1 files changed, 46 insertions, 0 deletions
diff --git a/build.rs b/build.rs
new file mode 100644
index 0000000..dcf1cc3
--- /dev/null
+++ b/build.rs
@@ -0,0 +1,46 @@
+use std::fs::File;
+use std::io::{BufRead, BufReader, BufWriter, Result, Write};
+use std::path::Path;
+
+const NUM_LETTERS: usize = 26;
+
+fn main() -> Result<()> {
+    let chars = {
+        let file = File::open("/usr/share/dict/words")?;
+        let reader = BufReader::new(file);
+        parse(reader)?
+    };
+
+    let out_path = Path::new(&std::env::var("OUT_DIR").unwrap()).join("prebuilt_model.rs");
+    let file = File::create(out_path)?;
+    let mut writer = BufWriter::new(file);
+    writeln!(writer, "[")?;
+    for i in 0..(NUM_LETTERS + 1) {
+        write!(writer, "[")?;
+        for j in 0..(NUM_LETTERS + 1) {
+            write!(writer, "{},", chars[i][j])?;
+        }
+        writeln!(writer, "],")?;
+    }
+    writeln!(writer, "]")?;
+
+    Ok(())
+}
+
+fn parse(r: BufReader<File>) -> Result<[[usize; NUM_LETTERS + 1]; NUM_LETTERS + 1]> {
+    let mut chars = [[0; NUM_LETTERS + 1]; NUM_LETTERS + 1];
+    for line in r.lines() {
+        let word = line?;
+        let mut prefix = NUM_LETTERS;
+        for c in word.bytes() {
+            let c = c.to_ascii_lowercase();
+            if !c.is_ascii_lowercase() {
+                continue;
+            }
+            let i = (c - b'a') as usize;
+            chars[prefix][i] += 1;
+            prefix = i;
+        }
+    }
+    Ok(chars)
+}