use std::collections::HashMap;
use std::error::Error as StdError;
use std::fmt;
use rustc_serialize::Decodable;
use parse::Parser;
use synonym::SynonymMap;
use self::Value::{Switch, Counted, Plain, List};
use self::Error::{Usage, Argv, NoMatch, Decode, WithProgramUsage, Help, Version};
/// Represents the different types of Docopt errors.
///
/// This error type has a lot of variants. In the common case, you probably
/// don't care why Docopt has failed, and would rather just quit the program
/// and show an error message instead. The `exit` method defined on the `Error`
/// type will do just that. It will also set the exit code appropriately
/// (no error for `--help` or `--version`, but an error code for bad usage,
/// bad argv, no match or bad decode).
///
/// ### Example
///
/// Generally, you want to parse the usage string, try to match the argv
/// and then quit the program if there was an error reported at any point
/// in that process. This can be achieved like so:
///
/// ```no_run
/// use docopt::Docopt;
///
/// const USAGE: &'static str = "
/// Usage: ...
/// ";
///
/// let args = Docopt::new(USAGE)
/// .and_then(|d| d.parse())
/// .unwrap_or_else(|e| e.exit());
/// ```
#[derive(Debug)]
pub enum Error {
/// Parsing the usage string failed.
///
/// This error can only be triggered by the programmer, i.e., the writer
/// of the Docopt usage string. This error is usually indicative of a bug
/// in your program.
Usage(String),
/// Parsing the argv specified failed.
///
/// The payload is a string describing why the arguments provided could not
/// be parsed.
///
/// This is distinct from `NoMatch` because it will catch errors like
/// using flags that aren't defined in the usage string.
Argv(String),
/// The given argv parsed successfully, but it did not match any example
/// usage of the program.
///
/// Regrettably, there is no descriptive message describing *why* the
/// given argv didn't match any of the usage strings.
NoMatch,
/// This indicates a problem decoding a successful argv match into a
/// decodable value.
Decode(String),
/// Parsing failed, and the program usage should be printed next to the
/// failure message. Typically this wraps `Argv` and `NoMatch` errors.
WithProgramUsage(Box<Error>, String),
/// Decoding or parsing failed because the command line specified that the
/// help message should be printed.
Help,
/// Decoding or parsing failed because the command line specified that the
/// version should be printed
///
/// The version is included as a payload to this variant.
Version(String),
}
impl Error {
/// Return whether this was a fatal error or not.
///
/// Non-fatal errors include requests to print the help or version
/// information of a program, while fatal errors include those such as
/// failing to decode or parse.
pub fn fatal(&self) -> bool {
match *self {
Help | Version(..) => false,
Usage(..) | Argv(..) | NoMatch | Decode(..) => true,
WithProgramUsage(ref b, _) => b.fatal(),
}
}
/// Print this error and immediately exit the program.
///
/// If the error is non-fatal (e.g., `Help` or `Version`), then the
/// error is printed to stdout and the exit status will be `0`. Otherwise,
/// when the error is fatal, the error is printed to stderr and the
/// exit status will be `1`.
pub fn exit(&self) -> ! {
if self.fatal() {
werr!("{}\n", self);
::std::process::exit(1)
} else {
println!("{}", self);
::std::process::exit(0)
}
}
}
impl fmt::Display for Error {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match *self {
WithProgramUsage(ref other, ref usage) => {
let other = other.to_string();
if other.is_empty() {
write!(f, "{}", usage)
} else {
write!(f, "{}\n\n{}", other, usage)
}
}
Help => write!(f, ""),
NoMatch => write!(f, "Invalid arguments."),
Usage(ref s) | Argv(ref s) | Decode(ref s) | Version(ref s) => {
write!(f, "{}", s)
}
}
}
}
impl StdError for Error {
fn description(&self) -> &str {
match *self {
Usage(..) => "invalid usage string",
Argv(..) => "failed to parse specified argv",
NoMatch => "could not match specified argv",
Decode(..) => "failed to decode",
WithProgramUsage(..) => "failed to parse specified argv",
Help => "help message requested",
Version(..) => "version message requested",
}
}
fn cause(&self) -> Option<&StdError> {
match *self {
WithProgramUsage(ref cause, _) => Some(&**cause),
_ => None,
}
}
}
/// The main Docopt type, which is constructed with a Docopt usage string.
