Release calc version 2.10.2t30

const.c

@@ -0,0 +1,113 @@
+/*
+ * Copyright (c) 1993 David I. Bell
+ * Permission is granted to use, distribute, or modify this source,
+ * provided that this copyright notice remains intact.
+ *
+ * Constant number storage module.
+ */
+
+#include "calc.h"
+
+#define CONSTALLOCSIZE 400	/* number of constants to allocate */
+
+
+static long constcount;		/* number of constants defined */
+static long constavail;		/* number of constants available */
+static NUMBER **consttable;	/* table of constants */
+
+
+/*
+ * Read in a constant number and add it to the table of constant numbers,
+ * creating a new entry if necessary.  The incoming number is a string
+ * value which must have a correct format, otherwise an undefined number
+ * will result.  Returns the index of the number in the constant table.
+ * Returns zero if the number could not be saved.
+ *
+ * given:
+ *	str		string representation of number
+ */
+long
+addnumber(char *str)
+{
+	NUMBER *q;
+
+	q = str2q(str);
+	if (q == NULL)
+		return 0;
+	return addqconstant(q);
+}
+
+
+/*
+ * Add a particular number to the constant table.
+ * Returns the index of the number in the constant table, or zero
+ * if the number could not be saved.  The incoming number if freed
+ * if it is already in the table.
+ *
+ * XXX - we should hash the constant table
+ *
+ * given:
+ *	q		number to be added
+ */
+long
+addqconstant(NUMBER *q)
+{
+	register NUMBER **tp;	/* pointer to current number */
+	register NUMBER *t;	/* number being tested */
+	long index;		/* index into constant table */
+	long numlen;		/* numerator length */
+	long denlen;		/* denominator length */
+	HALF numlow;		/* bottom value of numerator */
+	HALF denlow;		/* bottom value of denominator */
+
+	numlen = q->num.len;
+	denlen = q->den.len;
+	numlow = q->num.v[0];
+	denlow = q->den.v[0];
+	tp = &consttable[1];
+	for (index = 1; index <= constcount; index++) {
+		t = *tp++;
+		if ((numlen != t->num.len) || (numlow != t->num.v[0]))
+			continue;
+		if ((denlen != t->den.len) || (denlow != t->den.v[0]))
+			continue;
+		if (q->num.sign != t->num.sign)
+			continue;
+		if (qcmp(q, t) == 0) {
+			qfree(q);
+			return index;
+		}
+	}
+	if (constavail <= 0) {
+		if (consttable == NULL) {
+			tp = (NUMBER **)
+				malloc(sizeof(NUMBER *) * (CONSTALLOCSIZE + 1));
+			*tp = NULL;
+		} else
+			tp = (NUMBER **) realloc((char *) consttable,
+			sizeof(NUMBER *) * (constcount+CONSTALLOCSIZE + 1));
+		if (tp == NULL)
+			return 0;
+		consttable = tp;
+		constavail = CONSTALLOCSIZE;
+	}
+	constavail--;
+	constcount++;
+	consttable[constcount] = q;
+	return constcount;
+}
+
+
+/*
+ * Return the value of a constant number given its index.
+ * Returns address of the number, or NULL if the index is illegal.
+ */
+NUMBER *
+constvalue(unsigned long index)
+{
+	if ((index <= 0) || (index > constcount))
+		return NULL;
+	return consttable[index];
+}
+
+/* END CODE */