comm-central/third_party/rust/yaml-rust/src/emitter.rs

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use std::convert::From;
use std::error::Error;
use std::fmt::{self, Display};
use crate::yaml::{Hash, Yaml};
#[derive(Copy, Clone, Debug)]
pub enum EmitError {
FmtError(fmt::Error),
BadHashmapKey,
}
impl Error for EmitError {
fn cause(&self) -> Option<&dyn Error> {
None
}
}
impl Display for EmitError {
fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
match *self {
EmitError::FmtError(ref err) => Display::fmt(err, formatter),
EmitError::BadHashmapKey => formatter.write_str("bad hashmap key"),
}
}
}
impl From<fmt::Error> for EmitError {
fn from(f: fmt::Error) -> Self {
EmitError::FmtError(f)
}
}
pub struct YamlEmitter<'a> {
writer: &'a mut dyn fmt::Write,
best_indent: usize,
compact: bool,
level: isize,
}
pub type EmitResult = Result<(), EmitError>;
// from serialize::json
fn escape_str(wr: &mut dyn fmt::Write, v: &str) -> Result<(), fmt::Error> {
wr.write_str("\"")?;
let mut start = 0;
for (i, byte) in v.bytes().enumerate() {
let escaped = match byte {
b'"' => "\\\"",
b'\\' => "\\\\",
b'\x00' => "\\u0000",
b'\x01' => "\\u0001",
b'\x02' => "\\u0002",
b'\x03' => "\\u0003",
b'\x04' => "\\u0004",
b'\x05' => "\\u0005",
b'\x06' => "\\u0006",
b'\x07' => "\\u0007",
b'\x08' => "\\b",
b'\t' => "\\t",
b'\n' => "\\n",
b'\x0b' => "\\u000b",
b'\x0c' => "\\f",
b'\r' => "\\r",
b'\x0e' => "\\u000e",
b'\x0f' => "\\u000f",
b'\x10' => "\\u0010",
b'\x11' => "\\u0011",
b'\x12' => "\\u0012",
b'\x13' => "\\u0013",
b'\x14' => "\\u0014",
b'\x15' => "\\u0015",
b'\x16' => "\\u0016",
b'\x17' => "\\u0017",
b'\x18' => "\\u0018",
b'\x19' => "\\u0019",
b'\x1a' => "\\u001a",
b'\x1b' => "\\u001b",
b'\x1c' => "\\u001c",
b'\x1d' => "\\u001d",
b'\x1e' => "\\u001e",
b'\x1f' => "\\u001f",
b'\x7f' => "\\u007f",
_ => continue,
};
if start < i {
wr.write_str(&v[start..i])?;
}
wr.write_str(escaped)?;
start = i + 1;
}
if start != v.len() {
wr.write_str(&v[start..])?;
}
wr.write_str("\"")?;
Ok(())
}
impl<'a> YamlEmitter<'a> {
pub fn new(writer: &'a mut dyn fmt::Write) -> YamlEmitter {
YamlEmitter {
writer,
best_indent: 2,
compact: true,
level: -1,
}
}
/// Set 'compact inline notation' on or off, as described for block
/// and
///
/// In this form, blocks cannot have any properties (such as anchors
/// or tags), which should be OK, because this emitter doesn't
/// (currently) emit those anyways.
pub fn compact(&mut self, compact: bool) {
self.compact = compact;
}
/// Determine if this emitter is using 'compact inline notation'.
