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starship/src/formatter/string_formatter.rs

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use ansi_term::Style;
use pest::error::Error as PestError;
use rayon::prelude::*;
use std::borrow::Cow;
use std::collections::{BTreeMap, BTreeSet};
use std::error::Error;
use std::fmt;
use crate::config::parse_style_string;
use crate::context::{Context, Shell};
use crate::segment::Segment;
use super::model::*;
use super::parser::{parse, Rule};
#[derive(Clone)]
enum VariableValue<'a> {
Plain(Cow<'a, str>),
NoEscapingPlain(Cow<'a, str>),
Styled(Vec<Segment>),
Meta(Vec<FormatElement<'a>>),
}
impl<'a> Default for VariableValue<'a> {
fn default() -> Self {
VariableValue::Plain(Cow::Borrowed(""))
}
}
type VariableMapType<'a> =
BTreeMap<String, Option<Result<VariableValue<'a>, StringFormatterError>>>;
type StyleVariableMapType<'a> =
BTreeMap<String, Option<Result<Cow<'a, str>, StringFormatterError>>>;
#[derive(Debug, Clone, PartialEq)]
pub enum StringFormatterError {
Custom(String),
Parse(PestError<Rule>),
}
impl fmt::Display for StringFormatterError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
Self::Custom(error) => write!(f, "{}", error),
Self::Parse(error) => write!(f, "{}", error),
}
}
}
impl Error for StringFormatterError {}
impl From<String> for StringFormatterError {
fn from(error: String) -> Self {
Self::Custom(error)
}
}
pub struct StringFormatter<'a> {
format: Vec<FormatElement<'a>>,
variables: VariableMapType<'a>,
style_variables: StyleVariableMapType<'a>,
}
impl<'a> StringFormatter<'a> {
/// Creates an instance of StringFormatter from a format string
///
/// This method will throw an Error when the given format string fails to parse.
pub fn new(format: &'a str) -> Result<Self, StringFormatterError> {
let format = parse(format).map_err(StringFormatterError::Parse)?;
// Cache all variables
let variables = format
.get_variables()
.into_iter()
.map(|key| (key.to_string(), None))
.collect::<VariableMapType>();
let style_variables = format
.get_style_variables()
.into_iter()
.map(|key| (key.to_string(), None))
.collect::<StyleVariableMapType>();
Ok(Self {
format,
variables,
style_variables,
})
}
/// A StringFormatter that does no formatting, parse just returns the raw text
pub fn raw(text: &'a str) -> Self {
Self {
format: vec![FormatElement::Text(text.into())],
variables: BTreeMap::new(),
style_variables: BTreeMap::new(),
}
}
/// Maps variable name to its value
///
/// You should provide a function or closure that accepts the variable name `name: &str` as a
/// parameter and returns the one of the following values:
///
/// - `None`: This variable will be reserved for further mappers. If it is `None` when
/// `self.parse()` is called, it will be dropped.
///
/// - `Some(Err(StringFormatterError))`: This variable will throws `StringFormatterError` when
/// `self.parse()` is called. Return this if some fatal error occurred and the format string
/// should not be rendered.
///
/// - `Some(Ok(_))`: The value of this variable will be displayed in the format string.
///
pub fn map<T, M>(mut self, mapper: M) -> Self
where
T: Into<Cow<'a, str>>,
M: Fn(&str) -> Option<Result<T, StringFormatterError>> + Sync,
{
self.variables
.par_iter_mut()
.filter(|(_, value)| value.is_none())
.for_each(|(key, value)| {
*value = mapper(key).map(|var| var.map(|var| VariableValue::Plain(var.into())));
});
self
}
/// Maps variable name into a value which is wrapped to prevent escaping later
///
/// This should be used for variables that should not be escaped before inclusion in the prompt
///
/// See `StringFormatter::map` for description on the parameters.
