version 0.2.6 finished✅

1. penguin will create directory `graph` automatically now
2. you can draw many picture in one program now(call `show;` more than one times)

code.pg

@@ -4,25 +4,37 @@ scale is (1, 1);
 // draw the graph
 set x (-100, 100);
 set y (-100, 100);
+
 set size 2;
 set color red;
 rot is PI / 4;
 origin is (-20, -20);
 for t from -100 to 100 step 0.8 draw(80 * sin(t), 35 * cos(t)); // circle
+
 set size 1;
 set color blue;
 rot is 0;
 origin is (0, 0);
 for t from -100 to 100 step 0.01 draw(t, 40 * sin(t / 2)); //sine
+
 set color green;
 for t from -100 to 100 step 0.01 draw(t, 10 * cos(t / 10+ 10)); // cosine
+
+show;
+
 set size 3;
 set color cyan;
 for t from -100 to 100 step 5 draw(t, t);
+
 set color yellow;
 for t from -2*PI to 2*PI step 0.07 draw(60*sin(t), 60*cos(t));
+
+show;
+
 set color MAGENTA;
 for t from 0 to 2*PI step 0.1 draw (t, sin(PI/2));
+
 set color black;
 for t from 0 to 2*PI step 0.1 draw (t+10, sin(90));
+
 show;

src/main.rs

@@ -2,7 +2,7 @@ mod rt_util;
 mod tree_node;
 
 use std::fs;
-use std::io::{self, BufRead, Write};
+use std::io::{self, BufRead, ErrorKind, Write};
 use lazy_static::lazy_static;
 use regex::Regex;
 use lrlex::lrlex_mod;
@@ -18,7 +18,7 @@ lrlex_mod!("lexer.l");
 // with a suffix of `_y`).
 lrpar_mod!("parser.y");
 
-const VERSION: &str = "0.2.5";
+const VERSION: &str = "0.2.6";
 
 lazy_static!(
     static ref EXIT: Vec<String> = {
@@ -44,11 +44,19 @@ fn info() {
 
 fn main() {
     info();
-
     #[cfg(feature = "debug")] {
         println!("### debug mode is open. ###");
     }
 
+    // create directory for graph that user will draw
+    match fs::create_dir("graph") {
+        Err(e) => match e.kind() {
+            ErrorKind::AlreadyExists => {}
+            _ => eprintln!("!{:?}", e),
+        }
+        Ok(_) => { println!("# Created directory `graph` for output.") }
+    }
+
     let runtime = RunTime::new();
 
     let args = std::env::args();

src/rt_util.rs

@@ -1,15 +1,18 @@
+use std::fmt::format;
 use std::process::exit;
 use lazy_static::lazy_static;
 use lrlex::{DefaultLexeme, lrlex_mod};
 use lrpar::lrpar_mod;
 use plotters::prelude::*;
 use crate::tree_node::TreeNode;
-use crate::tree_node;
+use crate::{file, tree_node};
 lrlex_mod!("lexer.l");
 lrpar_mod!("parser.y");
 
+
 lazy_static!(
     static ref LEXER_DEF: lrlex::LRNonStreamingLexerDef<DefaultLexeme, u32> = lexer_l::lexerdef();
+    static ref PIC_NUM: u32 = 0;
 );
 
 #[derive(Debug)]
@@ -44,6 +47,7 @@ pub struct RunTime {
     y_range: (f64, f64),
     size: f64,
     color: String,
+    pic_num: u32,
 }
 
 impl RunTime {
@@ -57,6 +61,7 @@ impl RunTime {
             y_range: (-4.0, 4.0),
             size: 2.0,
             color: "blue".to_string(),
+            pic_num: 0,
         }
     }
 
@@ -71,6 +76,7 @@ impl RunTime {
             y_range: (0.0, 0.0),
             size,
             color,
+            pic_num: 0,
         }
     }
 
@@ -114,9 +120,11 @@ impl RunTime {
     }
 
     pub fn show(&mut self) {
+        let file_name = format!("graph/{}.png", self.pic_num);
         let root =
-            BitMapBackend::new("graph/0.png", (1024, 1024))
+            BitMapBackend::new(file_name.as_str(), (1024, 1024))
                 .into_drawing_area();
+
         root.fill(&WHITE).unwrap();
         let mut chart = ChartBuilder::on(&root)
             .margin(60)
@@ -163,8 +171,9 @@ impl RunTime {
                 },
             )).unwrap();
         });
-        println!("Draw success in ./graph/0.png");
+        println!("Draw success in {}", file_name);
         self.graph.clear();
+        self.pic_num += 1;
     }