459 lines
13 KiB
Rust
459 lines
13 KiB
Rust
use std::fmt::{self, Display};
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use std::convert::From;
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use std::error::Error;
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use yaml::{Hash, Yaml};
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#[derive(Copy, Clone, Debug)]
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pub enum EmitError {
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FmtError(fmt::Error),
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BadHashmapKey,
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}
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impl Error for EmitError {
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fn description(&self) -> &str {
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match *self {
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EmitError::FmtError(ref err) => err.description(),
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EmitError::BadHashmapKey => "bad hashmap key",
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}
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}
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}
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impl Display for EmitError {
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fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
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match *self {
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EmitError::FmtError(ref err) => Display::fmt(err, formatter),
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EmitError::BadHashmapKey => formatter.write_str("bad hashmap key"),
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}
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}
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}
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impl From<fmt::Error> for EmitError {
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fn from(f: fmt::Error) -> Self {
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EmitError::FmtError(f)
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}
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}
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pub struct YamlEmitter<'a> {
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writer: &'a mut fmt::Write,
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best_indent: usize,
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level: isize,
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}
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pub type EmitResult = Result<(), EmitError>;
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// from serialize::json
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fn escape_str(wr: &mut fmt::Write, v: &str) -> Result<(), fmt::Error> {
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try!(wr.write_str("\""));
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let mut start = 0;
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for (i, byte) in v.bytes().enumerate() {
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let escaped = match byte {
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b'"' => "\\\"",
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b'\\' => "\\\\",
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b'\x00' => "\\u0000",
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b'\x01' => "\\u0001",
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b'\x02' => "\\u0002",
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b'\x03' => "\\u0003",
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b'\x04' => "\\u0004",
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b'\x05' => "\\u0005",
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b'\x06' => "\\u0006",
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b'\x07' => "\\u0007",
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b'\x08' => "\\b",
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b'\t' => "\\t",
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b'\n' => "\\n",
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b'\x0b' => "\\u000b",
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b'\x0c' => "\\f",
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b'\r' => "\\r",
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b'\x0e' => "\\u000e",
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b'\x0f' => "\\u000f",
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b'\x10' => "\\u0010",
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b'\x11' => "\\u0011",
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b'\x12' => "\\u0012",
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b'\x13' => "\\u0013",
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b'\x14' => "\\u0014",
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b'\x15' => "\\u0015",
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b'\x16' => "\\u0016",
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b'\x17' => "\\u0017",
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b'\x18' => "\\u0018",
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b'\x19' => "\\u0019",
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b'\x1a' => "\\u001a",
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b'\x1b' => "\\u001b",
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b'\x1c' => "\\u001c",
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b'\x1d' => "\\u001d",
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b'\x1e' => "\\u001e",
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b'\x1f' => "\\u001f",
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b'\x7f' => "\\u007f",
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_ => { continue; }
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};
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if start < i {
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try!(wr.write_str(&v[start..i]));
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}
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try!(wr.write_str(escaped));
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start = i + 1;
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}
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if start != v.len() {
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try!(wr.write_str(&v[start..]));
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}
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try!(wr.write_str("\""));
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Ok(())
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}
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impl<'a> YamlEmitter<'a> {
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pub fn new(writer: &'a mut fmt::Write) -> YamlEmitter {
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YamlEmitter {
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writer: writer,
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best_indent: 2,
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level: -1
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}
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}
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pub fn dump(&mut self, doc: &Yaml) -> EmitResult {
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// write DocumentStart
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try!(write!(self.writer, "---\n"));
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self.level = -1;
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self.emit_node(doc)
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}
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fn write_indent(&mut self) -> EmitResult {
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if self.level <= 0 { return Ok(()); }
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for _ in 0..self.level {
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for _ in 0..self.best_indent {
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try!(write!(self.writer, " "));
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}
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}
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Ok(())
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}
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fn emit_node_compact(&mut self, node: &Yaml) -> EmitResult {
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match *node {
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Yaml::Array(ref v) => {
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try!(write!(self.writer, "["));
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if self.level >= 0 {
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try!(write!(self.writer, "+ "));
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}
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self.level += 1;
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for (cnt, x) in v.iter().enumerate() {
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try!(self.write_indent());
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if cnt > 0 { try!(write!(self.writer, ", ")); }
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try!(self.emit_node(x));
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}
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self.level -= 1;
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try!(write!(self.writer, "]"));
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Ok(())
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},
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Yaml::Hash(ref h) => {
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try!(self.writer.write_str("{"));
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self.level += 1;
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for (cnt, (k, v)) in h.iter().enumerate() {