///
pub fn map_no_escaping<T, M>(mut self, mapper: M) -> Self
where
T: Into<Cow<'a, str>>,
M: Fn(&str) -> Option<Result<T, StringFormatterError>> + Sync,
{
self.variables
.par_iter_mut()
.filter(|(_, value)| value.is_none())
.for_each(|(key, value)| {
*value = mapper(key)
.map(|var| var.map(|var| VariableValue::NoEscapingPlain(var.into())));
});
self
}
/// Maps a meta-variable to a format string containing other variables.
///
/// This function should be called **before** other map methods so that variables found in
/// the format strings of meta-variables can be cached properly.
///
/// See `StringFormatter::map` for description on the parameters.
pub fn map_meta<M>(mut self, mapper: M) -> Self
where
M: Fn(&str, &BTreeSet<String>) -> Option<&'a str> + Sync,
{
let variables = self.get_variables();
let (variables, style_variables) = self
.variables
.iter_mut()
.filter(|(_, value)| value.is_none())
.fold(
(VariableMapType::new(), StyleVariableMapType::new()),
|(mut v, mut sv), (key, value)| {
*value = mapper(key, &variables).map(|format| {
StringFormatter::new(format).map(|formatter| {
let StringFormatter {
format,
mut variables,
mut style_variables,
} = formatter;
// Add variables in meta variables to self
v.append(&mut variables);
sv.append(&mut style_variables);
VariableValue::Meta(format)
})
});
(v, sv)
},
);
self.variables.extend(variables);
self.style_variables.extend(style_variables);
self
}
/// Maps variable name to an array of segments
///
/// See `StringFormatter::map` for description on the parameters.
pub fn map_variables_to_segments<M>(mut self, mapper: M) -> Self
where
M: Fn(&str) -> Option<Result<Vec<Segment>, StringFormatterError>> + Sync,
{
self.variables
.par_iter_mut()
.filter(|(_, value)| value.is_none())
.for_each(|(key, value)| {
*value = mapper(key).map(|var| var.map(VariableValue::Styled));
});
self
}
/// Maps variable name in a style string to its value
///
/// See `StringFormatter::map` for description on the parameters.
pub fn map_style<T, M>(mut self, mapper: M) -> Self
where
T: Into<Cow<'a, str>>,
M: Fn(&str) -> Option<Result<T, StringFormatterError>> + Sync,
{
self.style_variables
.par_iter_mut()
.filter(|(_, value)| value.is_none())
.for_each(|(key, value)| {
*value = mapper(key).map(|var| var.map(std::convert::Into::into));
});
self
}
/// Parse the format string and consume self.
///
/// This method will throw an Error in the following conditions:
///
/// - Format string in meta variables fails to parse
/// - Variable mapper returns an error.
pub fn parse(
self,
default_style: Option<Style>,
context: Option<&Context>,
) -> Result<Vec<Segment>, StringFormatterError> {
fn parse_textgroup<'a>(
textgroup: TextGroup<'a>,
variables: &'a VariableMapType<'a>,
style_variables: &'a StyleVariableMapType<'a>,
context: Option<&Context>,
) -> Result<Vec<Segment>, StringFormatterError> {
let style = parse_style(textgroup.style, style_variables);
parse_format(
textgroup.format,
style.transpose()?,
variables,
style_variables,
context,
)
}
fn parse_style<'a>(
style: Vec<StyleElement>,
variables: &'a StyleVariableMapType<'a>,
) -> Option<Result<Style, StringFormatterError>> {
let style_strings = style
.into_iter()
.map(|style| match style {
StyleElement::Text(text) => Ok(text),
StyleElement::Variable(name) => {
let variable = variables.get(name.as_ref()).unwrap_or(&None);
match variable {
2020-10-13 16:03:33 +00:00
Some(style_string) => style_string.clone(),
None => Ok("".into()),
}
}
})
.collect::<Result<Vec<Cow<str>>, StringFormatterError>>();
style_strings
.map(|style_strings| {
let style_string: String =
style_strings.iter().flat_map(|s| s.chars()).collect();
parse_style_string(&style_string)
})
.transpose()
}
fn parse_format<'a>(
format: Vec<FormatElement<'a>>,
style: Option<Style>,
variables: &'a VariableMapType<'a>,
style_variables: &'a StyleVariableMapType<'a>,
context: Option<&Context>,
) -> Result<Vec<Segment>, StringFormatterError> {
let results: Result<Vec<Vec<Segment>>, StringFormatterError> = format
.into_iter()
.map(|el| {
match el {
FormatElement::Text(text) => Ok(Segment::from_text(style, text)),
FormatElement::TextGroup(textgroup) => {
let textgroup = TextGroup {
format: textgroup.format,
style: textgroup.style,
};
parse_textgroup(textgroup, variables, style_variables, context)
}
FormatElement::Variable(name) => variables
.get(name.as_ref())
.expect("Uncached variable found")
.as_ref()
.map(|segments| match segments.clone()? {
VariableValue::Styled(segments) => Ok(segments
.into_iter()
.map(|mut segment| {
// Derive upper style if the style of segments are none.
