From 79ffae6c11811f206c5b9aa3b127b0a5eadc7189 Mon Sep 17 00:00:00 2001
From: linsy king <linsy_king@sjtu.edu.cn>
Date: Tue, 4 Apr 2023 10:13:27 +0800
Subject: [PATCH] fix

---
 examples/syn.cat  | 36 ++++++++++++++++++++++++++++++++++++
 examples/syn.meow |  7 +++++++
 src/prog.rs       | 42 +++++++++++++++++++++++++++---------------
 3 files changed, 70 insertions(+), 15 deletions(-)
 create mode 100644 examples/syn.cat

diff --git a/examples/syn.cat b/examples/syn.cat
new file mode 100644
index 0000000..10e9ed9
--- /dev/null
+++ b/examples/syn.cat
@@ -0,0 +1,36 @@
+true() {"T"}
+
+false() {"F"}
+
+zero() {"0"}
+
+succ(x) {cat "S" x}
+
+pred(x) {
+    let "S0" "0" x
+}
+
+dr(x,y,z) {
+    let y x let x y z
+}
+
+encode(s) {
+    cat cat "_^" let "$" "\$" let "^" "\^" let "\" "\\" s "_$"
+}
+
+eq(x,y) {
+    let encode x "F" encode y "T" encode "x"
+}
+
+if(c,x,y) {
+    decode let "T$" encode x let "F$" encode y cat x "$"
+}
+
+in(x,y) {
+    eq y let x "" y
+}
+
+test2() {
+    let "bb" "g" cat "bc" "bc"
+}
+
diff --git a/examples/syn.meow b/examples/syn.meow
index 87fa290..6af0f8e 100644
--- a/examples/syn.meow
+++ b/examples/syn.meow
@@ -72,3 +72,10 @@ decode_add(s,x) {
 ife(x) {
     eq(x,"")
 }
+
+test2() {
+    "bb" = "g";
+    var x = "bc";
+    var y = { x };
+    y+x
+}
diff --git a/src/prog.rs b/src/prog.rs
index f1fd1df..aa9dd8a 100644
--- a/src/prog.rs
+++ b/src/prog.rs
@@ -67,6 +67,28 @@ fn apply_rule(x: &String, rules: &Vec<Rule>) -> String {
     result
 }
 
+fn clear_context(context: &Context) -> Context {
+    // clear the context
+    let mut newcontext = Context::new();
+    newcontext.symbols = context
+        .symbols
+        .iter()
+        .filter(|(_, v)| match v {
+            Symbol::Variable(_) => false,
+            Symbol::Macro(_) => true,
+        })
+        .map(|(k, v)| (k.clone(), v.clone()))
+        .collect();
+    newcontext
+}
+
+fn clear_rules(context: &Context) -> Context {
+    // clear the context
+    let mut newcontext = Context::new();
+    newcontext.symbols = context.symbols.clone();
+    newcontext
+}
+
 pub fn eval_raw(expr: &Box<Expr>, context: &Box<Context>) -> String {
     // Evaluate an expression in a given context.
     // Will not apply rules
@@ -83,8 +105,9 @@ pub fn eval_raw(expr: &Box<Expr>, context: &Box<Context>) -> String {
             }
         }
         Expr::MacAp(macap) => {
-            let mut newcontext: Context = *context.clone();
+            let mut newcontext = *context.clone();
             // macro application
+            newcontext = clear_context(&newcontext);
             let mac = context
                 .symbols
                 .get(&macap.name)
@@ -107,26 +130,15 @@ pub fn eval_raw(expr: &Box<Expr>, context: &Box<Context>) -> String {
             }
             eval_block(&mac.block, &Box::new(newcontext))
         }
-        Expr::Block(x) => eval_block(x, context),
+        Expr::Block(x) => eval_block(x, &Box::new(clear_rules(context))),
     }
 }
 
 pub fn eval(expr: &Box<Expr>, context: &Box<Context>) -> String {
     // Evaluate an expression in a given context.
     // Not allow to change context
-    match &**expr {
-        Expr::Literal(x) => apply_rule(x, &context.rules),
-        Expr::Cat(x, y) => {
-            let cat = eval_raw(x, context) + eval_raw(y, context).as_str();
-            apply_rule(&cat, &context.rules)
-        }
-        _ =>
-        // other cases
-        {
-            let res = eval_raw(expr, context);
-            apply_rule(&res, &context.rules)
-        }
-    }
+    let res = eval_raw(expr, context);
+    apply_rule(&res, &context.rules)
 }
 
 pub fn eval_block(block: &Box<Block>, context: &Box<Context>) -> String {