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internal: Split unresolve proc-macro error out of mbe

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This commit is contained in:
Lukas Wirth 2022-02-21 19:14:06 +01:00
parent b663b733d9
commit 1505b6a9b4
13 changed files with 147 additions and 104 deletions
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6
crates/hir_def/src/body.rs
View file

@ -97,9 +97,9 @@ impl Expander {
) -> Result<ExpandResult<Option<(Mark, T)>>, UnresolvedMacro> {
if self.recursion_limit(db).check(self.recursion_limit + 1).is_err() {
cov_mark::hit!(your_stack_belongs_to_me);
return Ok(ExpandResult::str_err(
return Ok(ExpandResult::only_err(ExpandError::Other(
"reached recursion limit during macro expansion".into(),
));
)));
}
let macro_call = InFile::new(self.current_file_id, &macro_call);
@ -151,7 +151,7 @@ impl Expander {
}
return ExpandResult::only_err(err.unwrap_or_else(|| {
mbe::ExpandError::Other("failed to parse macro invocation".into())
ExpandError::Other("failed to parse macro invocation".into())
}));
}
};

12
crates/hir_def/src/lib.rs
View file

@ -63,8 +63,8 @@ use hir_expand::{
ast_id_map::FileAstId,
eager::{expand_eager_macro, ErrorEmitted, ErrorSink},
hygiene::Hygiene,
AstId, ExpandTo, HirFileId, InFile, MacroCallId, MacroCallKind, MacroDefId, MacroDefKind,
UnresolvedMacro,
AstId, ExpandError, ExpandTo, HirFileId, InFile, MacroCallId, MacroCallKind, MacroDefId,
MacroDefKind, UnresolvedMacro,
};
use item_tree::ExternBlock;
use la_arena::Idx;
@ -662,7 +662,7 @@ pub trait AsMacroCall {
db: &dyn db::DefDatabase,
krate: CrateId,
resolver: impl Fn(path::ModPath) -> Option<MacroDefId>,
error_sink: &mut dyn FnMut(mbe::ExpandError),
error_sink: &mut dyn FnMut(ExpandError),
) -> Result<Result<MacroCallId, ErrorEmitted>, UnresolvedMacro>;
}
@ -672,7 +672,7 @@ impl AsMacroCall for InFile<&ast::MacroCall> {
db: &dyn db::DefDatabase,
krate: CrateId,
resolver: impl Fn(path::ModPath) -> Option<MacroDefId>,
mut error_sink: &mut dyn FnMut(mbe::ExpandError),
mut error_sink: &mut dyn FnMut(ExpandError),
) -> Result<Result<MacroCallId, ErrorEmitted>, UnresolvedMacro> {
let expands_to = hir_expand::ExpandTo::from_call_site(self.value);
let ast_id = AstId::new(self.file_id, db.ast_id_map(self.file_id).ast_id(self.value));
@ -681,7 +681,7 @@ impl AsMacroCall for InFile<&ast::MacroCall> {
self.value.path().and_then(|path| path::ModPath::from_src(db.upcast(), path, &h));
let path = match error_sink
.option(path, || mbe::ExpandError::Other("malformed macro invocation".into()))
.option(path, || ExpandError::Other("malformed macro invocation".into()))
{
Ok(path) => path,
Err(error) => {
@ -719,7 +719,7 @@ fn macro_call_as_call_id(
db: &dyn db::DefDatabase,
krate: CrateId,
resolver: impl Fn(path::ModPath) -> Option<MacroDefId>,
error_sink: &mut dyn FnMut(mbe::ExpandError),
error_sink: &mut dyn FnMut(ExpandError),
) -> Result<Result<MacroCallId, ErrorEmitted>, UnresolvedMacro> {
let def: MacroDefId =
resolver(call.path.clone()).ok_or_else(|| UnresolvedMacro { path: call.path.clone() })?;

5
crates/hir_expand/src/builtin_attr_macro.rs
View file

@ -1,9 +1,10 @@
//! Builtin attributes.
use mbe::ExpandResult;
use syntax::ast;
use crate::{db::AstDatabase, name, AstId, CrateId, MacroCallId, MacroDefId, MacroDefKind};
use crate::{
db::AstDatabase, name, AstId, CrateId, ExpandResult, MacroCallId, MacroDefId, MacroDefKind,
};
macro_rules! register_builtin {
( $(($name:ident, $variant:ident) => $expand:ident),* ) => {

