Property lookup

LookupKey

LookupKey is either LocalName(name) or Computed(value).

LookupKey.Value

LookupKey.Value returns:

• For LocalName(name), a StringConstant equivalent to name or defer if String is unresolved.
• For Computed(value), value.

LookupKey.Type

LookupKey.Type returns:

• For LocalName(name), the String type or defer.
• For Computed(value), the static type of value or defer.

LookupKey.Double

LookupKey.Double returns:

• For LocalName(name), undefined.
• For Computed(value), value is NumberConstant(v) ? force convert v to a Number : undefined.

PropertyLookup()

PropertyLookup(base, openNsSet, qual, key as LookupKey, followedByCall as Boolean, forceFixture as Boolean) takes the following steps in order, where forceFixture allows forcing access to a fixture property on dynamic types (used by the <?fixed={}?> expression):

• If base is invalidation
  • Return invalidation
• Let localName = key is LocalName(name) ? name : undefined
• Let doubleKey = key.Double
• If base is a TypeConstant(type)
  • base = type
• Else if base is a FixtureReferenceValue and base.Property is a type
  • base = base.Property
• If base is a class
  • If localName is undefined or (qual is specified and qual is not a namespace nor a NamespaceConstant)
    • Return StaticDynamicReferenceValue(base, qual, k.Value)
  • For each descending class in base hierarchy
    • Defer if class is unresolved.
    • Let r = GetQNameInNsSetOrAnyPublicNs(class static properties, openNsSet, qual, localName)
    • If r != undefined
      • Mark r as used.
      • Let r = r.ResolveAlias()
      • Defer if r property's static type is unresolved.
      • Return r.Wrap()
  • Return undefined
• If base is an interface
  • Return undefined
• If base is a value
  • Let baseType = static type of base or defer
  • If baseType is invalid
    • Return invalid
  • baseType = baseType.ResolveAlias()
  • If (followedByCall == false and forceFixture == false) and baseType defines an instance method shock_proxy::get (possibly a multi method)
    • Let foundRegularProperty = false
    • For each shock_proxy::get(k:K):V method
      • If qual != undefined
        • If K == * or K == (Object or defer) or K == (QName or defer) or K ?union contains (QName or defer)
          • Return KeyValuePairReferenceValue(base, proxy method, qual as a Namespace object, key.Value coerced to (String or defer))
        • Continue loop
      • If key.Value is a (String or defer) value and (K == (QName or defer) or (K ?union does not contain String and K union contains QName))
        • Return KeyValuePairReferenceValue(base, proxy method, undefined, key.Value)
      • If K == * or K == (Object or defer) or K == (String or defer) or K == (QName or defer) or (K ?union contains String or K union contains QName)
        • foundRegularProperty = true
      • If (static type of key.Value or defer) fails on implicit coercion to K
        • Continue loop
      • Return KeyValuePairReferenceValue(base, proxy method, undefined, key.Value implicitly coerced to K)
    • If (static type of key.Value or defer) != (String or defer) or foundRegularProperty
      • Throw a verify error
  • Let hasKnownNs = qual == undefined or (qual is a namespace or NamespaceConstant)
  • If localName == undefined
    • If doubleKey != undefined and baseType is a tuple
      • Let i = doubleKey coercion to integer
      • If i < 0 or i >= baseType.ElementTypes.Length
        • Throw a verify error
      • Return TupleReferenceValue(base, i)
    • Return DynamicReferenceValue(base, qual, key.Value, followedByCall, forceFixture)
  • If baseType == *
    • Return DynamicReferenceValue(base, qual, key.Value, followedByCall, forceFixture)
  • If baseType is a class
    • For each descending class in baseType hierarchy
      • Defer if class is unresolved
      • Let prop = GetQNameInNsSetOrAnyPublicNs(class prototype properties, openNsSet, qual, localName)
      • If prop != undefined
        • Mark prop as used
        • prop = prop.ResolveAlias()
        • Call prop.Defer() (if about to defer, implementation may report the cause as unresolved expression in a location)
        • If prop is a namespace or NamespaceConstant
          • Return NamespaceConstant(prop) if prop is a namespace, or otherwise prop as is
        • Return InstanceReferenceValue(base, prop)
    • For implemented interfaces of baseType
      • Lookup method (step required for optional methods)
  • Else if baseType is an interface
    • For each descending itrfc in baseType hierarchy
      • Defer if itrfc is unresolved
      • Let prop = GetQNameInNsSetOrAnyPublicNs(itrfc prototype properties, openNsSet, qual, localName)
      • If prop != undefined
        • Mark prop as used
        • prop = prop.ResolveAlias()
        • Call prop.Defer() (if about to defer, implementation may report the cause as unresolved expression in a location)
        • Return InstanceReferenceValue(base, prop)
    • Lookup for the Object instance definitions
  • Return undefined.
• If base is a package
  • If localName is undefined or (qual is specified and qual is not a namespace nor a NamespaceConstant)
    • Throw a verify error
  • Let r = undefined
  • Let prop = GetQNameInNsSetOrAnyPublicNs(base properties, openNsSet, qual, localName)
  • If prop != undefined
    • Mark r as used.
    • prop = prop.ResolveAlias()
    • Call prop.Defer() (if about to defer, implementation may report the cause as unresolved expression in a location)
    • r = prop.Wrap()
  • Return r
• If base is a type parameter with an eventOf=, match="type" constraint
  • If localName is undefined or (qual is specified)
    • Return undefined.
  • If localName = name
    • Return EventNameType(type parameter).Wrap()
  • If localName = type
    • Return EventTypeType(previously introduced EventNameType).Wrap().
  • Return undefined.
• Return undefined.

Note: entity.Wrap() wraps entities into values. For instance, wrapping a variable into a property reference, where it belongs to a package, will produce a PackageReferenceValue.

Note: entity.Defer() defers if an entity is unresolved or if a direct compound is unresolved.

InScopeLookup()

InScopeLookup(scope, qual, key as LookupKey, followedByCall as Boolean, forceFixture as Boolean) takes the following steps in order:

Note: Content lacking.