nushell/src/errors.rs
Yehuda Katz 34292b282a Add support for ~ expansion
This ended up being a bit of a yak shave. The basic idea in this commit is to
expand `~` in paths, but only in paths.

The way this is accomplished is by doing the expansion inside of the code that
parses literal syntax for `SyntaxType::Path`.

As a quick refresher: every command is entitled to expand its arguments in a
custom way. While this could in theory be used for general-purpose macros,
today the expansion facility is limited to syntactic hints.

For example, the syntax `where cpu > 0` expands under the hood to
`where { $it.cpu > 0 }`. This happens because the first argument to `where`
is defined as a `SyntaxType::Block`, and the parser coerces binary expressions
whose left-hand-side looks like a member into a block when the command is
expecting one.

This is mildly more magical than what most programming languages would do,
but we believe that it makes sense to allow commands to fine-tune the syntax
because of the domain nushell is in (command-line shells).

The syntactic expansions supported by this facility are relatively limited.
For example, we don't allow `$it` to become a bare word, simply because the
command asks for a string in the relevant position. That would quickly
become more confusing than it's worth.

This PR adds a new `SyntaxType` rule: `SyntaxType::Path`. When a command
declares a parameter as a `SyntaxType::Path`, string literals and bare
words passed as an argument to that parameter are processed using the
path expansion rules. Right now, that only means that `~` is expanded into
the home directory, but additional rules are possible in the future.

By restricting this expansion to a syntactic expansion when passed as an
argument to a command expecting a path, we avoid making `~` a generally
reserved character. This will also allow us to give good tab completion
for paths with `~` characters in them when a command is expecting a path.

In order to accomplish the above, this commit changes the parsing functions
to take a `Context` instead of just a `CommandRegistry`. From the perspective
of macro expansion, you can think of the `CommandRegistry` as a dictionary
of in-scope macros, and the `Context` as the compile-time state used in
expansion. This could gain additional functionality over time as we find
more uses for the expansion system.
2019-08-26 21:03:24 -07:00

