nushell/src/errors.rs
Yehuda Katz c2c10e2bc0 Overhaul the coloring system
This commit replaces the previous naive coloring system with a coloring
system that is more aligned with the parser.

The main benefit of this change is that it allows us to use parsing
rules to decide how to color tokens.

For example, consider the following syntax:

```
$ ps | where cpu > 10
```

Ideally, we could color `cpu` like a column name and not a string,
because `cpu > 10` is a shorthand block syntax that expands to
`{ $it.cpu > 10 }`.

The way that we know that it's a shorthand block is that the `where`
command declares that its first parameter is a `SyntaxShape::Block`,
which allows the shorthand block form.

In order to accomplish this, we need to color the tokens in a way that
corresponds to their expanded semantics, which means that high-fidelity
coloring requires expansion.

This commit adds a `ColorSyntax` trait that corresponds to the
`ExpandExpression` trait. The semantics are fairly similar, with a few
differences.

First `ExpandExpression` consumes N tokens and returns a single
`hir::Expression`. `ColorSyntax` consumes N tokens and writes M
`FlatShape` tokens to the output.

Concretely, for syntax like `[1 2 3]`

- `ExpandExpression` takes a single token node and produces a single
  `hir::Expression`
- `ColorSyntax` takes the same token node and emits 7 `FlatShape`s
  (open delimiter, int, whitespace, int, whitespace, int, close
  delimiter)

Second, `ColorSyntax` is more willing to plow through failures than
`ExpandExpression`.

In particular, consider syntax like

```
$ ps | where cpu >
```

In this case

- `ExpandExpression` will see that the `where` command is expecting a
  block, see that it's not a literal block and try to parse it as a
  shorthand block. It will successfully find a member followed by an
  infix operator, but not a following expression. That means that the
  entire pipeline part fails to parse and is a syntax error.
- `ColorSyntax` will also try to parse it as a shorthand block and
  ultimately fail, but it will fall back to "backoff coloring mode",
  which parsing any unidentified tokens in an unfallible, simple way. In
  this case, `cpu` will color as a string and `>` will color as an
  operator.

Finally, it's very important that coloring a pipeline infallibly colors
the entire string, doesn't fail, and doesn't get stuck in an infinite
loop.

In order to accomplish this, this PR separates `ColorSyntax`, which is
infallible from `FallibleColorSyntax`, which might fail. This allows the
type system to let us know if our coloring rules bottom out at at an
infallible rule.

It's not perfect: it's still possible for the coloring process to get
stuck or consume tokens non-atomically. I intend to reduce the
opportunity for those problems in a future commit. In the meantime, the
current system catches a number of mistakes (like trying to use a
fallible coloring rule in a loop without thinking about the possibility
that it will never terminate).
2019-10-10 19:30:04 -07:00

