feat: Splice api (fixes #43)

README.md

@@ -327,7 +327,7 @@ Cursor api `paredit.cursor`
   - `placement` - enumeration `left_edge`,`inner_start`,`inner_end`,`right_edge`
   - `mode` - currently only `insert` is supported, defaults to `normal`
 
-## API usage recipes
+## Additional API usage recipes
 
 ### `vim-sexp` wrap form (head/tail) replication
 
@@ -383,6 +383,14 @@ Add following keybindings to config:
 ```
 Same approach can be used for other `vim-sexp` keybindings (e.g. `<localleader>e[`) with cursor placement or without.
 
+### `vim-sexp` splice sexp
+
+```lua
+  ["<localleader>@"] = {
+    paredit.unwrap.unwrap_form_under_cursor,
+    "Splice sexp",
+  },
+```
 ## Prior Art
 
 ### [vim-sexp](https://github.com/guns/vim-sexp)

lua/nvim-paredit/api/unwrap.lua

@@ -0,0 +1,47 @@
+local traversal = require("nvim-paredit.utils.traversal")
+local langs = require("nvim-paredit.lang")
+local ts = require("nvim-treesitter.ts_utils")
+
+local M = {}
+
+function M.unwrap_form(buf, form)
+  local lang = langs.get_language_api()
+  local edges = lang.get_form_edges(form)
+  local left = edges.left
+  local right = edges.right
+  vim.api.nvim_buf_set_text(
+    buf,
+    right.range[1],
+    right.range[2],
+    right.range[3],
+    right.range[4],
+    { "" }
+  )
+  vim.api.nvim_buf_set_text(
+    buf,
+    left.range[1],
+    left.range[2],
+    left.range[3],
+    left.range[4],
+    { "" }
+  )
+end
+
+function M.unwrap_form_under_cursor()
+  local buf = vim.api.nvim_get_current_buf()
+  local lang = langs.get_language_api()
+  local node = ts.get_node_at_cursor()
+  local current_element = lang.get_node_root(node)
+  local form = traversal.find_nearest_form(
+    current_element,
+    { lang = lang, use_source = false }
+  )
+  if not form then
+    return false
+  end
+
+  M.unwrap_form(buf, form)
+  return true
+end
+
+return M

lua/nvim-paredit/init.lua

@@ -33,6 +33,7 @@ end
 local M = {
   api = require("nvim-paredit.api"),
   wrap = require("nvim-paredit.api.wrap"),
+  unwrap = require("nvim-paredit.api.unwrap"),
   cursor = require("nvim-paredit.api.cursor"),
   extension = {
     add_language_extension = add_language_extension,

tests/nvim-paredit/form_unwrap_spec.lua

@@ -0,0 +1,56 @@
+local paredit = require("nvim-paredit")
+local prepare_buffer = require("tests.nvim-paredit.utils").prepare_buffer
+local expect = require("tests.nvim-paredit.utils").expect
+
+describe("form uwrap (e.g. splice)", function()
+  vim.api.nvim_buf_set_option(0, "filetype", "clojure")
+  local unwrap = paredit.unwrap
+
+  it("should uwrap list under cursor", function()
+    prepare_buffer({
+      content = { "(+ 2 :foo/bar)" },
+      cursor = { 1, 0 },
+    })
+
+    unwrap.unwrap_form_under_cursor()
+    expect({
+      content = { "+ 2 :foo/bar" },
+    })
+  end)
+
+  it("should uwrap list under cursor", function()
+    prepare_buffer({
+      content = { "(+ 2 :foo/bar)" },
+      cursor = { 1, 13 },
+    })
+
+    unwrap.unwrap_form_under_cursor()
+    expect({
+      content = { "+ 2 :foo/bar" },
+    })
+  end)
+
+  it("should uwrap set under cursor", function()
+    prepare_buffer({
+      content = { "#{1 2 3}" },
+      cursor = { 1, 4 },
+    })
+
+    unwrap.unwrap_form_under_cursor()
+    expect({
+      content = { "1 2 3" },
+    })
+  end)
+
+  it("should uwrap fn under cursor", function()
+    prepare_buffer({
+      content = { "#(+ % 2 3)" },
+      cursor = { 1, 4 },
+    })
+
+    unwrap.unwrap_form_under_cursor()
+    expect({
+      content = { "+ % 2 3" },
+    })
+  end)
+end)