e68aa82b2de08a6e037f1385455759df6e445a8df5e005b4297191dbf18aa"
 "checksum fnv 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "2fad85553e09a6f881f739c29f0b00b0f01357c743266d478b68951ce23285f3"
 "checksum fuchsia-cprng 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "a06f77d526c1a601b7c4cdd98f54b5eaabffc14d5f2f0296febdc7f357c6d3ba"
+"checksum futures 0.1.27 (registry+https://github.com/rust-lang/crates.io-index)" = "a2037ec1c6c1c4f79557762eab1f7eae1f64f6cb418ace90fae88f0942b60139"
 "checksum futures-channel-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)" = "4cd523712fc272e9b714669165a2832debee5a5b7e409bfccdc7c0d5cd0cf07a"
 "checksum futures-core-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)" = "719770f328642b657b849856bb5a607db9538dd5bb3000122e5ead55d0a58c36"
 "checksum futures-executor-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)" = "315dc58c908535d059576a329b86cd185933433382cfcd394fb2fa353330de03"
@@ -1849,10 +1966,12 @@ dependencies = [
 "checksum futures-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)" = "fcfeac5f016a4b5835bb93eb7961f50a64f0e001207562703d9ddf4109d7b263"
 "checksum futures-sink-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)" = "49dcfdacd6b5974ca0b9b78bc38ffd1071da0206179735c3df82e279f5b784e4"
 "checksum futures-util-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)" = "f7a0451b9c5047c2b9ab93425ffd0793165511e93c04b977cd45fbd41c6e34b2"
+"checksum futures_codec 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "b60f48aa03e365df015d2fbf0b79f17b440350c268a5e20305da17b394adcc1e"
 "checksum hashbrown 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "570178d5e4952010d138b0f1d581271ff3a02406d990f887d1e87e3d6e43b0ac"
 "checksum humantime 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "3ca7e5f2e110db35f93b837c81797f3714500b81d517bf20c431b16d3ca4f114"
 "checksum ident_case 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "b9e0384b61958566e926dc50660321d12159025e767c18e043daf26b70104c39"
 "checksum indexmap 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7e81a7c05f79578dbc15793d8b619db9ba32b4577003ef3af1a91c416798c58d"
+"checksum iovec 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "dbe6e417e7d0975db6512b90796e8ce223145ac4e33c377e4a42882a0e88bb08"
 "checksum itertools 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5b8467d9c1cebe26feb08c640139247fac215782d35371ade9a2136ed6085358"
 "checksum itoa 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)" = "501266b7edd0174f8530248f87f99c88fbe60ca4ef3dd486835b8d8d53136f7f"
 "checksum kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7507624b29483431c0ba2d82aece8ca6cdba9382bff4ddd0f7490560c056098d"
@@ -1954,6 +2073,10 @@ dependencies = [
 "checksum textwrap 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d326610f408c7a4eb6f51c37c330e496b08506c9457c9d34287ecc38809fb060"
 "checksum thread_local 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)" = "c6b53e329000edc2b34dbe8545fd20e55a333362d0a321909685a19bd28c3f1b"
 "checksum time 0.1.42 (registry+https://github.com/rust-lang/crates.io-index)" = "db8dcfca086c1143c9270ac42a2bbd8a7ee477b78ac8e45b19abfb0cbede4b6f"
+"checksum tokio-executor 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)" = "83ea44c6c0773cc034771693711c35c677b4b5a4b21b9e7071704c54de7d555e"
+"checksum tokio-fs 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "3fe6dc22b08d6993916647d108a1a7d15b9cd29c4f4496c62b92c45b5041b7af"
+"checksum tokio-io 0.1.12 (registry+https://github.com/rust-lang/crates.io-index)" = "5090db468dad16e1a7a54c8c67280c5e4b544f3d3e018f0b913b400261f85926"
+"checksum tokio-threadpool 0.1.14 (registry+https://github.com/rust-lang/crates.io-index)" = "72558af20be886ea124595ea0f806dd5703b8958e4705429dd58b3d8231f72f2"
 "checksum toml 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "b8c96d7873fa7ef8bdeb3a9cda3ac48389b4154f32b9803b4bc26220b677b039"
 "checksum ucd-util 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "535c204ee4d8434478593480b8f86ab45ec9aae0e83c568ca81abf0fd0e88f86"
 "checksum unicode-segmentation 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1967f4cdfc355b37fd76d2a954fb2ed3871034eb4f26d60537d88795cfc332a9"

