implicit multiply, negatives, solve

1 files changed, 64 insertions, 0 deletions

diff --git a/variable.c b/variable.c
index c170f79..957a130 100644
--- a/variable.c
+++ b/variable.c
@@ -1,6 +1,7 @@
 #include "variable.h"
 #include "parser.h"
 
+#include <ctype.h>
 #include <stdlib.h>
 #include <memory.h>
 #include <string.h>
@@ -69,3 +70,66 @@ variable *make_vare(variable *v, const char *expr)
 	return v;
 }
 
+int try_variable(char **name, const char *text)
+{
+	if (name == 0)
+		return 0;
+
+	int neg = 1;
+	int i = 0;
+
+	if (text[0] == '-') {
+		neg = -1;
+		i++;
+	}
+	if (!isalpha(text[i]))
+		return 0;
+
+	for (i++; isalnum(text[i]); i++);
+
+	int o = (neg < 0);
+	if (neg < 0)
+		i--;
+	*name = (char *)malloc(i + 1);
+	strncpy(*name, text + o, i);
+	(*name)[i] = '\0';
+	return (neg > 0) ? i : -(i + 1);
+}
+
+int try_number(variable *v, const char *text)
+{
+	if (v == 0)
+		return 0;
+
+	int decimal = -1;
+	char valid = 0;
+
+	int i = 0;
+	if (text[0] == '-')
+		i++;
+	do {
+		if (text[i] == '.') {
+			if (decimal >= 0) {
+				valid = 0;
+				break;
+			}
+			decimal = i;
+		} else if (isdigit(text[i])) {
+			valid |= 1;
+		} else {
+			break;
+		}
+	} while (text[++i] != '\0');
+
+	if (valid == 0)
+		return 0;
+
+	char *buf = (char *)malloc(i + 1);
+	strncpy(buf, text, i);
+	buf[i] = '\0';
+
+	make_varn(v, strtof(buf, 0));
+
+	free(buf);
+	return i;
+}