520 lines
16 KiB
Rust

#[allow(unused)]
use crate::prelude::*;
use ansi_term::Color;
use derive_new::new;
use language_reporting::{Diagnostic, Label, Severity};
use serde::{Deserialize, Serialize};
use std::fmt;
#[derive(Debug, Eq, PartialEq, Clone, Ord, PartialOrd, Serialize, Deserialize)]
pub enum Description {
Source(Tagged<String>),
Synthetic(String),
}
impl Description {
pub fn from(value: Tagged<impl Into<String>>) -> Description {
let value_span = value.span();
let value_tag = value.tag();
match value_span {
Span { start: 0, end: 0 } => Description::Synthetic(value.item.into()),
_ => Description::Source(Tagged::from_item(value.item.into(), value_tag)),
}
}
}
impl Description {
fn into_label(self) -> Result<Label<Span>, String> {
match self {
Description::Source(s) => Ok(Label::new_primary(s.span()).with_message(s.item)),
Description::Synthetic(s) => Err(s),
}
}
}
#[derive(Debug, Eq, PartialEq, Clone, Ord, PartialOrd, Serialize, Deserialize)]
pub enum ArgumentError {
MissingMandatoryFlag(String),
MissingMandatoryPositional(String),
MissingValueForName(String),
}
// pub fn labelled(
// span: impl Into<Span>,
// heading: &'a str,
// span_message: &'a str,
// ) -> impl FnOnce(ShellError) -> ShellError + 'a {
// let span = span.into();
// move |_| ShellError::labeled_error(heading, span_message, span)
// }
#[derive(Debug, Eq, PartialEq, Clone, Ord, PartialOrd, Serialize, Deserialize)]
pub struct ShellError {
error: ProximateShellError,
cause: Option<Box<ProximateShellError>>,
}
impl ToDebug for ShellError {
fn fmt_debug(&self, f: &mut fmt::Formatter, source: &str) -> fmt::Result {
self.error.fmt_debug(f, source)
}
}
impl serde::de::Error for ShellError {
fn custom<T>(msg: T) -> Self
where
T: std::fmt::Display,
{
ShellError::string(msg.to_string())
}
}
impl ShellError {
crate fn type_error(
expected: impl Into<String>,
actual: Tagged<impl Into<String>>,
) -> ShellError {
ProximateShellError::TypeError {
expected: expected.into(),
actual: actual.map(|i| Some(i.into())),
}
.start()
}
crate fn syntax_error(problem: Tagged<impl Into<String>>) -> ShellError {
ProximateShellError::SyntaxError {
problem: problem.map(|p| p.into()),
}
.start()
}
crate fn invalid_command(problem: impl Into<Tag>) -> ShellError {
ProximateShellError::InvalidCommand {
command: problem.into(),
}
.start()
}
crate fn coerce_error(
left: Tagged<impl Into<String>>,
right: Tagged<impl Into<String>>,
) -> ShellError {
ProximateShellError::CoerceError {
left: left.map(|l| l.into()),
right: right.map(|r| r.into()),
}
.start()
}
crate fn missing_property(subpath: Description, expr: Description) -> ShellError {
ProximateShellError::MissingProperty { subpath, expr }.start()
}
crate fn missing_value(span: Option<Span>, reason: impl Into<String>) -> ShellError {
ProximateShellError::MissingValue {
span,
reason: reason.into(),
}
.start()
}
crate fn argument_error(
command: impl Into<String>,
kind: ArgumentError,
span: Span,
) -> ShellError {
ProximateShellError::ArgumentError {
command: command.into(),
error: kind,
span: span,
}
.start()
}
crate fn parse_error(
error: nom::Err<(nom5_locate::LocatedSpan<&str>, nom::error::ErrorKind)>,
) -> ShellError {
use language_reporting::*;
match error {
nom::Err::Incomplete(_) => unreachable!(),
nom::Err::Failure(span) | nom::Err::Error(span) => {
let diagnostic = Diagnostic::new(Severity::Error, format!("Parse Error"))
.with_label(Label::new_primary(Span::from(span.0)));
ShellError::diagnostic(diagnostic)
}
}
}
crate fn diagnostic(diagnostic: Diagnostic<Span>) -> ShellError {
ProximateShellError::Diagnostic(ShellDiagnostic { diagnostic }).start()
}
crate fn to_diagnostic(self) -> Diagnostic<Span> {
match self.error {
ProximateShellError::String(StringError { title, .. }) => {
Diagnostic::new(Severity::Error, title)
}
ProximateShellError::InvalidCommand { command } => {
Diagnostic::new(Severity::Error, "Invalid command")
.with_label(Label::new_primary(command.span))
}
ProximateShellError::MissingValue { span, reason } => {
let mut d = Diagnostic::new(
Severity::Bug,
format!("Internal Error (missing value) :: {}", reason),
);
if let Some(span) = span {