Cargo.toml

@@ -27,8 +27,11 @@ byte-unit = "2.1.0"
 ordered-float = "1.0.2"
 prettyprint = "0.6.0"
 cursive = { version = "0.12.0", features = ["pancurses-backend"], default-features = false }
-futures-preview = "0.3.0-alpha.16"
+futures-preview = { version = "0.3.0-alpha.16", features = ["compat", "io-compat"] }
 futures-sink-preview = "0.3.0-alpha.16"
+tokio-fs = "0.1.6"
+futures_codec = "0.2.2"
+term = "0.5.2"
 
 [dependencies.pancurses]
 version = "0.16"

src/cli.rs

@@ -1,7 +1,7 @@
 use crate::prelude::*;
 
 use crate::commands::classified::{
-    ClassifiedCommand, ClassifiedInputStream, ExternalCommand, InternalCommand,
+    ClassifiedCommand, ClassifiedInputStream, ExternalCommand, InternalCommand, StreamNext,
 };
 use crate::context::Context;
 crate use crate::errors::ShellError;
@@ -185,7 +185,7 @@ async fn process_line(readline: Result<String, ReadlineError>, ctx: &mut Context
                     (
                         Some(ClassifiedCommand::External(left)),
                         Some(ClassifiedCommand::External(_)),
-                    ) => match left.run(ctx, input, true).await {
+                    ) => match left.run(ctx, input, StreamNext::External).await {
                         Ok(val) => val,
                         Err(err) => return LineResult::Error(format!("{}", err.description())),
                     },
@@ -196,12 +196,15 @@ async fn process_line(readline: Result<String, ReadlineError>, ctx: &mut Context
                     ) => unimplemented!(),
 
                     (
-                        Some(ClassifiedCommand::External(_)),
+                        Some(ClassifiedCommand::External(left)),
                         Some(ClassifiedCommand::Internal(_)),
-                    ) => unimplemented!(),
+                    ) => match left.run(ctx, input, StreamNext::Internal).await {
+                        Ok(val) => val,
+                        Err(err) => return LineResult::Error(format!("{}", err.description())),
+                    },
 
                     (Some(ClassifiedCommand::External(left)), None) => {
-                        match left.run(ctx, input, false).await {
+                        match left.run(ctx, input, StreamNext::Last).await {
                             Ok(val) => val,
                             Err(err) => return LineResult::Error(format!("{}", err.description())),
                         }

src/commands/classified.rs

@@ -1,4 +1,6 @@
 use crate::prelude::*;
+use futures::compat::AsyncRead01CompatExt;
+use futures_codec::{Framed, LinesCodec};
 use std::sync::Arc;
 use subprocess::Exec;
 
@@ -107,20 +109,29 @@ crate struct ExternalCommand {
     crate args: Vec<String>,
 }
 
+crate enum StreamNext {
+    Last,
+    External,
+    Internal,
+}
+
 impl ExternalCommand {
     crate async fn run(
         self,
         context: &mut Context,
         mut input: ClassifiedInputStream,
-        stream_next: bool,
+        stream_next: StreamNext,
     ) -> Result<ClassifiedInputStream, ShellError> {
         let mut process = Exec::shell(&self.name)
             .args(&self.args)
             .cwd(context.env.lock().unwrap().cwd());
 