///
/// This can be used to match command line arguments to produce a `ArgvMap`.
#[derive(Clone, Debug)]
pub struct Docopt {
p: Parser,
argv: Option<Vec<String>>,
options_first: bool,
help: bool,
version: Option<String>,
}
impl Docopt {
/// Parse the Docopt usage string given.
///
/// The `Docopt` value returned may be used immediately to parse command
/// line arguments with a default configuration.
///
/// If there was a problem parsing the usage string, a `Usage` error
/// is returned.
pub fn new<S>(usage: S) -> Result<Docopt, Error>
where S: ::std::ops::Deref<Target=str> {
Parser::new(usage.deref())
.map_err(Usage)
.map(|p| Docopt {
p: p,
argv: None,
options_first: false,
help: true,
version: None,
})
}
/// Parse and decode the given argv.
///
/// This is a convenience method for
/// `parse().and_then(|vals| vals.decode())`.
///
/// For details on how decoding works, please see the documentation for
/// `ArgvMap`.
pub fn decode<D>(&self) -> Result<D, Error> where D: Decodable {
self.parse().and_then(|vals| vals.decode())
}
/// Parse command line arguments and try to match them against a usage
/// pattern specified in the Docopt string.
///
/// If there is a match, then an `ArgvMap` is returned, which maps
/// flags, commands and arguments to values.
///
/// If parsing the command line arguments fails, then an `Argv` error is
/// returned. If parsing succeeds but there is no match, then a `NoMatch`
/// error is returned. Both of these errors are always returned inside a
/// `WithProgramUsage` error.
///
/// If special handling of `help` or `version` is enabled (the former is
/// enabled by default), then `Help` or `Version` errors are returned
/// if `--help` or `--version` is present.
pub fn parse(&self) -> Result<ArgvMap, Error> {
let argv = self.argv.clone().unwrap_or_else(|| Docopt::get_argv());
let vals = try!(
self.p.parse_argv(argv, self.options_first)
.map_err(|s| self.err_with_usage(Argv(s)))
.and_then(|argv|
match self.p.matches(&argv) {
Some(m) => Ok(ArgvMap { map: m }),
None => Err(self.err_with_usage(NoMatch)),
}));
if self.help && vals.get_bool("--help") {
return Err(self.err_with_full_doc(Help));
}
match self.version {
Some(ref v) if vals.get_bool("--version") => {
return Err(Version(v.clone()))
}
_ => {},
}
Ok(vals)
}
/// Set the argv to be used for Docopt parsing.
///
/// By default, when no argv is set, and it is automatically taken from
/// `std::env::args()`.
///
/// The `argv` given *must* be the full set of `argv` passed to the
/// program. e.g., `["cp", "src", "dest"]` is right while `["src", "dest"]`
/// is wrong.
pub fn argv<I, S>(mut self, argv: I) -> Docopt
where I: IntoIterator<Item=S>, S: AsRef<str> {
self.argv = Some(
argv.into_iter().skip(1).map(|s| s.as_ref().to_owned()).collect()
);
self
}
/// Enables the "options first" Docopt behavior.
///
/// The options first behavior means that all flags *must* appear before
/// position arguments. That is, after the first position argument is
/// seen, all proceeding arguments are interpreted as positional
/// arguments unconditionally.
pub fn options_first(mut self, yes: bool) -> Docopt {
self.options_first = yes;
self
}
/// Enables automatic handling of `--help`.
///
/// When this is enabled and `--help` appears anywhere in the arguments,
/// then a `Help` error will be returned. You may then use the `exit`
/// method on the error value to conveniently quit the program (which will
/// print the full usage string to stdout).
