# HG changeset patch
# User lost@l-w.ca
# Date 1295755989 25200
# Node ID 25a4aef9c5eda8bade1137e1ddf966debd9b8028
# Parent  7c35fa8dbc91f906501d9db8b7ed6d149e91a76d
lwbasic: Added basic character input framework

diff -r 7c35fa8dbc91 -r 25a4aef9c5ed lwbasic/input.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lwbasic/input.c	Sat Jan 22 21:13:09 2011 -0700
@@ -0,0 +1,85 @@
+/*
+input.c
+
+Copyright © 2011 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/>.
+*/
+
+/*
+handle reading input for the rest of the system
+*/
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <lw_alloc.h>
+
+#define __input_c_seen__
+#include "lwbasic.h"
+
+struct input_state
+{
+	FILE *fp;
+	int error;
+};
+
+static void input_init(cstate *state)
+{
+	struct input_state *sp;
+	
+	sp = lw_alloc(sizeof(struct input_state));
+	sp -> error = 0;
+	
+	if (!(state -> input_file) || strcmp(state -> input_file, "-"))
+	{
+		sp -> fp = stdin;
+	}
+	else
+	{
+		sp -> fp = fopen(state -> input_file, "rb");
+		if (!(sp -> fp))
+		{
+			fprintf(stderr, "Cannot open input file\n");
+			exit(1);
+		}
+	}
+	
+	state -> input_state = sp;
+}
+
+int input_getchar(cstate *state)
+{
+	int r;
+	struct input_state *sp;
+	
+	if (!(state -> input_state))
+		input_init(state);
+	sp = state -> input_state;
+	
+
+	if (sp -> error)
+		return -2;
+	
+	if (feof(sp -> fp))
+		return -1;
+	
+	r = fgetc(sp -> fp);
+	if (r == EOF)
+		return -1;
+	return r;	
+}
diff -r 7c35fa8dbc91 -r 25a4aef9c5ed lwbasic/lwbasic.h
--- a/lwbasic/lwbasic.h	Sat Jan 22 21:01:03 2011 -0700
+++ b/lwbasic/lwbasic.h	Sat Jan 22 21:13:09 2011 -0700
@@ -32,6 +32,12 @@
 	char *input_file;
 	
 	int debug_level;
+	
+	void *input_state;
 } cstate;
 
+#ifndef __input_c_seen__
+extern int input_getchar(cstate *state);
+#endif
+
 #endif /* __lwbasic_h_seen__ */
diff -r 7c35fa8dbc91 -r 25a4aef9c5ed lwbasic/rules.make
--- a/lwbasic/rules.make	Sat Jan 22 21:01:03 2011 -0700
+++ b/lwbasic/rules.make	Sat Jan 22 21:13:09 2011 -0700
@@ -1,7 +1,7 @@
 dirname := $(dir $(lastword $(MAKEFILE_LIST)))
 lwbasic_dir := $(dirname)
 
-lwbasic_lsrcs := main.c
+lwbasic_lsrcs := main.c input.c
 
 lwbasic_srcs := $(addprefix $(dirname),$(lwbasic_lsrcs))
 lwbasic_objs := $(lwbasic_srcs:.c=.o)