factorial working

1 files changed, 33 insertions, 0 deletions

diff --git a/src/forth/mod.rs b/src/forth/mod.rs
index fdda066..5792148 100644..100755
--- a/src/forth/mod.rs
+++ b/src/forth/mod.rs
@@ -1,2 +1,35 @@
 mod interp;
 mod parser;
+
+#[cfg(test)]
+mod tests {
+    use super::{
+        interp::{Interp, WordList},
+        parser::Parser
+    };
+
+    fn parser_for(text: &str) -> Parser {
+        let mut p = Parser::new(text);
+        p.parse().expect("badparse");
+        p
+    }
+
+    fn eprintwordlist(wordlist: &WordList) {
+        for i in 0..wordlist.0.len() {
+            eprintln!("wordlist[{}]: {:?}", i, wordlist.0[i]);
+        }
+    }
+
+    // recursive!
+    #[test]
+    fn fac() {
+        let prog = ": fac dup 1 > if dup 1 - fac * then ; 5 fac\n";
+        let p = parser_for(prog);
+        eprintwordlist(&p.wordlist);
+        let mut interp = Interp::new(p.wordlist);
+        interp.run().expect("should run to completion");
+        eprintln!("stack: {:?}", interp.stack);
+        assert_eq!(interp.stack.0.len(), 1, "factorial result stack len");
+        assert_eq!(interp.stack.0[0], 120, "factorial result value");
+    }
+}