d = d.with_label(Label::new_primary(span));
}
d
}
ProximateShellError::ArgumentError {
command,
error,
span,
} => match error {
ArgumentError::MissingMandatoryFlag(name) => Diagnostic::new(
Severity::Error,
format!(
"{} requires {}{}",
Color::Cyan.paint(command),
Color::Black.bold().paint("--"),
Color::Black.bold().paint(name)
),
)
.with_label(Label::new_primary(span)),
ArgumentError::MissingMandatoryPositional(name) => Diagnostic::new(
Severity::Error,
format!(
"{} requires {} parameter",
Color::Cyan.paint(command),
Color::Green.bold().paint(name.clone())
),
)
.with_label(
Label::new_primary(span).with_message(format!("requires {} parameter", name)),
),
ArgumentError::MissingValueForName(name) => Diagnostic::new(
Severity::Error,
format!(
"{} is missing value for flag {}{}",
Color::Cyan.paint(command),
Color::Black.bold().paint("--"),
Color::Black.bold().paint(name)
),
)
.with_label(Label::new_primary(span)),
},
ProximateShellError::TypeError {
expected,
actual:
Tagged {
item: Some(actual),
tag: Tag { span, .. },
},
} => Diagnostic::new(Severity::Error, "Type Error").with_label(
Label::new_primary(span)
.with_message(format!("Expected {}, found {}", expected, actual)),
),
ProximateShellError::TypeError {
expected,
actual:
Tagged {
item: None,
tag: Tag { span, .. },
},
} => Diagnostic::new(Severity::Error, "Type Error")
.with_label(Label::new_primary(span).with_message(expected)),
ProximateShellError::SyntaxError {
problem:
Tagged {
tag: Tag { span, .. },
..
},
} => Diagnostic::new(Severity::Error, "Syntax Error")
.with_label(Label::new_primary(span).with_message("Unexpected external command")),
ProximateShellError::MissingProperty { subpath, expr } => {
let subpath = subpath.into_label();
let expr = expr.into_label();
let mut diag = Diagnostic::new(Severity::Error, "Missing property");
match subpath {
Ok(label) => diag = diag.with_label(label),
Err(ty) => diag.message = format!("Missing property (for {})", ty),
}
if let Ok(label) = expr {
diag = diag.with_label(label);
}
diag
}
ProximateShellError::Diagnostic(diag) => diag.diagnostic,
ProximateShellError::CoerceError { left, right } => {
Diagnostic::new(Severity::Error, "Coercion error")
.with_label(Label::new_primary(left.span()).with_message(left.item))
.with_label(Label::new_secondary(right.span()).with_message(right.item))
}
}
}
pub fn labeled_error(
msg: impl Into<String>,
label: impl Into<String>,
span: impl Into<Span>,
) -> ShellError {
ShellError::diagnostic(
Diagnostic::new(Severity::Error, msg.into())
.with_label(Label::new_primary(span.into()).with_message(label.into())),
)
}
pub fn labeled_error_with_secondary(
msg: impl Into<String>,
primary_label: impl Into<String>,
primary_span: Span,
secondary_label: impl Into<String>,
secondary_span: Span,
) -> ShellError {
ShellError::diagnostic(
Diagnostic::new_error(msg.into())
.with_label(Label::new_primary(primary_span).with_message(primary_label.into()))
.with_label(
Label::new_secondary(secondary_span).with_message(secondary_label.into()),
),
)
}
pub fn string(title: impl Into<String>) -> ShellError {
ProximateShellError::String(StringError::new(title.into(), Value::nothing())).start()
}
crate fn unimplemented(title: impl Into<String>) -> ShellError {
ShellError::string(&format!("Unimplemented: {}", title.into()))
}
crate fn unexpected(title: impl Into<String>) -> ShellError {
ShellError::string(&format!("Unexpected: {}", title.into()))
}
}
#[derive(Debug, Eq, PartialEq, Clone, Ord, PartialOrd, Serialize, Deserialize)]
pub enum ProximateShellError {
String(StringError),
SyntaxError {
problem: Tagged<String>,
},
InvalidCommand {
command: Tag,
},
TypeError {
expected: String,
actual: Tagged<Option<String>>,
},
MissingProperty {
subpath: Description,
expr: Description,
},
MissingValue {
span: Option<Span>,
reason: String,
},
ArgumentError {
command: String,
error: ArgumentError,
span: Span,
},
Diagnostic(ShellDiagnostic),
CoerceError {
left: Tagged<String>,
right: Tagged<String>,
},
}
impl ProximateShellError {
fn start(self) -> ShellError {
ShellError {
cause: None,
error: self,
}
}
}
impl ToDebug for ProximateShellError {