///
/// Note that for this to work, `--help` must be a valid pattern.
///
/// When disabled, there is no special handling of `--help`.
pub fn help(mut self, yes: bool) -> Docopt {
self.help = yes;
self
}
/// Enables automatic handling of `--version`.
///
/// When this is enabled and `--version` appears anywhere in the arguments,
/// then a `Version(s)` error will be returned, where `s` is the string
/// given here. You may then use the `exit` method on the error value to
/// convenient quit the program (which will print the version to stdout).
///
/// When disabled (a `None` value), there is no special handling of
/// `--version`.
pub fn version(mut self, version: Option<String>) -> Docopt {
self.version = version;
self
}
#[doc(hidden)]
// Exposed for use in `docopt_macros`.
pub fn parser<'a>(&'a self) -> &'a Parser {
&self.p
}
fn err_with_usage(&self, e: Error) -> Error {
WithProgramUsage(
Box::new(e), self.p.usage.trim().to_string())
}
fn err_with_full_doc(&self, e: Error) -> Error {
WithProgramUsage(
Box::new(e), self.p.full_doc.trim().to_string())
}
fn get_argv() -> Vec<String> {
// Hmm, we should probably handle a Unicode decode error here... ---AG
::std::env::args().skip(1).map(|v| v.to_string()).collect()
}
}
/// A map containing matched values from command line arguments.
///
/// The keys are just as specified in Docopt: `--flag` for a long flag or
/// `-f` for a short flag. (If `-f` is a synonym for `--flag`, then either
/// key will work.) `ARG` or `<arg>` specify a positional argument and `cmd`
/// specifies a command.
#[derive(Clone)]
pub struct ArgvMap {
#[doc(hidden)]
pub map: SynonymMap<String, Value>,
}
impl ArgvMap {
/// Tries to decode the map of values into a struct.
///
/// This method should always be called to decode a `ArgvMap` into
/// a struct. All fields of the struct must map to a corresponding key
/// in the `ArgvMap`. To this end, each member must have a special prefix
/// corresponding to the different kinds of patterns in Docopt. There are
/// three prefixes: `flag_`, `arg_` and `cmd_` which respectively
/// correspond to short/long flags, positional arguments and commands.
///
/// If a Docopt item has a `-` in its name, then it is converted to an `_`.
///
/// # Example
///
/// ```rust
/// # extern crate docopt;
/// # extern crate rustc_serialize;
/// # fn main() {
/// use docopt::Docopt;
///
/// const USAGE: &'static str = "
/// Usage: cargo [options] (build | test)
/// cargo --help
///
/// Options: -v, --verbose
/// -h, --help
/// ";
///
/// #[derive(RustcDecodable)]
/// struct Args {
/// cmd_build: bool,
/// cmd_test: bool,
/// flag_verbose: bool,
/// flag_h: bool,
/// }
///
/// let argv = || vec!["cargo", "build", "-v"].into_iter();
/// let args: Args = Docopt::new(USAGE)
/// .and_then(|d| d.argv(argv()).decode())
/// .unwrap_or_else(|e| e.exit());
/// assert!(args.cmd_build && !args.cmd_test
/// && args.flag_verbose && !args.flag_h);
/// # }
/// ```
///
/// Note that in the above example, `flag_h` is used but `flag_help`
/// could also be used. (In fact, both could be used at the same time.)
///
/// In this example, only the `bool` type was used, but any type satisfying
/// the `Decodable` trait is valid.
pub fn decode<T: Decodable>(self) -> Result<T, Error> {
Decodable::decode(&mut Decoder { vals: self, stack: vec!() })
}
/// Finds the value corresponding to `key` and calls `as_bool()` on it.
/// If the key does not exist, `false` is returned.
pub fn get_bool(&self, key: &str) -> bool {
self.find(key).map(|v| v.as_bool()).unwrap_or(false)
}
/// Finds the value corresponding to `key` and calls `as_count()` on it.
