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-rw-r--r--examples/bfinterp.rs84
1 files changed, 84 insertions, 0 deletions
diff --git a/examples/bfinterp.rs b/examples/bfinterp.rs
new file mode 100644
index 0000000..d5a0c2a
--- /dev/null
+++ b/examples/bfinterp.rs
@@ -0,0 +1,84 @@
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+ let input_str = if let Some(string) = std::env::args().skip(1).next() {
+ string
+ } else {
+ return Err("An input program is required.".into());
+ };
+
+ let input = tokenize(&input_str)?;
+
+ let grammar_string = "brainfuck = *unit
+
+unit = \">\" / \"<\" / \"+\" / \"-\" / \",\" / \";\" /
+ \"[\" brainfuck \"]\"";
+
+ let grammar: grammar::Grammar = grammar_string.parse().map_err(|err| format!("{err}"))?;
+
+ println!("grammar = {grammar}");
+
+ let atom: chain::atom::DefaultAtom =
+ chain::atom::DefaultAtom::from_grammar(grammar).map_err(|err| format!("{err}"))?;
+
+ // atom.print_viz("nfa.gv")?;
+
+ use chain::Chain;
+
+ let mut chain: chain::default::DefaultChain =
+ chain::default::DefaultChain::unit(atom).map_err(|err| format!("{err}"))?;
+
+ // let input = [0, 1, 6, 2, 6, 3, 4, 6, 5, 2, 7, 4, 7, 3, 2, 7, 2];
+
+ for (index, token) in input.iter().copied().enumerate() {
+ chain.chain(token, index, false)?;
+ // if (5..=12).contains(&index) {
+ // chain.print_current(&format!("chain {index}.gv"))?;
+ // }
+ }
+
+ let _extracted = chain.end_of_input(input.len(), input[input.len() - 1])?;
+
+ // use graph::Graph;
+
+ // extracted.print_viz("bf.gv")?;
+
+ Ok(())
+}
+
+fn tokenize(input: &str) -> Result<Vec<usize>, String> {
+ let mut result: Vec<usize> = Vec::with_capacity(input.len());
+
+ for (index, c) in input.chars().enumerate() {
+ match c {
+ '>' => {
+ result.push(0);
+ }
+ '<' => {
+ result.push(1);
+ }
+ '+' => {
+ result.push(2);
+ }
+ '-' => {
+ result.push(3);
+ }
+ ',' => {
+ result.push(4);
+ }
+ ';' => {
+ result.push(5);
+ }
+ '[' => {
+ result.push(6);
+ }
+ ']' => {
+ result.push(7);
+ }
+ ' ' | '\t' | '\n' | '\r' => {}
+ _ => {
+ return Err(format!("Unknown character {c} at {index}"));
+ }
+ }
+ }
+
+ Ok(result)
+}