-        if stream_next {
+        let mut process = match stream_next {
-            process = process.stdout(subprocess::Redirection::Pipe)
+            StreamNext::Last => process,
+            StreamNext::External | StreamNext::Internal => {
+                process.stdout(subprocess::Redirection::Pipe)
             }
+        };
 
         if let Some(stdin) = input.stdin {
             process = process.stdin(stdin);
@@ -128,15 +139,31 @@ impl ExternalCommand {
 
         let mut popen = process.popen().unwrap();
 
-        if stream_next {
+        match stream_next {
-            match &popen.stdout {
+            StreamNext::Last => {
-                None => unreachable!(),
-                Some(stdout) => Ok(ClassifiedInputStream::from_stdout(stdout.try_clone()?)),
-            }
-        } else {
-            popen.stdin.take();
                 popen.wait()?;
                 Ok(ClassifiedInputStream::new())
             }
+            StreamNext::External => {
+                let stdout = popen.stdout.take().unwrap();
+                Ok(ClassifiedInputStream::from_stdout(stdout))
+            }
+            StreamNext::Internal => {
+                let stdout = popen.stdout.take().unwrap();
+                let file = futures::io::AllowStdIo::new(stdout);
+                let stream = Framed::new(file, LinesCodec {});
+                let stream = stream.map(|line| Value::string(line.unwrap()));
+                Ok(ClassifiedInputStream::from_input_stream(stream.boxed()))
+            }
+        }
+
+        // if stream_next {
+        //     let stdout = popen.stdout.take().unwrap();
+        //     Ok(ClassifiedInputStream::from_stdout(stdout))
+        // } else {
+        //     // popen.stdin.take();
+        //     popen.wait()?;
+        //     Ok(ClassifiedInputStream::new())
+        // }
     }
 }

src/env/host.rs

@@ -1,9 +1,20 @@
 pub trait Host {
+    fn out_terminal(&self) -> Box<term::StdoutTerminal>;
+    fn err_terminal(&self) -> Box<term::StderrTerminal>;
+
     fn stdout(&mut self, out: &str);
     fn stderr(&mut self, out: &str);
 }
 
 impl Host for Box<dyn Host> {
+    fn out_terminal(&self) -> Box<term::StdoutTerminal> {
+        (**self).out_terminal()
+    }
+
+    fn err_terminal(&self) -> Box<term::StderrTerminal> {
+        (**self).err_terminal()
+    }
+
     fn stdout(&mut self, out: &str) {
         (**self).stdout(out)
     }
@@ -16,6 +27,14 @@ impl Host for Box<dyn Host> {
 crate struct BasicHost;
 
 impl Host for BasicHost {
+    fn out_terminal(&self) -> Box<term::StdoutTerminal> {
+        term::stdout().unwrap()
+    }
+
+    fn err_terminal(&self) -> Box<term::StderrTerminal> {
+        term::stderr().unwrap()
+    }
+
     fn stdout(&mut self, out: &str) {
         match out {
             "\n" => println!(""),

src/format.rs

@@ -10,16 +10,9 @@ crate use generic::GenericView;
 crate use table::TableView;
 
 crate trait RenderView {
-    fn render_view(&self, host: &dyn Host) -> Vec<String>;
+    fn render_view(&self, host: &mut dyn Host) -> Result<(), ShellError>;
 }
 
-fn print_rendered(lines: &[String], host: &mut dyn Host) {
+crate fn print_view(view: &impl RenderView, host: &mut dyn Host) -> Result<(), ShellError> {
-    for line in lines {
+    view.render_view(host)
-        host.stdout(line);
-    }
-}
-
-crate fn print_view(view: &impl RenderView, host: &mut Host) {
-    // let mut ctx = context.lock().unwrap();
-    crate::format::print_rendered(&view.render_view(host), host);
 }

src/format/entries.rs

@@ -10,7 +10,7 @@ use derive_new::new;
 // another_name : ...
 #[derive(new)]
 pub struct EntriesView {
-    entries: Vec<(String, String)>,
+    entries: Vec<(crate::object::DescriptorName, String)>,
 }
 
 impl EntriesView {
@@ -31,17 +31,28 @@ impl EntriesView {
 }
 
 impl RenderView for EntriesView {
-    fn render_view(&self, _host: &dyn Host) -> Vec<String> {
+    fn render_view(&self, _host: &mut dyn Host) -> Result<(), ShellError> {
         if self.entries.len() == 0 {
-            return vec![];
+            return Ok(());
         }
 