/// If the key does not exist, `0` is returned.
pub fn get_count(&self, key: &str) -> u64 {
self.find(key).map(|v| v.as_count()).unwrap_or(0)
}
/// Finds the value corresponding to `key` and calls `as_str()` on it.
/// If the key does not exist, `""` is returned.
pub fn get_str<'a>(&'a self, key: &str) -> &'a str {
self.find(key).map(|v| v.as_str()).unwrap_or("")
}
/// Finds the value corresponding to `key` and calls `as_vec()` on it.
/// If the key does not exist, `vec!()` is returned.
pub fn get_vec<'a>(&'a self, key: &str) -> Vec<&'a str> {
self.find(key).map(|v| v.as_vec()).unwrap_or(vec!())
}
/// Return the raw value corresponding to some `key`.
///
/// `key` should be a string in the traditional Docopt format. e.g.,
/// `<arg>` or `--flag`.
pub fn find<'a>(&'a self, key: &str) -> Option<&'a Value> {
self.map.find(&key.to_string())
}
/// Return the number of values, not including synonyms.
pub fn len(&self) -> usize {
self.map.len()
}
/// Converts a Docopt key to a struct field name.
/// This makes a half-hearted attempt at making the key a valid struct
/// field name (like replacing `-` with `_`), but it does not otherwise
/// guarantee that the result is a valid struct field name.
#[doc(hidden)]
pub fn key_to_struct_field(name: &str) -> String {
fn sanitize(name: &str) -> String {
name.replace("-", "_")
}
let r = regex!(r"^(?:--?(?P<flag>\S+)|(?:(?P<argu>\p{Lu}+)|<(?P<argb>[^>]+)>)|(?P<cmd>\S+))$");
r.replace(name, |cap: &::regex::Captures| {
let (flag, cmd) = (
cap.name("flag").unwrap_or(""),
cap.name("cmd").unwrap_or(""),
);
let (argu, argb) = (
cap.name("argu").unwrap_or(""),
cap.name("argb").unwrap_or(""),
);
let (prefix, name) =
if !flag.is_empty() {
("flag_", flag)
} else if !argu.is_empty() {
("arg_", argu)
} else if !argb.is_empty() {
("arg_", argb)
} else if !cmd.is_empty() {
("cmd_", cmd)
} else {
panic!("Unknown ArgvMap key: '{}'", name)
};
let mut prefix = prefix.to_string();
prefix.push_str(&sanitize(name));
prefix
})
}
/// Converts a struct field name to a Docopt key.
#[doc(hidden)]
pub fn struct_field_to_key(field: &str) -> String {
fn desanitize(name: &str) -> String {
name.replace("_", "-")
}
let name =
if field.starts_with("flag_") {
let name = regex!(r"^flag_").replace(field, "");
let mut pre_name = (if name.len() == 1 { "-" } else { "--" })
.to_string();
pre_name.push_str(&*name);
pre_name
} else if field.starts_with("arg_") {
let name = regex!(r"^arg_").replace(field, "");
if regex!(r"^\p{Lu}+$").is_match(&name) {
name
} else {
let mut pre_name = "<".to_string();
pre_name.push_str(&*name);
pre_name.push('>');
pre_name
}
} else if field.starts_with("cmd_") {
{ regex!(r"^cmd_") }.replace(field, "")
} else {
panic!("Unrecognized struct field: '{}'", field)
};
desanitize(&*name)
}
}
impl fmt::Debug for ArgvMap {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
if self.len() == 0 {
return write!(f, "{{EMPTY}}");
}
// This is a little crazy, but we want to group synonyms with
// their keys and sort them for predictable output.
let reverse: HashMap<&String, &String> =
self.map.synonyms().map(|(from, to)| (to, from)).collect();
let mut keys: Vec<&String> = self.map.keys().collect();
keys.sort();
let mut first = true;
for &k in keys.iter() {
if !first { try!(write!(f, "\n")); } else { first = false; }
match reverse.get(&k) {
None => {
try!(write!(f, "{} => {:?}", k, self.map.get(k)))
}
Some(s) => {
try!(write!(f, "{}, {} => {:?}", s, k, self.map.get(k)))
}
}
}
Ok(())
}
}
/// A matched command line value.