692 lines
22 KiB
Rust

use crate::prelude::*;
use crate::parser::parse::parser::TracableContext;
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 {
fn into_label(self) -> Result<Label<Tag>, String> {
match self {
Description::Source(s) => Ok(Label::new_primary(s.tag()).with_message(s.item)),
Description::Synthetic(s) => Err(s),
}
}
#[allow(unused)]
fn tag(&self) -> Tag {
match self {
Description::Source(tagged) => tagged.tag,
Description::Synthetic(_) => Tag::unknown(),
}
}
}
#[derive(Debug, Eq, PartialEq, Clone, Ord, PartialOrd, Serialize, Deserialize)]
pub enum ArgumentError {
MissingMandatoryFlag(String),
MissingMandatoryPositional(String),
MissingValueForName(String),
InvalidExternalWord,
}
#[derive(Debug, Eq, PartialEq, Clone, Ord, PartialOrd, Serialize, Deserialize)]
pub struct ShellError {
error: ProximateShellError,
cause: Option<Box<ProximateShellError>>,
}
impl ShellError {
#[allow(unused)]
pub(crate) fn tag(&self) -> Option<Tag> {
self.error.tag()
}
}
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::untagged_runtime_error(msg.to_string())
}
}
impl ShellError {
pub 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()
}
pub fn untagged_runtime_error(error: impl Into<String>) -> ShellError {
ProximateShellError::UntaggedRuntimeError {
reason: error.into(),
}
.start()
}
pub(crate) fn unexpected_eof(expected: impl Into<String>, tag: Tag) -> ShellError {
ProximateShellError::UnexpectedEof {
expected: expected.into(),
tag,
}
.start()
}
pub(crate) fn range_error(
expected: impl Into<ExpectedRange>,
actual: &Tagged<impl fmt::Debug>,
operation: String,
) -> ShellError {
ProximateShellError::RangeError {
kind: expected.into(),
actual_kind: actual.copy_tag(format!("{:?}", actual.item)),
operation,
}
.start()
}
pub(crate) fn syntax_error(problem: Tagged<impl Into<String>>) -> ShellError {
ProximateShellError::SyntaxError {
problem: problem.map(|p| p.into()),
}
.start()
}
#[allow(unused)]
pub(crate) fn invalid_command(problem: impl Into<Tag>) -> ShellError {
ProximateShellError::InvalidCommand {
command: problem.into(),
}
.start()
}
pub(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()
}
pub(crate) fn missing_value(tag: Option<Tag>, reason: impl Into<String>) -> ShellError {
ProximateShellError::MissingValue {
tag,
reason: reason.into(),
}
.start()
}
pub(crate) fn argument_error(
command: impl Into<String>,
kind: ArgumentError,
tag: Tag,
) -> ShellError {
ProximateShellError::ArgumentError {
command: command.into(),
error: kind,
tag,
}
.start()
}
pub(crate) fn invalid_external_word(tag: Tag) -> ShellError {
ProximateShellError::ArgumentError {
command: "Invalid argument to Nu command (did you mean to call an external command?)"
.into(),
error: ArgumentError::InvalidExternalWord,
tag,
}
.start()
}
pub(crate) fn parse_error(
error: nom::Err<(
nom_locate::LocatedSpanEx<&str, TracableContext>,
nom::error::ErrorKind,
)>,
) -> ShellError {
use language_reporting::*;
match error {
nom::Err::Incomplete(_) => {
// TODO: Get span of EOF
let diagnostic = Diagnostic::new(
Severity::Error,
format!("Parse Error: Unexpected end of line"),
);
ShellError::diagnostic(diagnostic)
}
nom::Err::Failure(span) | nom::Err::Error(span) => {
let diagnostic = Diagnostic::new(Severity::Error, format!("Parse Error"))
.with_label(Label::new_primary(Tag::from(span.0)));
ShellError::diagnostic(diagnostic)
}
}
}
pub(crate) fn diagnostic(diagnostic: Diagnostic<Tag>) -> ShellError {
ProximateShellError::Diagnostic(ShellDiagnostic { diagnostic }).start()
}
pub(crate) fn to_diagnostic(self) -> Diagnostic<Tag> {
match self.error {
ProximateShellError::InvalidCommand { command } => {
Diagnostic::new(Severity::Error, "Invalid command")
.with_label(Label::new_primary(command))
}
ProximateShellError::MissingValue { tag, reason } => {
let mut d = Diagnostic::new(
Severity::Bug,
format!("Internal Error (missing value) :: {}", reason),
);
if let Some(tag) = tag {
d = d.with_label(Label::new_primary(tag));
}
d
}
ProximateShellError::ArgumentError {
command,
error,
tag,
} => match error {
ArgumentError::InvalidExternalWord => Diagnostic::new(
Severity::Error,
format!("Invalid bare word for Nu command (did you intend to invoke an external command?)"))
.with_label(Label::new_primary(tag)),
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(tag)),
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(tag).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(tag)),
},