-        let max_name_size: usize = self.entries.iter().map(|(n, _)| n.len()).max().unwrap();
+        let max_name_size: usize = self
-
+            .entries
-        self.entries
             .iter()
-            .map(|(k, v)| format!("{:width$} : {}", k, v, width = max_name_size))
+            .map(|(n, _)| n.display().len())
-            .collect()
+            .max()
+            .unwrap();
+
+        for (name, value) in &self.entries {
+            println!(
+                "{:width$} : {}",
+                name.display(),
+                value,
+                width = max_name_size
+            )
+        }
+
+        Ok(())
     }
 }
 
@@ -58,26 +69,22 @@ impl EntriesListView {
 }
 
 impl RenderView for EntriesListView {
-    fn render_view(&self, host: &dyn Host) -> Vec<String> {
+    fn render_view(&self, host: &mut dyn Host) -> Result<(), ShellError> {
         if self.values.len() == 0 {
-            return vec![];
+            return Ok(());
         }
 
-        let mut strings = vec![];
-
         let last = self.values.len() - 1;
 
         for (i, item) in self.values.iter().enumerate() {
             let view = EntriesView::from_value(item);
-            let out = view.render_view(host);
+            view.render_view(host);
-
-            strings.extend(out);
 
             if i != last {
-                strings.push("\n".to_string());
+                host.stdout("\n");
             }
         }
 
-        strings
+        Ok(())
     }
 }

src/format/generic.rs

@@ -10,17 +10,17 @@ pub struct GenericView<'value> {
 }
 
 impl RenderView for GenericView<'value> {
-    fn render_view(&self, host: &dyn Host) -> Vec<String> {
+    fn render_view(&self, host: &mut dyn Host) -> Result<(), ShellError> {
         match self.value {
-            Value::Primitive(p) => vec![p.format(None)],
+            Value::Primitive(p) => Ok(host.stdout(&p.format(None))),
             Value::List(l) => {
                 let view = TableView::from_list(l);
 
                 if let Some(view) = view {
-                    view.render_view(host)
+                    view.render_view(host);
-                } else {
-                    vec![]
                 }
+
+                Ok(())
                 // let mut list: Vec<String> = vec![];
                 // for item in l {
                 //     match item {
@@ -39,11 +39,14 @@ impl RenderView for GenericView<'value> {
 
             o @ Value::Object(_) => {
                 let view = EntriesView::from_value(o);
-                let out = view.render_view(host);
+                view.render_view(host);
-                out
+                Ok(())
             }
 
-            Value::Error(e) => vec![format!("{}", e)],
+            Value::Error(e) => {
+                host.stdout(&format!("{:?}", e));
+                Ok(())
+            }
         }
     }
 }

src/format/list.rs

@@ -11,14 +11,12 @@ pub struct ListView {
 }
 
 impl RenderView for ListView {
-    fn render_view(&self, _host: &dyn Host) -> Vec<String> {
+    fn render_view(&self, host: &mut dyn Host) -> Result<(), ShellError> {
-        let mut out = vec![];
-
         for output in &self.list {
             let string: String = output.iter().map(|l| format!("{}\n", l)).collect();
-            out.push(format!("{}{}", string, self.sep));
+            host.stdout(&format!("{}{}", string, self.sep));
         }
 
-        out
+        Ok(())
     }
 }

src/format/table.rs

@@ -1,8 +1,9 @@
 use crate::format::RenderView;
 use crate::object::Value;
 use crate::prelude::*;
+use ansi_term::Color;
 use derive_new::new;
-use prettytable::{Cell, Row, Table};
+use prettytable::{color, Attr, Cell, Row, Table};
 
