first commit

str.c

@@ -0,0 +1,86 @@
+#include "dat.h"
+#include "fn.h"
+
+enum
+{
+	Maxrunes = nelem(((Str*)0)->r),
+};
+
+void
+sinit(Str *s, char *src, int n)
+{
+	int len;
+
+	s->n = 0;
+	while(n > 0 && s->n < Maxrunes){
+		len = chartorune(&s->r[s->n], src);
+		s->n++;
+		src += len;
+		n -= len;
+	}
+}
+
+void
+sclear(Str *s)
+{
+	s->n = 0;
+}
+
+void
+sputr(Str *s, Rune r)
+{
+	if(s->n >= Maxrunes)
+		die("sputr overflow");
+	s->r[s->n++] = r;
+}
+
+void
+spopr(Str *s)
+{
+	if(s->n > 0)
+		s->r[--s->n] = 0;
+}
+
+void
+sappend(Str *dst, Str *src)
+{
+	int i;
+
+	for(i = 0; i < src->n && dst->n < Maxrunes; i++)
+		dst->r[dst->n++] = src->r[i];
+}
+
+int
+scmp(Str *a, Str *b)
+{
+	int i;
+
+	if(a->n != b->n)
+		return 1;
+	for(i = 0; i < a->n; i++)
+		if(a->r[i] != b->r[i])
+			return 1;
+	return 0;
+}
+
+int
+stoutf(Str *s, char *buf, int sz)
+{
+	int i, n, len;
+
+	n = 0;
+	for(i = 0; i < s->n && n < sz - UTFmax; i++){
+		len = runetochar(buf + n, &s->r[i]);
+		n += len;
+	}
+	buf[n] = '\0';
+	return n;
+}
+
+Rune
+slastr(Str *s)
+{
+	if(s->n < 1)
+		return 0;
+	return s->r[s->n-1];
+}