syntax serializers

crates/nu-plugin/build.rs

@@ -1,7 +1,7 @@
 fn main() {
     capnpc::CompilerCommand::new()
         .src_prefix("schema")
-        .file("schema/value.capnp")
+        .file("schema/plugin.capnp")
         .run()
         .expect("compiling schema");
 }

crates/nu-plugin/schema/plugin.capnp

@@ -0,0 +1,102 @@
+@0xb299d30dc02d72bc;
+# Schema representing all the structs that are used to comunicate with
+# the plugins.
+# This schema, together with the command capnp proto is used to generate
+# the rust file that defines the serialization/deserialization objects
+# required to comunicate with the plugins created for nushell
+
+# Generic structs used as helpers for the encoding
+struct Option(Value) {
+	union {
+		none @0 :Void;
+		some @1 :Value;
+	}
+}
+
+struct Map(Key, Value) {
+  struct Entry {
+    key @0 :Key;
+    value @1 :Value;
+  }
+  entries @0 :List(Entry);
+}
+
+# Main plugin structures
+struct Span {
+	start @0 :UInt64;
+	end @1 :UInt64;
+}
+
+struct Value {
+	span @0: Span;
+
+	union {
+		void @1 :Void;
+		bool @2 :Bool;
+		int @3 :Int64;
+		float @4 :Float64;
+		string @5 :Text;
+		list @6 :List(Value);
+	}
+}
+
+struct Signature {
+    name @0 :Text;
+    usage @1 :Text;
+    extraUsage @2 :Text;
+    requiredPositional @3 :List(Argument);
+    optionalPositional @4 :List(Argument);
+    rest @5 :Option(Argument);
+    named @6 :List(Flag);
+    isFilter @7 :Bool;
+}
+
+struct Flag {
+    long @0 :Text;
+    short @1 :Option(Text);
+    arg @2 :Shape;
+    required @3 :Bool;
+    desc @4 :Text;
+}
+
+struct Argument {
+    name @0 :Text;
+    desc @1 :Text;
+    shape @2 :Shape;
+}
+
+# If we require more complex signatures for the plugins this could be
+# changed to a union
+enum Shape {
+	none @0;
+	any @1;
+	string @2;
+	number @3;
+	int @4;
+	boolean @5;
+}
+
+struct Expression {
+	union {
+		garbage @0 :Void;
+		bool @1 :Bool;
+		int @2 :Int64;
+		float @3 :Float64;
+		string @4 :Text;
+		list @5 :List(Expression);
+		# The expression list can be exteded based on the user need
+		# If a plugin requires something from the expression object, it
+		# will need to be added to this list
+	}
+}
+
+struct Call {
+	head @0: Span;
+	positional @1 :List(Expression);
+	named @2 :Map(Text, Option(Expression));
+}
+
+struct CallInfo {
+	call @0: Call;
+	input @1: Value;
+}

crates/nu-plugin/schema/value.capnp

@@ -1,57 +0,0 @@
-@0xb299d30dc02d72bc;
-
-# Generic structs used as helpers for the encoding
-struct Option(Value) {
-	union {
-		none @0 :Void;
-		some @1 :Value;
-	}
-}
-
-struct Map(Key, Value) {
-  struct Entry {
-    key @0 :Key;
-    value @1 :Value;
-  }
-  entries @0 :List(Entry);
-}
-
-struct Span {
-	start @0 :UInt64;
-	end @1 :UInt64;
-}
-
-struct Value {
-	span @0: Span;
-
-	union {
-		void @1 :Void;
-		bool @2 :Bool;
-		int @3 :Int64;
-		float @4 :Float64;
-		string @5 :Text;
-		list @6 :List(Value);
-	}
-}
-
-struct Expression {
-	union {
-		garbage @0 :Void;
-		bool @1 :Bool;
-		int @2 :Int64;
-		float @3 :Float64;
-		string @4 :Text;
-		list @5 :List(Expression);
-	}
-}
-
-struct Call {
-	head @0: Span;
-	positional @1 :List(Expression);
-	named @2 :Map(Text, Option(Expression));
-}
-
-struct CallInfo {
-	call @0: Call;
-	input @1: Value;
-}

crates/nu-plugin/src/lib.rs

@@ -1,6 +1,6 @@
 pub mod plugin;
 pub mod serializers;
 
