Note It is not recommended to change the class of the special characters, since in some cases it might make it impossible to correctly parse Prolog terms.
The following table lists the character classes and the default corresponding characters:
Class Default member characters --------------------------------------------------------- upper-case all upper case letters underline - lower-case all lower case letters digit digits blank-space space and nonprintable ASCII characters end-ofline carriage return and line feed atom-quote ' string-quote " list-quote radix ascii solo ( ) ] } special ! , ; [ { | line-comment % escape \ first-comment / second-comment * symbol # + - . : < = > ? @ ^ ` ~ & $ unused ASCII codes 8, 17, 21, 24 null null character
Success: % The following example illustrates the use % of set_chtab/2 to redefine the class of the % dollar symbol. % [eclipse]: X = $a. ^ (here?) syntax error: postfix/infix operator expected [eclipse]: set_chtab(0'$, lower_case). yes. [eclipse]: X = $a. X = $a yes. [eclipse]: Error: set_chtab("a",symbol). (Error 5) set_chtab(97,fred). (Error 6)