// buildYieldStatement builds the CodeDOM for a yield statement.
func (db *domBuilder) buildYieldStatement(node compilergraph.GraphNode) codedom.Statement {
if _, isBreak := node.TryGet(parser.NodeYieldStatementBreak); isBreak {
return codedom.YieldBreak(node)
}
if streamExpr, hasStreamExpr := db.tryGetExpression(node, parser.NodeYieldStatementStreamValue); hasStreamExpr {
return codedom.YieldStream(streamExpr, node)
}
return codedom.YieldValue(db.getExpression(node, parser.NodeYieldStatementValue), node)
}
// buildSmlExpression builds the CodeDOM for a SML expression.
func (db *domBuilder) buildSmlExpression(node compilergraph.GraphNode) codedom.Expression {
smlScope, _ := db.scopegraph.GetScope(node)
funcOrTypeRefNode := node.GetNode(parser.NodeSmlExpressionTypeOrFunction)
funcOrTypeRefScope, _ := db.scopegraph.GetScope(funcOrTypeRefNode)
// Build the expression for the function or constructor to be called to construct the expression.
var declarationFunction = db.buildExpression(funcOrTypeRefNode)
var declarationFunctionType = db.scopegraph.TypeGraph().AnyTypeReference()
if smlScope.HasLabel(proto.ScopeLabel_SML_CONSTRUCTOR) {
constructor, _ := funcOrTypeRefScope.StaticTypeRef(db.scopegraph.TypeGraph()).ResolveMember("Declare", typegraph.MemberResolutionStatic)
declarationFunctionType = constructor.MemberType()
declarationFunction = codedom.MemberReference(declarationFunction, constructor, node)
} else {
declarationFunctionType = funcOrTypeRefScope.ResolvedTypeRef(db.scopegraph.TypeGraph())
}
var declarationArguments = make([]codedom.Expression, 0)
declFunctionParams := declarationFunctionType.Parameters()
// If the SML expression expects any attributes, then construct the props struct, class or mapping.
if len(declFunctionParams) > 0 {
attributeExpressions := map[string]codedom.Expression{}
ait := node.StartQuery().
Out(parser.NodeSmlExpressionAttribute).
BuildNodeIterator()
for ait.Next() {
attributeNode := ait.Node()
attributeName := attributeNode.Get(parser.NodeSmlAttributeName)
attributeExpressions[attributeName] = db.getExpressionOrDefault(
attributeNode,
parser.NodeSmlAttributeValue,
codedom.NominalWrapping(
codedom.LiteralValue("true", attributeNode),
db.scopegraph.TypeGraph().BoolType(),
attributeNode))
}
// Construct the props object expression, either as a struct, class or as a mapping.
propsType := declFunctionParams[0]
if smlScope.HasLabel(proto.ScopeLabel_SML_PROPS_MAPPING) {
declarationArguments = append(declarationArguments, db.buildMappingInitializerExpression(propsType, attributeExpressions, node))
} else {
declarationArguments = append(declarationArguments, db.buildStructInitializerExpression(propsType, attributeExpressions, node))
}
}
// If the SML expression expects any children, then construct the children stream or value (if any).
if len(declFunctionParams) > 1 {
cit := node.StartQuery().
Out(parser.NodeSmlExpressionChild).
BuildNodeIterator()
children := db.buildExpressions(cit, buildExprNormally)
switch {
case smlScope.HasLabel(proto.ScopeLabel_SML_SINGLE_CHILD):
// If there is a child, it is a value. If missing, the child is nullable, so we don't put
// anything there.
if len(children) > 0 {
declarationArguments = append(declarationArguments, children[0])
}
case smlScope.HasLabel(proto.ScopeLabel_SML_STREAM_CHILD):
// Single child which is a stream. Passed directly to the declaring function as an argument.
declarationArguments = append(declarationArguments, children[0])
case smlScope.HasLabel(proto.ScopeLabel_SML_CHILDREN):
// The argument is a stream of the child expressions. Build it as a generator.
if len(children) == 0 {
// Add an empty generator.
declarationArguments = append(declarationArguments,
codedom.RuntimeFunctionCall(codedom.EmptyGeneratorDirect, []codedom.Expression{}, node))
} else {
yielders := make([]codedom.Statement, len(children))
for index, child := range children {
yielders[index] = codedom.YieldValue(child, child.BasisNode())
if index > 0 {
yielders[index-1].(codedom.HasNextStatement).SetNext(yielders[index])
}
}
generatorFunc := codedom.FunctionDefinition([]string{}, []string{}, yielders[0], false, codedom.GeneratorFunction, node)
generatorExpr := codedom.FunctionCall(generatorFunc, []codedom.Expression{}, node)
declarationArguments = append(declarationArguments, codedom.AwaitPromise(generatorExpr, node))
}
default:
panic("Unknown SML children scope label")
}
}
// The value of declaration function invoked with the arguments is the initial definition.
var definition = codedom.AwaitPromise(
codedom.FunctionCall(declarationFunction, declarationArguments, node), node)
// Add any decorators as wrapping around the definition call.
dit := node.StartQuery().
Out(parser.NodeSmlExpressionDecorator).
BuildNodeIterator()
for dit.Next() {
decoratorNode := dit.Node()
decoratorFunc := db.getExpression(decoratorNode, parser.NodeSmlDecoratorPath)
// The value for the decorator is either the value expression given or the literal
// value "true" if none specified.
decoratorValue := db.getExpressionOrDefault(
decoratorNode,
parser.NodeSmlDecoratorValue,
codedom.NominalWrapping(
codedom.LiteralValue("true", decoratorNode),
db.scopegraph.TypeGraph().BoolType(),
decoratorNode))
// The decorator is invoked over the definition.
decoratorArgs := []codedom.Expression{definition, decoratorValue}
definition = codedom.AwaitPromise(
codedom.FunctionCall(decoratorFunc, decoratorArgs, decoratorNode),
decoratorNode)
}
return definition
}