26
crates/hir_expand/src/builtin_derive_macro.rs
View file

@ -2,13 +2,16 @@
use tracing::debug;
use mbe::ExpandResult;
use syntax::{
ast::{self, AstNode, HasGenericParams, HasModuleItem, HasName},
match_ast,
};
use tt::TokenId;
use crate::{db::AstDatabase, name, quote, AstId, CrateId, MacroCallId, MacroDefId, MacroDefKind};
use crate::{
db::AstDatabase, name, quote, AstId, CrateId, ExpandError, ExpandResult, MacroCallId,
MacroDefId, MacroDefKind,
};
macro_rules! register_builtin {
( $($trait:ident => $expand:ident),* ) => {
@ -71,15 +74,15 @@ struct BasicAdtInfo {
type_params: usize,
}
fn parse_adt(tt: &tt::Subtree) -> Result<BasicAdtInfo, mbe::ExpandError> {
let (parsed, token_map) = mbe::token_tree_to_syntax_node(tt, mbe::TopEntryPoint::MacroItems); // FragmentKind::Items doesn't parse attrs?
fn parse_adt(tt: &tt::Subtree) -> Result<BasicAdtInfo, ExpandError> {
let (parsed, token_map) = mbe::token_tree_to_syntax_node(tt, mbe::TopEntryPoint::MacroItems);
let macro_items = ast::MacroItems::cast(parsed.syntax_node()).ok_or_else(|| {
debug!("derive node didn't parse");
mbe::ExpandError::UnexpectedToken
ExpandError::Other("invalid item definition".into())
})?;
let item = macro_items.items().next().ok_or_else(|| {
debug!("no module item parsed");
mbe::ExpandError::NoMatchingRule
ExpandError::Other("no item found".into())
})?;
let node = item.syntax();
let (name, params) = match_ast! {
@ -89,18 +92,17 @@ fn parse_adt(tt: &tt::Subtree) -> Result<BasicAdtInfo, mbe::ExpandError> {
ast::Union(it) => (it.name(), it.generic_param_list()),
_ => {
debug!("unexpected node is {:?}", node);
return Err(mbe::ExpandError::ConversionError)
return Err(ExpandError::Other("expected struct, enum or union".into()))
},
}
};
let name = name.ok_or_else(|| {
debug!("parsed item has no name");
mbe::ExpandError::NoMatchingRule
})?;
let name_token_id = token_map.token_by_range(name.syntax().text_range()).ok_or_else(|| {
debug!("name token not found");
mbe::ExpandError::ConversionError
ExpandError::Other("missing name".into())
})?;
let name_token_id = token_map
.token_by_range(name.syntax().text_range())
.unwrap_or_else(|| TokenId::unspecified());
let name_token = tt::Ident { id: name_token_id, text: name.text().into() };
let type_params = params.map_or(0, |type_param_list| type_param_list.type_params().count());
Ok(BasicAdtInfo { name: name_token, type_params })