pub fn is_compact(&self) -> bool {
self.compact
}
pub fn dump(&mut self, doc: &Yaml) -> EmitResult {
// write DocumentStart
writeln!(self.writer, "---")?;
self.level = -1;
self.emit_node(doc)
}
fn write_indent(&mut self) -> EmitResult {
if self.level <= 0 {
return Ok(());
}
for _ in 0..self.level {
for _ in 0..self.best_indent {
write!(self.writer, " ")?;
}
}
Ok(())
}
fn emit_node(&mut self, node: &Yaml) -> EmitResult {
match *node {
Yaml::Array(ref v) => self.emit_array(v),
Yaml::Hash(ref h) => self.emit_hash(h),
Yaml::String(ref v) => {
if need_quotes(v) {
escape_str(self.writer, v)?;
} else {
write!(self.writer, "{}", v)?;
}
Ok(())
}
Yaml::Boolean(v) => {
if v {
self.writer.write_str("true")?;
} else {
self.writer.write_str("false")?;
}
Ok(())
}
Yaml::Integer(v) => {
write!(self.writer, "{}", v)?;
Ok(())
}
Yaml::Real(ref v) => {
write!(self.writer, "{}", v)?;
Ok(())
}
Yaml::Null | Yaml::BadValue => {
write!(self.writer, "~")?;
Ok(())
}
// XXX(chenyh) Alias
_ => Ok(()),
}
}
fn emit_array(&mut self, v: &[Yaml]) -> EmitResult {
if v.is_empty() {
write!(self.writer, "[]")?;
} else {
self.level += 1;
for (cnt, x) in v.iter().enumerate() {
if cnt > 0 {
writeln!(self.writer)?;
self.write_indent()?;
}
write!(self.writer, "-")?;
self.emit_val(true, x)?;
}
self.level -= 1;
}
Ok(())
}
fn emit_hash(&mut self, h: &Hash) -> EmitResult {
if h.is_empty() {
self.writer.write_str("{}")?;
} else {
self.level += 1;
for (cnt, (k, v)) in h.iter().enumerate() {
let complex_key = match *k {
Yaml::Hash(_) | Yaml::Array(_) => true,
_ => false,
};
if cnt > 0 {
writeln!(self.writer)?;
self.write_indent()?;
}
if complex_key {
write!(self.writer, "?")?;
self.emit_val(true, k)?;
writeln!(self.writer)?;
self.write_indent()?;
write!(self.writer, ":")?;
self.emit_val(true, v)?;
} else {
self.emit_node(k)?;
write!(self.writer, ":")?;
self.emit_val(false, v)?;
}
}
self.level -= 1;
}
Ok(())
}
/// Emit a yaml as a hash or array value: i.e., which should appear
/// following a ":" or "-", either after a space, or on a new line.
/// If `inline` is true, then the preceding characters are distinct
/// and short enough to respect the compact flag.
fn emit_val(&mut self, inline: bool, val: &Yaml) -> EmitResult {
match *val {
Yaml::Array(ref v) => {
if (inline && self.compact) || v.is_empty() {
write!(self.writer, " ")?;
} else {
writeln!(self.writer)?;
self.level += 1;
self.write_indent()?;
self.level -= 1;
}
self.emit_array(v)
}
Yaml::Hash(ref h) => {
if (inline && self.compact) || h.is_empty() {
write!(self.writer, " ")?;
} else {
writeln!(self.writer)?;
self.level += 1;
self.write_indent()?;
self.level -= 1;
}
self.emit_hash(h)
}
_ => {
write!(self.writer, " ")?;
self.emit_node(val)
}
}
}
}
/// Check if the string requires quoting.
/// Strings starting with any of the following characters must be quoted.
/// :, &, *, ?, |, -, <, >, =, !, %, @
/// Strings containing any of the following characters must be quoted.
/// {, }, [, ], ,, #, `
///
/// If the string contains any of the following control characters, it must be escaped with double quotes:
/// \0, \x01, \x02, \x03, \x04, \x05, \x06, \a, \b, \t, \n, \v, \f, \r, \x0e, \x0f, \x10, \x11, \x12, \x13, \x14, \x15, \x16, \x17, \x18, \x19, \x1a, \e, \x1c, \x1d, \x1e, \x1f, \N, \_, \L, \P
///
/// Finally, there are other cases when the strings must be quoted, no matter if you're using single or double quotes:
/// * When the string is true or false (otherwise, it would be treated as a boolean value);
/// * When the string is null or ~ (otherwise, it would be considered as a null value);
/// * When the string looks like a number, such as integers (e.g. 2, 14, etc.), floats (e.g. 2.6, 14.9) and exponential numbers (e.g. 12e7, etc.) (otherwise, it would be treated as a numeric value);
/// * When the string looks like a date (e.g. 2014-12-31) (otherwise it would be automatically converted into a Unix timestamp).