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if cnt > 0 {
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try!(write!(self.writer, ", "));
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}
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match *k {
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// complex key is not supported
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Yaml::Array(_) | Yaml::Hash(_) => {
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return Err(EmitError::BadHashmapKey);
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},
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_ => { try!(self.emit_node(k)); }
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}
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try!(write!(self.writer, ": "));
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try!(self.emit_node(v));
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}
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try!(self.writer.write_str("}"));
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self.level -= 1;
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Ok(())
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},
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_ => self.emit_node(node),
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}
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}
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fn emit_node(&mut self, node: &Yaml) -> EmitResult {
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match *node {
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Yaml::Array(ref v) => self.emit_array(v),
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Yaml::Hash(ref h) => self.emit_hash(h),
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Yaml::String(ref v) => {
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if need_quotes(v) {
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try!(escape_str(self.writer, v));
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}
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else {
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try!(write!(self.writer, "{}", v));
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}
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Ok(())
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},
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Yaml::Boolean(v) => {
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if v {
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try!(self.writer.write_str("true"));
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} else {
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try!(self.writer.write_str("false"));
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}
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Ok(())
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},
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Yaml::Integer(v) => {
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try!(write!(self.writer, "{}", v));
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Ok(())
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},
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Yaml::Real(ref v) => {
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try!(write!(self.writer, "{}", v));
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Ok(())
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},
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Yaml::Null | Yaml::BadValue => {
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try!(write!(self.writer, "~"));
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Ok(())
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},
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// XXX(chenyh) Alias
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_ => { Ok(()) }
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}
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}
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fn emit_array(&mut self, v: &[Yaml]) -> EmitResult {
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if v.is_empty() {
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try!(write!(self.writer, "[]"));
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} else {
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for (cnt, x) in v.iter().enumerate() {
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if cnt > 0 {
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try!(write!(self.writer, "\n"));
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}
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try!(self.write_indent());
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self.level += 1;
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try!(write!(self.writer, "- "));
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try!(self.emit_node(x));
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self.level -= 1;
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}
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}
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Ok(())
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}
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fn emit_hash(&mut self, h: &Hash) -> EmitResult {
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if h.is_empty() {
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try!(self.writer.write_str("{}"));
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} else {
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self.level += 1;
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for (cnt, (k, v)) in h.iter().enumerate() {
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if cnt > 0 {
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try!(write!(self.writer, "\n"));
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try!(self.write_indent());
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}
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match *k {
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Yaml::Array(_) | Yaml::Hash(_) => {
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try!(self.emit_node_compact(k));
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}
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_ => {
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try!(self.emit_node(k));
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}
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}
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match *v {
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Yaml::Array(ref v) => {
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if v.is_empty() {
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try!(write!(self.writer, ": "));
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} else {
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try!(write!(self.writer, ":\n"));
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}
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try!(self.emit_array(v));
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}
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Yaml::Hash(ref h) => {
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if h.is_empty() {
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try!(write!(self.writer, ": "));
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} else {
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try!(write!(self.writer, ":\n"));
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self.level += 1;
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try!(self.write_indent());
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self.level -= 1;
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}
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try!(self.emit_hash(h));
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}
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_ => {
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try!(write!(self.writer, ": "));
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try!(self.emit_node(v));
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}
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}
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}
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self.level -= 1;
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}
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Ok(())
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}
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}
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/// Check if the string requires quoting.
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/// Strings containing any of the following characters must be quoted.
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/// :, {, }, [, ], ,, &, *, #, ?, |, -, <, >, =, !, %, @, `
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///
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/// If the string contains any of the following control characters, it must be escaped with double quotes:
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/// \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
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///
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/// Finally, there are other cases when the strings must be quoted, no matter if you're using single or double quotes:
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/// * When the string is true or false (otherwise, it would be treated as a boolean value);
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/// * When the string is null or ~ (otherwise, it would be considered as a null value);
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/// * 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);
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/// * When the string looks like a date (e.g. 2014-12-31) (otherwise it would be automatically converted into a Unix timestamp).