39
crates/hir_expand/src/builtin_fn_macro.rs
View file

@ -1,15 +1,16 @@
//! Builtin macro
use crate::{
db::AstDatabase, name, quote, AstId, CrateId, MacroCallId, MacroCallLoc, MacroDefId,
MacroDefKind,
};
use base_db::{AnchoredPath, Edition, FileId};
use cfg::CfgExpr;
use either::Either;
use mbe::{parse_exprs_with_sep, parse_to_token_tree, ExpandResult};
use mbe::{parse_exprs_with_sep, parse_to_token_tree};
use syntax::ast::{self, AstToken};
use crate::{
db::AstDatabase, name, quote, AstId, CrateId, ExpandError, ExpandResult, MacroCallId,
MacroCallLoc, MacroDefId, MacroDefKind,
};
macro_rules! register_builtin {
( LAZY: $(($name:ident, $kind: ident) => $expand:ident),* , EAGER: $(($e_name:ident, $e_kind: ident) => $e_expand:ident),* ) => {
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
@ -257,7 +258,7 @@ fn format_args_expand(
let mut args = parse_exprs_with_sep(tt, ',');
if args.is_empty() {
return ExpandResult::only_err(mbe::ExpandError::NoMatchingRule);
return ExpandResult::only_err(mbe::ExpandError::NoMatchingRule.into());
}
for arg in &mut args {
// Remove `key =`.
@ -368,12 +369,12 @@ fn compile_error_expand(
let text = it.text.as_str();
if text.starts_with('"') && text.ends_with('"') {
// FIXME: does not handle raw strings
mbe::ExpandError::Other(text[1..text.len() - 1].into())
ExpandError::Other(text[1..text.len() - 1].into())
} else {
mbe::ExpandError::BindingError("`compile_error!` argument must be a string".into())
ExpandError::Other("`compile_error!` argument must be a string".into())
}
}
_ => mbe::ExpandError::BindingError("`compile_error!` argument must be a string".into()),
_ => ExpandError::Other("`compile_error!` argument must be a string".into()),
};
ExpandResult { value: ExpandedEager::new(quote! {}), err: Some(err) }
@ -414,7 +415,7 @@ fn concat_expand(
}
tt::TokenTree::Leaf(tt::Leaf::Punct(punct)) if i % 2 == 1 && punct.char == ',' => (),
_ => {
err.get_or_insert(mbe::ExpandError::UnexpectedToken);
err.get_or_insert(mbe::ExpandError::UnexpectedToken.into());
}
}
}
@ -435,7 +436,7 @@ fn concat_idents_expand(
}
tt::TokenTree::Leaf(tt::Leaf::Punct(punct)) if i % 2 == 1 && punct.char == ',' => (),
_ => {
err.get_or_insert(mbe::ExpandError::UnexpectedToken);
err.get_or_insert(mbe::ExpandError::UnexpectedToken.into());
}
}
}
@ -448,28 +449,28 @@ fn relative_file(
call_id: MacroCallId,
path_str: &str,
allow_recursion: bool,
) -> Result<FileId, mbe::ExpandError> {
) -> Result<FileId, ExpandError> {
let call_site = call_id.as_file().original_file(db);
let path = AnchoredPath { anchor: call_site, path: path_str };
let res = db.resolve_path(path).ok_or_else(|| {
mbe::ExpandError::Other(format!("failed to load file `{path_str}`").into())
})?;
let res = db
.resolve_path(path)
.ok_or_else(|| ExpandError::Other(format!("failed to load file `{path_str}`").into()))?;
// Prevent include itself
if res == call_site && !allow_recursion {
Err(mbe::ExpandError::Other(format!("recursive inclusion of `{path_str}`").into()))
Err(ExpandError::Other(format!("recursive inclusion of `{path_str}`").into()))
} else {
Ok(res)
}
}
fn parse_string(tt: &tt::Subtree) -> Result<String, mbe::ExpandError> {
fn parse_string(tt: &tt::Subtree) -> Result<String, ExpandError> {
tt.token_trees
.get(0)
.and_then(|tt| match tt {
tt::TokenTree::Leaf(tt::Leaf::Literal(it)) => unquote_str(it),
_ => None,
})
.ok_or(mbe::ExpandError::ConversionError)
.ok_or(mbe::ExpandError::ConversionError.into())
}
fn include_expand(
@ -561,7 +562,7 @@ fn env_expand(
// The only variable rust-analyzer ever sets is `OUT_DIR`, so only diagnose that to avoid
// unnecessary diagnostics for eg. `CARGO_PKG_NAME`.
if key == "OUT_DIR" {
err = Some(mbe::ExpandError::Other(
err = Some(ExpandError::Other(
r#"`OUT_DIR` not set, enable "run build scripts" to fix"#.into(),
));
}