///
/// The value can be a boolean, counted repetition, a plain string or a list
/// of strings.
///
/// The various `as_{bool,count,str,vec}` methods provide convenient access
/// to values without destructuring manually.
#[derive(Clone, Debug, PartialEq)]
pub enum Value {
/// A boolean value from a flag that has no argument.
///
/// The presence of a flag means `true` and the absence of a flag
/// means `false`.
Switch(bool),
/// The number of occurrences of a repeated flag.
Counted(u64),
/// A positional or flag argument.
///
/// This is `None` when the positional argument or flag is not present.
/// Note that it is possible to have `Some("")` for a present but empty
/// argument.
Plain(Option<String>),
/// A List of positional or flag arguments.
///
/// This list may be empty when no arguments or flags are present.
List(Vec<String>),
}
impl Value {
/// Returns the value as a bool.
///
/// Counted repetitions are `false` if `0` and `true` otherwise.
/// Plain strings are `true` if present and `false` otherwise.
/// Lists are `true` if non-empty and `false` otherwise.
pub fn as_bool(&self) -> bool {
match *self {
Switch(b) => b,
Counted(n) => n > 0,
Plain(None) => false,
Plain(Some(_)) => true,
List(ref vs) => !vs.is_empty(),
}
}
/// Returns the value as a count of the number of times it occurred.
///
/// Booleans are `1` if `true` and `0` otherwise.
/// Plain strings are `1` if present and `0` otherwise.
/// Lists correspond to its length.
pub fn as_count(&self) -> u64 {
match *self {
Switch(b) => if b { 1 } else { 0 },
Counted(n) => n,
Plain(None) => 0,
Plain(Some(_)) => 1,
List(ref vs) => vs.len() as u64,
}
}
/// Returns the value as a string.
///
/// All values return an empty string except for a non-empty plain string.
pub fn as_str<'a>(&'a self) -> &'a str {
match *self {
Switch(_) | Counted(_) | Plain(None) | List(_) => "",
Plain(Some(ref s)) => &**s,
}
}
/// Returns the value as a list of strings.
///
/// Booleans, repetitions and empty strings correspond to an empty list.
/// Plain strings correspond to a list of length `1`.
pub fn as_vec<'a>(&'a self) -> Vec<&'a str> {
match *self {
Switch(_) | Counted(_) | Plain(None) => vec![],
Plain(Some(ref s)) => vec![&**s],
List(ref vs) => vs.iter().map(|s| &**s).collect(),
}
}
}
/// Decoder for `ArgvMap` into your own `Decodable` types.
///
/// In general, you shouldn't have to use this type directly. It is exposed
/// in case you want to write a generic function that produces a decodable
/// value. For example, here's a function that takes a usage string, an argv
/// and produces a decodable value:
///
/// ```rust
/// # extern crate docopt;
/// # extern crate rustc_serialize;
/// # fn main() {
/// use docopt::Docopt;
/// use rustc_serialize::Decodable;
///
/// fn decode<D: Decodable>(usage: &str, argv: &[&str])
/// -> Result<D, docopt::Error> {
/// Docopt::new(usage)
/// .and_then(|d| d.argv(argv.iter().cloned()).decode())
/// }
/// # }
pub struct Decoder {
vals: ArgvMap,
stack: Vec<DecoderItem>,
}
#[derive(Debug)]
struct DecoderItem {
key: String,
struct_field: String,
val: Option<Value>,
}
macro_rules! derr(
($($arg:tt)*) => (return Err(Decode(format!($($arg)*))))
);
impl Decoder {
fn push(&mut self, struct_field: &str) {
let key = ArgvMap::struct_field_to_key(struct_field);
self.stack.push(DecoderItem {
key: key.clone(),
struct_field: struct_field.to_string(),
val: self.vals.find(&*key).map(|v| v.clone()),
});
}
fn pop(&mut self) -> Result<DecoderItem, Error> {
match self.stack.pop() {
None => derr!("Could not decode value into unknown key."),
Some(it) => Ok(it),
}
}
fn pop_key_val(&mut self) -> Result<(String, Value), Error> {
let it = try!(self.pop());
match it.val {
None => derr!(
"Could not find argument '{}' (from struct field '{}').
