打印换行缩减为一行

zuisong · Jun 27, 2019 · 5c09276 · 5c09276
1 parent c36db31
commit 5c09276
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Showing 3 changed files with 17 additions and 41 deletions.
diff --git a/src/expression.rs b/src/expression.rs
@@ -112,33 +112,22 @@ impl Expression for Not {
     }
 }
 
-///
-/// 打印换行
-#[derive(Debug)]
-pub struct Println {
-    /// 要打印换行的表达式对象
-    pub expression: Box<dyn Expression>,
-}
-
-impl Expression for Println {
-    fn evaluate(&self, ctx: &mut Context) -> Result<Value, failure::Error> {
-        let res = self.expression.evaluate(ctx).unwrap();
-        ctx.output.push(format!("{}\n", res.to_string()));
-        Ok(Value::Void)
-    }
-}
-
-/// 打印不换行
+/// 打印
 #[derive(Debug)]
 pub struct Print {
     /// 要打印的表达式对象
     pub expression: Box<dyn Expression>,
+    /// 是否换行
+    pub is_newline: bool,
 }
 
 impl Expression for Print {
     fn evaluate(&self, ctx: &mut Context) -> Result<Value, failure::Error> {
         let res = self.expression.evaluate(ctx).unwrap();
         ctx.output.push(res.to_string());
+        if self.is_newline {
+            ctx.output.push(String::from("\n"));
+        }
         Ok(Value::Void)
     }
 }

diff --git a/src/parse.rs b/src/parse.rs
@@ -1,3 +1,5 @@
+#![deny(missing_docs)]
+
 use std::collections::VecDeque;
 
 use crate::*;
@@ -150,13 +152,8 @@ pub fn parse_sequence(
                 v.push_back(var.1);
                 start_line = var.0 + 1;
             }
-            Token::StdFunction(StdFunction::Println) => {
-                let var = parse_println(&lines[start_line])?;
-                v.push_back(var);
-                start_line += 1;
-            }
-            Token::StdFunction(StdFunction::Print) => {
-                let var = parse_print(&lines[start_line])?;
+            Token::StdFunction(StdFunction::Print(is_newline)) => {
+                let var = parse_print(&lines[start_line], *is_newline)?;
                 v.push_back(var);
                 start_line += 1;
             }
@@ -224,18 +221,11 @@ pub fn parse_for(
     return Ok((cmd.0, box loop_expr));
 }
 
-fn parse_println(line: &[Token]) -> Result<Box<dyn Expression>, failure::Error> {
-    debug!("{:?}", line);
-    let expression = parse_expression(&line[2..(line.len() - 1)])?;
-    Ok(box Println {
-        expression: expression,
-    })
-}
-
-fn parse_print(line: &[Token]) -> Result<Box<dyn Expression>, failure::Error> {
+fn parse_print(line: &[Token], is_newline: bool) -> Result<Box<dyn Expression>, failure::Error> {
     debug!("{:?}", line);
     let expression = parse_expression(&line[2..(line.len() - 1)])?;
     Ok(box Print {
-        expression: expression,
+        expression,
+        is_newline,
     })
 }
diff --git a/src/token.rs b/src/token.rs
@@ -52,10 +52,8 @@ pub enum Operator {
 /// 标准库函数
 #[derive(Debug, Eq, PartialEq, Clone)]
 pub enum StdFunction {
-    /// println
-    Println,
-    /// print
-    Print,
+    /// print  bool表示是否换行
+    Print(bool),
 }
 
 /// token 类型
@@ -113,7 +111,6 @@ pub fn tokenlizer(code: String) -> Result<Vec<Token>, failure::Error> {
                 continue;
             }
             '\r' | '\n' => (Token::NewLine, 1),
-
             '{' => (Token::LBig, 1),
             '}' => (Token::RBig, 1),
             '[' => (Token::LSquare, 1),
@@ -174,8 +171,8 @@ pub fn tokenlizer(code: String) -> Result<Vec<Token>, failure::Error> {
                 }
                 let s: String = chars.as_slice()[i..j].iter().collect();
                 let token = match s.as_str() {
-                    "println" => Token::StdFunction(StdFunction::Println),
-                    "print" => Token::StdFunction(StdFunction::Print),
+                    "println" => Token::StdFunction(StdFunction::Print(true)),
+                    "print" => Token::StdFunction(StdFunction::Print(false)),
                     "int" => Token::Keyword(Keyword::INT),
                     "if" => Token::Keyword(Keyword::IF),
                     "else" => Token::Keyword(Keyword::ELSE),