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use crate::search;
use serde::de::DeserializeOwned;
use serde_json::Value;
use std::{fmt, io, path::Path, process::Command};
/// Represents a vim variable to be extracted
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct VimVar<Name: AsRef<str>> {
cmd: Cmd,
scope: Scope,
name: Name,
}
impl<Name: AsRef<str>> VimVar<Name> {
/// Creates a new vim variable definition that can be used later to
/// load the variable's contents
pub fn new(cmd: Cmd, scope: Scope, name: Name) -> Self {
Self { cmd, scope, name }
}
/// Returns [`Cmd`] tied to variable
pub fn cmd(&self) -> Cmd {
self.cmd
}
/// Returns [`Scope`] tied to variable
pub fn scope(&self) -> Scope {
self.scope
}
/// Returns name tied to variable
pub fn name(&self) -> &str {
self.name.as_ref()
}
}
impl<Name: AsRef<str>> VimVar<Name> {
/// Loads variable with [`Self::load`] and then attempts to convert it
/// to the specified type
///
/// ### Notes
///
/// * If `allow_zero` is true, then a value of 0 is considered the value of
/// the variable rather than vim's default of not being found
pub fn load_typed<T>(&self, allow_zero: bool) -> io::Result<Option<T>>
where
T: DeserializeOwned,
{
self.load(allow_zero)?
.map(|value| serde_json::from_value(value).map_err(Into::into))
.transpose()
}
/// Loads the variable's value using neovim's headless mode or vim's ex
/// mode using the default vimrc available in scope
///
/// ### Notes
///
/// * Will leverage [`search::find_vimrc`] to load in the appropriate vimrc
/// during ex mode
/// * If `allow_zero` is true, then a value of 0 is considered the value of
/// the variable rather than vim's default of not being found
pub fn load(&self, allow_zero: bool) -> io::Result<Option<Value>> {
let vimrc = search::find_vimrc()
.ok_or_else(|| io::Error::new(io::ErrorKind::NotFound, "vimrc not found"))?;
self.load_with_config(vimrc, allow_zero)
}
/// Loads variable with [`Self::load_with_config`] and then attempts to
/// convert it to the specified type
///
/// ### Notes
///
/// * If `allow_zero` is true, then a value of 0 is considered the value of
/// the variable rather than vim's default of not being found
pub fn load_typed_with_config<P: AsRef<Path>, T>(
&self,
config: P,
allow_zero: bool,
) -> io::Result<Option<T>>
where
T: DeserializeOwned,
{
self.load_with_config(config, allow_zero)?
.map(|value| serde_json::from_value(value).map_err(Into::into))
.transpose()
}
/// Loads the variable's value using neovim's headless mode or vim's ex
/// mode
///
/// ### Notes
///
/// * Spawns a vim process whose goal is to print out the contents of a
/// variable as a JSON string
/// * Leverages batch & ex modes with redir to execute and capture output
/// * Relies on the variable being available upon loading vim configs
/// * If `allow_zero` is true, then a value of 0 is considered the value of
/// the variable rather than vim's default of not being found
pub fn load_with_config<P: AsRef<Path>>(
&self,
config: P,
allow_zero: bool,
) -> io::Result<Option<Value>> {
let cmd = self.cmd;
let scope = self.scope.as_str();
let var = self.name.as_ref();
let full_cmd = {
if config.as_ref().as_os_str().is_empty() {
return Err(io::Error::new(
io::ErrorKind::InvalidInput,
"path to vimrc is required for neovim/vim",
));
}
// NOTE: We have a lot of settings being applied, so documenting
// them here
//
// 1. -Es is our silent, batch, ex mode
// 2. -i NONE removes shada/viminfo file reading and writing
// 3. -u "{}" loads our vimrc, which is required as -Es does