Note that each struct field must have the right key prefix, which must
be one of `cmd_`, `flag_` or `arg_`.",
it.key, it.struct_field),
Some(v) => Ok((it.key, v)),
}
}
fn pop_val(&mut self) -> Result<Value, Error> {
let (_, v) = try!(self.pop_key_val());
Ok(v)
}
fn to_number(&mut self, expect: &str) -> Result<u64, Error> {
let (k, v) = try!(self.pop_key_val());
match v {
Counted(n) => Ok(n),
_ => {
if v.as_str().trim().is_empty() {
Ok(0)
} else {
match v.as_str().parse() {
Err(_) => {
derr!("Could not decode '{}' to {} for '{}'.",
v.as_str(), expect, k)
}
Ok(v) => Ok(v),
}
}
}
}
}
fn to_float(&mut self, expect: &str) -> Result<f64, Error> {
let (k, v) = try!(self.pop_key_val());
match v {
Counted(n) => Ok(n as f64),
_ => {
match v.as_str().parse() {
Err(_) => derr!("Could not decode '{}' to {} for '{}'.",
v.as_str(), expect, k),
Ok(v) => Ok(v),
}
}
}
}
}
macro_rules! read_num {
($name:ident, $ty:ty) => (
fn $name(&mut self) -> Result<$ty, Error> {
self.to_number(stringify!($ty)).map(|n| n as $ty)
}
);
}
impl ::rustc_serialize::Decoder for Decoder {
type Error = Error;
fn error(&mut self, err: &str) -> Error {
Decode(err.to_string())
}
fn read_nil(&mut self) -> Result<(), Error> {
// I don't know what the right thing is here, so just fail for now.
panic!("I don't know how to read into a nil value.")
}
read_num!(read_usize, usize);
read_num!(read_u64, u64);
read_num!(read_u32, u32);
read_num!(read_u16, u16);
read_num!(read_u8, u8);
read_num!(read_isize, isize);
read_num!(read_i64, i64);
read_num!(read_i32, i32);
read_num!(read_i16, i16);
read_num!(read_i8, i8);
fn read_bool(&mut self) -> Result<bool, Error> {
self.pop_val().map(|v| v.as_bool())
}
fn read_f64(&mut self) -> Result<f64, Error> {
self.to_float("f64")
}
fn read_f32(&mut self) -> Result<f32, Error> {
self.to_float("f32").map(|n| n as f32)
}
fn read_char(&mut self) -> Result<char, Error> {
let (k, v) = try!(self.pop_key_val());
let vstr = v.as_str();
match vstr.chars().count() {
1 => Ok(vstr.chars().next().unwrap()),
_ => derr!("Could not decode '{}' into char for '{}'.", vstr, k),
}
}
fn read_str(&mut self) -> Result<String, Error> {
self.pop_val().map(|v| v.as_str().to_string())
}
fn read_enum<T, F>(&mut self, _: &str, f: F) -> Result<T, Error>
where F: FnOnce(&mut Decoder) -> Result<T, Error> {
f(self)
}
fn read_enum_variant<T, F>(&mut self, names: &[&str], mut f: F)
-> Result<T, Error>
where F: FnMut(&mut Decoder, usize) -> Result<T, Error> {
let v = to_lowercase(try!(self.pop_val()).as_str());
let i =
match names.iter().map(|&n| to_lowercase(n)).position(|n| n == v) {
Some(i) => i,
None => {
derr!("Could not match '{}' with any of \
the allowed variants: {:?}", v, names)
}
};
f(self, i)
}
