diff --git a/src/ins.rs b/src/ins.rs
index 5a72716..8bd0d3a 100644
--- a/src/ins.rs
+++ b/src/ins.rs
@@ -1,148 +1,3 @@
-
-#[derive(Debug)]
-pub enum InsId {
-    Push, // has data
-    Dup,
-    CopyN, // has data
-    Swap,
-    Pop,
-    PopN, // has data
-    Add,
-    Sub,
-    Mul,
-    Div,
-    Mod,
-    Store,
-    Retrieve,
-    DefineLabel, // has data
-    CallAtLabel, // has data
-    GotoLabel, // has data
-    GotoLabelE0, // has data
-    GotoLabelL0, // has data
-    ReturnCallAt,
-    End,
-    StdOutChar,
-    StdOutNum,
-    StdInChar,
-    StdInNum,
-}
-
-impl InsId {
-    pub fn has_data(&self) -> bool {
-        match self {
-            InsId::Push | InsId::CopyN | InsId::PopN |
-            InsId::DefineLabel | InsId::CallAtLabel |
-            InsId::GotoLabel | InsId::GotoLabelE0 | InsId::GotoLabelL0 => true,
-            _ => false,
-        }
-    }
-
-    pub fn new_instruction(&self, data: Option<isize>) -> Instruction {
-        match self {
-            InsId::Push => Instruction::Push(data.unwrap_or(0)),
-            InsId::Dup => Instruction::Dup,
-            InsId::CopyN => Instruction::CopyN(data.unwrap_or(0)),
-            InsId::Swap => Instruction::Swap,
-            InsId::Pop => Instruction::Pop,
-            InsId::PopN => Instruction::PopN(data.unwrap_or(0)),
-            InsId::Add => Instruction::Add,
-            InsId::Sub => Instruction::Sub,
-            InsId::Mul => Instruction::Mul,
-            InsId::Div => Instruction::Div,
-            InsId::Mod => Instruction::Mod,
-            InsId::Store => Instruction::Store,
-            InsId::Retrieve => Instruction::Retrieve,
-            InsId::DefineLabel => Instruction::DefineLabel(data.unwrap_or(0)),
-            InsId::CallAtLabel => Instruction::CallAtLabel(data.unwrap_or(0)),
-            InsId::GotoLabel => Instruction::GotoLabel(data.unwrap_or(0)),
-            InsId::GotoLabelE0 => Instruction::GotoLabelE0(data.unwrap_or(0)),
-            InsId::GotoLabelL0 => Instruction::GotoLabelL0(data.unwrap_or(0)),
-            InsId::ReturnCallAt => Instruction::ReturnCallAt,
-            InsId::End => Instruction::End,
-            InsId::StdOutChar => Instruction::StdOutChar,
-            InsId::StdOutNum => Instruction::StdOutNum,
-            InsId::StdInChar => Instruction::StdInChar,
-            InsId::StdInNum => Instruction::StdInNum,
-        }
-    }
-}
-
-#[derive(Debug)]
-pub enum InsType {
-    Path(InsColl),
-    Node(InsId),
-}
-
-#[derive(Debug)]
-pub struct Ins {
-    pub c: char,
-    pub ins_type: InsType,
-}
-
-#[derive(Debug)]
-pub struct InsColl {
-    pub inses: Vec<Ins>,
-}
-
-pub fn make_instruction_tree() -> InsColl {
-    InsColl{ inses: vec![
-        Ins{ c: '草', ins_type: InsType::Path(InsColl{ inses: vec![
-            Ins{ c: '草', ins_type: InsType::Node(InsId::Push) },
-            Ins{ c: '马', ins_type: InsType::Path(InsColl{ inses: vec![
-                Ins{ c: '草', ins_type: InsType::Node(InsId::Dup) },
-                Ins{ c: '泥', ins_type: InsType::Node(InsId::Swap) },
-                Ins{ c: '马', ins_type: InsType::Node(InsId::Pop) }
-            ]})},
-            Ins{ c: '泥', ins_type: InsType::Path(InsColl{ inses: vec![
-                Ins{ c: '草', ins_type: InsType::Node(InsId::CopyN) },
-                Ins{ c: '马', ins_type: InsType::Node(InsId::PopN) }
-            ]})},
-        ]})},
-        Ins{ c: '泥', ins_type: InsType::Path(InsColl{ inses: vec![
-            Ins{ c: '草', ins_type: InsType::Path(InsColl{ inses: vec![
-                Ins{ c: '草', ins_type: InsType::Path(InsColl{ inses: vec![
-                    Ins{ c: '草', ins_type: InsType::Node(InsId::Add) },
-                    Ins{ c: '泥', ins_type: InsType::Node(InsId::Sub) },
-                    Ins{ c: '马', ins_type: InsType::Node(InsId::Mul) },
-                ]})},
-                Ins{ c: '泥', ins_type: InsType::Path(InsColl{ inses: vec![
-                    Ins{ c: '草', ins_type: InsType::Node(InsId::Div) },
-                    Ins{ c: '泥', ins_type: InsType::Node(InsId::Mod) },