 // An entries list is printed like this:
 //
@@ -24,7 +25,7 @@ impl TableView {
         let item = &values[0];
         let descs = item.data_descriptors();
 
-        let headers: Vec<String> = descs.iter().map(|d| d.name.clone()).collect();
+        let headers: Vec<String> = descs.iter().map(|d| d.name.display().to_string()).collect();
 
         let mut entries = vec![];
 
@@ -43,13 +44,27 @@ impl TableView {
 }
 
 impl RenderView for TableView {
-    fn render_view(&self, _host: &dyn Host) -> Vec<String> {
+    fn render_view(&self, host: &mut dyn Host) -> Result<(), ShellError> {
         if self.entries.len() == 0 {
-            return vec![];
+            return Ok(());
         }
 
         let mut table = Table::new();
-        let header: Vec<Cell> = self.headers.iter().map(|h| Cell::new(h)).collect();
+
+        // let format = prettytable::format::FormatBuilder::new();
+        // .column_separator(Color::Black.bold().paint("|"));
+
+        table.set_format(*prettytable::format::consts::FORMAT_NO_COLSEP);
+
+        let header: Vec<Cell> = self
+            .headers
+            .iter()
+            .map(|h| {
+                Cell::new(h)
+                    .with_style(Attr::ForegroundColor(color::GREEN))
+                    .with_style(Attr::Bold)
+            })
+            .collect();
 
         table.add_row(Row::new(header));
 
@@ -57,9 +72,8 @@ impl RenderView for TableView {
             table.add_row(Row::new(row.iter().map(|h| Cell::new(h)).collect()));
         }
 
-        let mut out = vec![];
+        table.print_term(&mut *host.out_terminal()).unwrap();
-        table.print(&mut out).unwrap();
 
-        vec![String::from_utf8_lossy(&out).to_string()]
+        Ok(())
     }
 }

src/object.rs

@@ -6,5 +6,6 @@ crate mod process;
 crate mod types;
 
 crate use base::{Primitive, Value};
+crate use desc::{DataDescriptor, DescriptorName};
 crate use dict::Dictionary;
 crate use files::dir_entry_dict;

src/object/base.rs

@@ -1,5 +1,5 @@
 use crate::errors::ShellError;
-use crate::object::desc::DataDescriptor;
+use crate::object::{DataDescriptor, DescriptorName};
 use crate::parser::parse::Operator;
 use crate::prelude::*;
 use ansi_term::Color;
@@ -69,7 +69,7 @@ pub enum Value {
 impl Value {
     crate fn data_descriptors(&self) -> Vec<DataDescriptor> {
         match self {
-            Value::Primitive(_) => vec![],
+            Value::Primitive(_) => vec![DataDescriptor::value_of()],
             Value::Object(o) => o.data_descriptors(),
             Value::List(_) => vec![],
             Value::Error(_) => vec![],
@@ -87,7 +87,7 @@ impl Value {
 
     crate fn get_data(&'a self, desc: &DataDescriptor) -> MaybeOwned<'a, Value> {
         match self {
-            Value::Primitive(_) => MaybeOwned::Owned(Value::nothing()),
+            p @ Value::Primitive(_) => MaybeOwned::Borrowed(p),
             Value::Object(o) => o.get_data(desc),
             Value::List(_) => MaybeOwned::Owned(Value::nothing()),
             Value::Error(_) => MaybeOwned::Owned(Value::nothing()),
@@ -203,9 +203,9 @@ crate fn select_fields(obj: &Value, fields: &[String]) -> crate::object::Diction
     let descs = obj.data_descriptors();
 
     for field in fields {
-        match descs.iter().find(|d| d.name == *field) {
+        match descs.iter().find(|d| d.name.is_string(field)) {
-            None => out.add(field.to_string(), Value::nothing()),
+            None => out.add(DataDescriptor::for_string_name(field), Value::nothing()),
-            Some(desc) => out.add(field.to_string(), obj.get_data(desc).borrow().copy()),
+            Some(desc) => out.add(desc.copy(), obj.get_data(desc).borrow().copy()),
         }
     }
 
