From 2d88207853a38fa3f73c03ef1f9d5a1b8ce9924a Mon Sep 17 00:00:00 2001 From: Aleksey Kladov Date: Thu, 31 Jan 2019 13:46:40 +0300 Subject: reshuffle --- crates/ra_macros/src/lib.rs | 1 + crates/ra_macros/src/mbe.rs | 225 +++++-------------------------------- crates/ra_macros/src/mbe_parser.rs | 184 ++++++++++++++++++++++++++++++ 3 files changed, 210 insertions(+), 200 deletions(-) create mode 100644 crates/ra_macros/src/mbe_parser.rs (limited to 'crates') diff --git a/crates/ra_macros/src/lib.rs b/crates/ra_macros/src/lib.rs index 6063c06c2..8c284fa71 100644 --- a/crates/ra_macros/src/lib.rs +++ b/crates/ra_macros/src/lib.rs @@ -12,3 +12,4 @@ macro_rules! impl_froms { pub mod tt; pub mod mbe; +mod mbe_parser; diff --git a/crates/ra_macros/src/mbe.rs b/crates/ra_macros/src/mbe.rs index 1aa6be736..72d6707aa 100644 --- a/crates/ra_macros/src/mbe.rs +++ b/crates/ra_macros/src/mbe.rs @@ -2,19 +2,21 @@ use smol_str::SmolStr; use crate::tt::{self, Delimiter}; +pub use crate::mbe_parser::parse; + #[derive(Debug)] pub struct MacroRules { - rules: Vec, + pub(crate) rules: Vec, } #[derive(Debug)] -struct Rule { - lhs: Subtree, - rhs: Subtree, +pub(crate) struct Rule { + pub(crate) lhs: Subtree, + pub(crate) rhs: Subtree, } #[derive(Debug)] -enum TokenTree { +pub(crate) enum TokenTree { Leaf(Leaf), Subtree(Subtree), Repeat(Repeat), @@ -22,7 +24,7 @@ enum TokenTree { impl_froms!(TokenTree: Leaf, Subtree, Repeat); #[derive(Debug)] -enum Leaf { +pub(crate) enum Leaf { Literal(Literal), Punct(Punct), Ident(Ident), @@ -31,219 +33,42 @@ enum Leaf { impl_froms!(Leaf: Literal, Punct, Ident, Var); #[derive(Debug)] -struct Subtree { - delimiter: Delimiter, - token_trees: Vec, +pub(crate) struct Subtree { + pub(crate) delimiter: Delimiter, + pub(crate) token_trees: Vec, } #[derive(Debug)] -struct Repeat { - subtree: Subtree, - kind: RepeatKind, - separator: Option, +pub(crate) struct Repeat { + pub(crate) subtree: Subtree, + pub(crate) kind: RepeatKind, + pub(crate) separator: Option, } #[derive(Debug)] -enum RepeatKind { +pub(crate) enum RepeatKind { ZeroOrMore, OneOrMore, ZeroOrOne, } #[derive(Debug)] -struct Literal { - text: SmolStr, +pub(crate) struct Literal { + pub(crate) text: SmolStr, } #[derive(Debug)] -struct Punct { - char: char, +pub(crate) struct Punct { + pub(crate) char: char, } #[derive(Debug)] -struct Ident { - text: SmolStr, +pub(crate) struct Ident { + pub(crate) text: SmolStr, } #[derive(Debug)] -struct Var { - text: SmolStr, - kind: Option, -} - -pub fn parse(tt: &tt::Subtree) -> Option { - let mut parser = RulesParser::new(tt); - let mut rules = Vec::new(); - while !parser.is_eof() { - rules.push(parse_rule(&mut parser)?) - } - Some(MacroRules { rules }) -} - -fn parse_rule(p: &mut RulesParser) -> Option { - let lhs = parse_subtree(p.eat_subtree()?)?; - p.expect_char('=')?; - p.expect_char('>')?; - let rhs = parse_subtree(p.eat_subtree()?)?; - Some(Rule { lhs, rhs }) -} - -fn parse_subtree(tt: &tt::Subtree) -> Option { - let mut token_trees = Vec::new(); - let mut p = RulesParser::new(tt); - while let Some(tt) = p.eat() { - let child: TokenTree = match tt { - tt::TokenTree::Leaf(leaf) => match leaf { - tt::Leaf::Punct(tt::Punct { char: '$' }) => { - if p.at_ident().is_some() { - Leaf::from(parse_var(&mut p)?).into() - } else { - parse_repeat(&mut p)?.into() - } - } - tt::Leaf::Punct(tt::Punct { char }) => Leaf::from(Punct { char: *char }).into(), - tt::Leaf::Ident(tt::Ident { text }) => { - Leaf::from(Ident { text: text.clone() }).into() - } - tt::Leaf::Literal(tt::Literal { text }) => { - Leaf::from(Literal { text: text.clone() }).into() - } - }, - tt::TokenTree::Subtree(subtree) => parse_subtree(subtree)?.into(), - }; - token_trees.push(child); - } - Some(Subtree { - token_trees, - delimiter: tt.delimiter, - }) -} - -fn parse_var(p: &mut RulesParser) -> Option { - let ident = p.eat_ident().unwrap(); - let text = ident.text.clone(); - let kind = if p.at_char(':') { - p.bump(); - if let Some(ident) = p.eat_ident() { - Some(ident.text.clone()) - } else { - // ugly as hell :( - p.pos -= 1; - None - } - } else { - None - }; - Some(Var { text, kind }) -} - -fn parse_repeat(p: &mut RulesParser) -> Option { - let subtree = p.eat_subtree().unwrap(); - let subtree = parse_subtree(subtree)?; - let sep = p.eat_punct()?; - let (separator, rep) = match sep.char { - '*' | '+' | '?' => (None, sep.char), - char => (Some(Punct { char }), p.eat_punct()?.char), - }; - - let kind = match rep { - '*' => RepeatKind::ZeroOrMore, - '+' => RepeatKind::OneOrMore, - '?' => RepeatKind::ZeroOrMore, - _ => return None, - }; - p.bump(); - Some(Repeat { - subtree, - kind, - separator, - }) -} - -struct RulesParser<'a> { - subtree: &'a tt::Subtree, - pos: usize, -} - -impl<'a> RulesParser<'a> { - fn new(subtree: &'a tt::Subtree) -> RulesParser<'a> { - RulesParser { subtree, pos: 0 } - } - - fn is_eof(&self) -> bool { - self.pos == self.subtree.token_trees.len() - } - - fn current(&self) -> Option<&'a tt::TokenTree> { - self.subtree.token_trees.get(self.pos) - } - - fn at_punct(&self) -> Option<&'a tt::Punct> { - match self.current() { - Some(tt::TokenTree::Leaf(tt::Leaf::Punct(it))) => Some(it), - _ => None, - } - } - - fn at_char(&self, char: char) -> bool { - match self.at_punct() { - Some(tt::Punct { char: c }) if *c == char => true, - _ => false, - } - } - - fn at_ident(&mut self) -> Option<&'a tt::Ident> { - match self.current() { - Some(tt::TokenTree::Leaf(tt::Leaf::Ident(i))) => Some(i), - _ => None, - } - } - - fn bump(&mut self) { - self.pos += 1; - } - - fn eat(&mut self) -> Option<&'a tt::TokenTree> { - match self.current() { - Some(it) => { - self.bump(); - Some(it) - } - None => None, - } - } - - fn eat_subtree(&mut self) -> Option<&'a tt::Subtree> { - match self.current()? { - tt::TokenTree::Subtree(sub) => { - self.bump(); - Some(sub) - } - _ => return None, - } - } - - fn eat_punct(&mut self) -> Option<&'a tt::Punct> { - if let Some(it) = self.at_punct() { - self.bump(); - return Some(it); - } - None - } - - fn eat_ident(&mut self) -> Option<&'a tt::Ident> { - if let Some(i) = self.at_ident() { - self.bump(); - return Some(i); - } - None - } - - fn expect_char(&mut self, char: char) -> Option<()> { - if self.at_char(char) { - self.bump(); - return Some(()); - } - None - } +pub(crate) struct Var { + pub(crate) text: SmolStr, + pub(crate) kind: Option, } diff --git a/crates/ra_macros/src/mbe_parser.rs b/crates/ra_macros/src/mbe_parser.rs new file mode 100644 index 000000000..93c2d40b4 --- /dev/null +++ b/crates/ra_macros/src/mbe_parser.rs @@ -0,0 +1,184 @@ +use crate::{tt, mbe}; + +/// This module parses a raw `tt::TokenStream` into macro-by-example token +/// stream. This is a *mostly* identify function, expect for handling of +/// `$var:tt_kind` and `$(repeat),*` constructs. + +struct RulesParser<'a> { + subtree: &'a tt::Subtree, + pos: usize, +} + +impl<'a> RulesParser<'a> { + fn new(subtree: &'a tt::Subtree) -> RulesParser<'a> { + RulesParser { subtree, pos: 0 } + } + + fn is_eof(&self) -> bool { + self.pos == self.subtree.token_trees.len() + } + + fn current(&self) -> Option<&'a