github.com/paultyng/terraform@v0.6.11-0.20180227224804-66ff8f8bed40/configs/variable_type_hint.go (about)

     1  package configs
     2  
     3  // VariableTypeHint is an enumeration used for the Variable.TypeHint field,
     4  // which is an incompletely-specified type for the variable which is used
     5  // as a hint for whether a value provided in an ambiguous context (on the
     6  // command line or in an environment variable) should be taken literally as a
     7  // string or parsed as an HCL expression to produce a data structure.
     8  //
     9  // The type hint is applied to runtime values as well, but since it does not
    10  // accurately describe a precise type it is not fully-sufficient to infer
    11  // the dynamic type of a value passed through a variable.
    12  //
    13  // These hints use inaccurate terminology for historical reasons. Full details
    14  // are in the documentation for each constant in this enumeration, but in
    15  // summary:
    16  //
    17  //     TypeHintString requires a primitive type
    18  //     TypeHintList requires a type that could be converted to a tuple
    19  //     TypeHintMap requires a type that could be converted to an object
    20  type VariableTypeHint rune
    21  
    22  //go:generate stringer -type VariableTypeHint
    23  
    24  // TypeHintNone indicates the absense of a type hint. Values specified in
    25  // ambiguous contexts will be treated as literal strings, as if TypeHintString
    26  // were selected, but no runtime value checks will be applied. This is reasonable
    27  // type hint for a module that is never intended to be used at the top-level
    28  // of a configuration, since descendent modules never recieve values from
    29  // ambiguous contexts.
    30  const TypeHintNone VariableTypeHint = 0
    31  
    32  // TypeHintString spec indicates that a value provided in an ambiguous context
    33  // should be treated as a literal string, and additionally requires that the
    34  // runtime value for the variable is of a primitive type (string, number, bool).
    35  const TypeHintString VariableTypeHint = 'S'
    36  
    37  // TypeHintList indicates that a value provided in an ambiguous context should
    38  // be treated as an HCL expression, and additionally requires that the
    39  // runtime value for the variable is of an tuple, list, or set type.
    40  const TypeHintList VariableTypeHint = 'L'
    41  
    42  // TypeHintMap indicates that a value provided in an ambiguous context should
    43  // be treated as an HCL expression, and additionally requires that the
    44  // runtime value for the variable is of an object or map type.
    45  const TypeHintMap VariableTypeHint = 'M'