segment.set_style_if_empty(style);
segment
})
.collect()),
VariableValue::Plain(text) => Ok(Segment::from_text(
style,
shell_prompt_escape(
text,
match context {
None => Shell::Unknown,
Some(c) => c.shell,
},
),
)),
VariableValue::NoEscapingPlain(text) => {
Ok(Segment::from_text(style, text))
}
VariableValue::Meta(format) => {
let formatter = StringFormatter {
format,
variables: clone_without_meta(variables),
style_variables: style_variables.clone(),
};
formatter.parse(style, context)
}
})
.unwrap_or_else(|| Ok(Vec::new())),
FormatElement::Conditional(format) => {
// Show the conditional format string if all the variables inside are not
// none or empty string.
fn should_show_elements<'a>(
format_elements: &[FormatElement],
variables: &'a VariableMapType<'a>,
) -> bool {
format_elements.get_variables().iter().any(|var| {
variables
.get(var.as_ref())
// false if can't find the variable in format string
.map_or(false, |map_result| {
let map_result = map_result.as_ref();
map_result
.and_then(|result| result.as_ref().ok())
// false if the variable is None or Err, or a meta variable
// that shouldn't show
.map_or(false, |result| match result {
// If the variable is a meta variable, also
// check the format string inside it.
VariableValue::Meta(meta_elements) => {
let meta_variables =
clone_without_meta(variables);
should_show_elements(
meta_elements,
&meta_variables,
)
}
VariableValue::Plain(plain_value) => {
!plain_value.is_empty()
}
VariableValue::NoEscapingPlain(
no_escaping_plain_value,
) => !no_escaping_plain_value.is_empty(),
VariableValue::Styled(segments) => segments
.iter()
.any(|x| !x.value().is_empty()),
})
})
})
}
let should_show: bool = should_show_elements(&format, variables);
if should_show {
parse_format(format, style, variables, style_variables, context)
} else {
Ok(Vec::new())
}
}
}
})
.collect();
Ok(results?.into_iter().flatten().collect())
}
parse_format(
self.format,
default_style,
&self.variables,
&self.style_variables,
context,
)
}
}
impl<'a> VariableHolder<String> for StringFormatter<'a> {
fn get_variables(&self) -> BTreeSet<String> {
self.variables.keys().cloned().collect()
}
}
impl<'a> StyleVariableHolder<String> for StringFormatter<'a> {
fn get_style_variables(&self) -> BTreeSet<String> {
self.style_variables.keys().cloned().collect()
}
}
fn clone_without_meta<'a>(variables: &VariableMapType<'a>) -> VariableMapType<'a> {
variables
.iter()
.map(|(key, value)| {
let value = match value {
Some(Ok(value)) => match value {
VariableValue::Meta(_) => None,
other => Some(Ok(other.clone())),
},
Some(Err(e)) => Some(Err(e.clone())),
None => None,
};
(key.clone(), value)
})
.collect()
}
/// Escape interpretable characters for the shell prompt
pub fn shell_prompt_escape<T>(text: T, shell: Shell) -> String
where
T: Into<String>,
{
// Handle other interpretable characters
match shell {
// Bash might interepret baskslashes, backticks and $
// see #658 for more details
Shell::Bash => text
.into()
.replace('\\', r"\\")
.replace('$', r"\$")
.replace('`', r"\`"),
Shell::Zsh => {
// % is an escape in zsh, see PROMPT in `man zshmisc`
text.into().replace('%', "%%")
