// TODO: Check indentation. The following line will error if indent suddenly shifts
                // from 1 to 3.

//! name: self.value("hobbit::name")?

//! self.value("a::b::c")?

//! hobbit: self.at("hobbit")?

//! self.at("a::b::c")?

//! self.opt_value()

//! self.opt_value("a::b::c")?

//! self.opt_at()

//! self.opt_at("a::b::c")

//! self.vec_value()

//! self.vec_value("a::b::c")?

//! self.vec_at()

//! self.vec_at("a::b::c")?

//! self.opt_vec_at()

//! self.opt_vec_at("a::b::c")?

//! self.opt_vec_value()

//! self.opt_vec_value("a::b::c")?

//! receiving data-structure. Following a path into a keytree involves a scan of differently names

//! receiving data-structure. Following a path into a keytree involves a scan of differently named

            .map_err(|_| failed_to_parse_value(&token.to_string(), token.line()))

            .map_err(|_| parse_value_failed(&token.to_string(), token.line()))

        "[keytree:01] line {}, token [{}]. Bad first segment [{}].",

        "[keytree] line {}, token [{}]. Bad first segment [{}].",

        "[keytree:02] line {}, token [{}]. Indentation of {} is incorrect.",

        "[keytree] line {}, token [{}]. Indentation of {} is incorrect.",

        "[keytree:03] line {}, token [{}]. Cannot resolve token with siblings.",

        "[keytree] line {}, token [{}]. Cannot resolve token with siblings.",

        "[keytree:04:{}:{}] Line {}, token [{}]. Colon before key.",

        "[keytree:{}:{}] Line {}, token [{}]. Colon before key.",

        "[keytree:07] line {}, token [{}]. Expected [key:] but found [key: value].",

        "[keytree] line {}, token [{}]. Expected [key:] but found [key: value].",

        "[keytree:08] line {}, token [{}]. Expected [key: value] but found [key:].",

        "[keytree] line {}, token [{}]. Expected [key: value] but found [key:].",

        "[keytree:09:{}:{}] Expected non-empty collection at [{}].",

        "[keytree:{}:{}] Expected non-empty collection at [{}].",

        "[keytree:09] keypath: [{}]. Expected unique token but found multiple tokens.",

        "[keytree] keypath: [{}]. Expected unique token but found multiple tokens.",

        "[keytree:10:{}:{}] keypath: [{}]. Expected unique [key: value] but found multiple tokens.",

        "[keytree:{}:{}] keypath: [{}]. Expected unique [key: value] but found multiple tokens.",

        "[keytree:11:{}:{}] Keypath [{}]. Expected unique [key: value] but found none.",

        "[keytree:{}:{}] Keypath [{}]. Expected unique [key: value] but found none.",

        "[keytree:12:{}:{}] Keypath [{}]. Expected a unique token but found multiple.",

        "[keytree:{}:{}] Keypath [{}]. Expected a unique token but found multiple.",

pub fn failed_to_parse_value(token: &str, line: usize) -> Error {

pub fn external(
    code_file: &str,
    code_line: u32,
    msg: &str) -> Error
{

        "[keytree:13] line {}, token [{}]. Failed to parse value.",
        line,
        token,

        "[keytree:{}:{}] External error [{}].",
        code_file,
        code_line,
        msg,

        "[keytree:14:{}:{}] token {}. First token must be [key:].",

        "[keytree:{}:{}] token {}. First token must be [key:].",

        "[keytree:15] line {}, token [{}]. The first segment of [{}] does not match.",

        "[keytree] line {}, token [{}]. The first segment of [{}] does not match.",

        "[keytree:16:{}:{}] line {}, token [{}]. Incomplete comment or key.",

        "[keytree:{}:{}] line {}, token [{}]. Incomplete comment or key.",

       "[keytree:17:{}:{}] line {}, token [{}]. Incomplete line.",

       "[keytree:{}:{}] line {}, token [{}]. Incomplete line.",

        "[keytree:18] line {} token [{}], keypath [{}]. Keypath extends beyond keyvalue.",

        "[keytree] line {} token [{}], keypath [{}]. Keypath extends beyond keyvalue.",

        "[keytree:20] line {} token [{}]. Keypath segment {} does not match key.",

        "[keytree] line {} token [{}]. Keypath segment {} does not match key.",

        "[keytree:21] line {} token [{}]. Failed to find key [{}]",

        "[keytree] line {} token [{}]. Failed to find key [{}]",

        "[keytree:22:{}:{}] line {} token [{}], No colon after key.",

        "[keytree:{}:{}] line {} token [{}], No colon after key.",

        "[keytree:23:{}:{}] line {} token [{}]. No space after key.",

        "[keytree:{}:{}] line {} token [{}]. No space after key.",

        "[keytree:24:{}:{}] No tokens in parsed keytree.",

        "[keytree:{}:{}] No tokens in parsed keytree.",

        "[keytree:25:{}:{}] line {}, token [{}]. Token other than root token as zero indent.",

        "[keytree:{}:{}] line {}, token [{}]. Token other than root token as zero indent.",

        line,
        token,
    ))
}
pub fn parse_value_failed(token: &str, line: usize) -> Error {
    Error(format!(
        "[keytree] line [{}], token [{}]. Failed to parse value.",