40
crates/hir_expand/src/db.rs
View file

@ -5,7 +5,7 @@ use std::sync::Arc;
use base_db::{salsa, SourceDatabase};
use either::Either;
use limit::Limit;
use mbe::{syntax_node_to_token_tree, ExpandError, ExpandResult};
use mbe::syntax_node_to_token_tree;
use rustc_hash::FxHashSet;
use syntax::{
algo::diff,
@ -15,8 +15,9 @@ use syntax::{
use crate::{
ast_id_map::AstIdMap, fixup, hygiene::HygieneFrame, BuiltinAttrExpander, BuiltinDeriveExpander,
BuiltinFnLikeExpander, ExpandTo, HirFileId, HirFileIdRepr, MacroCallId, MacroCallKind,
MacroCallLoc, MacroDefId, MacroDefKind, MacroFile, ProcMacroExpander,
BuiltinFnLikeExpander, ExpandError, ExpandResult, ExpandTo, HirFileId, HirFileIdRepr,
MacroCallId, MacroCallKind, MacroCallLoc, MacroDefId, MacroDefKind, MacroFile,
ProcMacroExpander,
};
/// Total limit on the number of tokens produced by any macro invocation.
@ -47,10 +48,10 @@ impl TokenExpander {
db: &dyn AstDatabase,
id: MacroCallId,
tt: &tt::Subtree,
) -> mbe::ExpandResult<tt::Subtree> {
) -> ExpandResult<tt::Subtree> {
match self {
TokenExpander::DeclarativeMacro { mac, .. } => mac.expand(tt),
TokenExpander::Builtin(it) => it.expand(db, id, tt),
TokenExpander::DeclarativeMacro { mac, .. } => mac.expand(tt).map_err(Into::into),
TokenExpander::Builtin(it) => it.expand(db, id, tt).map_err(Into::into),
TokenExpander::BuiltinAttr(it) => it.expand(db, id, tt),
TokenExpander::BuiltinDerive(it) => it.expand(db, id, tt),
TokenExpander::ProcMacro(_) => {
@ -432,7 +433,11 @@ fn macro_expand(db: &dyn AstDatabase, id: MacroCallId) -> ExpandResult<Option<Ar
let macro_arg = match db.macro_arg(id) {
Some(it) => it,
None => return ExpandResult::str_err("Failed to lower macro args to token tree".into()),
None => {
return ExpandResult::only_err(ExpandError::Other(
"Failed to lower macro args to token tree".into(),
))
}
};
let expander = match db.macro_def(loc.def) {
@ -440,16 +445,23 @@ fn macro_expand(db: &dyn AstDatabase, id: MacroCallId) -> ExpandResult<Option<Ar
// FIXME: This is weird -- we effectively report macro *definition*
// errors lazily, when we try to expand the macro. Instead, they should
// be reported at the definition site (when we construct a def map).
Err(err) => return ExpandResult::str_err(format!("invalid macro definition: {}", err)),
Err(err) => {
return ExpandResult::only_err(ExpandError::Other(
format!("invalid macro definition: {}", err).into(),
))
}
};
let ExpandResult { value: mut tt, err } = expander.expand(db, id, &macro_arg.0);
// Set a hard limit for the expanded tt
let count = tt.count();
if TOKEN_LIMIT.check(count).is_err() {
return ExpandResult::str_err(format!(
"macro invocation exceeds token limit: produced {} tokens, limit is {}",
count,
TOKEN_LIMIT.inner(),
return ExpandResult::only_err(ExpandError::Other(
format!(
"macro invocation exceeds token limit: produced {} tokens, limit is {}",
count,
TOKEN_LIMIT.inner(),
)
.into(),
));
}
@ -466,7 +478,9 @@ fn expand_proc_macro(db: &dyn AstDatabase, id: MacroCallId) -> ExpandResult<tt::
let loc: MacroCallLoc = db.lookup_intern_macro_call(id);
let macro_arg = match db.macro_arg(id) {
Some(it) => it,
None => return ExpandResult::str_err("No arguments for proc-macro".to_string()),
None => {
return ExpandResult::only_err(ExpandError::Other("No arguments for proc-macro".into()))
}
};
let expander = match loc.def.kind {

