31 lines
849 B
C
31 lines
849 B
C
/* go-strslice.c -- the go string slice function.
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Copyright 2009 The Go Authors. All rights reserved.
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Use of this source code is governed by a BSD-style
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license that can be found in the LICENSE file. */
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#include "runtime.h"
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String
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__go_string_slice (String s, intgo start, intgo end)
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{
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intgo len;
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String ret;
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len = s.len;
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if (end == -1)
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end = len;
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if (start > len || end < start || end > len)
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runtime_panicstring ("string index out of bounds");
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ret.len = end - start;
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// If the length of the new string is zero, the str field doesn't
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// matter, so just set it to nil. This avoids the problem of
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// s.str + start pointing just past the end of the string,
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// which may keep the next memory block alive unnecessarily.
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if (ret.len == 0)
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ret.str = nil;
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else
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ret.str = s.str + start;
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return ret;
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}
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