feat: add floating terminal window option for flix commands

README.md

@@ -68,6 +68,14 @@ require("flix").setup({
   java = "java",              -- executable used to launch the jar
   jar = "flix.jar",           -- relative paths resolve from the project root
   root_markers = { "flix.toml" },
+  terminal = {                -- how `flix_cmd` opens its terminal
+    window = "split",         -- "split" (default) or "float" (floating window)
+    width = 0.60,             -- float = fraction of editor, integer = columns
+    height = 0.5,             -- float = fraction of editor, integer = rows
+    pos_x = "center",         -- number or "center" (float = fraction of width)
+    pos_y = "center",         -- number or "center" (float = fraction of height)
+    close_binding = "q",      -- Normal-mode key that closes the floating window
+  },
   features = {
     codelens = true,          -- refresh code lenses while editing
     completion = false,       -- native autocompletion (see below)
@@ -78,6 +86,14 @@ require("flix").setup({
 })
 ```
 
+### Floating terminal
+
+By default `flix_cmd` opens in a `belowright split`. Set `terminal.window = "float"`
+to open it in a floating window instead. The remaining `terminal` fields only
+apply to the float: `width`/`height` accept a fraction of the editor size (e.g.
+`0.5`) or an integer column/row count, `pos_x`/`pos_y` accept a number or
+`"center"`, and `close_binding` (default `q`) closes the window from Normal mode.
+
 ### Native completion (Neovim 0.11+)
 
 Set `features.completion = true` to get insert-mode autocompletion straight from

lua/flix/commands.lua

@@ -2,6 +2,36 @@ local config = require("flix.config")
 
 local M = {}
 
+--- resolve a size spec to an integer number of cells
+--- a whole number is used as-is (columns/rows); a fractional value is a fraction of `total`
+--- @param spec number
+--- @param total integer
+--- @return integer
+local function resolve_size(spec, total)
+  if spec % 1 ~= 0 then
+    return math.max(1, math.floor(spec * total))
+  end
+  return spec
+end
+
+--- resolve a position spec to an integer cell offset
+--- "center" centers a window of `size` cells within `total`;
+--- a whole number is used as-is; a fractional value is a fraction of `total`
+--- @param spec number|string
+--- @param total integer
+--- @param size integer
+--- @return integer
+local function resolve_pos(spec, total, size)
+  if spec == "center" then
+    return math.floor((total - size) / 2)
+  end
+  if type(spec) == "number" and spec % 1 ~= 0 then
+    return math.floor(spec * total)
+  end
+---@diagnostic disable-next-line: return-type-mismatch
+  return spec
+end
+
 --- run `java -jar <jar> <cmd>` from the Flix project root in a terminal split
 --- works without the LSP being attached: the root is found from `root_markers`
 ---@param cmd string the Flix CLI subcommand, e.g. "run" or "test"
@@ -28,9 +58,36 @@ function M.flix_cmd(cmd)
     return
   end
 
-  vim.cmd("belowright split")
-  local term_buf = vim.api.nvim_create_buf(false, true)
-  vim.api.nvim_win_set_buf(0, term_buf)
+  local t = o.terminal
+
+  if t.window == "float" then
+    local term_buf = vim.api.nvim_create_buf(false, true)
+
+    local total_cols = vim.o.columns
+    local total_rows = vim.o.lines
+
+    local width = resolve_size(t.width, total_cols)
+    local height = resolve_size(t.height, total_rows)
+    local col = resolve_pos(t.pos_x, total_cols, width)
+    local row = resolve_pos(t.pos_y, total_rows, height)
+
+    vim.api.nvim_open_win(term_buf, true, {
+      relative = "win",
+      width = width,
+      height = height,
+      row = row,
+      col = col,
+      title = "Flix Run",
+      title_pos = "center",
+      border = "single"
+    })
+
+    vim.keymap.set("n", t.close_binding, "<Cmd>bdelete!<CR>", { buffer = term_buf, silent = true })
+  else
+    vim.cmd("belowright split")
+    local term_buf = vim.api.nvim_create_buf(false, true)
+    vim.api.nvim_win_set_buf(0, term_buf)
+  end
 
   vim.fn.jobstart({ o.java, "-jar", jar, cmd }, {
     term = true,

lua/flix/config.lua

@@ -1,11 +1,36 @@
 local M = {}
 
+---@class flix.TerminalOptions
+---@field window "float"|"split" how the terminal is opened
+---@field width number integer = columns; float in (0,1) = fraction of editor width
+---@field height number integer = rows; float in (0,1) = fraction of editor height
+---@field pos_x number|"center" integer = columns from left; float = fraction of editor width; "center" = centered on x
+---@field pos_y number|"center" integer = rows from top; float = fraction of editor height; "center" = centered on y
+---@field close_binding string Normal-mode key that closes the terminal window
+
+---@class flix.Config
+---@field java string path or name of the java executable
+---@field jar string path to flix.jar, relative to the project root or absolute
+---@field root_markers string[] files used to detect the project root
+---@field terminal flix.TerminalOptions options for the floating terminal window
+---@field features table feature flags
+---@field lsp table options forwarded to `vim.lsp.config("flix", ...)`
+
 -- default configuration
 -- override any field via `require("flix").setup({ ... })`
+---@type flix.Config
 M.defaults = {
   java = "java",
   jar = "flix.jar",
   root_markers = { "flix.toml" },
+  terminal = {
+    window = "split",
+    width = 0.60,
+    height = 0.5,
+    pos_x = "center",
+    pos_y = "center",
+    close_binding = "q"
+  },
   features = {
     codelens = true,
     completion = false,
@@ -14,6 +39,7 @@ M.defaults = {
 }
 
 -- active configuration
+---@type flix.Config
 M.options = vim.deepcopy(M.defaults)
 
 --- merge user options over the defaults