2.8 Symbols

There are no implementation-specific limits on the size or content of symbol names. It is however not allowed to write on the strings which have been passed to #'make-symbol or returned from #'symbol-name.

2.8.1 C Reference

Function: cl_object ecl_make_keyword (char *name);

Find a lisp keyword

Description

Many Lisp functions take keyword arguments. When invoking a function with keyword arguments we need keywords, which are a kind of symbols that live in the keyword package. This function does the task of finding or creating those keywords from C strings.

• It is usually safe to store the resulting pointer, because keywords are always referenced by their package and will not be garbage collected (unless of course, you decide to delete it).
• Remember that the case of the string is significant. ecl_make_keyword("TO") with return :TO, while ecl_make_keyword("to") returns a completely different keyword, :|to|. In short, you usually want to use uppercase.

Example

The following example converts a section of a string to uppercase characters:

cl_object start = ecl_make_keyword("START");
cl_object end = ecl_make_keyword("END");
...
sup = cl_string_upcase(4, s, start, ecl_make_fixnum(2),
                       end, ecl_make_fixnum(6));

Function: cl_object ecl_make_symbol (const char *name, const char *package_name);

Find a lisp symbol

Description

This function finds or create a symbol in the given package. First of all, it tries to find the package named by package_name. If it does not exist, an error is signaled. Then, a symbol with the supplied name is created and interned in the given package.

2.8.1.1 ANSI Dictionary

Common Lisp and C equivalence