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fn need_quotes(string: &str) -> bool {
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fn need_quotes_spaces(string: &str) -> bool {
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string.starts_with(' ')
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|| string.ends_with(' ')
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}
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string == ""
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|| need_quotes_spaces(string)
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|| string.contains(|character: char| {
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match character {
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':' | '{' | '}' | '[' | ']' | ',' | '&' | '*' | '#' | '?' | '|' | '-' | '<' | '>' | '=' | '!' | '%' | '@' | '`' | '\"' | '\'' | '\\' | '\0' ... '\x06' | '\t' | '\n' | '\r' | '\x0e' ... '\x1a' | '\x1c' ... '\x1f' => true,
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_ => false,
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}
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})
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|| string == "true"
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|| string == "false"
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|| string == "null"
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|| string == "~"
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|| string.starts_with('.')
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|| string.parse::<i64>().is_ok()
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|| string.parse::<f64>().is_ok()
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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use YamlLoader;
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#[test]
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fn test_emit_simple() {
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let s = "
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# comment
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a0 bb: val
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a1:
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b1: 4
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b2: d
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a2: 4 # i'm comment
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a3: [1, 2, 3]
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a4:
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- - a1
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- a2
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- 2
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- []
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- {}
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a5: 'single_quoted'
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a6: \"double_quoted\"
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a7: 你好
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'key 1': \"ddd\\\tbbb\"
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";
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let docs = YamlLoader::load_from_str(&s).unwrap();
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let doc = &docs[0];
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let mut writer = String::new();
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{
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let mut emitter = YamlEmitter::new(&mut writer);
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emitter.dump(doc).unwrap();
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}
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let docs_new = YamlLoader::load_from_str(&s).unwrap();
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let doc_new = &docs_new[0];
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assert_eq!(doc, doc_new);
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}
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#[test]
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fn test_emit_complex() {
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let s = r#"
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cataloge:
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product: &coffee { name: Coffee, price: 2.5 , unit: 1l }
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product: &cookies { name: Cookies!, price: 3.40 , unit: 400g}
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products:
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*coffee:
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amount: 4
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*cookies:
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amount: 4
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[1,2,3,4]:
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array key
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2.4:
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real key
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true:
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bool key
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{}:
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empty hash key
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"#;
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let docs = YamlLoader::load_from_str(&s).unwrap();
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let doc = &docs[0];
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let mut writer = String::new();
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{
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let mut emitter = YamlEmitter::new(&mut writer);
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emitter.dump(doc).unwrap();
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}
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let docs_new = YamlLoader::load_from_str(&s).unwrap();
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let doc_new = &docs_new[0];
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assert_eq!(doc, doc_new);
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}
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#[test]
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fn test_emit_avoid_quotes() {
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let s = r#"---
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a7: 你好
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boolean: "true"
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boolean2: "false"
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date: "2014-12-31"
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empty_string: ""
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empty_string1: " "
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empty_string2: " a"
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empty_string3: " a "
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exp: "12e7"
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field: ":"
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field2: "{"
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field3: "\\"
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field4: "\n"
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float: "2.6"
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int: "4"
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nullable: "null"
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nullable2: "~"
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products:
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"*coffee":
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amount: 4
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"*cookies":
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amount: 4
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".milk":
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amount: 1
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"2.4": real key
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"[1,2,3,4]": array key
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"true": bool key
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"{}": empty hash key
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x: test
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y: string with spaces"#;
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let docs = YamlLoader::load_from_str(&s).unwrap();
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let doc = &docs[0];
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let mut writer = String::new();
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{
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let mut emitter = YamlEmitter::new(&mut writer);
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emitter.dump(doc).unwrap();
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}
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assert_eq!(s, writer, "actual:\n\n{}\n", writer);
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}
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#[test]
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fn test_empty_and_nested() {
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let s = r#"---
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a:
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b:
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c: hello
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d: {}
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e:
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- f
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- g
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- h: []"#;
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let docs = YamlLoader::load_from_str(&s).unwrap();
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let doc = &docs[0];
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let mut writer = String::new();
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{
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let mut emitter = YamlEmitter::new(&mut writer);
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emitter.dump(doc).unwrap();
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}
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assert_eq!(s, writer);
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}
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}
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