Lisp Syntax
Last modified by WikiBot on 2025/03/20 14:15
Lisp Syntax
The Lisp code is a sequence of items. An item is one of the following:
- A sequence of non-special characters (treated as a number or a symbol). The sequence is terminated by blank space or some special character except \, |, and #.
- A sequence of characters starting with a special character. The end of the sequence and the interpretation vary depending on the special character.
Here is the list of Lisp special characters used in IDA:
| ( | list | A sequence of items enclosed in matching parentheses is treated as a list; |
| " | string | A sequence of characters (even special) enclosed in double quotes is treated as a string; |
| ; | comment | All subsequent characters in this line are ignored; |
| ' | quote | ‘item is treated as a list (QUOTE item); |
| \ | single escape | The next character is treated as non-special (even inside strings enclosed in double quotes); |
| multiple escape | The following characters up to the next are treated as non-special; | |
| # | dispatch | Treated as special only if it starts an item. The meaning depends on the next character (with possible numerical parameter between # and that character); |
| #( | vector | A sequence of items enclosed in matching parentheses is treated as a 1-dimensional array; |
| #nA | array | #nA( … ) is treated as an n-dimensional array. The list in parentheses should be nested n times. The default value of n is 1; |
| #X | hex | An integer number in hexadecimal format; |
| #S | structure | #S(name field value field value …) is treated as a Lisp structure with given name and field values; |
| #\ | character | #\c is treated as character c. #\Name is treated as the named character. The named characters are Backspace, Tab, Linefeed, Page, Newline (alias Return), Escape, Delete (alias Rubout), and Control-A, …, Control-Z. |
| # | comment | All text till # is ignored. |
Here are IDA extensions to Lisp syntax:
| [ | bracket | This special character is reserved for Lisp users. IDA Modeler treats a sequence of items enclosed in matching brackets as a reference to object; |
| { | brace | This character is treated as special in IDA though it is not special in Lisp. IDA Modeler treats a sequence of items {item1 … } enclosed in matching braces as a list (:vector item1 … ). When used in a script expression, this list is evaluated to a vector. |
The special characters ` (back quote) and , (comma) are not used in IDA Modeler and treated as illegal. The closing parenthesis, bracket, and brace are also treated as special; they are illegal unless they match the opening ones.