我正在构建一个使用Lex和Yacc的计算器编译器。该想法基于以下资源:http://epaperpress.com/lexandyacc/index.html。完整的注释REGEX为LEX
因为我需要找出所有的评论给定的输入文件:
//.TEST -- JWJ
//.Step final -- testing all requirements
//.source: test-1m.cal
//.expected output: test-1m_expected.out
/**
* This program will use Newton's method to estimate the roots of
This should be a comment as well, but does not get picked up
* f(x) = x^3 - 3*x
*/
float xn;
float xo;
// int num_iterations;
xo = 3.0;
xn = 3.0;
num_iterations = 1;
/* A do-while loop */
do {
print xo;
xo = xn;
xn = xo - (xo * xo * xo - 3.0 * xo )/(3.0 * xo * xo - 3.0);
num_iterations = num_iterations + 1;
} while (num_iterations <= 6)
print xn; // The root found using Newton's method.
print (xo * xo * xo - 3.0 * xo); // Print f(xn), which should be 0.
我用我的lex文件下面的正则表达式:
"//"[^\n]*|"\/\*".*"\*\/"
"\/\*"([^\n])*
(.)*"\*\/"
我不明白为什么多在线评论没有被匹配?有人可以提供一些见解吗?