fn fmt_debug(&self, f: &mut fmt::Formatter, _source: &str) -> fmt::Result {
// TODO: Custom debug for inner spans
write!(f, "{:?}", self)
}
}
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ShellDiagnostic {
crate diagnostic: Diagnostic<Span>,
}
impl ShellDiagnostic {
#[allow(unused)]
crate fn simple_diagnostic(
span: impl Into<Span>,
source: impl Into<String>,
) -> ShellDiagnostic {
use language_reporting::*;
let span = span.into();
let source = source.into();
let diagnostic =
Diagnostic::new(Severity::Error, "Parse error").with_label(Label::new_primary(span));
ShellDiagnostic { diagnostic }
}
}
impl PartialEq for ShellDiagnostic {
fn eq(&self, _other: &ShellDiagnostic) -> bool {
false
}
}
impl Eq for ShellDiagnostic {}
impl std::cmp::PartialOrd for ShellDiagnostic {
fn partial_cmp(&self, _other: &Self) -> Option<std::cmp::Ordering> {
Some(std::cmp::Ordering::Less)
}
}
impl std::cmp::Ord for ShellDiagnostic {
fn cmp(&self, _other: &Self) -> std::cmp::Ordering {
std::cmp::Ordering::Less
}
}
#[derive(Debug, Ord, PartialOrd, Eq, PartialEq, new, Clone, Serialize, Deserialize)]
pub struct StringError {
title: String,
error: Value,
}
impl std::fmt::Display for ShellError {
fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
match &self.error {
ProximateShellError::String(s) => write!(f, "{}", &s.title),
ProximateShellError::MissingValue { .. } => write!(f, "MissingValue"),
ProximateShellError::InvalidCommand { .. } => write!(f, "InvalidCommand"),
ProximateShellError::TypeError { .. } => write!(f, "TypeError"),
ProximateShellError::SyntaxError { .. } => write!(f, "SyntaxError"),
ProximateShellError::MissingProperty { .. } => write!(f, "MissingProperty"),
ProximateShellError::ArgumentError { .. } => write!(f, "ArgumentError"),
ProximateShellError::Diagnostic(_) => write!(f, "<diagnostic>"),
ProximateShellError::CoerceError { .. } => write!(f, "CoerceError"),
}
}
}
impl std::error::Error for ShellError {}
impl std::convert::From<Box<dyn std::error::Error>> for ShellError {
fn from(input: Box<dyn std::error::Error>) -> ShellError {
ProximateShellError::String(StringError {
title: format!("{}", input),
error: Value::nothing(),
})
.start()
}
}
impl std::convert::From<std::io::Error> for ShellError {
fn from(input: std::io::Error) -> ShellError {
ProximateShellError::String(StringError {
title: format!("{}", input),
error: Value::nothing(),
})
.start()
}
}
impl std::convert::From<subprocess::PopenError> for ShellError {
fn from(input: subprocess::PopenError) -> ShellError {
ProximateShellError::String(StringError {
title: format!("{}", input),
error: Value::nothing(),
})
.start()
}
}
impl std::convert::From<serde_yaml::Error> for ShellError {
fn from(input: serde_yaml::Error) -> ShellError {
ProximateShellError::String(StringError {
title: format!("{:?}", input),
error: Value::nothing(),
})
.start()
}
}
impl std::convert::From<toml::ser::Error> for ShellError {
fn from(input: toml::ser::Error) -> ShellError {
ProximateShellError::String(StringError {
title: format!("{:?}", input),
error: Value::nothing(),
})
.start()
}
}
impl std::convert::From<serde_json::Error> for ShellError {
fn from(input: serde_json::Error) -> ShellError {
ProximateShellError::String(StringError {
title: format!("{:?}", input),
error: Value::nothing(),
})
.start()
}
}
impl std::convert::From<regex::Error> for ShellError {
fn from(input: regex::Error) -> ShellError {
ProximateShellError::String(StringError {
title: format!("{:?}", input),
error: Value::nothing(),
})
.start()
}
}
impl std::convert::From<Box<dyn std::error::Error + Send + Sync>> for ShellError {
fn from(input: Box<dyn std::error::Error + Send + Sync>) -> ShellError {
ProximateShellError::String(StringError {
title: format!("{:?}", input),
error: Value::nothing(),
})
.start()
}
}
pub trait ShellErrorUtils<T> {
fn unwrap_error(self, desc: impl Into<String>) -> Result<T, ShellError>;
}
impl<T> ShellErrorUtils<Tagged<T>> for Option<Tagged<T>> {
fn unwrap_error(self, desc: impl Into<String>) -> Result<Tagged<T>, ShellError> {
match self {
Some(value) => Ok(value),
None => Err(ShellError::missing_value(None, desc.into())),
}
}
}