This commit is contained in:
Aleksey Kladov 2019-01-31 21:43:54 +03:00
parent 2d1f0b105d
commit a16f6bb27d
3 changed files with 42 additions and 40 deletions

View file

@ -1,13 +1,13 @@
use rustc_hash::FxHashMap; use rustc_hash::FxHashMap;
use ra_syntax::SmolStr; use ra_syntax::SmolStr;
use crate::{self as mbe, tt_cursor::TtCursor}; use crate::tt_cursor::TtCursor;
pub fn exapnd(rules: &mbe::MacroRules, input: &tt::Subtree) -> Option<tt::Subtree> { pub fn exapnd(rules: &crate::MacroRules, input: &tt::Subtree) -> Option<tt::Subtree> {
rules.rules.iter().find_map(|it| expand_rule(it, input)) rules.rules.iter().find_map(|it| expand_rule(it, input))
} }
fn expand_rule(rule: &mbe::Rule, input: &tt::Subtree) -> Option<tt::Subtree> { fn expand_rule(rule: &crate::Rule, input: &tt::Subtree) -> Option<tt::Subtree> {
let mut input = TtCursor::new(input); let mut input = TtCursor::new(input);
let bindings = match_lhs(&rule.lhs, &mut input)?; let bindings = match_lhs(&rule.lhs, &mut input)?;
expand_subtree(&rule.rhs, &bindings, &mut Vec::new()) expand_subtree(&rule.rhs, &bindings, &mut Vec::new())
@ -52,12 +52,12 @@ impl Bindings {
} }
} }
fn match_lhs(pattern: &mbe::Subtree, input: &mut TtCursor) -> Option<Bindings> { fn match_lhs(pattern: &crate::Subtree, input: &mut TtCursor) -> Option<Bindings> {
let mut res = Bindings::default(); let mut res = Bindings::default();
for pat in pattern.token_trees.iter() { for pat in pattern.token_trees.iter() {
match pat { match pat {
mbe::TokenTree::Leaf(leaf) => match leaf { crate::TokenTree::Leaf(leaf) => match leaf {
mbe::Leaf::Var(mbe::Var { text, kind }) => { crate::Leaf::Var(crate::Var { text, kind }) => {
let kind = kind.clone()?; let kind = kind.clone()?;
match kind.as_str() { match kind.as_str() {
"ident" => { "ident" => {
@ -70,14 +70,14 @@ fn match_lhs(pattern: &mbe::Subtree, input: &mut TtCursor) -> Option<Bindings> {
_ => return None, _ => return None,
} }
} }
mbe::Leaf::Punct(punct) => { crate::Leaf::Punct(punct) => {
if input.eat_punct()? != punct { if input.eat_punct()? != punct {
return None; return None;
} }
} }
_ => return None, _ => return None,
}, },
mbe::TokenTree::Repeat(mbe::Repeat { crate::TokenTree::Repeat(crate::Repeat {
subtree, subtree,
kind: _, kind: _,
separator, separator,
@ -114,7 +114,7 @@ impl_froms! (Foo: Bar, Baz)
*/ */
fn expand_subtree( fn expand_subtree(
template: &mbe::Subtree, template: &crate::Subtree,
bindings: &Bindings, bindings: &Bindings,
nesting: &mut Vec<usize>, nesting: &mut Vec<usize>,
) -> Option<tt::Subtree> { ) -> Option<tt::Subtree> {
@ -131,13 +131,13 @@ fn expand_subtree(
} }
fn expand_tt( fn expand_tt(
template: &mbe::TokenTree, template: &crate::TokenTree,
bindings: &Bindings, bindings: &Bindings,
nesting: &mut Vec<usize>, nesting: &mut Vec<usize>,
) -> Option<tt::TokenTree> { ) -> Option<tt::TokenTree> {
let res: tt::TokenTree = match template { let res: tt::TokenTree = match template {
mbe::TokenTree::Subtree(subtree) => expand_subtree(subtree, bindings, nesting)?.into(), crate::TokenTree::Subtree(subtree) => expand_subtree(subtree, bindings, nesting)?.into(),
mbe::TokenTree::Repeat(repeat) => { crate::TokenTree::Repeat(repeat) => {
let mut token_trees = Vec::new(); let mut token_trees = Vec::new();
nesting.push(0); nesting.push(0);
while let Some(t) = expand_subtree(&repeat.subtree, bindings, nesting) { while let Some(t) = expand_subtree(&repeat.subtree, bindings, nesting) {
@ -152,14 +152,14 @@ fn expand_tt(
} }
.into() .into()
} }
mbe::TokenTree::Leaf(leaf) => match leaf { crate::TokenTree::Leaf(leaf) => match leaf {
mbe::Leaf::Ident(ident) => tt::Leaf::from(tt::Ident { crate::Leaf::Ident(ident) => tt::Leaf::from(tt::Ident {
text: ident.text.clone(), text: ident.text.clone(),
}) })
.into(), .into(),
mbe::Leaf::Punct(punct) => tt::Leaf::from(punct.clone()).into(), crate::Leaf::Punct(punct) => tt::Leaf::from(punct.clone()).into(),
mbe::Leaf::Var(v) => bindings.get(&v.text, nesting)?.clone(), crate::Leaf::Var(v) => bindings.get(&v.text, nesting)?.clone(),
mbe::Leaf::Literal(l) => tt::Leaf::from(tt::Literal { crate::Leaf::Literal(l) => tt::Leaf::from(tt::Literal {
text: l.text.clone(), text: l.text.clone(),
}) })
.into(), .into(),

