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SFL Version 2.11

Symbol-table functions

Filename: sflsymb.h
Package: Standard Function Library (SFL)
Written: 1993/12/27 iMatix SFL project team sfl@imatix.com
Revised: 1999/08/07
Copyright: Copyright (c) 1996-2000 iMatix Corporation

Synopsis

Symbol lookup is by name. Symbols contain a string value and a pointer to an caller-defined memory block. The symbol-table functions let you create and manage symbol tables. The functions are designed to be as general as possible (to support a wide variety of applications), but at the same time fast. The symbol table data structure is based on a combined linked list & hash table representation. The file sflsymb.h contains definitions for the various structures and external functions used in the sflsymb.c. Both the linked-list and hash-table representations have a guaranteed order. In the linked-list, new symbols are pushed on to the head of the list. In the hash table each bucket just contains a pointer to a linked-list of symbols. When a new symbol is created, it is pushed onto the front of this list. The reason that both data structures are used is to make the algorithm faster. Each representation has its stengths and weaknesses. For instance, if you wanted to lookup a symbol table entry for a given name using the hash table you could find it immediately, whereas with the linked- list, you would need to traverse most of the table to find the symbol. Some of these functions are called through macros that add the filename and line number of the call, for tracing. Do NOT call these functions directly.

List of Functions

• SYMTAB * sym create table
  (const char *source_file, size_t source_line);
• void sym delete table
  (SYMTAB *symtab);
• void sym empty table
  (SYMTAB *symtab);
• int sym merge tables
  (SYMTAB *symtab, const SYMTAB *import);
• SYMBOL * sym lookup symbol
  (const SYMTAB *symtab, const char *name);
• SYMBOL * sym create symbol
  (SYMTAB *symtab, const char *name, const char *val, const char *source_file, size_t source_line);
• SYMBOL * sym assume symbol
  (SYMTAB *symtab, const char *name, const char *val, const char *source_file, size_t source_line);
• SYMBOL * sym delete symbol
  (SYMTAB *symtab, SYMBOL *symbol);
• const char * sym get name
  (const SYMBOL *sym);
• char * sym get value
  (const SYMTAB *symtab, const char *name, const char *default_value);
• long sym get number
  (const SYMTAB *symtab, const char *key, const long default_value);
• Bool sym get boolean
  (const SYMTAB *symtab, const char *key, const Bool default_value);
• void sym set value
  (SYMBOL *symbol, const char *value);
• int sym exec all
  (const SYMTAB *symtab, symfunc handler, ...);
• int sym hash
  (const char *name);
• void sym sort table
  (SYMTAB *symtab, symsort sort_function);
• char * symb2strt
  (const SYMTAB *symtab, const char *source_file, size_t source_line);
• SYMTAB * strt2symb
  (char **strings, const char *source_file, size_t source_line);
• DESCR * symb2descr
  (const SYMTAB *symtab, const char *source_file, size_t source_line);
• SYMTAB * descr2symb
  (const DESCR *descr, const char *source_file, size_t source_line);

List of Symbol Definitions

sflsymb.h defines these symbols, possibly conditionally:

Symbol:	Defined as:
SFLSYMB_INCLUDED	TRUE
SYM_HASH_SIZE	256 /* Assumed by sym_hash () */
descr2symb(d)	(various)
strt2symb(s)	(various)
sym_assume_symbol(t,n,v)	(various)
sym_create_symbol(t,n,v)	(various)
sym_create_table()	(various)
symb2descr(t)	(various)
symb2strt(t)	(various)

List of Type Definitions

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Copyright © 1996-2000 iMatix Corporation