--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lwlib/lw_expr.h	Wed Jan 19 22:27:17 2011 -0700
@@ -0,0 +1,115 @@
+/*
+lwexpr.h
+
+Copyright © 2010 William Astle
+
+This file is part of LWTOOLS.
+
+LWTOOLS is free software: you can redistribute it and/or modify it under the
+terms of the GNU General Public License as published by the Free Software
+Foundation, either version 3 of the License, or (at your option) any later
+version.
+
+This program is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+more details.
+
+You should have received a copy of the GNU General Public License along with
+this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef ___lw_expr_h_seen___
+#define ___lw_expr_h_seen___
+
+#include <stdio.h>
+
+enum
+{
+	lw_expr_type_oper,			// operator term
+	lw_expr_type_int,			// integer
+	lw_expr_type_var,			// a "variable" (string for the name)
+	lw_expr_type_special		// a "special" reference (user defined)
+};
+
+enum
+{
+	lw_expr_oper_plus = 1,		// addition
+	lw_expr_oper_minus,			// subtraction
+	lw_expr_oper_times,			// multiplication
+	lw_expr_oper_divide,		// division
+	lw_expr_oper_mod,			// modulus
+	lw_expr_oper_intdiv,		// integer division
+	lw_expr_oper_bwand,			// bitwise and
+	lw_expr_oper_bwor,			// bitwise or
+	lw_expr_oper_bwxor,			// bitwise xor
+	lw_expr_oper_and,			// boolean and
+	lw_expr_oper_or,			// boolean or
+	lw_expr_oper_neg,			// unary negation, 2's complement
+	lw_expr_oper_com,			// unary 1's complement
+	lw_expr_oper_none = 0
+};
+
+#ifdef ___lw_expr_c_seen___
+
+typedef struct lw_expr_priv * lw_expr_t;
+
+struct lw_expr_opers
+{
+	lw_expr_t p;
+	struct lw_expr_opers *next;
+};
+
+struct lw_expr_priv
+{
+	int type;							// type of term
+	int value;							// integer value
+	void *value2;						// misc pointer value
+	struct lw_expr_opers *operands;		// ptr to list of operands (for operators)
+};
+
+typedef lw_expr_t lw_expr_fn_t(int t, void *ptr, void *priv);
+typedef lw_expr_t lw_expr_fn2_t(char *var, void *priv);
+typedef lw_expr_t lw_expr_fn3_t(char **p, void *priv);
+typedef int lw_expr_testfn_t(lw_expr_t e, void *priv);
+
+#else /* def ___lw_expr_c_seen___ */
+
+typedef void * lw_expr_t;
+
+extern lw_expr_t lwexpr_create(void);
+extern void lw_expr_destroy(lw_expr_t E);
+extern lw_expr_t lw_expr_copy(lw_expr_t E);
+extern void lw_expr_add_operand(lw_expr_t E, lw_expr_t O);
+extern lw_expr_t lw_expr_build(int exprtype, ...);
+extern char *lw_expr_print(lw_expr_t E);
+extern int lw_expr_compare(lw_expr_t E1, lw_expr_t E2);
+extern void lw_expr_simplify(lw_expr_t E, void *priv);
+
+typedef lw_expr_t lw_expr_fn_t(int t, void *ptr, void *priv);
+typedef lw_expr_t lw_expr_fn2_t(char *var, void *priv);
+typedef lw_expr_t lw_expr_fn3_t(char **p, void *priv);
+
+extern void lw_expr_set_special_handler(lw_expr_fn_t *fn);
+extern void lw_expr_set_var_handler(lw_expr_fn2_t *fn);
+extern void lw_expr_set_term_parser(lw_expr_fn3_t *fn);
+
+extern lw_expr_t lw_expr_parse(char **p, void *priv);
+extern int lw_expr_istype(lw_expr_t e, int t);
+extern int lw_expr_intval(lw_expr_t e);
+extern int lw_expr_specint(lw_expr_t e);
+extern void *lw_expr_specptr(lw_expr_t e);
+extern int lw_expr_whichop(lw_expr_t e);
+
+extern int lw_expr_type(lw_expr_t e);
+
+typedef int lw_expr_testfn_t(lw_expr_t e, void *priv);
+
+// run a function on all terms in an expression; if the function
+// returns non-zero for any term, return non-zero, else return
+// zero
+extern int lw_expr_testterms(lw_expr_t e, lw_expr_testfn_t *fn, void *priv);
+
+#endif /* def ___lw_expr_c_seen___ */
+
+#endif /* ___lw_expr_h_seen___ */