合法的变量名 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 4.2 命名规范 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 5 整数和浮点数 Kronecker 积）。运算符也可以使用修改标记、引号和上 标/下标进行加缀，例如 +̂ₐ″ 被解析成一个与 + 具有相同优先级的中缀运算符。 唯一明确禁止的变量名称是内置关键字的名称： 4.2. 命名规范 19 julia> else = false ERROR: syntax: unexpected "else" julia> try = "No" ERROR: syntax: unexpected small letter open e) 和 µ (U+00B5: micro sign) 被视为等同于相应的希腊字母，因为前者很容易通过一些方法输入。 4.2 命名规范 虽然 Julia 语言对合法名字的限制非常少，但是遵循以下这些命名规范是非常有用的： • 变量的名字采用小写。 • 用下划线（_）分隔名字中的单词，但是不鼓励使用下划线，除非在不使用下划线时名字会非 常难读。 • 类型（Typ

arbitrary-precision integers and floating point numbers, Julia wraps the GNU Mul- tiple Precision Arithmetic Library (GMP) and the GNU MPFR Library, respectively. The BigInt and BigFloat types are available hidden arguments at the end of the argument list. While this behaviour is fixed for some com- pilers (GNU), others optionally permit placing hidden arguments directly after the character argument (Intel, == C_NULL # Could not allocate memory throw(OutOfMemoryError()) end return output_ptr end The GNU Scientific Library (here assumed to be accessible through :libgsl) defines an opaque pointer, gsl_permutation

arbitrary-precision integers and floating point numbers, Julia wraps the GNU Mul- tiple Precision Arithmetic Library (GMP) and the GNU MPFR Library, respectively. The BigInt and BigFloat types are available hidden arguments at the end of the argument list. While this behaviour is fixed for some com- pilers (GNU), others optionally permit placing hidden arguments directly after the character argument (Intel, throw(OutOfMemoryError()) end return output_ptr endCHAPTER 27. CALLING C AND FORTRAN CODE 357 The GNU Scientific Library (here assumed to be accessible through :libgsl) defines an opaque pointer, gsl_permutation

arbitrary-precision integers and floating point numbers, Julia wraps the GNU Multiple Precision Arithmetic Library (GMP) and the GNU MPFR Library, respectively. The BigInt and BigFloat types are available hidden arguments at the end of the argument list. While this behaviour is fixed for some compilers (GNU), others optionally permit placing hidden arguments directly after the character argument (Intel, == C_NULL # Could not allocate memory throw(OutOfMemoryError()) end return output_ptr end The GNU Scientific Library (here assumed to be accessible through :libgsl) defines an opaque pointer, gsl_permutation

arbitrary-precision integers and floating point numbers, Julia wraps the GNU Mul- tiple Precision Arithmetic Library (GMP) and the GNU MPFR Library, respectively. The BigInt and BigFloat types are available hidden arguments at the end of the argument list. While this behaviour is fixed for some compilers (GNU), others optionally permit placing hidden arguments directly after the character argument (Intel, throw(OutOfMemoryError()) end return output_ptr endCHAPTER 28. CALLING C AND FORTRAN CODE 379 The GNU Scientific Library (here assumed to be accessible through :libgsl) defines an opaque pointer, gsl_permutation

arbitrary-precision integers and floating point numbers, Julia wraps the GNU Mul- tiple Precision Arithmetic Library (GMP) and the GNU MPFR Library, respectively. The BigInt and BigFloat types are available hidden arguments at the end of the argument list. While this behaviour is fixed for some compilers (GNU), others optionally permit placing hidden arguments directly after the character argument (Intel, memoryCHAPTER 28. CALLING C AND FORTRAN CODE 379 throw(OutOfMemoryError()) end return output_ptr end The GNU Scientific Library (here assumed to be accessible through :libgsl) defines an opaque pointer, gsl_permutation

arbitrary-precision integers and floating point numbers, Julia wraps the GNU Mul- tiple Precision Arithmetic Library (GMP) and the GNU MPFR Library, respectively. The BigInt and BigFloat types are available hidden arguments at the end of the argument list. While this behaviour is fixed for some com- pilers (GNU), others optionally permit placing hidden arguments directly after the character argument (Intel, throw(OutOfMemoryError()) end return output_ptr end CHAPTER 27. CALLING C AND FORTRAN CODE 354 The GNU Scientific Library (here assumed to be accessible through :libgsl) defines an opaque pointer, gsl_permutation

arbitrary-precision integers and floating point numbers, Julia wraps the GNU Mul- tiple Precision Arithmetic Library (GMP) and the GNU MPFR Library, respectively. The BigInt and BigFloat types are available hidden arguments at the end of the argument list. While this behaviour is fixed for some com- pilers (GNU), others optionally permit placing hidden arguments directly after the character argument (Intel, throw(OutOfMemoryError()) end return output_ptr end CHAPTER 27. CALLING C AND FORTRAN CODE 354 The GNU Scientific Library (here assumed to be accessible through :libgsl) defines an opaque pointer, gsl_permutation

arbitrary-precision integers and floating point numbers, Julia wraps the GNU Mul- tiple Precision Arithmetic Library (GMP) and the GNU MPFR Library, respectively. The BigInt and BigFloat types are available hidden arguments at the end of the argument list. While this behaviour is fixed for some com- pilers (GNU), others optionally permit placing hidden arguments directly after the character argument (Intel, throw(OutOfMemoryError()) end return output_ptr end CHAPTER 27. CALLING C AND FORTRAN CODE 354 The GNU Scientific Library (here assumed to be accessible through :libgsl) defines an opaque pointer, gsl_permutation

arbitrary-precision integers and floating point numbers, Julia wraps the GNU Mul- tiple Precision Arithmetic Library (GMP) and the GNU MPFR Library, respectively. The BigInt and BigFloat types are available hidden arguments at the end of the argument list. While this behaviour is fixed for some com- pilers (GNU), others optionally permit placing hidden arguments directly after the character argument (Intel, throw(OutOfMemoryError()) end return output_ptr end CHAPTER 27. CALLING C AND FORTRAN CODE 356 The GNU Scientific Library (here assumed to be accessible through :libgsl) defines an opaque pointer, gsl_permutation