简易绘图语言解释器

介绍：

该程序为一个简单绘图语言的编译器，该编译器接受简单绘图语言源程序，生成对应图案。

实现方法：

该编译器首先读取所有的绘图语言源程序，然后逐条将源码传递到词法分析部分，经过词法分析后，传递记号流到语法分析，经过语法分析传递完整句子到语义分析部分，经过语义分析，保存颜色参数和点的坐标，继续下一条源码分析。当源码分析完成之后，将颜色参数和点坐标序列传递到绘图方法中，实现绘图。

运行环境：

• Ubuntu 16.04
• IDEA 2017.2.2
• java-1.8.0-openjdk-amd64

绘图示例：

源程序：

ROT IS 0;
ORIGIN IS (50,400);
SCALE IS (2,1);
FOR T FROM 0 TO 300 STEP 1 DRAW(T,0);
//横坐标
FOR T FROM 0 TO 300 STEP 1 DRAW(0,-T);
--纵坐标
SCALE IS (1,1);
FOR T FROM 0 TO 300 STEP 1 DRAW(T,-T);
SCALE IS (20,0.1);
FOR T FROM 0 TO 50 STEP 0.1 DRAW(T,-EXP(T));
SCALE IS (2,0.1);
FOR T FROM 0 TO 100 STEP 1 DRAW(T,-(T*T));
SCALE IS (10,5);
FOR T FROM 0 TO 60 STEP 1 DRAW(T,-SQRT(T));
origin is (50,400);
scale is (50,50);
for t from 0 to 100 step 1 draw(sin(t),cos(t));

setcolor(blue);
origin is (400,200);
scale is (50,50);
for t from 0 to 100 step 1 draw(sin(t),cos(t));
setcolor(black);
origin is (500,200);
scale is (50,50);
for t from 0 to 100 step 1 draw(sin(t),cos(t));
setcolor(red);
origin is (600,200);
scale is (50,50);
for t from 0 to 100 step 1 draw(sin(t),cos(t));
setcolor(yellow);
origin is (450,250);
scale is (50,50);
for t from 0 to 100 step 1 draw(sin(t),cos(t));
setcolor(green);
origin is (550,250);
scale is (50,50);
for t from 0 to 100 step 1 draw(sin(t),cos(t));

绘图结果：