fn read_enum_variant_arg<T, F>(&mut self, _: usize, _: F)
-> Result<T, Error>
where F: FnOnce(&mut Decoder) -> Result<T, Error> {
unimplemented!()
}
fn read_enum_struct_variant<T, F>(&mut self, _: &[&str], _: F)
-> Result<T, Error>
where F: FnMut(&mut Decoder, usize) -> Result<T, Error> {
unimplemented!()
}
fn read_enum_struct_variant_field<T, F>(&mut self, _: &str, _: usize, _: F)
-> Result<T, Error>
where F: FnOnce(&mut Decoder) -> Result<T, Error> {
unimplemented!()
}
fn read_struct<T, F>(&mut self, _: &str, _: usize, f: F) -> Result<T, Error>
where F: FnOnce(&mut Decoder) -> Result<T, Error> {
f(self)
}
fn read_struct_field<T, F>(&mut self, f_name: &str, _: usize, f: F)
-> Result<T, Error>
where F: FnOnce(&mut Decoder) -> Result<T, Error> {
self.push(f_name);
f(self)
}
fn read_tuple<T, F>(&mut self, _: usize, _: F) -> Result<T, Error>
where F: FnOnce(&mut Decoder) -> Result<T, Error> {
unimplemented!()
}
fn read_tuple_arg<T, F>(&mut self, _: usize, _: F) -> Result<T, Error>
where F: FnOnce(&mut Decoder) -> Result<T, Error> {
unimplemented!()
}
fn read_tuple_struct<T, F>(&mut self, _: &str, _: usize, _: F)
-> Result<T, Error>
where F: FnOnce(&mut Decoder) -> Result<T, Error> {
unimplemented!()
}
fn read_tuple_struct_arg<T, F>(&mut self, _: usize, _: F)
-> Result<T, Error>
where F: FnOnce(&mut Decoder) -> Result<T, Error> {
unimplemented!()
}
fn read_option<T, F>(&mut self, mut f: F) -> Result<T, Error>
where F: FnMut(&mut Decoder, bool) -> Result<T, Error> {
let option =
match self.stack.last() {
None => derr!("Could not decode value into unknown key."),
Some(it) => it.val.as_ref()
.map(|v| v.as_bool())
.unwrap_or(false),
};
f(self, option)
}
fn read_seq<T, F>(&mut self, f: F) -> Result<T, Error>
where F: FnOnce(&mut Decoder, usize) -> Result<T, Error> {
let it = try!(self.pop());
let list = it.val.unwrap_or(List(vec!()));
let vals = list.as_vec();
for val in vals.iter().rev() {
self.stack.push(DecoderItem {
key: it.key.clone(),
struct_field: it.struct_field.clone(),
val: Some(Plain(Some(val.to_string()))),
})
}
f(self, vals.len())
}
fn read_seq_elt<T, F>(&mut self, _: usize, f: F) -> Result<T, Error>
where F: FnOnce(&mut Decoder) -> Result<T, Error> {
f(self)
}
fn read_map<T, F>(&mut self, _: F) -> Result<T, Error>
where F: FnOnce(&mut Decoder, usize) -> Result<T, Error> {
unimplemented!()
}
fn read_map_elt_key<T, F>(&mut self, _: usize, _: F) -> Result<T, Error>
where F: FnOnce(&mut Decoder) -> Result<T, Error> {
unimplemented!()
}
fn read_map_elt_val<T, F>(&mut self, _: usize, _: F) -> Result<T, Error>
where F: FnOnce(&mut Decoder) -> Result<T, Error> {
unimplemented!()
}
}
fn to_lowercase<S: Into<String>>(s: S) -> String {
s.into().chars().map(|c| c.to_lowercase().next().unwrap()).collect()
}