refactor into lib-style crate, and add some early tests

5 files changed, 99 insertions, 35 deletions

diff --git a/src/main.rs b/src/bin/casual.rs
index f09e0f0..828c4b6 100644
--- a/src/main.rs
+++ b/src/bin/casual.rs
@@ -1,38 +1,7 @@
 use std::env;
-use std::io;
-use std::io::Write;
 use std::path::Path;
 
-mod cexpr;
-mod sexpr;
-
-use cexpr::CExpr;
-
-fn repl(_verbose: bool) {
-    let stdin = io::stdin();
-    let mut stdout = io::stdout();
-
-    loop {
-        let raw_input = &mut String::new();
-        stdout.write(b"\ncasual> ").unwrap();
-        stdout.flush().unwrap();
-        stdin.read_line(raw_input).unwrap();
-        let raw_input = raw_input; // mutable to immutable reference
-        if raw_input.len() == 0 {
-            // end-of-line, aka Ctrl-D. Blank line will still have newline char
-            stdout.write(b"\nCiao!\n").unwrap();
-            return;
-        }
-        let expr = match CExpr::from_str(&raw_input) {
-            Ok(expr) => expr,
-            Err(e) => {
-                println!("error: {}", e);
-                continue;
-            }
-        };
-        println!("{}", expr);
-    }
-}
+use casual::{repl, sexpr_parse_file};
 
 fn usage() {
     println!("usage:\tcasual [-h] [-v] [--no-repl] [<files>]");
@@ -81,7 +50,7 @@ fn main() {
             return;
         }
         println!("Loading {}...", fname);
-        match sexpr::sexpr_parse_file(&fpath) {
+        match sexpr_parse_file(&fpath) {
             Err(e) => {
                 println!("Error loading file: {}\n    {}", fname, e);
                 return;
diff --git a/src/cexpr.rs b/src/cexpr.rs
index b183c4a..357caff 100644
--- a/src/cexpr.rs
+++ b/src/cexpr.rs
@@ -37,7 +37,7 @@ impl NumericConstant {
     }
 }
 
-#[derive(Clone, PartialEq, PartialOrd)]
+#[derive(Clone, PartialEq, PartialOrd, Debug)]
 pub enum CNumber {
     // order here is important for sorting, etc
     Integer(i64),
@@ -99,7 +99,7 @@ impl CNumber {
     }
 }
 
-#[derive(Clone, PartialEq, PartialOrd)]
+#[derive(Clone, PartialEq, PartialOrd, Debug)]
 pub enum CExpr {
     // order here is important for sorting, etc
     Number(CNumber),
diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..950329b
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,34 @@
+use std::io;
+use std::io::Write;
+
+mod cexpr;
+mod sexpr;
+
+pub use cexpr::{CExpr, CNumber};
+pub use sexpr::{sexpr_parse_file, SExpr};
+
+pub fn repl(_verbose: bool) {
+    let stdin = io::stdin();
+    let mut stdout = io::stdout();
+
+    loop {
+        let raw_input = &mut String::new();
+        stdout.write(b"\ncasual> ").unwrap();
+        stdout.flush().unwrap();
+        stdin.read_line(raw_input).unwrap();
+        let raw_input = raw_input; // mutable to immutable reference
+        if raw_input.len() == 0 {
+            // end-of-line, aka Ctrl-D. Blank line will still have newline char
+            stdout.write(b"\nCiao!\n").unwrap();
+            return;
+        }
+        let expr = match CExpr::from_str(&raw_input) {
+            Ok(expr) => expr,
+            Err(e) => {
+                println!("error: {}", e);
+                continue;
+            }
+        };
+        println!("{}", expr);
+    }
+}
diff --git a/tests/canonicalize.rs b/tests/canonicalize.rs
new file mode 100644
index 0000000..3ef088a
--- /dev/null
+++ b/tests/canonicalize.rs
@@ -0,0 +1,26 @@
+use casual::{CExpr, CNumber};
+
+#[test]
+fn basics() {
+    assert_eq!(
+        CExpr::from_str("(+ 1 2 3)").unwrap(),
+        CExpr::Number(CNumber::Integer(6)),
+    );
+}
+
+#[test]
+fn canonicalization() {
+    let cases = vec![
+        ("(+ (+ a 2) (+ b 2))", "(+ 4 a b)"),
+        ("(+ (+ a 2) (+ b 2))", "(+ 4 a b)"),
+        ("(+ 1 2 b)", "(+ 3 b)"),
+        ("(+ 1 2 3)", "6"),
+        ("(* (/ 2 3) (/ 3 2))", "1"),
+    ];
+
+    for (input, output) in cases.iter() {
+        assert_eq!(CExpr::from_str(input).unwrap().to_string(), *output);
+    }
+}
+
+// TODO: helper to read an examples file, as pairs of rows
diff --git a/tests/things.txt b/tests/things.txt
new file mode 100644
index 0000000..f525f6e
--- /dev/null
+++ b/tests/things.txt
@@ -0,0 +1,35 @@
+
+(+ (+ a 2) (+ b 2))
+(+ 4 a b)
+
+(+ 1 2 b)
+(+ 3 b)
+
+(+ 1 2 3)
+6
+
+(* (/ 2 3) (/ 3 2))
+1
+
+# TODO
+(* (/ -2 3) (/ 3 2))
+-1
+
+
+(* (* a b 1) (* c d))
+(* a b c d)
+
+(+ (+ a b) (+ c d))
+(+ a b c d)
+
+(+ (+ a b 1) (+ c d 3))
+(+ 4 a b c d)
+
+(^ 4 -1)
+(/ 1 4)
+
+(^ (/ 2 3) -1)
+(/ 3 2)
+
+(^ (/ 1 3) -1)
+3