}
_ => text.into(),
}
}
#[cfg(test)]
mod tests {
use super::*;
use ansi_term::Color;
// match_next(result: IterMut<Segment>, value, style)
macro_rules! match_next {
($iter:ident, $value:literal, $($style:tt)+) => {
let _next = $iter.next().unwrap();
assert_eq!(_next.value(), $value);
assert_eq!(_next.style(), $($style)+);
}
}
fn empty_mapper(_: &str) -> Option<Result<String, StringFormatterError>> {
None
}
#[test]
fn test_default_style() {
const FORMAT_STR: &str = "text";
let style = Some(Color::Red.bold());
let formatter = StringFormatter::new(FORMAT_STR).unwrap().map(empty_mapper);
let result = formatter.parse(style, None).unwrap();
let mut result_iter = result.iter();
match_next!(result_iter, "text", style);
}
#[test]
fn test_textgroup_text_only() {
const FORMAT_STR: &str = "[text](red bold)";
let formatter = StringFormatter::new(FORMAT_STR).unwrap().map(empty_mapper);
let result = formatter.parse(None, None).unwrap();
let mut result_iter = result.iter();
match_next!(result_iter, "text", Some(Color::Red.bold()));
}
#[test]
fn test_variable_only() {
const FORMAT_STR: &str = "$var1";
let formatter = StringFormatter::new(FORMAT_STR)
.unwrap()
.map(|variable| match variable {
"var1" => Some(Ok("text1".to_owned())),
_ => None,
});
let result = formatter.parse(None, None).unwrap();
let mut result_iter = result.iter();
match_next!(result_iter, "text1", None);
}
#[test]
fn test_variable_in_style() {
const FORMAT_STR: &str = "[root]($style)";
let root_style = Some(Color::Red.bold());
let formatter = StringFormatter::new(FORMAT_STR)
.unwrap()
.map_style(|variable| match variable {
"style" => Some(Ok("red bold".to_owned())),
_ => None,
});
let result = formatter.parse(None, None).unwrap();
let mut result_iter = result.iter();
match_next!(result_iter, "root", root_style);
}
#[test]
fn test_scoped_variable() {
const FORMAT_STR: &str = "${env:PWD}";
let formatter = StringFormatter::new(FORMAT_STR)
.unwrap()
.map(|variable| Some(Ok(format!("${{{}}}", variable))));
let result = formatter.parse(None, None).unwrap();
let mut result_iter = result.iter();
match_next!(result_iter, "${env:PWD}", None);
}
#[test]
fn test_escaped_chars() {
const FORMAT_STR: &str = r#"\\\[\$text\]\(red bold\)"#;
let formatter = StringFormatter::new(FORMAT_STR).unwrap().map(empty_mapper);
let result = formatter.parse(None, None).unwrap();
let mut result_iter = result.iter();
match_next!(result_iter, r#"\[$text](red bold)"#, None);
}
#[test]
fn test_nested_textgroup() {
const FORMAT_STR: &str = "outer [middle [inner](blue)](red bold)";
let outer_style = Some(Color::Green.normal());
let middle_style = Some(Color::Red.bold());
let inner_style = Some(Color::Blue.normal());
let formatter = StringFormatter::new(FORMAT_STR).unwrap().map(empty_mapper);
let result = formatter.parse(outer_style, None).unwrap();
let mut result_iter = result.iter();
match_next!(result_iter, "outer ", outer_style);
match_next!(result_iter, "middle ", middle_style);
match_next!(result_iter, "inner", inner_style);
}
#[test]
fn test_styled_variable_as_text() {
const FORMAT_STR: &str = "[$var](red bold)";
let var_style = Some(Color::Red.bold());
