X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=ginac%2Fparser%2Fparse_context.h;h=1145a871cb4b2da67a95373d44ea0812ab2567a5;hp=b227c6654fb40d4e917e39e0067b859f5865ef60;hb=866b3eb23253a272788d8791b1ed023e63674d50;hpb=95ede03f00106be5fb087d76c86ca5c27edb9122

diff --git a/ginac/parser/parse_context.h b/ginac/parser/parse_context.h
index b227c665..1145a871 100644
--- a/ginac/parser/parse_context.h
+++ b/ginac/parser/parse_context.h
@@ -41,12 +41,12 @@ namespace GiNaC {
 typedef std::map<std::string, ex> symtab;
 
 /**
- * Find the symbol with the @a name in the symbol table @a syms.
+ * Find the symbol (or abbreviation) with the @a name in the symbol table @a syms.
  *
  * If symbol is missing and @a strict = false, insert it, otherwise
  * throw an exception.
  */
-extern symbol
+extern ex 
 find_or_insert_symbol(const std::string& name, symtab& syms,
 	              const bool strict);
 
@@ -72,18 +72,36 @@ typedef ex (*reader_func)(const exvector& args);
  * foo(x+y, z^2, t)), it looks up such a table to find out which
  * function (or class) corresponds to the given name and has the given
  * number of the arguments.
+ *
+ * N.B.
+ *
+ * 1. The function don't have to return a (GiNaC) function or class, it
+ *    can return any expression.
+ * 2. Overloaded functions/ctors are paritally supported, i.e. there might
+ *    be several functions with the same name, but they should take different
+ *    number of arguments.
+ * 3. User can extend the parser via custom prototype tables. It's possible
+ *    to read user defined classes, create abbreviations, etc.
+ *
+ * NOTE: due to a hack that allows user defined functions to be parsed, the map
+ *       value of type reader_func is internally treated as an unsigned and not as a
+ *       function pointer!! The unsigned has to correspond to the serial number of
+ *       the defined GiNaC function.
  */
-typedef std::map<prototype, unsigned> prototype_table;
+typedef std::map<prototype, reader_func> prototype_table;
 
 /**
- * Creates a default prototype table containing all defined GiNaC functions.
+ * Default prototype table.
+ *
+ * It supports all defined GiNaC functions and "pow", "sqrt", and "power".
+ */
+extern const prototype_table& get_default_reader();
+/**
+ * Builtin prototype table.
  *
- * The data referenced by the return value is only created once when this
- * function is called for the first time. This might cause problems in very
- * rare stituations (i.e. if functions are added after this first call). In
- * that case, a new initialization can be forced with an "true" argument.
+ * It supports only the builtin GiNaC functions and "pow", "sqrt", and "power".
  */
-extern const prototype_table& get_default_reader(bool force_init = false);
+extern const prototype_table& get_builtin_reader();
 
 } // namespace GiNaC