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authorJSDurand <mmemmew@gmail.com>2022-12-14 23:48:22 +0800
committerJSDurand <mmemmew@gmail.com>2022-12-14 23:48:22 +0800
commit9f1c88b863e247da3cd60d2792a7a13b18e25e53 (patch)
treed29c0e19793a88a1de6898fdfd2a376fca21378f /repcore/src/grammar.rs
parentcb7bcfad4ab0041aaf3fde3185e27ee46bb37788 (diff)
a temporary check point
just to save things in a commit
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+//! This file implements the extected behaviours of grammars.
+
+// NOTE: We shall first start with a parser that works at the level of
+// characters. The purpose is to first experiment with the workings
+// and the performance of the algorithms, before optimising by using
+// regular expressions to classify inputs into tokens. In other
+// words, the current focus is not on the optimisations, whereas
+// scanners are for optimisations only, so to speak.
+
+/// The type of a terminal.
+///
+/// For the time being this is a wrapper around a string, but in the
+/// future it may hold more information of scanners.
+pub struct Terminal {
+ // If we want to use scanners, per chance add them as a new field
+ // here.
+ name: String,
+}
+
+impl Terminal {
+ /// Create a terminal with the given name.
+ #[inline]
+ pub fn new(name: String) -> Self {
+ Self { name }
+ }
+
+ /// Return the name of the terminal.
+ #[inline]
+ pub fn name(&self) -> &str {
+ &self.name
+ }
+}
+
+/// The type of a non-terminal.
+///
+/// This is just a wrapper around a string.
+pub struct Nonterminal(String);
+
+impl Nonterminal {
+ /// Return the name of the nonterminal.
+ ///
+ /// Just to improve readability.
+ #[inline]
+ pub fn name(&self) -> &str {
+ &self.0
+ }
+}
+
+/// The type of a terminal or a non-terminal.
+///
+/// Only an index is stored here. Actual data are stored in two other
+/// arrays.
+#[derive(Debug, Hash, Eq, PartialEq, Clone, Copy, Ord, PartialOrd)]
+pub enum TNT {
+ /// Terminal variant
+ Ter(usize),
+ /// Nonterminal variant
+ Non(usize),
+}