let formatter = StringFormatter::new(FORMAT_STR)
.unwrap()
.map(|variable| match variable {
"var" => Some(Ok("text".to_owned())),
_ => None,
});
let result = formatter.parse(None, None).unwrap();
let mut result_iter = result.iter();
match_next!(result_iter, "text", var_style);
}
#[test]
fn test_styled_variable_as_segments() {
const FORMAT_STR: &str = "[$var](red bold)";
let var_style = Some(Color::Red.bold());
let styled_style = Some(Color::Green.italic());
let styled_no_modifier_style = Some(Color::Green.normal());
let mut segments: Vec<Segment> = Vec::new();
segments.extend(Segment::from_text(None, "styless"));
segments.extend(Segment::from_text(styled_style, "styled"));
segments.extend(Segment::from_text(
styled_no_modifier_style,
"styled_no_modifier",
));
let formatter = StringFormatter::new(FORMAT_STR)
.unwrap()
.map_variables_to_segments(|variable| match variable {
"var" => Some(Ok(segments.clone())),
_ => None,
});
let result = formatter.parse(None, None).unwrap();
let mut result_iter = result.iter();
match_next!(result_iter, "styless", var_style);
match_next!(result_iter, "styled", styled_style);
match_next!(result_iter, "styled_no_modifier", styled_no_modifier_style);
}
#[test]
fn test_meta_variable() {
const FORMAT_STR: &str = "$all";
const FORMAT_STR__ALL: &str = "$a$b";
let formatter = StringFormatter::new(FORMAT_STR)
.unwrap()
.map_meta(|var, _| match var {
"all" => Some(FORMAT_STR__ALL),
_ => None,
})
.map(|var| match var {
"a" => Some(Ok("$a")),
"b" => Some(Ok("$b")),
_ => None,
});
let result = formatter.parse(None, None).unwrap();
let mut result_iter = result.iter();
match_next!(result_iter, "$a", None);
match_next!(result_iter, "$b", None);
}
#[test]
fn test_multiple_mapper() {
const FORMAT_STR: &str = "$a$b$c";
let formatter = StringFormatter::new(FORMAT_STR)
.unwrap()
.map(|var| match var {
"a" => Some(Ok("$a")),
"b" => Some(Ok("$b")),
_ => None,
})
.map(|var| match var {
"b" => Some(Ok("$B")),
"c" => Some(Ok("$c")),
_ => None,
});
let result = formatter.parse(None, None).unwrap();
let mut result_iter = result.iter();
match_next!(result_iter, "$a", None);
match_next!(result_iter, "$b", None);
match_next!(result_iter, "$c", None);
}
#[test]
fn test_conditional() {
const FORMAT_STR: &str = "($some) should render but ($none) shouldn't";
let formatter = StringFormatter::new(FORMAT_STR)
.unwrap()
.map(|var| match var {
"some" => Some(Ok("$some")),
_ => None,
});
let result = formatter.parse(None, None).unwrap();
let mut result_iter = result.iter();
match_next!(result_iter, "$some", None);
match_next!(result_iter, " should render but ", None);
match_next!(result_iter, " shouldn't", None);
}
#[test]
fn test_empty() {
const FORMAT_STR: &str = "(@$empty)";
let formatter = StringFormatter::new(FORMAT_STR)
.unwrap()
.map(|var| match var {
"empty" => Some(Ok("")),
_ => None,
});
let result = formatter.parse(None, None).unwrap();
assert_eq!(result.len(), 0);
}
#[test]
fn test_styled_empty() {
const FORMAT_STR: &str = "[(@$empty)](red bold)";
let formatter = StringFormatter::new(FORMAT_STR)
.unwrap()
.map(|variable| match variable {