25
crates/hir_expand/src/eager.rs
View file

@ -21,7 +21,6 @@
use std::sync::Arc;
use base_db::CrateId;
use mbe::ExpandResult;
use syntax::{ted, SyntaxNode};
use crate::{
@ -29,8 +28,8 @@ use crate::{
db::AstDatabase,
hygiene::Hygiene,
mod_path::ModPath,
EagerCallInfo, ExpandTo, InFile, MacroCallId, MacroCallKind, MacroCallLoc, MacroDefId,
MacroDefKind, UnresolvedMacro,
EagerCallInfo, ExpandError, ExpandResult, ExpandTo, InFile, MacroCallId, MacroCallKind,
MacroCallLoc, MacroDefId, MacroDefKind, UnresolvedMacro,
};
#[derive(Debug)]
@ -39,12 +38,12 @@ pub struct ErrorEmitted {
}
pub trait ErrorSink {
fn emit(&mut self, err: mbe::ExpandError);
fn emit(&mut self, err: ExpandError);
fn option<T>(
&mut self,
opt: Option<T>,
error: impl FnOnce() -> mbe::ExpandError,
error: impl FnOnce() -> ExpandError,
) -> Result<T, ErrorEmitted> {
match opt {
Some(it) => Ok(it),
@ -58,12 +57,12 @@ pub trait ErrorSink {
fn option_with<T>(
&mut self,
opt: impl FnOnce() -> Option<T>,
error: impl FnOnce() -> mbe::ExpandError,
error: impl FnOnce() -> ExpandError,
) -> Result<T, ErrorEmitted> {
self.option(opt(), error)
}
fn result<T>(&mut self, res: Result<T, mbe::ExpandError>) -> Result<T, ErrorEmitted> {
fn result<T>(&mut self, res: Result<T, ExpandError>) -> Result<T, ErrorEmitted> {
match res {
Ok(it) => Ok(it),
Err(e) => {
@ -90,8 +89,8 @@ pub trait ErrorSink {
}
}
impl ErrorSink for &'_ mut dyn FnMut(mbe::ExpandError) {
fn emit(&mut self, err: mbe::ExpandError) {
impl ErrorSink for &'_ mut dyn FnMut(ExpandError) {
fn emit(&mut self, err: ExpandError) {
self(err);
}
}
@ -102,7 +101,7 @@ pub fn expand_eager_macro(
macro_call: InFile<ast::MacroCall>,
def: MacroDefId,
resolver: &dyn Fn(ModPath) -> Option<MacroDefId>,
diagnostic_sink: &mut dyn FnMut(mbe::ExpandError),
diagnostic_sink: &mut dyn FnMut(ExpandError),
) -> Result<Result<MacroCallId, ErrorEmitted>, UnresolvedMacro> {
let hygiene = Hygiene::new(db, macro_call.file_id);
let parsed_args = macro_call
@ -147,7 +146,7 @@ pub fn expand_eager_macro(
if let MacroDefKind::BuiltInEager(eager, _) = def.kind {
let res = eager.expand(db, arg_id, &subtree);
if let Some(err) = res.err {
diagnostic_sink(err);
diagnostic_sink(err.into());
}
let loc = MacroCallLoc {
@ -199,7 +198,7 @@ fn eager_macro_recur(
curr: InFile<SyntaxNode>,
krate: CrateId,
macro_resolver: &dyn Fn(ModPath) -> Option<MacroDefId>,
mut diagnostic_sink: &mut dyn FnMut(mbe::ExpandError),
mut diagnostic_sink: &mut dyn FnMut(ExpandError),
) -> Result<Result<SyntaxNode, ErrorEmitted>, UnresolvedMacro> {
let original = curr.value.clone_for_update();
@ -211,7 +210,7 @@ fn eager_macro_recur(
let def = match child.path().and_then(|path| ModPath::from_src(db, path, &hygiene)) {
Some(path) => macro_resolver(path.clone()).ok_or_else(|| UnresolvedMacro { path })?,
None => {
diagnostic_sink(mbe::ExpandError::Other("malformed macro invocation".into()));
diagnostic_sink(ExpandError::Other("malformed macro invocation".into()));
continue;
}
};

