use anyhow::Context;
use clap::Parser;
use serde::{ser, Serialize};
pub(super) fn to_args<T>(value: &T) -> anyhow::Result<Vec<String>>
where
T: Serialize + Parser,
{
let mut help = Vec::new();
T::command()
.write_long_help(&mut help)
.context("reading subcommand help text")?;
let mut serializer = Serializer {
help_text: String::from_utf8(help)
.context("decoding subcommand help text")?
.replace('\n', " \n"),
output: Vec::new(),
field_stack: Vec::new(),
};
value.serialize(&mut serializer)?;
Ok(serializer.output)
}
struct Serializer {
help_text: String,
output: Vec<String>,
field_stack: Vec<Option<&'static str>>,
}
impl Serializer {
fn push_field(&mut self, name: &'static str) {
let field = if self.help_text.contains(&format!(" --{} ", name)) {
Some(name)
} else {
None
};
self.field_stack.push(field);
}
fn pop_field(&mut self) {
self.field_stack.pop();
}
fn output_option(&mut self) {
match &self.field_stack[self.field_stack.len() - 1] {
None => (),
Some(name) => {
let option = format!("--{}", name);
self.output_argument(option);
}
}
}
fn output_argument<T: ToString>(&mut self, arg: T) {
self.output.push(arg.to_string());
}
}
impl<'a> ser::Serializer for &'a mut Serializer {
type Ok = ();
type Error = SerializeError;
type SerializeSeq = Self;
type SerializeStruct = Self;
type SerializeMap = ser::Impossible<Self::Ok, Self::Error>;
type SerializeStructVariant = ser::Impossible<Self::Ok, Self::Error>;
type SerializeTuple = ser::Impossible<Self::Ok, Self::Error>;
type SerializeTupleStruct = ser::Impossible<Self::Ok, Self::Error>;
type SerializeTupleVariant = ser::Impossible<Self::Ok, Self::Error>;
fn serialize_bool(self, v: bool) -> Result<()> {
if v {
self.output_option();
}
Ok(())
}
fn serialize_i8(self, v: i8) -> Result<()> {
self.serialize_i64(i64::from(v))
}
fn serialize_i16(self, v: i16) -> Result<()> {
self.serialize_i64(i64::from(v))
}
fn serialize_i32(self, v: i32) -> Result<()> {
self.serialize_i64(i64::from(v))
}
fn serialize_i64(self, v: i64) -> Result<()> {
self.output_option();
self.output_argument(v);
Ok(())
}
fn serialize_u8(self, v: u8) -> Result<()> {
self.serialize_u64(u64::from(v))
}
fn serialize_u16(self, v: u16) -> Result<()> {
self.serialize_u64(u64::from(v))
}
fn serialize_u32(self, v: u32) -> Result<()> {
self.serialize_u64(u64::from(v))
}
fn serialize_u64(self, v: u64) -> Result<()> {
self.output_option();
self.output_argument(v);
Ok(())
}
fn serialize_f32(self, v: f32) -> Result<()> {
self.serialize_f64(f64::from(v))
}
fn serialize_f64(self, v: f64) -> Result<()> {
self.output_option();
self.output_argument(v);
Ok(())
}
fn serialize_char(self, v: char) -> Result<()> {
self.serialize_str(&v.to_string())
}
fn serialize_str(self, v: &str) -> Result<()> {
self.output_option();
self.output_argument(v);
Ok(())
}
fn serialize_bytes(self, _v: &[u8]) -> Result<()> {
unimplemented!()
}
fn serialize_none(self) -> Result<()> {
Ok(())
}
fn serialize_some<T>(self, value: &T) -> Result<()>
where
T: ?Sized + Serialize,
{
value.serialize(self)
}
fn serialize_unit(self) -> Result<()> {
Ok(())
}
fn serialize_unit_struct(self, _name: &'static str) -> Result<()> {
Ok(())
}
fn serialize_unit_variant(
self,
_name: &'static str,
_variant_index: u32,
_variant: &'static str,
) -> Result<()> {
unimplemented!()
}
fn serialize_newtype_struct<T>(self, _name: &'static str, _value: &T) -> Result<()>
where
T: ?Sized + Serialize,
{
unimplemented!()
}
fn serialize_newtype_variant<T>(
self,
_name: &'static str,
_variant_index: u32,
_variant: &'static str,
_value: &T,
) -> Result<()>
where
T: ?Sized + Serialize,
{
unimplemented!()
}
fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq> {
Ok(self)
}
fn serialize_tuple(self, _len: usize) -> Result<Self::SerializeTuple> {
unimplemented!();
}
fn serialize_tuple_struct(
self,
_name: &'static str,
_len: usize,
) -> Result<Self::SerializeTupleStruct> {
unimplemented!();
}
fn serialize_tuple_variant(
self,
_name: &'static str,
_variant_index: u32,
_variant: &'static str,
_len: usize,
) -> Result<Self::SerializeTupleVariant> {
unimplemented!();
}
fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap> {
unimplemented!();
}
fn serialize_struct(self, _name: &'static str, _len: usize) -> Result<Self::SerializeStruct> {
Ok(self)
}
fn serialize_struct_variant(
self,
_name: &'static str,
_variant_index: u32,
_variant: &'static str,
_len: usize,
) -> Result<Self::SerializeStructVariant> {
unimplemented!();
}
}
impl<'a> ser::SerializeSeq for &'a mut Serializer {
type Ok = ();
type Error = SerializeError;
fn serialize_element<T>(&mut self, value: &T) -> Result<()>
where
T: ?Sized + Serialize,
{
value.serialize(&mut **self)
}
fn end(self) -> Result<()> {
Ok(())
}
}
impl<'a> ser::SerializeStruct for &'a mut Serializer {
type Ok = ();
type Error = SerializeError;
fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<()>
where
T: ?Sized + Serialize,
{
self.push_field(key);
let ret = value.serialize(&mut **self);
self.pop_field();
ret
}
fn end(self) -> Result<()> {
Ok(())
}
}
pub(super) type Result<T> = std::result::Result<T, SerializeError>;
#[derive(Debug, thiserror::Error)]
#[error("{0}")]
pub(super) struct SerializeError(String);
impl ser::Error for SerializeError {
fn custom<T: ToString>(msg: T) -> Self {
SerializeError(msg.to_string())
}
}