@@ -218,10 +218,10 @@ crate fn reject_fields(obj: &Value, fields: &[String]) -> crate::object::Diction
     let descs = obj.data_descriptors();
 
     for desc in descs {
-        if fields.contains(&desc.name) {
+        match desc.name.as_string() {
-            continue;
+            None => continue,
-        } else {
+            Some(s) if fields.iter().any(|field| field == s) => continue,
-            out.add(desc.name.clone(), obj.get_data(&desc).borrow().copy())
+            Some(s) => out.add(desc.copy(), obj.get_data(&desc).borrow().copy()),
         }
     }
 
@@ -230,7 +230,7 @@ crate fn reject_fields(obj: &Value, fields: &[String]) -> crate::object::Diction
 
 crate fn find(obj: &Value, field: &str, op: &Operator, rhs: &Value) -> bool {
     let descs = obj.data_descriptors();
-    match descs.iter().find(|d| d.name == *field) {
+    match descs.iter().find(|d| d.name.is_string(field)) {
         None => false,
         Some(desc) => {
             let v = obj.get_data(desc).borrow().copy();

src/object/desc.rs

@@ -1,17 +1,110 @@
-use crate::object::types::Type;
+use crate::object::types::{AnyShell, Type};
 use derive_new::new;
 
-#[derive(new)]
+#[derive(Debug, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
+pub enum DescriptorName {
+    String(String),
+    ValueOf,
+}
+
+impl DescriptorName {
+    crate fn display(&self) -> &str {
+        match self {
+            DescriptorName::String(s) => s,
+            DescriptorName::ValueOf => "value",
+        }
+    }
+
+    crate fn as_string(&self) -> Option<&str> {
+        match self {
+            DescriptorName::String(s) => Some(s),
+            DescriptorName::ValueOf => None,
+        }
+    }
+
+    crate fn is_string(&self, string: &str) -> bool {
+        match self {
+            DescriptorName::String(s) => s == string,
+            DescriptorName::ValueOf => false,
+        }
+    }
+}
+
+#[derive(Debug, new)]
 pub struct DataDescriptor {
-    crate name: String,
+    crate name: DescriptorName,
     crate readonly: bool,
     crate ty: Box<dyn Type>,
 }
 
+impl From<&str> for DataDescriptor {
+    fn from(input: &str) -> DataDescriptor {
+        DataDescriptor {
+            name: DescriptorName::String(input.to_string()),
+            readonly: true,
+            ty: Box::new(AnyShell),
+        }
+    }
+}
+
+impl From<String> for DataDescriptor {
+    fn from(input: String) -> DataDescriptor {
+        DataDescriptor {
+            name: DescriptorName::String(input),
+            readonly: true,
+            ty: Box::new(AnyShell),
+        }
+    }
+}
+
 impl PartialEq for DataDescriptor {
     fn eq(&self, other: &DataDescriptor) -> bool {
         self.name == other.name && self.readonly == other.readonly && self.ty.equal(&*other.ty)
     }
 }
 
-impl DataDescriptor {}
+impl std::hash::Hash for DataDescriptor {
+    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+        self.name.hash(state);
+        self.readonly.hash(state);
+        self.ty.id().hash(state);
+    }
+}
+
+impl Eq for DataDescriptor {}
+
+impl DescriptorName {
+    crate fn for_string_name(name: impl Into<String>) -> DescriptorName {
+        DescriptorName::String(name.into())
+    }
+}
+
+impl DataDescriptor {
+    crate fn value_of() -> DataDescriptor {
+        DataDescriptor {
+            name: DescriptorName::ValueOf,
+            readonly: true,
+            ty: Box::new(AnyShell),
+        }
+    }
+
+    crate fn for_name(name: impl Into<DescriptorName>) -> DataDescriptor {
+        DataDescriptor {
+            name: name.into(),
+            readonly: true,
+            ty: Box::new(AnyShell),
+        }
+    }
+
+    crate fn for_string_name(name: impl Into<String>) -> DataDescriptor {
+        DataDescriptor::for_name(DescriptorName::for_string_name(name))
+    }
+
+    crate fn copy(&self) -> DataDescriptor {
+        DataDescriptor {
+            name: self.name.clone(),
+            readonly: self.readonly,
+            ty: self.ty.copy(),
+        }
+    }
+}

