Like preprocess in C, Melang supports simple preprocess.
#define NAME 'John' //define macro #NAME //use macro #undef NAME //undefine macro
Name is equivalent to ‘John’. Melang just simply replace ‘NAME’ with ‘John’ in code.
//example A #if NAME ... //code A #endif //example B #if NAME ... //code B #else ... //code C #endif
In example A, if NAME is defined, code A will be executed.
In example B, if NAME is defined, code B will be executed, otherwise execute code C.
Just like include in C, Melang also support it to load some script files into a file.
Note: the included file must be quoted by double quotes.
The path should follow these rules:
if path is an absolute path, just try to load it.
if path is not a absolute path, interpreter will search for file in the following order:
If failed, an error would be occurred.
//in /xxx/yyy/a.m #include "@/b.m"
@ is a special char stands for base directory of current file (
a.m). So its value is `/xxx/yyy’.
/xxx/yyy/b.m will be included in