github.com/cockroachdb/cockroach@v20.2.0-alpha.1+incompatible/pkg/sql/colexec/execgen/placeholders.go (about)

     1  // Copyright 2019 The Cockroach Authors.
     2  //
     3  // Use of this software is governed by the Business Source License
     4  // included in the file licenses/BSL.txt.
     5  //
     6  // As of the Change Date specified in that file, in accordance with
     7  // the Business Source License, use of this software will be governed
     8  // by the Apache License, Version 2.0, included in the file
     9  // licenses/APL.txt.
    10  
    11  package execgen
    12  
    13  import "github.com/cockroachdb/cockroach/pkg/sql/colexecbase/colexecerror"
    14  
    15  const nonTemplatePanic = "do not call from non-template code"
    16  
    17  // Remove unused warnings.
    18  var (
    19  	_ = UNSAFEGET
    20  	_ = RETURNUNSAFEGET
    21  	_ = COPYVAL
    22  	_ = SET
    23  	_ = SLICE
    24  	_ = COPYSLICE
    25  	_ = APPENDSLICE
    26  	_ = APPENDVAL
    27  	_ = LEN
    28  	_ = ZERO
    29  	_ = RANGE
    30  	_ = WINDOW
    31  )
    32  
    33  // UNSAFEGET is a template function. Use this if you are not keeping data
    34  // around (including passing it to SET).
    35  func UNSAFEGET(target, i interface{}) interface{} {
    36  	colexecerror.InternalError(nonTemplatePanic)
    37  	return nil
    38  }
    39  
    40  // RETURNUNSAFEGET is a template function. Use this if you are not keeping data
    41  // around (including passing it to SET).
    42  // This function is similar to UNSAFEGET with the only difference is that this
    43  // will be called on "return" type of an overload. For example, if we have an
    44  // overload like "a = b < c", "b" and "c" are arguments of the overload and can
    45  // be accessed via UNSAFEGET, but RETURNUNSAFEGET will operate on "a". At the
    46  // moment of this writing, it is used only for the purposes of bounds check
    47  // elimination in some templates.
    48  func RETURNUNSAFEGET(target, i interface{}) interface{} {
    49  	colexecerror.InternalError(nonTemplatePanic)
    50  	return nil
    51  }
    52  
    53  // COPYVAL is a template function that can be used to set a scalar to the value
    54  // of another scalar in such a way that the destination won't be modified if the
    55  // source is. You must use this on the result of UNSAFEGET if you wish to store
    56  // that result past the lifetime of the batch you UNSAFEGET'd from.
    57  func COPYVAL(dest, src interface{}) {
    58  	colexecerror.InternalError(nonTemplatePanic)
    59  }
    60  
    61  // SET is a template function.
    62  func SET(target, i, new interface{}) {
    63  	colexecerror.InternalError(nonTemplatePanic)
    64  }
    65  
    66  // SLICE is a template function.
    67  func SLICE(target, start, end interface{}) interface{} {
    68  	colexecerror.InternalError(nonTemplatePanic)
    69  	return nil
    70  }
    71  
    72  // COPYSLICE is a template function.
    73  func COPYSLICE(target, src, destIdx, srcStartIdx, srcEndIdx interface{}) {
    74  	colexecerror.InternalError(nonTemplatePanic)
    75  }
    76  
    77  // APPENDSLICE is a template function.
    78  func APPENDSLICE(target, src, destIdx, srcStartIdx, srcEndIdx interface{}) {
    79  	colexecerror.InternalError(nonTemplatePanic)
    80  }
    81  
    82  // APPENDVAL is a template function.
    83  func APPENDVAL(target, v interface{}) {
    84  	colexecerror.InternalError(nonTemplatePanic)
    85  }
    86  
    87  // LEN is a template function.
    88  func LEN(target interface{}) interface{} {
    89  	colexecerror.InternalError(nonTemplatePanic)
    90  	return nil
    91  }
    92  
    93  // ZERO is a template function.
    94  func ZERO(target interface{}) {
    95  	colexecerror.InternalError(nonTemplatePanic)
    96  }
    97  
    98  // RANGE is a template function.
    99  func RANGE(loopVariableIdent, target, start, end interface{}) bool {
   100  	colexecerror.InternalError(nonTemplatePanic)
   101  	return false
   102  }
   103  
   104  // WINDOW is a template function.
   105  func WINDOW(target, start, end interface{}) interface{} {
   106  	colexecerror.InternalError(nonTemplatePanic)
   107  	return nil
   108  }