// not load vim scripts by default
// 4. +set nonumber is used to turn off line numbers, which
// are getting picked up by neovim/vim in vimrc configs
// and showing up in output
// 5. redir writes to a register our message (json) and then
// places it in our buffer
// 6. prints out the content in our buffer (current line)
format!(
r#"{} -Es -i NONE -u "{}" '+set nonumber' '+redir => m | echon json_encode(get({}, "{}")) | redir END | put=m' '+%p' '+qa!'"#,
cmd,
config.as_ref().to_string_lossy(),
scope,
var,
)
};
// TODO: Support windows here (won't have sh)
let output = Command::new("sh").arg("-c").arg(full_cmd).output()?;
// If our program failed, we want to report the failure
//
// NOTE: neovim/vim seems to return exit code 1; so, for now we'll
// ignore that specific exit code for now
if !output.status.success() && (output.status.code() != Some(1)) {
let code = output
.status
.code()
.as_ref()
.map(ToString::to_string)
.unwrap_or_else(|| String::from("--"));
return Err(io::Error::new(
io::ErrorKind::Other,
format!(
"[Exit code {}]: {}",
code,
String::from_utf8_lossy(&output.stderr).trim()
)
.as_str(),
));
}
let output_string = String::from_utf8_lossy(&output.stdout);
// Report a better error than the serde one if the output was empty
if output_string.trim().is_empty() {
return Err(io::Error::new(
io::ErrorKind::InvalidData,
format!("Result from {} was empty", self.cmd),
));
}
let value: Value = serde_json::from_str(output_string.trim()).map_err(|_| {
io::Error::new(
io::ErrorKind::InvalidData,
format!("Failed to parse as JSON: \"{}\"", output_string.trim()),
)
})?;
if !allow_zero && value == serde_json::json!(0) {
Ok(None)
} else {
Ok(Some(value))
}
}
}
/// Represents type of vim instance being used
#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
pub enum Cmd {
Neovim,
Vim,
}
impl Cmd {
/// Converts to a str representing command
///
/// ### Examples
///
/// ```
/// use vimvar::Cmd;
///
/// assert_eq!(Cmd::Neovim.as_str(), "nvim");
/// assert_eq!(Cmd::Vim.as_str(), "vim");
/// ```
pub fn as_str(&self) -> &'static str {
match self {
Self::Vim => "vim",
Self::Neovim => "nvim",
}
}
}
impl fmt::Display for Cmd {
/// Writes cmd using the [`Self::as_str`] representation
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{}", self.as_str())
}
}
/// Represents a vim variable scope
#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
pub enum Scope {
Nothing,
Buffer,
Window,
Tabpage,
Global,
Local,
Script,
FunctionArg,
Vim,
}
impl Default for Scope {
/// Returns global as default
fn default() -> Self {
Self::Global
}
}
impl Scope {
/// Converts to a str representing scope
///
/// ### Examples
///
/// ```
/// use vimvar::Scope;
///
/// assert_eq!(Scope::Nothing.as_str(), "");
/// assert_eq!(Scope::Buffer.as_str(), "b:");
/// assert_eq!(Scope::Window.as_str(), "w:");
/// assert_eq!(Scope::Tabpage.as_str(), "t:");
/// assert_eq!(Scope::Global.as_str(), "g:");
/// assert_eq!(Scope::Local.as_str(), "l:");
/// assert_eq!(Scope::Script.as_str(), "s:");
/// assert_eq!(Scope::FunctionArg.as_str(), "a:");
/// assert_eq!(Scope::Vim.as_str(), "v:");
/// ```
pub fn as_str(&self) -> &'static str {
match self {
Self::Nothing => "",
Self::Buffer => "b:",
Self::Window => "w:",
Self::Tabpage => "t:",
Self::Global => "g:",
Self::Local => "l:",
Self::Script => "s:",
Self::FunctionArg => "a:",
Self::Vim => "v:",
}
}
}
impl fmt::Display for Scope {
/// Writes scope using the [`Self::as_str`] representation
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{}", self.as_str())
}
}