fn need_quotes(string: &str) -> bool {
fn need_quotes_spaces(string: &str) -> bool {
string.starts_with(' ') || string.ends_with(' ')
}
string == ""
|| need_quotes_spaces(string)
|| string.starts_with(|character: char| match character {
'&' | '*' | '?' | '|' | '-' | '<' | '>' | '=' | '!' | '%' | '@' => true,
_ => false,
})
|| string.contains(|character: char| match character {
':'
| '{'
| '}'
| '['
| ']'
| ','
| '#'
| '`'
| '\"'
| '\''
| '\\'
| '\0'..='\x06'
| '\t'
| '\n'
| '\r'
| '\x0e'..='\x1a'
| '\x1c'..='\x1f' => true,
_ => false,
})
|| [
// Note: 'y', 'Y', 'n', 'N', is not quoted deliberately, as in libyaml. PyYAML also parse
// them as string, not booleans, although it is violating the YAML 1.1 specification.
"yes", "Yes", "YES", "no", "No", "NO", "True", "TRUE", "true", "False", "FALSE",
"false", "on", "On", "ON", "off", "Off", "OFF",
"null", "Null", "NULL", "~",
]
.contains(&string)
|| string.starts_with('.')
|| string.starts_with("0x")
|| string.parse::<i64>().is_ok()
|| string.parse::<f64>().is_ok()
}
#[cfg(test)]
mod test {
use super::*;
use crate::YamlLoader;
#[test]
fn test_emit_simple() {
let s = "
# comment
a0 bb: val
a1:
b1: 4
b2: d
a2: 4 # i'm comment
a3: [1, 2, 3]
a4:
- [a1, a2]
- 2
";
let docs = YamlLoader::load_from_str(&s).unwrap();
let doc = &docs[0];
let mut writer = String::new();
{
let mut emitter = YamlEmitter::new(&mut writer);
emitter.dump(doc).unwrap();
}
println!("original:\n{}", s);
println!("emitted:\n{}", writer);
let docs_new = match YamlLoader::load_from_str(&writer) {
Ok(y) => y,
Err(e) => panic!(format!("{}", e)),
};
let doc_new = &docs_new[0];
assert_eq!(doc, doc_new);
}
#[test]
fn test_emit_complex() {
let s = r#"
cataloge:
product: &coffee { name: Coffee, price: 2.5 , unit: 1l }
product: &cookies { name: Cookies!, price: 3.40 , unit: 400g}
products:
*coffee:
amount: 4
*cookies:
amount: 4
[1,2,3,4]:
array key
2.4:
real key
true:
bool key
{}:
empty hash key
"#;
let docs = YamlLoader::load_from_str(&s).unwrap();
let doc = &docs[0];
let mut writer = String::new();
{
let mut emitter = YamlEmitter::new(&mut writer);
emitter.dump(doc).unwrap();
}
let docs_new = match YamlLoader::load_from_str(&writer) {
Ok(y) => y,
Err(e) => panic!(format!("{}", e)),
};
let doc_new = &docs_new[0];
assert_eq!(doc, doc_new);
}
#[test]
fn test_emit_avoid_quotes() {
let s = r#"---
a7: 你好
boolean: "true"
boolean2: "false"
date: 2014-12-31
empty_string: ""
empty_string1: " "
empty_string2: " a"
empty_string3: " a "
exp: "12e7"
field: ":"
field2: "{"
field3: "\\"
field4: "\n"
field5: "can't avoid quote"
float: "2.6"
int: "4"
nullable: "null"
nullable2: "~"
products:
"*coffee":
amount: 4
"*cookies":
amount: 4
".milk":
amount: 1
"2.4": real key
"[1,2,3,4]": array key
"true": bool key
"{}": empty hash key
x: test
