day7 parser

day7/Cargo.toml

@@ -6,5 +6,8 @@ edition = "2018"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
+[features]
+test = []
+
 [dependencies]
 generational-arena = "0.2.8"

day7/src/bag.rs

@@ -1,103 +1,91 @@
 use std::{
-    mem,
-    ops,
     hash::{Hash, Hasher,},
+    collections::HashSet,
+    borrow::Borrow,
 };
-use generational_arena::{
-    Arena,
-    Index,
-};
 
-#[derive(Debug, Clone, Eq)]
-pub struct Bag
+type Bags = HashSet<Rule>;
+type BagRef = String;
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct Rule
 {
-    name: String,
-    contains: Vec<Index>,
+    bag: BagRef,
+    contains: Vec<(usize, BagRef)>,
 }
 
-impl Hash for Bag {
-    #[inline] fn hash<H: Hasher>(&self, state: &mut H) {
-	self.as_ref().hash(state)
+impl Borrow<String> for Rule
+{
+    fn borrow(&self) -> &String {
+	&self.bag
     }
 }
 
-impl<T> PartialEq<T> for Bag
-where T: AsRef<BagRef>
-{
-    fn eq(&self, other: &T) -> bool
-    {
-	self.as_ref() == other.as_ref()
+impl Hash for Rule {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+	self.bag.hash(state)
     }
 }
 
-impl Bag
+impl Rule
 {
-    pub fn new(name: String) -> Self
+    #[inline] pub fn name(&self) -> &str
     {
-	Self {
-	    name,
-	    contains: Vec::new(),
-	}
+	&self.bag[..]
     }
-    pub fn push_contents(&mut self, idx: Index)
+    
+    /// Find the rules for each inner bag within this context
+    pub fn inner_rules<'a>(&'a self, hashes: &'a Bags) -> impl Iterator<Item = &'a Rule> + 'a
     {
-	self.contains.push(idx)
+	self.contains.iter().filter_map(move |(_, re)| hashes.get(re))
     }
-    pub fn bags_in<'a>(&'a self, w: &'a Arena<Bag>) -> impl Iterator<Item = &'a BagRef> + 'a
+    #[inline] pub fn new(bag: impl Into<String>, contains: impl IntoIterator<Item = (usize, String)>) -> Self
     {
-	self.contains.iter().filter_map(move |x| w.get(x.clone())).map(Self::as_ref)
+	return Self::new_ex(bag.into(), contains.into_iter().collect());
     }
-    pub fn contains_in(&self, w: &Arena<Bag>,  bag: impl AsRef<BagRef>) -> bool
+    pub fn new_ex(bag: String, contains: Vec<(usize, String)>) -> Self
     {
-	for x in self.bags_in(w)
-	{
-	    if x == bag.as_ref() {
-		return true;
-	    }
-	}
-	false
+	Self {bag, contains}
     }
-    
-}
 
-impl AsRef<BagRef> for Bag
-{
-    #[inline] fn as_ref(&self) -> &BagRef
+    pub fn all_rules<'a>(&'a self, hashes: &'a Bags) -> RuleIterator<'a>
     {
-	BagRef::new_unchecked(&self.name[..])
-    }
-}
-
-impl ops::Deref for Bag
-{
-    type Target = BagRef;
-    #[inline] fn deref(&self) -> &Self::Target {
-	self.as_ref()
+	RuleIterator
+	{
+	    base: self.contains.iter(),
+	    hashes,
+	    held: Vec::with_capacity(self.contains.len()),
+	}
     }
 }
 
-#[derive(Debug, PartialEq, Eq, Hash)]
-#[repr(transparent)]
-pub struct BagRef
+pub struct RuleIterator<'a>
 {
-    name: str
+    base: std::slice::Iter<'a, (usize, BagRef)>,
+    hashes: &'a Bags,
+    held: Vec<&'a Rule>,
 }
 
-impl AsRef<BagRef> for BagRef
+impl<'a> Iterator for RuleIterator<'a>
 {
-    #[inline] fn as_ref(&self) -> &BagRef
+    type Item = &'a Rule;
+    fn next(&mut self) -> Option<Self::Item>
     {
-	self
+	if self.held.is_empty() {
+	    match self.base.next() {
+		Some((_, re)) => {
+		    self.held.push(self.hashes.get(re).unwrap());
+		},
+		None => return None,
+	    }
+	}
+	let ret = self.held.remove(0);
+	self.held.extend(ret.inner_rules(self.hashes));
+	Some(ret)
     }
-}
-
 
-impl BagRef
-{
-    #[inline] fn new_unchecked<'a>(from: &'a str) -> &'a BagRef
-    {
-	unsafe {
-	    mem::transmute(from)
-	}
+    fn size_hint(&self) -> (usize, Option<usize>) {
+	(self.base.len(), None)
     }
 }
+impl<'a> std::iter::FusedIterator for RuleIterator<'a>{}

day7/src/main.rs

@@ -2,9 +2,28 @@
 
 #![allow(dead_code)]
 