ProximateShellError::TypeError {
expected,
actual:
Tagged {
item: Some(actual),
tag,
},
} => Diagnostic::new(Severity::Error, "Type Error").with_label(
Label::new_primary(tag)
.with_message(format!("Expected {}, found {}", expected, actual)),
),
ProximateShellError::TypeError {
expected,
actual:
Tagged {
item: None,
tag
},
} => Diagnostic::new(Severity::Error, "Type Error")
.with_label(Label::new_primary(tag).with_message(expected)),
ProximateShellError::UnexpectedEof {
expected, tag
} => Diagnostic::new(Severity::Error, format!("Unexpected end of input"))
.with_label(Label::new_primary(tag).with_message(format!("Expected {}", expected))),
ProximateShellError::RangeError {
kind,
operation,
actual_kind:
Tagged {
item,
tag
},
} => Diagnostic::new(Severity::Error, "Range Error").with_label(
Label::new_primary(tag).with_message(format!(
"Expected to convert {} to {} while {}, but it was out of range",
item,
kind.desc(),
operation
)),
),
ProximateShellError::SyntaxError {
problem:
Tagged {
tag,
item
},
} => Diagnostic::new(Severity::Error, "Syntax Error")
.with_label(Label::new_primary(tag).with_message(item)),
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.tag()).with_message(left.item))
.with_label(Label::new_secondary(right.tag()).with_message(right.item))
}
ProximateShellError::UntaggedRuntimeError { reason } => Diagnostic::new(Severity::Error, format!("Error: {}", reason))
}
}
pub fn labeled_error(
msg: impl Into<String>,
label: impl Into<String>,
tag: impl Into<Tag>,
) -> ShellError {
ShellError::diagnostic(
Diagnostic::new(Severity::Error, msg.into())
.with_label(Label::new_primary(tag.into()).with_message(label.into())),
)
}
pub fn labeled_error_with_secondary(
msg: impl Into<String>,
primary_label: impl Into<String>,
primary_span: impl Into<Tag>,
secondary_label: impl Into<String>,
secondary_span: impl Into<Tag>,
) -> ShellError {
ShellError::diagnostic(
Diagnostic::new_error(msg.into())
.with_label(
Label::new_primary(primary_span.into()).with_message(primary_label.into()),
)
.with_label(
Label::new_secondary(secondary_span.into())
.with_message(secondary_label.into()),
),
)
}
pub(crate) fn unimplemented(title: impl Into<String>) -> ShellError {
ShellError::untagged_runtime_error(&format!("Unimplemented: {}", title.into()))
}
pub(crate) fn unexpected(title: impl Into<String>) -> ShellError {
ShellError::untagged_runtime_error(&format!("Unexpected: {}", title.into()))
}
pub(crate) fn unreachable(title: impl Into<String>) -> ShellError {
ShellError::untagged_runtime_error(&format!("BUG: Unreachable: {}", title.into()))
}
}
#[derive(Debug, Eq, PartialEq, Clone, Ord, PartialOrd, Serialize, Deserialize)]
pub enum ExpectedRange {
I8,
I16,
I32,
I64,
I128,
U8,
U16,
U32,
U64,
U128,
F32,
F64,
BigInt,
BigDecimal,
}
impl ExpectedRange {
fn desc(&self) -> &'static str {
match self {
ExpectedRange::I8 => "an 8-bit signed integer",
ExpectedRange::I16 => "a 16-bit signed integer",
ExpectedRange::I32 => "a 32-bit signed integer",
ExpectedRange::I64 => "a 64-bit signed integer",
ExpectedRange::I128 => "a 128-bit signed integer",
ExpectedRange::U8 => "an 8-bit unsigned integer",
ExpectedRange::U16 => "a 16-bit unsigned integer",
ExpectedRange::U32 => "a 32-bit unsigned integer",
ExpectedRange::U64 => "a 64-bit unsigned integer",
ExpectedRange::U128 => "a 128-bit unsigned integer",
ExpectedRange::F32 => "a 32-bit float",
ExpectedRange::F64 => "a 64-bit float",
ExpectedRange::BigDecimal => "a decimal",
ExpectedRange::BigInt => "an integer",
}
}
}
#[derive(Debug, Eq, PartialEq, Clone, Ord, PartialOrd, Serialize, Deserialize)]
pub enum ProximateShellError {
SyntaxError {
problem: Tagged<String>,
},
UnexpectedEof {
expected: String,
tag: Tag,
},
InvalidCommand {
command: Tag,
},
TypeError {
expected: String,
actual: Tagged<Option<String>>,
},
MissingProperty {
subpath: Description,
expr: Description,
tag: Tag,
},
MissingValue {
tag: Option<Tag>,
reason: String,
},
ArgumentError {
command: String,
error: ArgumentError,
tag: Tag,
},
RangeError {
kind: ExpectedRange,
actual_kind: Tagged<String>,
operation: String,
},
Diagnostic(ShellDiagnostic),
CoerceError {
left: Tagged<String>,
right: Tagged<String>,
},
UntaggedRuntimeError {
reason: String,
},
}
impl ProximateShellError {
fn start(self) -> ShellError {
ShellError {
cause: None,
error: self,
}
}
pub(crate) fn tag(&self) -> Option<Tag> {
Some(match self {
ProximateShellError::SyntaxError { problem } => problem.tag(),