tt::TokenTree> { + self.subtree.token_trees.get(self.pos) + } + + fn at_punct(&self) -> Option<&'a tt::Punct> { + match self.current() { + Some(tt::TokenTree::Leaf(tt::Leaf::Punct(it))) => Some(it), + _ => None, + } + } + + fn at_char(&self, char: char) -> bool { + match self.at_punct() { + Some(tt::Punct { char: c }) if *c == char => true, + _ => false, + } + } + + fn at_ident(&mut self) -> Option<&'a tt::Ident> { + match self.current() { + Some(tt::TokenTree::Leaf(tt::Leaf::Ident(i))) => Some(i), + _ => None, + } + } + + fn bump(&mut self) { + self.pos += 1; + } + + fn eat(&mut self) -> Option<&'a tt::TokenTree> { + match self.current() { + Some(it) => { + self.bump(); + Some(it) + } + None => None, + } + } + + fn eat_subtree(&mut self) -> Option<&'a tt::Subtree> { + match self.current()? { + tt::TokenTree::Subtree(sub) => { + self.bump(); + Some(sub) + } + _ => return None, + } + } + + fn eat_punct(&mut self) -> Option<&'a tt::Punct> { + if let Some(it) = self.at_punct() { + self.bump(); + return Some(it); + } + None + } + + fn eat_ident(&mut self) -> Option<&'a tt::Ident> { + if let Some(i) = self.at_ident() { + self.bump(); + return Some(i); + } + None + } + + fn expect_char(&mut self, char: char) -> Option<()> { + if self.at_char(char) { + self.bump(); + return Some(()); + } + None + } +} + +pub fn parse(tt: &tt::Subtree) -> Option { + let mut parser = RulesParser::new(tt); + let mut rules = Vec::new(); + while !parser.is_eof() { + rules.push(parse_rule(&mut parser)?) + } + Some(mbe::MacroRules { rules }) +} + +fn parse_rule(p: &mut RulesParser) -> Option { + let lhs = parse_subtree(p.eat_subtree()?)?; + p.expect_char('=')?; + p.expect_char('>')?; + let rhs = parse_subtree(p.eat_subtree()?)?; + Some(mbe::Rule { lhs, rhs }) +} + +fn parse_subtree(tt: &tt::Subtree) -> Option { + let mut token_trees = Vec::new(); + let mut p = RulesParser::new(tt); + while let Some(tt) = p.eat() { + let child: mbe::TokenTree = match tt { + tt::TokenTree::Leaf(leaf) => match leaf { + tt::Leaf::Punct(tt::Punct { char: '$' }) => { + if p.at_ident().is_some() { + mbe::Leaf::from(parse_var(&mut p)?).into() + } else { + parse_repeat(&mut p)?.into() + } + } + tt::Leaf::Punct(tt::Punct { char }) => { + mbe::Leaf::from(mbe::Punct { char: *char }).into() + } + tt::Leaf::Ident(tt::Ident { text }) => { + mbe::Leaf::from(mbe::Ident { text: text.clone() }).into() + } + tt::Leaf::Literal(tt::Literal { text }) => { + mbe::Leaf::from(mbe::Literal { text: text.clone() }).into() + } + }, + tt::TokenTree::Subtree(subtree) => parse_subtree(subtree)?.into(), + }; + token_trees.push(child); + } + Some(mbe::Subtree { + token_trees, + delimiter: tt.delimiter, + }) +} + +fn parse_var(p: &mut RulesParser) -> Option { + let ident = p.eat_ident().unwrap(); + let text = ident.text.clone(); + let kind = if p.at_char(':') { + p.bump(); + if let Some(ident) = p.eat_ident() { + Some(ident.text.clone()) + } else { + // ugly as hell :( + p.pos -= 1; + None + } + } else { + None + }; + Some(mbe::Var { text, kind }) +} + +fn parse_repeat(p: &mut RulesParser) -> Option { + let subtree = p.eat_subtree().unwrap(); + let subtree = parse_subtree(subtree)?; + let sep = p.eat_punct()?; + let (separator, rep) = match sep.char { + '*' | '+' | '?' => (None, sep.char), + char => (Some(mbe::Punct { char }), p.eat_punct()?.char), + }; + + let kind = match rep { + '*' => mbe::RepeatKind::ZeroOrMore, + '+' => mbe::RepeatKind::OneOrMore, + '?' => mbe::RepeatKind::ZeroOrMore, + _ => return None, + }; + p.bump(); + Some(mbe::Repeat { + subtree, + kind, + separator, + }) +} -- cgit v1.2.3