136 lines
6.5 KiB
Go
136 lines
6.5 KiB
Go
// Copyright 2011 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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/*
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Package builtin provides documentation for Go's built-in functions.
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The functions documented here are not actually in package builtin
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but their descriptions here allow godoc to present documentation
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for the language's special functions.
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*/
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package builtin
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// Type is here for the purposes of documentation only. It is a stand-in
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// for any Go type, but represents the same type for any given function
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// invocation.
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type Type int
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// IntegerType is here for the purposes of documentation only. It is a stand-in
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// for any integer type: int, uint, int8 etc.
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type IntegerType int
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// FloatType is here for the purposes of documentation only. It is a stand-in
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// for either float type: float32 or float64.
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type FloatType int
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// ComplexType is here for the purposes of documentation only. It is a
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// stand-in for either complex type: complex64 or complex128.
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type ComplexType int
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// The append built-in function appends elements to the end of a slice. If
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// it has sufficient capacity, the destination is resliced to accommodate the
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// new elements. If it does not, a new underlying array will be allocated.
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// Append returns the updated slice. It is therefore necessary to store the
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// result of append, often in the variable holding the slice itself:
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// slice = append(slice, elem1, elem2)
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// slice = append(slice, anotherSlice...)
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func append(slice []Type, elems ...Type) []Type
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// The copy built-in function copies elements from a source slice into a
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// destination slice. (As a special case, it also will copy bytes from a
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// string to a slice of bytes.) The source and destination may overlap. Copy
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// returns the number of elements copied, which will be the minimum of
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// len(src) and len(dst).
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func copy(dst, src []Type) int
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// The len built-in function returns the length of v, according to its type:
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// Array: the number of elements in v.
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// Pointer to array: the number of elements in *v (even if v is nil).
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// Slice, or map: the number of elements in v; if v is nil, len(v) is zero.
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// String: the number of bytes in v.
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// Channel: the number of elements queued (unread) in the channel buffer;
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// if v is nil, len(v) is zero.
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func len(v Type) int
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// The cap built-in function returns the capacity of v, according to its type:
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// Array: the number of elements in v (same as len(v)).
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// Pointer to array: the number of elements in *v (same as len(v)).
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// Slice: the maximum length the slice can reach when resliced;
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// if v is nil, cap(v) is zero.
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// Channel: the channel buffer capacity, in units of elements;
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// if v is nil, cap(v) is zero.
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func cap(v Type) int
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// The make built-in function allocates and initializes an object of type
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// slice, map, or chan (only). Like new, the first argument is a type, not a
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// value. Unlike new, make's return type is the same as the type of its
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// argument, not a pointer to it. The specification of the result depends on
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// the type:
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// Slice: The size specifies the length. The capacity of the slice is
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// equal to its length. A second integer argument may be provided to
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// specify a different capacity; it must be no smaller than the
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// length, so make([]int, 0, 10) allocates a slice of length 0 and
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// capacity 10.
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// Map: An initial allocation is made according to the size but the
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// resulting map has length 0. The size may be omitted, in which case
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// a small starting size is allocated.
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// Channel: The channel's buffer is initialized with the specified
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// buffer capacity. If zero, or the size is omitted, the channel is
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// unbuffered.
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func make(Type, size IntegerType) Type
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// The new built-in function allocates memory. The first argument is a type,
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// not a value, and the value returned is a pointer to a newly
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// allocated zero value of that type.
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func new(Type) *Type
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// The complex built-in function constructs a complex value from two
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// floating-point values. The real and imaginary parts must be of the same
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// size, either float32 or float64 (or assignable to them), and the return
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// value will be the corresponding complex type (complex64 for float32,
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// complex128 for float64).
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func complex(r, i FloatType) ComplexType
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// The real built-in function returns the real part of the complex number c.
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// The return value will be floating point type corresponding to the type of c.
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func real(c ComplexType) FloatType
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// The imaginary built-in function returns the imaginary part of the complex
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// number c. The return value will be floating point type corresponding to
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// the type of c.
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func imag(c ComplexType) FloatType
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// The close built-in function closes a channel, which must be either
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// bidirectional or send-only. It should be executed only by the sender,
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// never the receiver, and has the effect of shutting down the channel after
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// the last sent value is received. After the last value has been received
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// from a closed channel c, any receive from c will succeed without
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// blocking, returning the zero value for the channel element. The form
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// x, ok := <-c
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// will also set ok to false for a closed channel.
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func close(c chan<- Type)
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// The panic built-in function stops normal execution of the current
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// goroutine. When a function F calls panic, normal execution of F stops
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// immediately. Any functions whose execution was deferred by F are run in
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// the usual way, and then F returns to its caller. To the caller G, the
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// invocation of F then behaves like a call to panic, terminating G's
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// execution and running any deferred functions. This continues until all
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// functions in the executing goroutine have stopped, in reverse order. At
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// that point, the program is terminated and the error condition is reported,
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// including the value of the argument to panic. This termination sequence
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// is called panicking and can be controlled by the built-in function
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// recover.
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func panic(v interface{})
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// The recover built-in function allows a program to manage behavior of a
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// panicking goroutine. Executing a call to recover inside a deferred
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// function (but not any function called by it) stops the panicking sequence
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// by restoring normal execution and retrieves the error value passed to the
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// call of panic. If recover is called outside the deferred function it will
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// not stop a panicking sequence. In this case, or when the goroutine is not
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// panicking, or if the argument supplied to panic was nil, recover returns
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// nil. Thus the return value from recover reports whether the goroutine is
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// panicking.
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func recover() interface{}
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