View file

@ -1,58 +1,59 @@
use crate::{self as mbe, tt_cursor::TtCursor}; use crate::tt_cursor::TtCursor;
/// This module parses a raw `tt::TokenStream` into macro-by-example token /// This module parses a raw `tt::TokenStream` into macro-by-example token
/// stream. This is a *mostly* identify function, expect for handling of /// stream. This is a *mostly* identify function, expect for handling of
/// `$var:tt_kind` and `$(repeat),*` constructs. /// `$var:tt_kind` and `$(repeat),*` constructs.
pub fn parse(tt: &tt::Subtree) -> Option<mbe::MacroRules> { pub fn parse(tt: &tt::Subtree) -> Option<crate::MacroRules> {
let mut parser = TtCursor::new(tt); let mut parser = TtCursor::new(tt);
let mut rules = Vec::new(); let mut rules = Vec::new();
while !parser.is_eof() { while !parser.is_eof() {
rules.push(parse_rule(&mut parser)?) rules.push(parse_rule(&mut parser)?)
} }
Some(mbe::MacroRules { rules }) Some(crate::MacroRules { rules })
} }
fn parse_rule(p: &mut TtCursor) -> Option<mbe::Rule> { fn parse_rule(p: &mut TtCursor) -> Option<crate::Rule> {
let lhs = parse_subtree(p.eat_subtree()?)?; let lhs = parse_subtree(p.eat_subtree()?)?;
p.expect_char('=')?; p.expect_char('=')?;
p.expect_char('>')?; p.expect_char('>')?;
let rhs = parse_subtree(p.eat_subtree()?)?; let mut rhs = parse_subtree(p.eat_subtree()?)?;
Some(mbe::Rule { lhs, rhs }) rhs.delimiter = crate::Delimiter::None;
Some(crate::Rule { lhs, rhs })
} }
fn parse_subtree(tt: &tt::Subtree) -> Option<mbe::Subtree> { fn parse_subtree(tt: &tt::Subtree) -> Option<crate::Subtree> {
let mut token_trees = Vec::new(); let mut token_trees = Vec::new();
let mut p = TtCursor::new(tt); let mut p = TtCursor::new(tt);
while let Some(tt) = p.eat() { while let Some(tt) = p.eat() {
let child: mbe::TokenTree = match tt { let child: crate::TokenTree = match tt {
tt::TokenTree::Leaf(leaf) => match leaf { tt::TokenTree::Leaf(leaf) => match leaf {
tt::Leaf::Punct(tt::Punct { char: '$', .. }) => { tt::Leaf::Punct(tt::Punct { char: '$', .. }) => {
if p.at_ident().is_some() { if p.at_ident().is_some() {
mbe::Leaf::from(parse_var(&mut p)?).into() crate::Leaf::from(parse_var(&mut p)?).into()
} else { } else {
parse_repeat(&mut p)?.into() parse_repeat(&mut p)?.into()
} }
} }
tt::Leaf::Punct(punct) => mbe::Leaf::from(*punct).into(), tt::Leaf::Punct(punct) => crate::Leaf::from(*punct).into(),
tt::Leaf::Ident(tt::Ident { text }) => { tt::Leaf::Ident(tt::Ident { text }) => {
mbe::Leaf::from(mbe::Ident { text: text.clone() }).into() crate::Leaf::from(crate::Ident { text: text.clone() }).into()
} }
tt::Leaf::Literal(tt::Literal { text }) => { tt::Leaf::Literal(tt::Literal { text }) => {
