rust(day19): Part 2

rust/src/main.rs

@@ -687,7 +687,9 @@ mod day18 {
 
 mod day19 {
     use std::collections::BTreeMap as HashMap;
-    use std::time::Duration;
+    use std::fs::File;
+    use std::io::{BufWriter, Write};
+    use std::time::{Duration, Instant};
 
     #[derive(Debug)]
     enum Rhs {
@@ -733,63 +735,76 @@ mod day19 {
         Some((rules, messages))
     }
 
-    pub fn run(_print: bool) -> Duration {
-        let input = std::fs::read_to_string("../inputs/19").unwrap();
+    fn generate(rules: &Rules, messages: &Vec<&str>, filename: &str) -> std::io::Result<()> {
+        let write_file = File::create(filename)?;
+        let mut w = BufWriter::new(&write_file);
 
-        println!("from typing import Tuple");
-        println!();
-
-        let (rules, messages) = parse(&input).unwrap();
+        writeln!(&mut w, "from typing import Tuple")?;
+        writeln!(&mut w)?;
 
         for (i, rule) in rules.iter() {
-            println!("def rule_{}(s: str) -> Tuple[bool, str]:", i);
+            writeln!(&mut w, "def rule_{}(s):", i)?;
+            writeln!(&mut w, "    if s != '':")?;
+
             match rule {
                 Rhs::Terminal(terminal) => {
-                    println!("    if s[0] == '{}':", terminal);
-                    println!("        return True, s[1:]");
-                    println!("    return False, s");
+                    writeln!(&mut w, "        if s[0] == '{}':", terminal)?;
+                    writeln!(&mut w, "            yield s[1:]")?;
                 }
 
                 Rhs::Variables(variables) => {
                     for term in variables {
-                        println!("    r = s");
-                        for (j, variable) in term.iter().enumerate() {
-                            println!("    valid_{}, r = rule_{}(r)", j, variable);
+                        for (j, rule) in term.iter().enumerate() {
+                            if j == 0 {
+                                writeln!(&mut w, "        v{} = rule_{}(s)", j, rule)?;
+                            } else {
+                                writeln!(
+                                    &mut w,
+                                    "        v{} = (out for inp in v{} for out in rule_{}(inp))",
+                                    j,
+                                    j - 1,
+                                    rule,
+                                )?;
                             }
-                        println!("    if all((");
-                        for j in 0..term.len() {
-                            println!("        valid_{}, ", j);
                         }
-                        println!("    )):");
-                        println!("        return True, r");
-                        println!();
+                        writeln!(&mut w, "        yield from v{}", term.len() - 1)?;
+                        writeln!(&mut w)?;
                     }
-                    println!("    return False, s");
                 }
             }
 
-            println!();
-            println!();
+            writeln!(&mut w)?;
         }
-        println!("def validate(s):");
-        for i in 0..rules.len() {
-            println!("    if rule_{}(s) == (True, ''):", i);
-            println!("        return True");
-        }
-        println!("    return False");
+        writeln!(&mut w, "def validate(s):")?;
+        writeln!(&mut w, "    return any(x == '' for x in rule_0(s))")?;
 
-        println!();
-        println!("if __name__ == '__main__':");
-        println!("    part1 = 0");
+        writeln!(&mut w)?;
+        writeln!(&mut w, "if __name__ == '__main__':")?;
+        writeln!(&mut w, "    result = 0")?;
         for message in messages {
-            println!("    if (result := validate('{}')):", message);
-            println!("        part1 += 1");
-            println!("    print('{}:', result)", message);
-            println!();
+            writeln!(&mut w, "    success = validate('{}')", message)?;
+            // writeln!(&mut w, "    print('{}:', success)", message)?;
+            writeln!(&mut w, "    if success:")?;
+            writeln!(&mut w, "        result += 1")?;
+            writeln!(&mut w)?;
         }
-        println!("    print('Part 1:', part1)");
+        writeln!(&mut w, "    print('Result:', result)")?;
 
-        Duration::new(0, 0)
+        Ok(())
+    }
+
+    pub fn run(_print: bool) -> Duration {
+        let input = std::fs::read_to_string("../inputs/19").unwrap();
+        let instant = Instant::now();
+
+        let (mut rules, messages) = parse(&input).unwrap();
+        generate(&rules, &messages, "/tmp/day19-1.py").unwrap();
+
+        rules.insert(8, Rhs::Variables(vec![vec![42], vec![42, 8]]));
+        rules.insert(11, Rhs::Variables(vec![vec![42, 31], vec![42, 11, 31]]));
+        generate(&rules, &messages, "/tmp/day19-2.py").unwrap();
+
+        instant.elapsed()
     }
 }