// buildArrowStatement builds the CodeDOM for an arrow statement.
func (db *domBuilder) buildArrowStatement(node compilergraph.GraphNode) (codedom.Statement, codedom.Statement) {
sourceExpr := codedom.RuntimeFunctionCall(
codedom.TranslatePromiseFunction,
[]codedom.Expression{db.getExpression(node, parser.NodeArrowStatementSource)},
node)
destinationNode := node.GetNode(parser.NodeArrowStatementDestination)
destinationScope, _ := db.scopegraph.GetScope(destinationNode)
var destinationTarget codedom.Expression = nil
var rejectionTarget codedom.Expression = nil
// Retrieve the expression of the destination variable.
if !destinationScope.GetIsAnonymousReference() {
destinationTarget = db.buildAssignmentExpression(destinationNode, codedom.LocalReference("resolved", node), node)
}
// Retrieve the expression of the rejection variable.
rejectionNode, hasRejection := node.TryGetNode(parser.NodeArrowStatementRejection)
if hasRejection {
rejectionScope, _ := db.scopegraph.GetScope(rejectionNode)
if !rejectionScope.GetIsAnonymousReference() {
rejectionTarget = db.buildAssignmentExpression(rejectionNode, codedom.LocalReference("rejected", node), node)
}
}
empty := codedom.EmptyStatement(node)
promise := codedom.ArrowPromise(sourceExpr, destinationTarget, rejectionTarget, empty, node)
return promise, empty
}
// buildInitializationCompoundExpression builds the compound expression for calling the specified initializers on a struct.
func (db *domBuilder) buildInitializationCompoundExpression(structType typegraph.TypeReference, initializers map[string]codedom.Expression, structValue codedom.Expression, node compilergraph.GraphNode) codedom.Expression {
// Create a variable to hold the struct instance.
structInstanceVarName := db.generateScopeVarName(node)
// Build the assignment expressions.
assignmentExpressions := make([]codedom.Expression, len(initializers))
var index = 0
for fieldName, initializer := range initializers {
member, found := structType.ResolveMember(fieldName, typegraph.MemberResolutionInstance)
if !found {
panic("Member not found in struct initializer construction")
}
assignmentExpressions[index] =
codedom.MemberAssignment(member,
codedom.MemberReference(
codedom.LocalReference(structInstanceVarName, node),
member,
node),
initializer,
node)
index = index + 1
}
// Return a compound expression that takes in the struct value and the assignment expressions,
// executes them, and returns the struct value.
return codedom.CompoundExpression(structInstanceVarName, structValue, assignmentExpressions, codedom.LocalReference(structInstanceVarName, node), node)
}
// buildMatchStatement builds the CodeDOM for a match statement.
func (db *domBuilder) buildMatchStatement(node compilergraph.GraphNode) (codedom.Statement, codedom.Statement) {
// Retrieve (or generate) the name of a variable to hold the value being matched against.
var matchExprVarName = ""
if namedValue, hasNamedValue := node.TryGetNode(parser.NodeStatementNamedValue); hasNamedValue {
matchExprVarName = namedValue.Get(parser.NodeNamedValueName)
} else {
matchExprVarName = db.generateScopeVarName(node)
}
// Set the match expression's value into the variable.
startStatement := codedom.VarDefinitionWithInit(matchExprVarName, db.getExpression(node, parser.NodeMatchStatementExpression), node)
getCheckExpression := func(caseTypeRefNode compilergraph.GraphNode) codedom.Expression {
caseTypeLiteral, _ := db.scopegraph.ResolveSRGTypeRef(
db.scopegraph.SourceGraph().GetTypeRef(caseTypeRefNode))
return codedom.NominalWrapping(
codedom.RuntimeFunctionCall(codedom.IsTypeFunction,
[]codedom.Expression{
codedom.LocalReference(matchExprVarName, caseTypeRefNode),
codedom.TypeLiteral(caseTypeLiteral, caseTypeRefNode),
},
caseTypeRefNode),
db.scopegraph.TypeGraph().BoolType(),
caseTypeRefNode)
}
return db.buildJumpingCaseStatement(node, parser.NodeMatchStatementCase,
parser.NodeMatchStatementCaseStatement, parser.NodeMatchStatementCaseTypeReference,
startStatement, getCheckExpression)
}
// generateWithShortCircuiting generates an expression with automatic short circuiting based on the value found
// in the resultName variable and compared to the given compare value.
