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author | reinelt <reinelt@3ae390bd-cb1e-0410-b409-cd5a39f66f1f> | 2003-10-06 04:34:06 +0000 |
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committer | reinelt <reinelt@3ae390bd-cb1e-0410-b409-cd5a39f66f1f> | 2003-10-06 04:34:06 +0000 |
commit | 9cda8378d11759032315ef79032e1ac3dc6beddb (patch) | |
tree | e98d75bdf53bfa0c7aa67165c13e647bb6e2e6c7 /expression.c | |
parent | 54945a6e1b3f8556a87c37d74693548321ae09e1 (diff) | |
download | lcd4linux-9cda8378d11759032315ef79032e1ac3dc6beddb.tar.gz |
[lcd4linux @ 2003-10-06 04:34:06 by reinelt]
expression evaluator added
git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@256 3ae390bd-cb1e-0410-b409-cd5a39f66f1f
Diffstat (limited to '')
-rw-r--r-- | expression.c | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/expression.c b/expression.c new file mode 100644 index 0000000..bae6ab8 --- /dev/null +++ b/expression.c @@ -0,0 +1,156 @@ +/* $Id: expression.c,v 1.1 2003/10/06 04:34:06 reinelt Exp $ + * + * expression handling + * + * Copyright 2003 Michael Reinelt <reinelt@eunet.at> + * + * This file is part of LCD4Linux. + * + * LCD4Linux 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 2, or (at your option) + * any later version. + * + * LCD4Linux 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, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + * + * $Log: expression.c,v $ + * Revision 1.1 2003/10/06 04:34:06 reinelt + * expression evaluator added + * + */ + +/* + * exported functions: + * + * int EX_init (void) + * initializes the expression evaluator + * adds some handy constants and functions + * + */ + + +#include <stdlib.h> +#include <stdio.h> +#include <math.h> +#include <string.h> + +#include "debug.h" +#include "cfg.h" +#include "evaluator.h" +#include "expression.h" + + + +static void my_sqrt (RESULT *result, RESULT *arg1) +{ + double value=sqrt(R2N(arg1)); + SetResult(&result, R_NUMBER, &value); +} + +static void my_exp (RESULT *result, RESULT *arg1) +{ + double value=exp(R2N(arg1)); + SetResult(&result, R_NUMBER, &value); +} + +static void my_ln (RESULT *result, RESULT *arg1) +{ + double value=log(R2N(arg1)); + SetResult(&result, R_NUMBER, &value); +} + +static void my_log (RESULT *result, RESULT *arg1) +{ + double value=log10(R2N(arg1)); + SetResult(&result, R_NUMBER, &value); +} + +static void my_sin (RESULT *result, RESULT *arg1) +{ + double value=sin(R2N(arg1)); + SetResult(&result, R_NUMBER, &value); +} + +static void my_cos (RESULT *result, RESULT *arg1) +{ + double value=cos(R2N(arg1)); + SetResult(&result, R_NUMBER, &value); +} + +static void my_tan (RESULT *result, RESULT *arg1) +{ + double value=tan(R2N(arg1)); + SetResult(&result, R_NUMBER, &value); +} + + +static void my_strlen (RESULT *result, RESULT *arg1) +{ + double value=strlen(R2S(arg1)); + SetResult(&result, R_NUMBER, &value); +} + + +static void my_cfg (RESULT *result, RESULT *arg1) +{ + char *value=cfg_get(R2S(arg1), ""); + SetResult(&result, R_STRING, value); +} + + +int EX_init (void) +{ + // set some handy constants + AddConstant ("Pi", M_PI); + AddConstant ("e", M_E); + + // register some basic math functions + AddFunction ("sqrt", 1, my_sqrt); + AddFunction ("exp", 1, my_exp); + AddFunction ("ln", 1, my_ln); + AddFunction ("log", 1, my_log); + AddFunction ("sin", 1, my_sin); + AddFunction ("cos", 1, my_cos); + AddFunction ("tan", 1, my_tan); + + // register some basic string functions + AddFunction ("strlen", 1, my_strlen); + + // config file access + AddFunction ("cfg", 1, my_cfg); + + + return 0; +} + + +#if 1 + +int EX_test(int argc, char* argv[]) +{ + int ec; + char line[1024]; + RESULT result = {0, 0.0, NULL}; + + printf("\nEE> "); + for(gets(line); !feof(stdin); gets(line)) { + ec=Eval(line, &result); + if (result.type==R_NUMBER) { + printf ("%g\n", R2N(&result)); + } else if (result.type==R_STRING) { + printf ("<%s>\n", R2S(&result)); + } + printf("EE> "); + } + + return 0; +} +#endif |