y: avoid quoting here
z: string with spaces"#;
let docs = YamlLoader::load_from_str(&s).unwrap();
let doc = &docs[0];
let mut writer = String::new();
{
let mut emitter = YamlEmitter::new(&mut writer);
emitter.dump(doc).unwrap();
}
assert_eq!(s, writer, "actual:\n\n{}\n", writer);
}
#[test]
fn emit_quoted_bools() {
let input = r#"---
string0: yes
string1: no
string2: "true"
string3: "false"
string4: "~"
null0: ~
[true, false]: real_bools
[True, TRUE, False, FALSE, y,Y,yes,Yes,YES,n,N,no,No,NO,on,On,ON,off,Off,OFF]: false_bools
bool0: true
bool1: false"#;
let expected = r#"---
string0: "yes"
string1: "no"
string2: "true"
string3: "false"
string4: "~"
null0: ~
? - true
- false
: real_bools
? - "True"
- "TRUE"
- "False"
- "FALSE"
- y
- Y
- "yes"
- "Yes"
- "YES"
- n
- N
- "no"
- "No"
- "NO"
- "on"
- "On"
- "ON"
- "off"
- "Off"
- "OFF"
: false_bools
bool0: true
bool1: false"#;
let docs = YamlLoader::load_from_str(&input).unwrap();
let doc = &docs[0];
let mut writer = String::new();
{
let mut emitter = YamlEmitter::new(&mut writer);
emitter.dump(doc).unwrap();
}
assert_eq!(
expected, writer,
"expected:\n{}\nactual:\n{}\n",
expected, writer
);
}
#[test]
fn test_empty_and_nested() {
test_empty_and_nested_flag(false)
}
#[test]
fn test_empty_and_nested_compact() {
test_empty_and_nested_flag(true)
}
fn test_empty_and_nested_flag(compact: bool) {
let s = if compact {
r#"---
a:
b:
c: hello
d: {}
e:
- f
- g
- h: []"#
} else {
r#"---
a:
b:
c: hello
d: {}
e:
- f
- g
-
h: []"#
};
let docs = YamlLoader::load_from_str(&s).unwrap();
let doc = &docs[0];
let mut writer = String::new();
{
let mut emitter = YamlEmitter::new(&mut writer);
emitter.compact(compact);
emitter.dump(doc).unwrap();
}
assert_eq!(s, writer);
}
#[test]
fn test_nested_arrays() {
let s = r#"---
a:
- b
- - c
- d
- - e
- f"#;
let docs = YamlLoader::load_from_str(&s).unwrap();
let doc = &docs[0];
let mut writer = String::new();
{
let mut emitter = YamlEmitter::new(&mut writer);
emitter.dump(doc).unwrap();
}
println!("original:\n{}", s);
println!("emitted:\n{}", writer);
assert_eq!(s, writer);
}
#[test]
fn test_deeply_nested_arrays() {
let s = r#"---
a:
- b
- - c
- d
- - e
- - f
- - e"#;
let docs = YamlLoader::load_from_str(&s).unwrap();
let doc = &docs[0];
let mut writer = String::new();
{
let mut emitter = YamlEmitter::new(&mut writer);
emitter.dump(doc).unwrap();
}
println!("original:\n{}", s);
println!("emitted:\n{}", writer);
assert_eq!(s, writer);
}
#[test]
fn test_nested_hashes() {
let s = r#"---
a:
b:
c:
d:
e: f"#;
let docs = YamlLoader::load_from_str(&s).unwrap();
let doc = &docs[0];
let mut writer = String::new();
{
let mut emitter = YamlEmitter::new(&mut writer);
emitter.dump(doc).unwrap();
}
println!("original:\n{}", s);
println!("emitted:\n{}", writer);
assert_eq!(s, writer);
}
}