func (eg *expressionGenerator) generateWithShortCircuiting(expr codedom.Expression, resultName string, compareValue codedom.Expression, context generationContext) esbuilder.ExpressionBuilder {
shortCircuiter := eg.generateExpression(
codedom.RuntimeFunctionCall(codedom.ShortCircuitPromiseFunction,
[]codedom.Expression{codedom.LocalReference(resultName, expr.BasisNode()), compareValue},
expr.BasisNode()),
context)
return eg.generateExpression(expr, generationContext{shortCircuiter})
}
// pushResource adds a resource to the resource stack with the given name.
func (sg *stateGenerator) pushResource(name string, basis compilergraph.GraphNode) {
sg.managesResources = true
// pushr(varName, 'varName');
pushCall := codedom.RuntimeFunctionCall(
codedom.StatePushResourceFunction,
[]codedom.Expression{
codedom.LocalReference(name, basis),
codedom.LiteralValue("'"+name+"'", basis),
},
basis,
)
sg.generateStates(codedom.ExpressionStatement(pushCall, basis), generateImplicitState)
sg.resources.Push(resource{
name: name,
basis: basis,
})
}
// buildNamedAccess builds the CodeDOM for a member access expression.
func (db *domBuilder) buildNamedAccess(node compilergraph.GraphNode, name string, childExprNode *compilergraph.GraphNode) codedom.Expression {
scope, _ := db.scopegraph.GetScope(node)
namedReference, hasNamedReference := db.scopegraph.GetReferencedName(scope)
// Reference to an unknown name or a nullable member access must be a dynamic access.
if !hasNamedReference || node.Kind() == parser.NodeNullableMemberAccessExpression {
return codedom.DynamicAccess(db.buildExpression(*childExprNode), name, node)
}
// Reference to a local name is a var or parameter.
if namedReference.IsLocal() {
return codedom.LocalReference(namedReference.Name(), node)
}
// Check for a reference to a type.
if typeRef, isType := namedReference.Type(); isType {
return codedom.StaticTypeReference(typeRef, node)
}
// Check for a reference to a member.
if memberRef, isMember := namedReference.Member(); isMember {
// If the member is under a child expression, build as an access expression.
if childExprNode != nil {
childExpr := db.buildExpression(*childExprNode)
_, underFuncCall := node.TryGetIncomingNode(parser.NodeFunctionCallExpressionChildExpr)
isAliasedFunctionReference := scope.ResolvedTypeRef(db.scopegraph.TypeGraph()).HasReferredType(db.scopegraph.TypeGraph().FunctionType())
if isAliasedFunctionReference && !underFuncCall {
return codedom.DynamicAccess(childExpr, memberRef.Name(), node)
} else {
return codedom.MemberReference(childExpr, memberRef, node)
}
} else {
// This is a direct access of a static member. Generate an access under the module.
return codedom.StaticMemberReference(memberRef, db.scopegraph.TypeGraph().AnyTypeReference(), node)
}
}
panic("Unknown kind of named access")
return nil
}
// buildThisLiteral builds the CodeDOM for the this literal.
func (db *domBuilder) buildThisLiteral(node compilergraph.GraphNode) codedom.Expression {
return codedom.LocalReference(DEFINED_THIS_PARAMETER, node)
}
// buildLoopStatement builds the CodeDOM for a loop statement.
func (db *domBuilder) buildLoopStatement(node compilergraph.GraphNode) (codedom.Statement, codedom.Statement) {
startStatement := codedom.EmptyStatement(node)
startStatement.MarkReferenceable()
finalStatement := codedom.EmptyStatement(node)
// Save initial continue and break statements for the loop.
db.continueStatementMap[node.NodeId] = startStatement
db.breakStatementMap[node.NodeId] = finalStatement
// A loop statement is buildd as a start statement which conditionally jumps to either the loop body
// (on true) or, on false, jumps to a final state after the loop.
if loopExpr, hasLoopExpr := db.tryGetExpression(node, parser.NodeLoopStatementExpression); hasLoopExpr {
// Check for a named value under the loop. If found, this is a loop over a stream or streamable.