ProximateShellError::UnexpectedEof { tag, .. } => *tag,
ProximateShellError::InvalidCommand { command } => *command,
ProximateShellError::TypeError { actual, .. } => actual.tag,
ProximateShellError::MissingProperty { tag, .. } => *tag,
ProximateShellError::MissingValue { tag, .. } => return *tag,
ProximateShellError::ArgumentError { tag, .. } => *tag,
ProximateShellError::RangeError { actual_kind, .. } => actual_kind.tag,
ProximateShellError::Diagnostic(..) => return None,
ProximateShellError::UntaggedRuntimeError { .. } => return None,
ProximateShellError::CoerceError { left, right } => left.tag.until(right.tag),
})
}
}
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 {
pub(crate) diagnostic: Diagnostic<Tag>,
}
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::MissingValue { .. } => write!(f, "MissingValue"),
ProximateShellError::InvalidCommand { .. } => write!(f, "InvalidCommand"),
ProximateShellError::TypeError { .. } => write!(f, "TypeError"),
ProximateShellError::UnexpectedEof { .. } => write!(f, "UnexpectedEof"),
ProximateShellError::RangeError { .. } => write!(f, "RangeError"),
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"),
ProximateShellError::UntaggedRuntimeError { .. } => write!(f, "UntaggedRuntimeError"),
}
}
}
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 {
ShellError::untagged_runtime_error(format!("{}", input))
}
}
impl std::convert::From<std::io::Error> for ShellError {
fn from(input: std::io::Error) -> ShellError {
ShellError::untagged_runtime_error(format!("{}", input))
}
}
impl std::convert::From<subprocess::PopenError> for ShellError {
fn from(input: subprocess::PopenError) -> ShellError {
ShellError::untagged_runtime_error(format!("{}", input))
}
}
impl std::convert::From<serde_yaml::Error> for ShellError {
fn from(input: serde_yaml::Error) -> ShellError {
ShellError::untagged_runtime_error(format!("{:?}", input))
}
}
impl std::convert::From<toml::ser::Error> for ShellError {
fn from(input: toml::ser::Error) -> ShellError {
ShellError::untagged_runtime_error(format!("{:?}", input))
}
}
impl std::convert::From<serde_json::Error> for ShellError {
fn from(input: serde_json::Error) -> ShellError {
ShellError::untagged_runtime_error(format!("{:?}", input))
}
}
impl std::convert::From<Box<dyn std::error::Error + Send + Sync>> for ShellError {
fn from(input: Box<dyn std::error::Error + Send + Sync>) -> ShellError {
ShellError::untagged_runtime_error(format!("{:?}", input))
}
}
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())),
}
}
}
pub trait CoerceInto<U> {
fn coerce_into(self, operation: impl Into<String>) -> Result<U, ShellError>;
}
trait ToExpectedRange {
fn to_expected_range() -> ExpectedRange;
}
macro_rules! ranged_int {
($ty:tt -> $op:tt -> $variant:tt) => {
impl ToExpectedRange for $ty {
fn to_expected_range() -> ExpectedRange {
ExpectedRange::$variant
}
}
impl CoerceInto<$ty> for Tagged<BigInt> {
fn coerce_into(self, operation: impl Into<String>) -> Result<$ty, ShellError> {
match self.$op() {
Some(v) => Ok(v),
None => Err(ShellError::range_error(
$ty::to_expected_range(),
&self,
operation.into(),
)),
}
}
}
impl CoerceInto<$ty> for Tagged<&BigInt> {
fn coerce_into(self, operation: impl Into<String>) -> Result<$ty, ShellError> {
match self.$op() {
Some(v) => Ok(v),
None => Err(ShellError::range_error(
$ty::to_expected_range(),
&self,
operation.into(),
)),
}
}
}
};
}
ranged_int!(u8 -> to_u8 -> U8);
ranged_int!(u16 -> to_u16 -> U16);
ranged_int!(u32 -> to_u32 -> U32);
ranged_int!(u64 -> to_u64 -> U64);
ranged_int!(i8 -> to_i8 -> I8);
ranged_int!(i16 -> to_i16 -> I16);
ranged_int!(i32 -> to_i32 -> I32);
ranged_int!(i64 -> to_i64 -> I64);
macro_rules! ranged_decimal {
($ty:tt -> $op:tt -> $variant:tt) => {
impl ToExpectedRange for $ty {
fn to_expected_range() -> ExpectedRange {
ExpectedRange::$variant
}
}
impl CoerceInto<$ty> for Tagged<BigDecimal> {
fn coerce_into(self, operation: impl Into<String>) -> Result<$ty, ShellError> {
match self.$op() {
Some(v) => Ok(v),
None => Err(ShellError::range_error(
$ty::to_expected_range(),
&self,
operation.into(),
)),
}
}
}
impl CoerceInto<$ty> for Tagged<&BigDecimal> {
fn coerce_into(self, operation: impl Into<String>) -> Result<$ty, ShellError> {
match self.$op() {
Some(v) => Ok(v),
None => Err(ShellError::range_error(
$ty::to_expected_range(),
&self,
operation.into(),
)),
}
}
}
};
}
ranged_decimal!(f32 -> to_f32 -> F32);
ranged_decimal!(f64 -> to_f64 -> F64);