-pub mod value_capnp {
-    include!(concat!(env!("OUT_DIR"), "/value_capnp.rs"));
+pub mod plugin_capnp {
+    include!(concat!(env!("OUT_DIR"), "/plugin_capnp.rs"));
 }

crates/nu-plugin/src/serializers/call.rs

@@ -1,4 +1,4 @@
-use crate::value_capnp::{call, expression, option};
+use crate::plugin_capnp::{call, expression, option};
 use capnp::serialize_packed;
 use nu_protocol::{
     ast::{Call, Expr, Expression},
@@ -69,7 +69,7 @@ fn serialize_expression(expression: &Expression, mut builder: expression::Builde
         Expr::Bool(val) => builder.set_bool(*val),
         Expr::Int(val) => builder.set_int(*val),
         Expr::Float(val) => builder.set_float(*val),
-        Expr::String(val) => builder.set_string(&val),
+        Expr::String(val) => builder.set_string(val),
         Expr::List(values) => {
             let mut list_builder = builder.reborrow().init_list(values.len() as u32);
             for (index, expression) in values.iter().enumerate() {
@@ -130,10 +130,9 @@ fn deserialize_positionals(
         .collect()
 }
 
-fn deserialize_named(
-    span: Span,
-    reader: call::Reader,
-) -> Result<Vec<(Spanned<String>, Option<Expression>)>, ShellError> {
+type NamedList = Vec<(Spanned<String>, Option<Expression>)>;
+
+fn deserialize_named(span: Span, reader: call::Reader) -> Result<NamedList, ShellError> {
     let named_reader = reader
         .get_named()
         .map_err(|e| ShellError::DecodingError(e.to_string()))?;

crates/nu-plugin/src/serializers/callinfo.rs

@@ -1,5 +1,5 @@
 use super::{call, value};
-use crate::value_capnp::call_info;
+use crate::plugin_capnp::call_info;
 use capnp::serialize_packed;
 use nu_protocol::{ast::Call, ShellError, Value};
 

crates/nu-plugin/src/serializers/mod.rs

@@ -1,3 +1,4 @@
 pub mod call;
 pub mod callinfo;
+pub mod signature;
 pub mod value;

