nushell/src/errors.rs
Yehuda Katz 1ad9d6f199 Overhaul the expansion system
The main thrust of this (very large) commit is an overhaul of the
expansion system.

The parsing pipeline is:

- Lightly parse the source file for atoms, basic delimiters and pipeline
  structure into a token tree
- Expand the token tree into a HIR (high-level intermediate
  representation) based upon the baseline syntax rules for expressions
  and the syntactic shape of commands.

Somewhat non-traditionally, nu doesn't have an AST at all. It goes
directly from the token tree, which doesn't represent many important
distinctions (like the difference between `hello` and `5KB`) directly
into a high-level representation that doesn't have a direct
correspondence to the source code.

At a high level, nu commands work like macros, in the sense that the
syntactic shape of the invocation of a command depends on the
definition of a command.

However, commands do not have the ability to perform unrestricted
expansions of the token tree. Instead, they describe their arguments in
terms of syntactic shapes, and the expander expands the token tree into
HIR based upon that definition.

For example, the `where` command says that it takes a block as its first
required argument, and the description of the block syntactic shape
expands the syntax `cpu > 10` into HIR that represents
`{ $it.cpu > 10 }`.

This commit overhauls that system so that the syntactic shapes are
described in terms of a few new traits (`ExpandSyntax` and
`ExpandExpression` are the primary ones) that are more composable than
the previous system.

The first big win of this new system is the addition of the `ColumnPath`
shape, which looks like `cpu."max ghz"` or `package.version`.
Previously, while a variable path could look like `$it.cpu."max ghz"`,
the tail of a variable path could not be easily reused in other
contexts. Now, that tail is its own syntactic shape, and it can be used
as part of a command's signature.

This cleans up commands like `inc`, `add` and `edit` as well as
shorthand blocks, which can now look like `| where cpu."max ghz" > 10`
2019-10-10 08:27:51 -07:00

685 lines
21 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),
}
}
}
#[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 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 {
pub(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()
}
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::String(StringError { title, .. }) => {
Diagnostic::new(Severity::Error, title)
}
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))
}
}
}
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 fn string(title: impl Into<String>) -> ShellError {
ProximateShellError::String(StringError::new(title.into(), Value::nothing())).start()
}
pub(crate) fn unimplemented(title: impl Into<String>) -> ShellError {
ShellError::string(&format!("Unimplemented: {}", title.into()))
}
pub(crate) fn unexpected(title: impl Into<String>) -> ShellError {
ShellError::string(&format!("Unexpected: {}", title.into()))
}
pub(crate) fn unreachable(title: impl Into<String>) -> ShellError {
ShellError::string(&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 {
String(StringError),
SyntaxError {
problem: Tagged<String>,
},
UnexpectedEof {
expected: String,
tag: Tag,
},
InvalidCommand {
command: Tag,
},
TypeError {
expected: String,
actual: Tagged<Option<String>>,
},
MissingProperty {
subpath: Description,
expr: Description,
},
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>,
},
}
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 {
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::String(s) => write!(f, "{}", &s.title),
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"),
}
}
}
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<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())),
}
}
}
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);