Macro.PreThere is no default env, but you can add any of these to your env.
val ignore : ('a, string) macroignore is a macro that ignores all its parameters and returns the empty string.
This is good for comments within a string: "{ignore|This is a comment.}This is not."
val name : ('a, string) macroname is a macro that returns its own name.
val parms : ('a, string) macroparms is a macro that returns its parameter list as a string, with the parameters separated by a spaces.
val self : ?left:char -> ?sep:char -> ?right:char -> ('a, string) macro(self ?left ?sep ?right) is a macro that returns a string representation of itself (with parameters expanded).
N.B. These macros only work for the default syntax; if you change the syntax, you might need to provide your own quoters.
val left : ('a, string) macroleft is a macro that expands to left.
This means "{left}" is a way to quote the left parenthesis.
val sep : ('a, string) macrosep is a macro that expands to sep.
This means "{sep}" is a way to quote the parameter separator.
val right : ('a, string) macroright is a macro that expands to right.
This means "{right}" is a way to quote the right parenthesis.
val trim : ('a, string) macrotrim is a macro that trims leading and trailing characters from its first parameter.
The default trimmed characters are Strings.whitespace. If you pass a second parameter, it is a string of the characters to be trimmed.
This macro just calls Strings.trim appropriately.