vendor tsgo

tools/tsgo/internal/ast/flow.go

@@ -0,0 +1,75 @@
+package ast
+
+// FlowFlags
+
+type FlowFlags uint32
+
+const (
+	FlowFlagsUnreachable    FlowFlags = 1 << 0  // Unreachable code
+	FlowFlagsStart          FlowFlags = 1 << 1  // Start of flow graph
+	FlowFlagsBranchLabel    FlowFlags = 1 << 2  // Non-looping junction
+	FlowFlagsLoopLabel      FlowFlags = 1 << 3  // Looping junction
+	FlowFlagsAssignment     FlowFlags = 1 << 4  // Assignment
+	FlowFlagsTrueCondition  FlowFlags = 1 << 5  // Condition known to be true
+	FlowFlagsFalseCondition FlowFlags = 1 << 6  // Condition known to be false
+	FlowFlagsSwitchClause   FlowFlags = 1 << 7  // Switch statement clause
+	FlowFlagsArrayMutation  FlowFlags = 1 << 8  // Potential array mutation
+	FlowFlagsCall           FlowFlags = 1 << 9  // Potential assertion call
+	FlowFlagsReduceLabel    FlowFlags = 1 << 10 // Temporarily reduce antecedents of label
+	FlowFlagsReferenced     FlowFlags = 1 << 11 // Referenced as antecedent once
+	FlowFlagsShared         FlowFlags = 1 << 12 // Referenced as antecedent more than once
+	FlowFlagsLabel                    = FlowFlagsBranchLabel | FlowFlagsLoopLabel
+	FlowFlagsCondition                = FlowFlagsTrueCondition | FlowFlagsFalseCondition
+)
+
+// FlowNode
+
+type FlowNode struct {
+	Flags       FlowFlags
+	Node        *Node     // Associated AST node
+	Antecedent  *FlowNode // Antecedent for all but FlowLabel
+	Antecedents *FlowList // Linked list of antecedents for FlowLabel
+}
+
+type FlowList struct {
+	Flow *FlowNode
+	Next *FlowList
+}
+
+type FlowLabel = FlowNode
+
+// FlowSwitchClauseData (synthetic AST node for FlowFlagsSwitchClause)
+
+type FlowSwitchClauseData struct {
+	NodeBase
+	SwitchStatement *Node
+	ClauseStart     int32 // Start index of case/default clause range
+	ClauseEnd       int32 // End index of case/default clause range
+}
+
+func NewFlowSwitchClauseData(switchStatement *Node, clauseStart int, clauseEnd int) *Node {
+	node := &FlowSwitchClauseData{}
+	node.SwitchStatement = switchStatement
+	node.ClauseStart = int32(clauseStart)
+	node.ClauseEnd = int32(clauseEnd)
+	return newNode(KindUnknown, node, NodeFactoryHooks{})
+}
+
+func (node *FlowSwitchClauseData) IsEmpty() bool {
+	return node.ClauseStart == node.ClauseEnd
+}
+
+// FlowReduceLabelData (synthetic AST node for FlowFlagsReduceLabel)
+
+type FlowReduceLabelData struct {
+	NodeBase
+	Target      *FlowLabel // Target label
+	Antecedents *FlowList  // Temporary antecedent list
+}
+
+func NewFlowReduceLabelData(target *FlowLabel, antecedents *FlowList) *Node {
+	node := &FlowReduceLabelData{}
+	node.Target = target
+	node.Antecedents = antecedents
+	return newNode(KindUnknown, node, NodeFactoryHooks{})
+}