-                ]})},
-            ]})},
-            Ins{ c: '泥', ins_type: InsType::Path(InsColl{ inses: vec![
-                Ins{ c: '草', ins_type: InsType::Node(InsId::Store) },
-                Ins{ c: '泥', ins_type: InsType::Node(InsId::Retrieve) },
-            ]})},
-            Ins{ c: '马', ins_type: InsType::Path(InsColl{ inses: vec![
-                Ins{ c: '草', ins_type: InsType::Path(InsColl{ inses: vec![
-                    Ins{ c: '草', ins_type: InsType::Node(InsId::StdOutChar) },
-                    Ins{ c: '泥', ins_type: InsType::Node(InsId::StdOutNum) },
-                ]})},
-                Ins{ c: '泥', ins_type: InsType::Path(InsColl{ inses: vec![
-                    Ins{ c: '草', ins_type: InsType::Node(InsId::StdInChar) },
-                    Ins{ c: '泥', ins_type: InsType::Node(InsId::StdInNum) },
-                ]})},
-            ]})},
-        ]})},
-        Ins{ c: '马', ins_type: InsType::Path(InsColl{ inses: vec![
-            Ins{ c: '草', ins_type: InsType::Path(InsColl{ inses: vec![
-                Ins{ c: '草', ins_type: InsType::Node(InsId::DefineLabel) },
-                Ins{ c: '泥', ins_type: InsType::Node(InsId::CallAtLabel) },
-                Ins{ c: '马', ins_type: InsType::Node(InsId::GotoLabel) },
-            ]})},
-            Ins{ c: '泥', ins_type: InsType::Path(InsColl{ inses: vec![
-                Ins{ c: '草', ins_type: InsType::Node(InsId::GotoLabelE0) },
-                Ins{ c: '泥', ins_type: InsType::Node(InsId::GotoLabelL0) },
-                Ins{ c: '马', ins_type: InsType::Node(InsId::ReturnCallAt) },
-            ]})},
-            Ins{ c: '马', ins_type: InsType::Path(InsColl{ inses: vec![
-                Ins{ c: '马', ins_type: InsType::Node(InsId::End) },
-            ]})},
-        ]})},
-    ]}
-}
-
 #[derive(Debug, Clone)]
 pub enum Instruction {
     Push(isize),
diff --git a/src/parser.rs b/src/parser.rs
index d9733f3..586749f 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -3,6 +3,91 @@ use super::ins::*;
 
 pub const VALID_INSTRUCTION_CHARS: &str = "草泥马河蟹";
 
+#[derive(Debug)]
+enum InsId {
+    Push, // has data
+    Dup,
+    CopyN, // has data
+    Swap,
+    Pop,
+    PopN, // has data
+    Add,
+    Sub,
+    Mul,
+    Div,
+    Mod,
+    Store,
+    Retrieve,
+    DefineLabel, // has data
+    CallAtLabel, // has data
+    GotoLabel, // has data
+    GotoLabelE0, // has data
+    GotoLabelL0, // has data
+    ReturnCallAt,
+    End,
+    StdOutChar,
+    StdOutNum,
+    StdInChar,
+    StdInNum,
+}
+
+impl InsId {
+    fn has_data(&self) -> bool {
+        match self {
+            InsId::Push | InsId::CopyN | InsId::PopN |
+            InsId::DefineLabel | InsId::CallAtLabel |
+            InsId::GotoLabel | InsId::GotoLabelE0 | InsId::GotoLabelL0 => true,
+            _ => false,
+        }
+    }
+
+    fn new_instruction(&self, data: Option<isize>) -> Instruction {
+        match self {
+            InsId::Push => Instruction::Push(data.unwrap_or(0)),
+            InsId::Dup => Instruction::Dup,
+            InsId::CopyN => Instruction::CopyN(data.unwrap_or(0)),
+            InsId::Swap => Instruction::Swap,
+            InsId::Pop => Instruction::Pop,
+            InsId::PopN => Instruction::PopN(data.unwrap_or(0)),
+            InsId::Add => Instruction::Add,
+            InsId::Sub => Instruction::Sub,
+            InsId::Mul => Instruction::Mul,
+            InsId::Div => Instruction::Div,
+            InsId::Mod => Instruction::Mod,
+            InsId::Store => Instruction::Store,
+            InsId::Retrieve => Instruction::Retrieve,
+            InsId::DefineLabel => Instruction::DefineLabel(data.unwrap_or(0)),
+            InsId::CallAtLabel => Instruction::CallAtLabel(data.unwrap_or(0)),
+            InsId::GotoLabel => Instruction::GotoLabel(data.unwrap_or(0)),
+            InsId::GotoLabelE0 => Instruction::GotoLabelE0(data.unwrap_or(0)),
+            InsId::GotoLabelL0 => Instruction::GotoLabelL0(data.unwrap_or(0)),
+            InsId::ReturnCallAt => Instruction::ReturnCallAt,
+            InsId::End => Instruction::End,
