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authorJSDurand <mmemmew@gmail.com>2023-06-18 15:03:34 +0800
committerJSDurand <mmemmew@gmail.com>2023-06-18 15:03:34 +0800
commita80db17473ff09cc72acba2c1975101e6dbedf39 (patch)
tree4d5dfcdfcd1537b51b92349d9a5274aa90a6d110 /nfa
parent6ce44bb3bdb79e8e727ee6fc7f5c6cd7fa0bb51e (diff)
fixed the bugs of node duplications and left-open nodes
There were two main issues in the previous version. One is that there are lots of duplications of nodes when manipulating the forest. This does not mean that labels repeat: by the use of the data type this cannot happen. What happened is that there were cloned nodes whose children are exactly equal. In this case there is no need to clone that node in the first place. This is now fixed by checking carefully before cloning, so that we do not clone unnecessary nodes. The other issue, which is perhaps more important, is that there are nodes which are not closed. This means that when there should be a reuction of grammar rules, the forest does not mark the corresponding node as already reduced. The incorrect forests thus caused is hard to fix: I tried several different approaches to fix it afterwards, but all to no avail. I also tried to record enough information to fix these nodes during the manipulations. It turned out that recording nodes is a dead end, as I cannot properly syncronize the information in the forest and the information in the chain-rule machine. Any inconsistencies will result in incorrect operations later on. The approach I finally adapt is to perform every possible reduction at each step. This might lead to some more nodes than what we need. But those are technically expected to be there after all, and it is easy to filter them out, so it is fine, from my point of view at the moment. Therefore, what remains is to filter those nodes out and connect it to the holy Emacs. :D
Diffstat (limited to 'nfa')
-rw-r--r--nfa/src/default/nfa.rs32
1 files changed, 11 insertions, 21 deletions
diff --git a/nfa/src/default/nfa.rs b/nfa/src/default/nfa.rs
index d2fe88e..e38a1a9 100644
--- a/nfa/src/default/nfa.rs
+++ b/nfa/src/default/nfa.rs
@@ -20,7 +20,7 @@ pub struct DefaultNFA<T: GraphLabel> {
graph: DLGraph<T>,
}
-impl<T: GraphLabel + Display> Default for DefaultNFA<T> {
+impl<T: GraphLabel> Default for DefaultNFA<T> {
fn default() -> Self {
Self {
graph: Default::default(),
@@ -85,10 +85,9 @@ impl<T: GraphLabel> LabelExtGraph<T> for DefaultNFA<T> {
}
impl<T: GraphLabel> Nfa<T> for DefaultNFA<T> {
- type FromRegex<S: GraphLabel + Display + Default> = DefaultNFA<S>;
+ type FromRegex<S: GraphLabel + Default> = DefaultNFA<S>;
- // Reminder: This is an adopted version of Thompson's
- // construction.
+ // NOTE: This is an adopted version of Thompson's construction.
fn to_nfa(
regexps: &[impl Regex<RegexType<T>>],
sub_pred: impl Fn(T) -> Result<SoC<T>, Error>,
@@ -107,10 +106,6 @@ impl<T: GraphLabel> Nfa<T> for DefaultNFA<T> {
builder.add_vertices(nfa_len);
- // for _ in 0..nfa_len {
- // builder.add_vertex();
- // }
-
let default = LabelType::new(DOption(default), total_regexps_len, false);
// add a default edge
@@ -122,7 +117,7 @@ impl<T: GraphLabel> Nfa<T> for DefaultNFA<T> {
result.push(0);
for regexp in regexps.iter().take(regexps.len() - 1) {
- result.push(result.last().unwrap() + regexp.nodes_len() * 2);
+ result.push(*result.last().unwrap() + regexp.nodes_len() * 2);
}
result
@@ -137,14 +132,14 @@ impl<T: GraphLabel> Nfa<T> for DefaultNFA<T> {
}
);
- /// Get offset from `accumulators` without checking bounds.
- macro_rules! get_offset_unsafe (
- ($num:expr) => {
- { unsafe { *accumulators.get_unchecked($num) } }
- }
- );
+ // /// Get offset from `accumulators` without checking bounds.
+ // macro_rules! get_offset_unsafe (
+ // ($num:expr) => {
+ // { unsafe { *accumulators.get_unchecked($num) } }
+ // }
+ // );
- for (index, regex) in regexps.iter().enumerate() {
+ for (regex, offset) in regexps.iter().zip(accumulators.iter().copied()) {
let root = if let Some(root) = regex.root() {
root
} else {
@@ -155,11 +150,6 @@ impl<T: GraphLabel> Nfa<T> for DefaultNFA<T> {
let regex_len = regex.nodes_len();
- // It is safe here to call `get_offset_unsafe`, as `index`
- // is guaranteed to be strictly less than the length of
- // `accumulators` by an assertion above.
- let offset = get_offset_unsafe!(index);
-
let mut stack: Vec<usize> = Vec::with_capacity(regex_len);
stack.push(root);