namedValue, hasNamedValue := node.TryGetNode(parser.NodeStatementNamedValue)
if hasNamedValue {
namedValueName := namedValue.Get(parser.NodeNamedValueName)
resultVarName := db.generateScopeVarName(node)
namedValueScope, _ := db.scopegraph.GetScope(namedValue)
// Create the stream variable.
streamVarName := db.generateScopeVarName(node)
var streamVariable = codedom.VarDefinitionWithInit(streamVarName, loopExpr, node)
// If the expression is Streamable, first call .Stream() on the expression to get the stream
// for the variable.
if namedValueScope.HasLabel(proto.ScopeLabel_STREAMABLE_LOOP) {
// Call .Stream() on the expression.
streamableMember, _ := db.scopegraph.TypeGraph().StreamableType().GetMember("Stream")
streamExpr := codedom.MemberCall(
codedom.MemberReference(loopExpr, streamableMember, namedValue),
streamableMember,
[]codedom.Expression{},
namedValue)
streamVariable = codedom.VarDefinitionWithInit(streamVarName, streamExpr, node)
}
// Create variables to hold the named value (as requested in the SRG) and the loop result.
namedVariable := codedom.VarDefinition(namedValueName, node)
resultVariable := codedom.VarDefinition(resultVarName, node)
// Create an expression statement to set the result variable to a call to Next().
streamMember, _ := db.scopegraph.TypeGraph().StreamType().GetMember("Next")
nextCallExpr := codedom.MemberCall(
codedom.MemberReference(codedom.LocalReference(streamVarName, node), streamMember, node),
streamMember,
[]codedom.Expression{},
namedValue)
resultExpressionStatement := codedom.ExpressionStatement(codedom.LocalAssignment(resultVarName, nextCallExpr, namedValue), namedValue)
resultExpressionStatement.MarkReferenceable()
// Set the continue statement to call Next() again.
db.continueStatementMap[node.NodeId] = resultExpressionStatement
// Create an expression statement to set the named variable to the first part of the tuple.
namedExpressionStatement := codedom.ExpressionStatement(
codedom.LocalAssignment(namedValueName,
codedom.NativeAccess(
codedom.LocalReference(resultVarName, namedValue), "First", namedValue),
namedValue),
namedValue)
// Jump to the body state if the second part of the tuple in the result variable is true.
bodyStart, bodyEnd := db.getStatements(node, parser.NodeLoopStatementBlock)
checkJump := codedom.ConditionalJump(
codedom.NativeAccess(codedom.LocalReference(resultVarName, node), "Second", node),
bodyStart,
finalStatement,
node)
// Steps:
// 1) Empty statement
// 2) Create the stream's variable (with no value)
// 3) Create the named value variable (with no value)
// 4) Create the result variable (with no value)
// 5) (loop starts here) Pull the Next() result out of the stream
// 6) Pull the true/false bool out of the result
// 7) Pull the named value out of the result
// 8) Jump based on the true/false boolean value
codedom.AssignNextStatement(startStatement, streamVariable)
codedom.AssignNextStatement(streamVariable, namedVariable)
codedom.AssignNextStatement(namedVariable, resultVariable)
codedom.AssignNextStatement(resultVariable, resultExpressionStatement)
codedom.AssignNextStatement(resultExpressionStatement, namedExpressionStatement)
codedom.AssignNextStatement(namedExpressionStatement, checkJump)
// Jump to the result checking expression once the loop body completes.
directJump := codedom.UnconditionalJump(resultExpressionStatement, node)
codedom.AssignNextStatement(bodyEnd, directJump)
return startStatement, finalStatement
} else {
bodyStart, bodyEnd := db.getStatements(node, parser.NodeLoopStatementBlock)
// Loop over a direct boolean expression which is evaluated on each iteration.
initialJump := codedom.ConditionalJump(loopExpr, bodyStart, finalStatement, node)
directJump := codedom.UnconditionalJump(initialJump, node)
codedom.AssignNextStatement(bodyEnd, directJump)
codedom.AssignNextStatement(startStatement, initialJump)
return startStatement, finalStatement
}
} else {
bodyStart, bodyEnd := db.getStatements(node, parser.NodeLoopStatementBlock)
// A loop without an expression just loops infinitely over the body.
directJump := codedom.UnconditionalJump(bodyStart, node)
codedom.AssignNextStatement(bodyEnd, directJump)
codedom.AssignNextStatement(startStatement, bodyStart)
return startStatement, directJump
}
}