crates/nu-plugin/src/serializers/signature.rs

@@ -0,0 +1,312 @@
+use crate::plugin_capnp::{argument, flag, option, signature, Shape};
+use capnp::serialize_packed;
+use nu_protocol::{Flag, PositionalArg, ShellError, Signature, SyntaxShape};
+
+pub fn write_buffer(
+    signature: &Signature,
+    writer: &mut impl std::io::Write,
+) -> Result<(), ShellError> {
+    let mut message = ::capnp::message::Builder::new_default();
+
+    let builder = message.init_root::<signature::Builder>();
+
+    serialize_signature(signature, builder);
+
+    serialize_packed::write_message(writer, &message)
+        .map_err(|e| ShellError::EncodingError(e.to_string()))
+}
+
+pub(crate) fn serialize_signature(signature: &Signature, mut builder: signature::Builder) {
+    builder.set_name(signature.name.as_str());
+    builder.set_usage(signature.usage.as_str());
+    builder.set_extra_usage(signature.extra_usage.as_str());
+    builder.set_is_filter(signature.is_filter);
+
+    // Serializing list of required arguments
+    let mut required_list = builder
+        .reborrow()
+        .init_required_positional(signature.required_positional.len() as u32);
+
+    for (index, arg) in signature.required_positional.iter().enumerate() {
+        let inner_builder = required_list.reborrow().get(index as u32);
+        serialize_argument(arg, inner_builder)
+    }
+
+    // Serializing list of optional arguments
+    let mut optional_list = builder
+        .reborrow()
+        .init_optional_positional(signature.optional_positional.len() as u32);
+
+    for (index, arg) in signature.optional_positional.iter().enumerate() {
+        let inner_builder = optional_list.reborrow().get(index as u32);
+        serialize_argument(arg, inner_builder)
+    }
+
+    // Serializing rest argument
+    let mut rest_argument = builder.reborrow().init_rest();
+    match &signature.rest_positional {
+        None => rest_argument.set_none(()),
+        Some(arg) => {
+            let inner_builder = rest_argument.init_some();
+            serialize_argument(arg, inner_builder)
+        }
+    }
+
+    // Serializing the named arguments
+    let mut named_list = builder.reborrow().init_named(signature.named.len() as u32);
+
+    for (index, arg) in signature.named.iter().enumerate() {
+        let inner_builder = named_list.reborrow().get(index as u32);
+        serialize_flag(arg, inner_builder)
+    }
+}
+
+fn serialize_argument(arg: &PositionalArg, mut builder: argument::Builder) {
+    builder.set_name(arg.name.as_str());
+    builder.set_desc(arg.desc.as_str());
+
+    match arg.shape {
+        SyntaxShape::Boolean => builder.set_shape(Shape::Boolean),
+        SyntaxShape::String => builder.set_shape(Shape::String),
+        SyntaxShape::Int => builder.set_shape(Shape::Int),
+        SyntaxShape::Number => builder.set_shape(Shape::Number),
+        _ => builder.set_shape(Shape::Any),
+    }
+}
+
+fn serialize_flag(arg: &Flag, mut builder: flag::Builder) {
+    builder.set_long(arg.long.as_str());
+    builder.set_required(arg.required);
+    builder.set_desc(arg.desc.as_str());
+
+    let mut short_builder = builder.reborrow().init_short();
+    match arg.short {
+        None => short_builder.set_none(()),
+        Some(val) => {
+            let mut inner_builder = short_builder.reborrow().initn_some(1);
+            inner_builder.push_str(format!("{}", val).as_str());
+        }
+    }
+
+    match &arg.arg {
+        None => builder.set_arg(Shape::None),
+        Some(shape) => match shape {
+            SyntaxShape::Boolean => builder.set_arg(Shape::Boolean),
+            SyntaxShape::String => builder.set_arg(Shape::String),
+            SyntaxShape::Int => builder.set_arg(Shape::Int),
+            SyntaxShape::Number => builder.set_arg(Shape::Number),
+            _ => builder.set_arg(Shape::Any),
+        },
+    }
+}
+
+pub fn read_buffer(reader: &mut impl std::io::BufRead) -> Result<Signature, ShellError> {
+    let message_reader =
+        serialize_packed::read_message(reader, ::capnp::message::ReaderOptions::new()).unwrap();
+
+    let reader = message_reader
+        .get_root::<signature::Reader>()
+        .map_err(|e| ShellError::DecodingError(e.to_string()))?;
+
+    deserialize_signature(reader)
+}
+
+pub(crate) fn deserialize_signature(reader: signature::Reader) -> Result<Signature, ShellError> {
+    let name = reader
+        .get_name()
+        .map_err(|e| ShellError::EncodingError(e.to_string()))?;
+    let usage = reader
+        .get_usage()
+        .map_err(|e| ShellError::EncodingError(e.to_string()))?;
+    let extra_usage = reader
+        .get_extra_usage()
+        .map_err(|e| ShellError::EncodingError(e.to_string()))?;
+    let is_filter = reader.get_is_filter();
+
+    // Deserializing required arguments
+    let required_list = reader
+        .get_required_positional()
+        .map_err(|e| ShellError::EncodingError(e.to_string()))?;
+
+    let required_positional = required_list
+        .iter()
+        .map(deserialize_argument)
+        .collect::<Result<Vec<PositionalArg>, ShellError>>()?;
+
+    // Deserializing optional arguments
+    let optional_list = reader
+        .get_optional_positional()
+        .map_err(|e| ShellError::EncodingError(e.to_string()))?;
+
+    let optional_positional = optional_list
+        .iter()
+        .map(deserialize_argument)
+        .collect::<Result<Vec<PositionalArg>, ShellError>>()?;
+
+    // Deserializing rest arguments
+    let rest_option = reader
+        .get_rest()
+        .map_err(|e| ShellError::EncodingError(e.to_string()))?;
+
+    let rest_positional = match rest_option.which() {
+        Err(capnp::NotInSchema(_)) => None,
+        Ok(option::None(())) => None,
+        Ok(option::Some(rest_reader)) => {