29
crates/hir_expand/src/lib.rs
View file

@ -17,9 +17,9 @@ pub mod eager;
pub mod mod_path;
mod fixup;
pub use mbe::{ExpandError, ExpandResult, Origin};
pub use mbe::{Origin, ValueResult};
use std::{hash::Hash, iter, sync::Arc};
use std::{fmt, hash::Hash, iter, sync::Arc};
use base_db::{impl_intern_key, salsa, CrateId, FileId, FileRange, ProcMacroKind};
use either::Either;
@ -39,6 +39,31 @@ use crate::{
proc_macro::ProcMacroExpander,
};
pub type ExpandResult<T> = ValueResult<T, ExpandError>;
#[derive(Debug, PartialEq, Eq, Clone)]
pub enum ExpandError {
UnresolvedProcMacro,
Mbe(mbe::ExpandError),
Other(Box<str>),
}
impl From<mbe::ExpandError> for ExpandError {
fn from(mbe: mbe::ExpandError) -> Self {
Self::Mbe(mbe)
}
}
impl fmt::Display for ExpandError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
ExpandError::UnresolvedProcMacro => f.write_str("unresolved proc-macro"),
ExpandError::Mbe(it) => it.fmt(f),
ExpandError::Other(it) => f.write_str(it),
}
}
}
/// Input to the analyzer is a set of files, where each file is identified by
/// `FileId` and contains source code. However, another source of source code in
/// Rust are macros: each macro can be thought of as producing a "temporary

15
crates/hir_expand/src/proc_macro.rs
View file

@ -1,9 +1,8 @@
//! Proc Macro Expander stub
use base_db::{CrateId, ProcMacroExpansionError, ProcMacroId, ProcMacroKind};
use mbe::ExpandResult;
use crate::db::AstDatabase;
use crate::{db::AstDatabase, ExpandError, ExpandResult};
#[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)]
pub struct ProcMacroExpander {
@ -37,7 +36,11 @@ impl ProcMacroExpander {
let krate_graph = db.crate_graph();
let proc_macro = match krate_graph[self.krate].proc_macro.get(id.0 as usize) {
Some(proc_macro) => proc_macro,
None => return ExpandResult::str_err("No proc-macro found.".to_string()),
None => {
return ExpandResult::only_err(ExpandError::Other(
"No proc-macro found.".into(),
))
}
};
// Proc macros have access to the environment variables of the invoking crate.
@ -51,17 +54,17 @@ impl ProcMacroExpander {
{
ExpandResult {
value: tt.clone(),
err: Some(mbe::ExpandError::Other(text.into())),
err: Some(ExpandError::Other(text.into())),
}
}
ProcMacroExpansionError::System(text)
| ProcMacroExpansionError::Panic(text) => {
ExpandResult::only_err(mbe::ExpandError::Other(text.into()))
ExpandResult::only_err(ExpandError::Other(text.into()))
}
},
}
}
None => ExpandResult::only_err(mbe::ExpandError::UnresolvedProcMacro),
None => ExpandResult::only_err(ExpandError::UnresolvedProcMacro),
}
}
}

4
crates/mbe/src/expander/matcher.rs
View file

@ -599,7 +599,7 @@ fn match_loop(pattern: &MetaTemplate, src: &tt::Subtree) -> Match {
src = it;
res.unmatched_tts += src.len();
}
res.add_err(ExpandError::binding_error("leftover tokens"));
res.add_err(ExpandError::LeftoverTokens);
if let Some(error_reover_item) = error_recover_item {
res.bindings = bindings_builder.build(&error_reover_item);
@ -658,7 +658,7 @@ fn match_loop(pattern: &MetaTemplate, src: &tt::Subtree) -> Match {
fn match_leaf(lhs: &tt::Leaf, src: &mut TtIter) -> Result<(), ExpandError> {
let rhs = src
.expect_leaf()
.map_err(|()| ExpandError::BindingError(format!("expected leaf: `{lhs}`").into()))?;
.map_err(|()| ExpandError::binding_error(format!("expected leaf: `{lhs}`")))?;
match (lhs, rhs) {
(
tt::Leaf::Punct(tt::Punct { char: lhs, .. }),