"empty" => Some(Ok("")),
_ => None,
});
let result = formatter.parse(None, None).unwrap();
assert_eq!(result.len(), 0);
}
#[test]
fn test_nested_conditional() {
const FORMAT_STR: &str = "($some ($none)) and ($none ($some))";
let formatter = StringFormatter::new(FORMAT_STR)
.unwrap()
.map(|var| match var {
"some" => Some(Ok("$some")),
_ => None,
});
let result = formatter.parse(None, None).unwrap();
let mut result_iter = result.iter();
match_next!(result_iter, "$some", None);
match_next!(result_iter, " ", None);
match_next!(result_iter, " and ", None);
match_next!(result_iter, " ", None);
match_next!(result_iter, "$some", None);
}
#[test]
fn test_conditional_meta_variable() {
const FORMAT_STR: &str = r"(\[$all\]) ";
let formatter = StringFormatter::new(FORMAT_STR)
.unwrap()
.map_meta(|var, _| match var {
"all" => Some("$some"),
_ => None,
});
let result = formatter.parse(None, None).unwrap();
let mut result_iter = result.iter();
match_next!(result_iter, " ", None);
}
#[test]
fn test_variable_holder() {
const FORMAT_STR: &str = "($a [($b) $c](none $s)) $d [t]($t)";
let expected_variables = vec!["a", "b", "c", "d"]
.into_iter()
.map(String::from)
.collect();
let formatter = StringFormatter::new(FORMAT_STR).unwrap().map(empty_mapper);
let variables = formatter.get_variables();
assert_eq!(variables, expected_variables);
}
#[test]
fn test_style_variable_holder() {
const FORMAT_STR: &str = "($a [($b) $c](none $s)) $d [t]($t)";
let expected_variables = vec!["s", "t"].into_iter().map(String::from).collect();
let formatter = StringFormatter::new(FORMAT_STR).unwrap().map(empty_mapper);
let variables = formatter.get_style_variables();
assert_eq!(variables, expected_variables);
}
#[test]
fn test_parse_error() {
// brackets without escape
{
const FORMAT_STR: &str = "[";
assert!(StringFormatter::new(FORMAT_STR).is_err());
}
// Dollar without variable
{
const FORMAT_STR: &str = "$ ";
assert!(StringFormatter::new(FORMAT_STR).is_err());
}
}
#[test]
fn test_variable_error() {
const FORMAT_STR: &str = "$never$some";
let never_error = StringFormatterError::Custom("NEVER".to_owned());
let segments = StringFormatter::new(FORMAT_STR).and_then(|formatter| {
formatter
.map(|var| match var {
"some" => Some(Ok("some")),
"never" => Some(Err(never_error.clone())),
_ => None,
})
.parse(None, None)
});
assert!(segments.is_err());
}
#[test]
fn test_bash_escape() {
let test = "$(echo a)";
assert_eq!(
shell_prompt_escape(test.to_owned(), Shell::Bash),
r"\$(echo a)"
);
assert_eq!(
shell_prompt_escape(test.to_owned(), Shell::PowerShell),
test
);
let test = r"\$(echo a)";
assert_eq!(
shell_prompt_escape(test.to_owned(), Shell::Bash),
r"\\\$(echo a)"
);
assert_eq!(
shell_prompt_escape(test.to_owned(), Shell::PowerShell),
test
);
let test = r"`echo a`";
assert_eq!(
shell_prompt_escape(test.to_owned(), Shell::Bash),
r"\`echo a\`"
);
assert_eq!(
shell_prompt_escape(test.to_owned(), Shell::PowerShell),
test
);
}
#[test]
fn test_zsh_escape() {
let test = "10%";
assert_eq!(shell_prompt_escape(test.to_owned(), Shell::Zsh), "10%%");
assert_eq!(
shell_prompt_escape(test.to_owned(), Shell::PowerShell),
test
);
}
}