+            let rest_reader = rest_reader.map_err(|e| ShellError::EncodingError(e.to_string()))?;
+            Some(deserialize_argument(rest_reader)?)
+        }
+    };
+
+    // Deserializing named arguments
+    let named_list = reader
+        .get_named()
+        .map_err(|e| ShellError::EncodingError(e.to_string()))?;
+
+    let named = named_list
+        .iter()
+        .map(deserialize_flag)
+        .collect::<Result<Vec<Flag>, ShellError>>()?;
+
+    Ok(Signature {
+        name: name.to_string(),
+        usage: usage.to_string(),
+        extra_usage: extra_usage.to_string(),
+        required_positional,
+        optional_positional,
+        rest_positional,
+        named,
+        is_filter,
+        creates_scope: false,
+    })
+}
+
+fn deserialize_argument(reader: argument::Reader) -> Result<PositionalArg, ShellError> {
+    let name = reader
+        .get_name()
+        .map_err(|e| ShellError::EncodingError(e.to_string()))?;
+
+    let desc = reader
+        .get_desc()
+        .map_err(|e| ShellError::EncodingError(e.to_string()))?;
+
+    let shape = reader
+        .get_shape()
+        .map_err(|e| ShellError::EncodingError(e.to_string()))?;
+
+    let shape = match shape {
+        Shape::String => SyntaxShape::String,
+        Shape::Int => SyntaxShape::Int,
+        Shape::Number => SyntaxShape::Number,
+        Shape::Boolean => SyntaxShape::Boolean,
+        Shape::Any => SyntaxShape::Any,
+        Shape::None => SyntaxShape::Any,
+    };
+
+    Ok(PositionalArg {
+        name: name.to_string(),
+        desc: desc.to_string(),
+        shape,
+        var_id: None,
+    })
+}
+
+fn deserialize_flag(reader: flag::Reader) -> Result<Flag, ShellError> {
+    let long = reader
+        .get_long()
+        .map_err(|e| ShellError::EncodingError(e.to_string()))?;
+
+    let desc = reader
+        .get_desc()
+        .map_err(|e| ShellError::EncodingError(e.to_string()))?;
+
+    let required = reader.get_required();
+
+    let short = reader
+        .get_short()
+        .map_err(|e| ShellError::EncodingError(e.to_string()))?;
+
+    let short = match short.which() {
+        Err(capnp::NotInSchema(_)) => None,
+        Ok(option::None(())) => None,
+        Ok(option::Some(reader)) => {
+            let reader = reader.map_err(|e| ShellError::EncodingError(e.to_string()))?;
+            reader.chars().next()
+        }
+    };
+
+    let arg = reader
+        .get_arg()
+        .map_err(|e| ShellError::EncodingError(e.to_string()))?;
+
+    let arg = match arg {
+        Shape::None => None,
+        Shape::Any => Some(SyntaxShape::Any),
+        Shape::String => Some(SyntaxShape::String),
+        Shape::Int => Some(SyntaxShape::Int),
+        Shape::Number => Some(SyntaxShape::Number),
+        Shape::Boolean => Some(SyntaxShape::Boolean),
+    };
+
+    Ok(Flag {
+        long: long.to_string(),
+        short,
+        arg,
+        required,
+        desc: desc.to_string(),
+        var_id: None,
+    })
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use nu_protocol::{Signature, SyntaxShape};
+
+    #[test]
+    fn value_round_trip() {
+        let signature = Signature::build("nu-plugin")
+            .required("first", SyntaxShape::String, "first required")
+            .required("second", SyntaxShape::Int, "second required")
+            .required_named("first_named", SyntaxShape::String, "first named", Some('f'))
+            .required_named(
+                "second_named",
+                SyntaxShape::String,
+                "second named",
+                Some('s'),
+            )
+            .rest("remaining", SyntaxShape::Int, "remaining");
+
+        let mut buffer: Vec<u8> = Vec::new();
+        write_buffer(&signature, &mut buffer).expect("unable to serialize message");
+        let returned_signature =
+            read_buffer(&mut buffer.as_slice()).expect("unable to deserialize message");
+
+        assert_eq!(signature.name, returned_signature.name);
+        assert_eq!(signature.usage, returned_signature.usage);
+        assert_eq!(signature.extra_usage, returned_signature.extra_usage);
+        assert_eq!(signature.is_filter, returned_signature.is_filter);
+
+        signature
+            .required_positional
+            .iter()
+            .zip(returned_signature.required_positional.iter())
+            .for_each(|(lhs, rhs)| assert_eq!(lhs, rhs));
+
+        signature
+            .optional_positional
+            .iter()
+            .zip(returned_signature.optional_positional.iter())
+            .for_each(|(lhs, rhs)| assert_eq!(lhs, rhs));
+
+        signature
+            .named
+            .iter()
+            .zip(returned_signature.named.iter())
+            .for_each(|(lhs, rhs)| assert_eq!(lhs, rhs));
+
+        assert_eq!(
+            signature.rest_positional,
+            returned_signature.rest_positional,
+        );
+    }
+}

crates/nu-plugin/src/serializers/value.rs

@@ -1,4 +1,4 @@
-use crate::value_capnp::value;
+use crate::plugin_capnp::value;
 use capnp::serialize_packed;
 use nu_protocol::{ShellError, Span, Value};
 
@@ -35,7 +35,7 @@ pub(crate) fn serialize_value(value: &Value, mut builder: value::Builder) -> Spa
             *span
         }
         Value::String { val, span } => {
-            builder.set_string(&val);
+            builder.set_string(val);
             *span
         }
         Value::List { vals, span } => {
@@ -92,7 +92,7 @@ pub(crate) fn deserialize_value(reader: value::Reader) -> Result<Value, ShellErr
 
             let values_list = values
                 .iter()
-                .map(|inner_reader| deserialize_value(inner_reader))
+                .map(deserialize_value)
                 .collect::<Result<Vec<Value>, ShellError>>()?;
 
             Ok(Value::List {