4
crates/mbe/src/expander/transcriber.rs
View file

@ -17,7 +17,7 @@ impl Bindings {
fn get(&self, name: &str, nesting: &mut [NestingState]) -> Result<&Fragment, ExpandError> {
macro_rules! binding_err {
($($arg:tt)*) => { ExpandError::BindingError(format!($($arg)*).into()) };
($($arg:tt)*) => { ExpandError::binding_error(format!($($arg)*)) };
}
let mut b: &Binding =
@ -178,7 +178,7 @@ fn expand_repeat(
);
return ExpandResult {
value: Fragment::Tokens(Subtree::default().into()),
err: Some(ExpandError::Other("Expand exceed limit".into())),
err: Some(ExpandError::LimitExceeded),
};
}

44
crates/mbe/src/lib.rs
View file

@ -67,18 +67,17 @@ impl fmt::Display for ParseError {
#[derive(Debug, PartialEq, Eq, Clone)]
pub enum ExpandError {
BindingError(Box<Box<str>>),
LeftoverTokens,
ConversionError,
LimitExceeded,
NoMatchingRule,
UnexpectedToken,
BindingError(Box<str>),
ConversionError,
// FIXME: no way mbe should know about proc macros.
UnresolvedProcMacro,
Other(Box<str>),
}
impl ExpandError {
fn binding_error(e: &str) -> ExpandError {
ExpandError::BindingError(e.into())
fn binding_error(e: impl Into<Box<str>>) -> ExpandError {
ExpandError::BindingError(Box::new(e.into()))
}
}
@ -89,8 +88,8 @@ impl fmt::Display for ExpandError {
ExpandError::UnexpectedToken => f.write_str("unexpected token in input"),
ExpandError::BindingError(e) => f.write_str(e),
ExpandError::ConversionError => f.write_str("could not convert tokens"),
ExpandError::UnresolvedProcMacro => f.write_str("unresolved proc macro"),
ExpandError::Other(e) => f.write_str(e),
ExpandError::LimitExceeded => f.write_str("Expand exceed limit"),
ExpandError::LeftoverTokens => f.write_str("leftover tokens"),
}
}
}
@ -311,42 +310,41 @@ fn validate(pattern: &MetaTemplate) -> Result<(), ParseError> {
Ok(())
}
pub type ExpandResult<T> = ValueResult<T, ExpandError>;
#[derive(Debug, Clone, Eq, PartialEq)]
pub struct ExpandResult<T> {
pub struct ValueResult<T, E> {
pub value: T,
pub err: Option<ExpandError>,
pub err: Option<E>,
}
impl<T> ExpandResult<T> {
impl<T, E> ValueResult<T, E> {
pub fn ok(value: T) -> Self {
Self { value, err: None }
}
pub fn only_err(err: ExpandError) -> Self
pub fn only_err(err: E) -> Self
where
T: Default,
{
Self { value: Default::default(), err: Some(err) }
}
pub fn str_err(err: String) -> Self
where
T: Default,
{
Self::only_err(ExpandError::Other(err.into()))
pub fn map<U>(self, f: impl FnOnce(T) -> U) -> ValueResult<U, E> {
ValueResult { value: f(self.value), err: self.err }
}
pub fn map<U>(self, f: impl FnOnce(T) -> U) -> ExpandResult<U> {
ExpandResult { value: f(self.value), err: self.err }
pub fn map_err<E2>(self, f: impl FnOnce(E) -> E2) -> ValueResult<T, E2> {
ValueResult { value: self.value, err: self.err.map(f) }
}
pub fn result(self) -> Result<T, ExpandError> {
pub fn result(self) -> Result<T, E> {
self.err.map_or(Ok(self.value), Err)
}
}
impl<T: Default> From<Result<T, ExpandError>> for ExpandResult<T> {
fn from(result: Result<T, ExpandError>) -> Self {
impl<T: Default, E> From<Result<T, E>> for ValueResult<T, E> {
fn from(result: Result<T, E>) -> Self {
result.map_or_else(Self::only_err, Self::ok)
}
}

2
crates/mbe/src/tt_iter.rs
View file

@ -106,7 +106,7 @@ impl<'a> TtIter<'a> {
}
let err = if error || !cursor.is_root() {
Some(ExpandError::BindingError(format!("expected {entry_point:?}").into()))
Some(ExpandError::binding_error(format!("expected {entry_point:?}")))
} else {
None
};