mbe::Leaf::from(mbe::Literal { text: text.clone() }).into() crate::Leaf::from(crate::Literal { text: text.clone() }).into()
} }
}, },
tt::TokenTree::Subtree(subtree) => parse_subtree(&subtree)?.into(), tt::TokenTree::Subtree(subtree) => parse_subtree(&subtree)?.into(),
}; };
token_trees.push(child); token_trees.push(child);
} }
Some(mbe::Subtree { Some(crate::Subtree {
token_trees, token_trees,
delimiter: tt.delimiter, delimiter: tt.delimiter,
}) })
} }
fn parse_var(p: &mut TtCursor) -> Option<mbe::Var> { fn parse_var(p: &mut TtCursor) -> Option<crate::Var> {
let ident = p.eat_ident().unwrap(); let ident = p.eat_ident().unwrap();
let text = ident.text.clone(); let text = ident.text.clone();
let kind = if p.at_char(':') { let kind = if p.at_char(':') {
@ -66,12 +67,13 @@ fn parse_var(p: &mut TtCursor) -> Option<mbe::Var> {
} else { } else {
None None
}; };
Some(mbe::Var { text, kind }) Some(crate::Var { text, kind })
} }
fn parse_repeat(p: &mut TtCursor) -> Option<mbe::Repeat> { fn parse_repeat(p: &mut TtCursor) -> Option<crate::Repeat> {
let subtree = p.eat_subtree().unwrap(); let subtree = p.eat_subtree().unwrap();
let subtree = parse_subtree(subtree)?; let mut subtree = parse_subtree(subtree)?;
subtree.delimiter = crate::Delimiter::None;
let sep = p.eat_punct()?; let sep = p.eat_punct()?;
let (separator, rep) = match sep.char { let (separator, rep) = match sep.char {
'*' | '+' | '?' => (None, sep.char), '*' | '+' | '?' => (None, sep.char),
@ -79,13 +81,13 @@ fn parse_repeat(p: &mut TtCursor) -> Option<mbe::Repeat> {
}; };
let kind = match rep { let kind = match rep {
'*' => mbe::RepeatKind::ZeroOrMore, '*' => crate::RepeatKind::ZeroOrMore,
'+' => mbe::RepeatKind::OneOrMore, '+' => crate::RepeatKind::OneOrMore,
'?' => mbe::RepeatKind::ZeroOrOne, '?' => crate::RepeatKind::ZeroOrOne,
_ => return None, _ => return None,
}; };
p.bump(); p.bump();
Some(mbe::Repeat { Some(crate::Repeat {
subtree, subtree,
kind, kind,
separator, separator,

View file

@ -107,7 +107,7 @@ impl_froms!(TokenTree: Leaf, Subtree);
let expansion = crate::exapnd(&mbe, &invocation_tt).unwrap(); let expansion = crate::exapnd(&mbe, &invocation_tt).unwrap();
assert_eq!( assert_eq!(
expansion.to_string(), expansion.to_string(),
"{(impl From < Leaf > for TokenTree {fn from (it : Leaf) -> TokenTree {TokenTree :: Leaf (it)}}) \ "impl From < Leaf > for TokenTree {fn from (it : Leaf) -> TokenTree {TokenTree :: Leaf (it)}} \
(impl From < Subtree > for TokenTree {fn from (it : Subtree) -> TokenTree {TokenTree :: Subtree (it)}})}" impl From < Subtree > for TokenTree {fn from (it : Subtree) -> TokenTree {TokenTree :: Subtree (it)}}"
) )
} }