+use std::{
+    io::BufReader,
+    fs::OpenOptions,
+    collections::HashSet,
+};
+
+#[cfg(feature="test")] 
+const INPUT: &str ="input-test";
+#[cfg(not(feature="test"))]
+const INPUT: &str = "input";
+
+
 mod parse;
 mod bag;
 
-fn main() {
-    println!("Hello, world!");
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let parsed: HashSet<_> = parse::parse(BufReader::new(OpenOptions::new().read(true).open(INPUT)?)).collect();
+    #[cfg(debug_assertions)]
+    for x in parsed.iter() {
+	eprintln!("{:?}", x);
+    }
+
+    
+    Ok(())
 }

day7/src/parse.rs

@@ -1,109 +1,48 @@
-use std::{
-    io::{
-	self, BufRead,
-    },
-    sync::{
-	mpsc,
-    },
-    thread,
-    marker::*,
-    collections::{HashMap, HashSet,},
-};
-use generational_arena::{
-    Arena, Index,
-};
+use std::io::BufRead;
 use super::bag;
 
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-struct Rule
+fn parse_rule(from: impl AsRef<str>) -> Option<bag::Rule>
 {
-    contents: Vec<(usize, String)>,
-}
-
-fn parse_rest(from: mpsc::Receiver<String>) -> HashMap<String, Rule>
-{
-    let mut out = HashMap::new();
-    while let Ok(line) = from.recv() {
-	
-    }
-    out
-}
-
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-struct UnlinkedBag<'a>
-{
-    name: &'a str,
-    cont: Rule,
-}
-
-enum MaybeLinked<'a>
-{
-    Unlinked(UnlinkedBag<'a>),
-    Linked(bag::Bag),
-}
-
-pub fn parse<R: BufRead>(from: R) -> Result<Arena<bag::Bag>, io::Error>
-{
-    let mut all_possible = HashSet::<String>::new();
-    let (tx, rx) = mpsc::channel();
-    let w = thread::spawn(move || parse_rest(rx));
+    let from = from.as_ref();
+    let mut ps = from.split("bag");
     
-    macro_rules! unwrap {
-	(? $opt:expr) => {
-	    match $opt {
-		Some(v) => v,
-		_ => continue,
-	    }
-	};
-	($res:expr) => {
-	    unwrap!(? $res.ok())
-	}
-    }
-    for line in from.lines()
-    {
-	let mut line = line?;
-
-	let irest = {
-	    const SPLIT: &str = "bags contain";
-	    let bn = {
-		let idx = unwrap!(? line.find(SPLIT));
-		&line[..idx]
+    let name = ps.next()?.trim();
+    Some(bag::Rule::new(name, (0..).zip(ps).filter_map(|(i, s)| {
+	let (n, s) = if i == 0 {
+	    const JUNK: &str = "s contain ";
+	    
+	    let (spec, rest)  = (&s[JUNK.len()..]).split_once(char::is_whitespace).unwrap();
+	    let n: usize = match spec {
+		"no" => 0,
+		x => x.parse().unwrap(),
 	    };
-	    all_possible.insert(bn.trim().to_owned());
+	    (n, rest.trim())
+	} else {
+	    if s.contains(".") { return None; }
+	    
+	    let s = if s.starts_with("s") {
+		&s[3..]
+	    } else if s.starts_with(",") {
+		&s[2..]
+	    } else {
+		s
+	    }.trim();
+	    //if s.starts_with(".") { return None; }
+
+	    let (spec, rest)  = s.split_once(char::is_whitespace).unwrap();
+	    (spec.parse().unwrap(), rest.trim())
 	};
-	unwrap!(tx.send(line));
-    }
-    let (mut unlinked, nref) = {
-	let mut ulinks = w.join().unwrap();
-	let mut unlinked = Arena::with_capacity(all_possible.len());
-	let mut nref = HashMap::new();
-	for name in all_possible.iter()
-	{
-	    let urule = ulinks.remove(name).unwrap();
-	    let idx = unlinked.insert(MaybeLinked::Unlinked(UnlinkedBag{name, cont: urule}));
-	    nref.insert(name, idx);
+	if n < 1 {
+	    None
+	} else {
+	    Some((n, s.to_owned()))
 	}
-	(unlinked, nref)
-    };
-
-    let indecies: Vec<_> = unlinked.iter().map(|(i, _)| i).collect();
-    for idx in indecies.into_iter()
-    {
-	let current = unlinked.get_mut(idx).unwrap();
-	let linked = match current {
-	    MaybeLinked::Unlinked(UnlinkedBag{name, cont: rule}) => {
-		let mut linking = bag::Bag::new(name.to_owned());
-		for (_, cont) in rule.contents.iter() {
-		    linking.push_contents(*nref.get(cont).unwrap());
-		}
-		linking
-	    },
-	    _=> continue,
-	};
-	*current = MaybeLinked::Linked(linked);
-    }
+    })))
+}
 
-    //TODO: how tf can we convert from Arena<MaybeLinked<_>> into Arena<_>?????
-    
-    todo!()
+pub fn parse<R: BufRead>(buf: R) -> impl Iterator<Item = bag::Rule>
+{
+    buf.lines().filter_map(|x| {
+	x.ok().map(parse_rule).flatten()
+    })
 }