src/object/dict.rs

@@ -1,13 +1,13 @@
 use crate::prelude::*;
 
-use crate::object::desc::DataDescriptor;
+use crate::object::{DataDescriptor, DescriptorName};
 use crate::object::{Primitive, Value};
 use indexmap::IndexMap;
 use std::cmp::{Ordering, PartialOrd};
 
 #[derive(Debug, Default, Eq, PartialEq)]
 pub struct Dictionary {
-    entries: IndexMap<String, Value>,
+    entries: IndexMap<DataDescriptor, Value>,
 }
 
 impl PartialOrd for Dictionary {
@@ -41,7 +41,7 @@ impl PartialEq<Value> for Dictionary {
 }
 
 impl Dictionary {
-    crate fn add(&mut self, name: impl Into<String>, value: Value) {
+    crate fn add(&mut self, name: impl Into<DataDescriptor>, value: Value) {
         self.entries.insert(name.into(), value);
     }
 
@@ -49,31 +49,30 @@ impl Dictionary {
         let mut out = Dictionary::default();
 
         for (key, value) in self.entries.iter() {
-            out.add(key.clone(), value.copy());
+            out.add(key.copy(), value.copy());
         }
 
         out
     }
 
     crate fn data_descriptors(&self) -> Vec<DataDescriptor> {
-        self.entries
+        self.entries.iter().map(|(name, _)| name.copy()).collect()
-            .iter()
-            .map(|(name, _)| {
-                DataDescriptor::new(name.clone(), true, Box::new(crate::object::types::AnyShell))
-            })
-            .collect()
     }
 
     crate fn get_data(&'a self, desc: &DataDescriptor) -> MaybeOwned<'a, Value> {
-        match self.entries.get(&desc.name) {
+        match self.entries.get(desc) {
             Some(v) => MaybeOwned::Borrowed(v),
             None => MaybeOwned::Owned(Value::Primitive(Primitive::Nothing)),
         }
     }
 
     crate fn get_data_by_key(&self, name: &str) -> MaybeOwned<'_, Value> {
-        match self.entries.get(name) {
+        match self
-            Some(v) => MaybeOwned::Borrowed(v),
+            .entries
+            .iter()
+            .find(|(desc_name, _)| desc_name.name.is_string(name))
+        {
+            Some((_, v)) => MaybeOwned::Borrowed(v),
             None => MaybeOwned::Owned(Value::Primitive(Primitive::Nothing)),
         }
     }

src/object/types.rs

@@ -1,11 +1,14 @@
 use std::any::Any;
+use std::fmt::Debug;
 
-pub trait Type {
+pub trait Type: Debug + Send {
     fn as_any(&self) -> &dyn Any;
     fn equal(&self, other: &dyn Type) -> bool;
+    fn id(&self) -> u64;
+    fn copy(&self) -> Box<Type>;
 }
 
-#[derive(Eq, PartialEq)]
+#[derive(Debug, Eq, PartialEq)]
 pub struct AnyShell;
 
 impl Type for AnyShell {
@@ -16,4 +19,12 @@ impl Type for AnyShell {
     fn equal(&self, other: &dyn Type) -> bool {
         other.as_any().is::<AnyShell>()
     }
+
+    fn id(&self) -> u64 {
+        0
+    }
+
+    fn copy(&self) -> Box<Type> {
+        Box::new(AnyShell)
+    }
 }