gcc/libgo/runtime/string.goc

// Copyright 2009, 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package runtime
#include "runtime.h"
#define charntorune(pv, str, len) __go_get_rune(str, len, pv)

enum
{
	Runeself	= 0x80,
};

func stringiter(s String, k int32) (retk int32) {
	int32 l, n;

	if(k >= s.__length) {
		// retk=0 is end of iteration
		retk = 0;
		goto out;
	}

	l = s.__data[k];
	if(l < Runeself) {
		retk = k+1;
		goto out;
	}

	// multi-char rune
	n = charntorune(&l, s.__data+k, s.__length-k);
	retk = k + (n ? n : 1);

out:
}

func stringiter2(s String, k int32) (retk int32, retv int32) {
	int32 n;

	if(k >= s.__length) {
		// retk=0 is end of iteration
		retk = 0;
		retv = 0;
		goto out;
	}

	retv = s.__data[k];
	if(retv < Runeself) {
		retk = k+1;
		goto out;
	}

	// multi-char rune
	n = charntorune(&retv, s.__data+k, s.__length-k);
	retk = k + (n ? n : 1);

out:
}