update the tag stack for jump to definition

Cargo.toml

@@ -25,6 +25,7 @@ maplit = "1"
 serde = "1"
 serde_derive = "1"
 serde_json = "1"
+serde_tuple = "0.5.0"
 json-patch = "0.2"
 crossbeam = "0.7.3"
 jsonrpc-core = "15"

src/language_client.rs

@@ -1036,6 +1036,8 @@ impl LanguageClient {
         let position = self.vim()?.get_position(params)?;
         let current_word = self.vim()?.get_current_word(params)?;
         let goto_cmd = self.vim()?.get_goto_cmd(params)?;
+        let bufnr = self.vim()?.get_bufnr(&filename, params)?;
+        let winnr = self.vim()?.get_winnr(params)?;
 
         let params = serde_json::to_value(TextDocumentPositionParams {
             text_document: TextDocumentIdentifier {
@@ -1080,6 +1082,21 @@ impl LanguageClient {
                     loc.range.start.line + 1,
                     loc.range.start.character + 1
                 ))?;
+
+                self.vim()?.update_tagstack(
+                    winnr,
+                    TagStackItem {
+                        bufnr,
+                        from: Pos {
+                            bufnr,
+                            lnum: position.line + 1,
+                            col: position.character + 1,
+                            off: 0,
+                        },
+                        matchnr: None,
+                        tagname: current_word,
+                    },
+                )?;
             }
             _ => {
                 let title = format!("[LC]: search for {}", current_word);

src/types.rs

@@ -22,6 +22,7 @@ use maplit::hashmap;
 use pathdiff::diff_paths;
 use serde::{Deserialize, Serialize};
 use serde_json::Value;
+use serde_tuple::{Deserialize_tuple, Serialize_tuple};
 use std::{
     collections::HashMap,
     io::{BufRead, BufReader, BufWriter, Write},
@@ -110,6 +111,8 @@ pub type Id = u64;
 pub type LanguageId = Option<String>;
 /// Buffer id/handle.
 pub type Bufnr = i64;
+/// Window id/handle.
+pub type Winnr = u32;
 
 #[derive(Debug, Serialize, Deserialize)]
 pub enum Message {
@@ -1199,3 +1202,30 @@ pub struct WorkspaceEditWithCursor {
     pub workspace_edit: WorkspaceEdit,
     pub cursor_position: Option<TextDocumentPositionParams>,
 }
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct TagStack {
+    pub curidx: u32,
+    pub items: Vec<TagStackItem>,
+    pub length: u32,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct TagStackItem {
+    pub bufnr: Bufnr,
+    pub from: Pos,
+    pub matchnr: Option<u32>,
+    pub tagname: String,
+}
+
+/// This represents a position in a buffer.
+///
+/// Vim returns this as a List from the `getpos()` function. It is also used as the `from` value in
+/// tag stack items.
+#[derive(Debug, Serialize_tuple, Deserialize_tuple)]
+pub struct Pos {
+    pub bufnr: Bufnr,
+    pub lnum: u32,
+    pub col: u32,
+    pub off: u32,
+}

src/vim.rs

@@ -1,7 +1,7 @@
 use crate::{
     rpcclient::RpcClient,
     sign::Sign,
-    types::{Bufnr, QuickfixEntry, VimExp, VirtualText},
+    types::{Bufnr, QuickfixEntry, TagStack, TagStackItem, VimExp, VirtualText, Winnr},
     utils::Canonicalize,
     viewport::Viewport,
 };
@@ -131,6 +131,12 @@ impl Vim {
         try_get(key, params)?.map_or_else(|| self.eval(format!("bufnr('{}')", filename)), Ok)
     }
 
+    pub fn get_winnr(&self, params: &Value) -> Result<Winnr> {
+        let key = "winnr";
+
+        try_get(key, params)?.map_or_else(|| self.eval("winnr()"), Ok)
+    }
+
     pub fn get_viewport(&self, params: &Value) -> Result<Viewport> {
         let key = "viewport";
         let expr = "LSP#viewport()";
@@ -275,4 +281,11 @@ impl Vim {
     pub fn set_signs(&self, filename: &str, signs: &[Sign]) -> Result<i8> {
         self.rpcclient.call("s:set_signs", json!([filename, signs]))
     }
+
+    pub fn update_tagstack(&self, winnr: Winnr, item: TagStackItem) -> Result<()> {
+        let mut stack: TagStack = self.rpcclient.call("gettagstack", winnr)?;
+        stack.items.clear();
+        stack.items.push(item);
+        self.rpcclient.notify("settagstack", (winnr, stack, "t"))
+    }
 }