+            InsId::StdOutChar => Instruction::StdOutChar,
+            InsId::StdOutNum => Instruction::StdOutNum,
+            InsId::StdInChar => Instruction::StdInChar,
+            InsId::StdInNum => Instruction::StdInNum,
+        }
+    }
+}
+
+#[derive(Debug)]
+enum InsType {
+    Path(InsColl),
+    Node(InsId),
+}
+
+#[derive(Debug)]
+struct Ins {
+    c: char,
+    ins_type: InsType,
+}
+
+#[derive(Debug)]
+struct InsColl {
+    inses: Vec<Ins>,
+}
+
 pub fn parse_lang(lang: &str) -> Result<Vec<Instruction>, ParseError> {
     let mut r = vec![];
 
@@ -22,6 +107,65 @@ pub fn parse_lang(lang: &str) -> Result<Vec<Instruction>, ParseError> {
     Ok(r)
 }
 
+fn make_instruction_tree() -> InsColl {
+    InsColl{ inses: vec![
+        Ins{ c: '草', ins_type: InsType::Path(InsColl{ inses: vec![
+            Ins{ c: '草', ins_type: InsType::Node(InsId::Push) },
+            Ins{ c: '马', ins_type: InsType::Path(InsColl{ inses: vec![
+                Ins{ c: '草', ins_type: InsType::Node(InsId::Dup) },
+                Ins{ c: '泥', ins_type: InsType::Node(InsId::Swap) },
+                Ins{ c: '马', ins_type: InsType::Node(InsId::Pop) }
+            ]})},
+            Ins{ c: '泥', ins_type: InsType::Path(InsColl{ inses: vec![
+                Ins{ c: '草', ins_type: InsType::Node(InsId::CopyN) },
+                Ins{ c: '马', ins_type: InsType::Node(InsId::PopN) }
+            ]})},
+        ]})},
+        Ins{ c: '泥', ins_type: InsType::Path(InsColl{ inses: vec![
+            Ins{ c: '草', ins_type: InsType::Path(InsColl{ inses: vec![
+                Ins{ c: '草', ins_type: InsType::Path(InsColl{ inses: vec![
+                    Ins{ c: '草', ins_type: InsType::Node(InsId::Add) },
+                    Ins{ c: '泥', ins_type: InsType::Node(InsId::Sub) },
+                    Ins{ c: '马', ins_type: InsType::Node(InsId::Mul) },
+                ]})},
+                Ins{ c: '泥', ins_type: InsType::Path(InsColl{ inses: vec![
+                    Ins{ c: '草', ins_type: InsType::Node(InsId::Div) },
+                    Ins{ c: '泥', ins_type: InsType::Node(InsId::Mod) },
+                ]})},
+            ]})},
+            Ins{ c: '泥', ins_type: InsType::Path(InsColl{ inses: vec![
+                Ins{ c: '草', ins_type: InsType::Node(InsId::Store) },
+                Ins{ c: '泥', ins_type: InsType::Node(InsId::Retrieve) },
+            ]})},
+            Ins{ c: '马', ins_type: InsType::Path(InsColl{ inses: vec![
+                Ins{ c: '草', ins_type: InsType::Path(InsColl{ inses: vec![
+                    Ins{ c: '草', ins_type: InsType::Node(InsId::StdOutChar) },
+                    Ins{ c: '泥', ins_type: InsType::Node(InsId::StdOutNum) },
+                ]})},
+                Ins{ c: '泥', ins_type: InsType::Path(InsColl{ inses: vec![
+                    Ins{ c: '草', ins_type: InsType::Node(InsId::StdInChar) },
+                    Ins{ c: '泥', ins_type: InsType::Node(InsId::StdInNum) },
+                ]})},
+            ]})},
+        ]})},
+        Ins{ c: '马', ins_type: InsType::Path(InsColl{ inses: vec![
+            Ins{ c: '草', ins_type: InsType::Path(InsColl{ inses: vec![
+                Ins{ c: '草', ins_type: InsType::Node(InsId::DefineLabel) },
+                Ins{ c: '泥', ins_type: InsType::Node(InsId::CallAtLabel) },
+                Ins{ c: '马', ins_type: InsType::Node(InsId::GotoLabel) },
+            ]})},
+            Ins{ c: '泥', ins_type: InsType::Path(InsColl{ inses: vec![
+                Ins{ c: '草', ins_type: InsType::Node(InsId::GotoLabelE0) },
+                Ins{ c: '泥', ins_type: InsType::Node(InsId::GotoLabelL0) },
+                Ins{ c: '马', ins_type: InsType::Node(InsId::ReturnCallAt) },
+            ]})},
+            Ins{ c: '马', ins_type: InsType::Path(InsColl{ inses: vec![
+                Ins{ c: '马', ins_type: InsType::Node(InsId::End) },
+            ]})},
+        ]})},
+    ]}
+}
+
 fn match_instruction(ins_coll: &InsColl, cs: &mut dyn Iterator<Item=char>) -> Result<Option<Instruction>, ParseError> {
     if let Some(c) = cs.next() {
         for ins in &ins_coll.inses {