nswrap/types/main.go
2019-04-26 10:07:34 -04:00

140 lines
2.9 KiB
Go

package types
import (
"fmt"
)
var (
Debug bool = false
)
func dbg(f string, xs ...interface{}) {
if Debug {
fmt.Printf(f,xs...)
}
}
func (n *Node) HasFunc() bool {
if n == nil {
return false
}
for _,c := range n.Children {
if c.Kind == "Function" || c.HasFunc() {
return true
}
}
return false
}
func Parse(s string) (*Node, error) {
s2, n := TypeName(s,NewNode("AST"))
if s2 != "" {
return n,fmt.Errorf("Parse failed or incomplete. Remainder: %s",s2)
}
return n, nil
}
//Evaluate a node to determine if it is a pointer or array
func (n *Node) isAbstract(k string) bool {
if n.stripAbstract(k) == nil {
return false
}
return true
}
//Strip one level of pointer or array indirection from a node
func (n *Node) stripAbstract(k string) *Node {
if n == nil {
return nil
}
i := len(n.Children) - 1
if i < 1 {
return nil
}
ret := NewNode(n.Kind)
cs := n.Children[:]
dbg("stripAbstract(): i = %d\n",i)
//Scan backwords skipping TypeQualifier and NullableAnnotation tags
for ;i > 0 &&
(cs[i].Kind == "TypeQualifier" ||
cs[i].Kind == "NullableAnnotation") ; i-- { }
if cs[i].Kind == k {
dbg("stripAbstract(): last node is %s\n",k)
ret.Children = cs[:i]
return ret
}
if i > 1 && cs[i-1].Kind == "Parenthesized" {
j := len(cs[i-1].Children) - 1
for ;j > 0 &&
(cs[i-1].Children[j].Kind == "TypeQualifier" ||
cs[i-1].Children[j].Kind == "NullableAnnotation");
j-- { }
if cs[i-1].Children[j].Kind != k {
return nil
}
if j == 0 { // strip Parenthesized tag
cs[i-1] = cs[i]
ret.Children = cs[:i]
return ret
}
// strip last child from Parenthesized tag
cs[i-1].Children = cs[i-1].Children[:j]
ret.Children = cs
return ret
}
return nil
}
//PointsTo, when called on a pointer node returns a node describing the type
//pointed to. Otherwise returns nil when called on non-pointer types.
func (n *Node) PointsTo() *Node {
dbg("PointsTo()\n")
return n.stripAbstract("Pointer")
}
//IsPointer returns true if the node is a pointer
func (n *Node) IsPointer() bool {
return n.PointsTo() != nil
}
//ArrayOf, when called on an array node returns a node describing the type
//of the elements of the array. Otherwise returns nil when called on
//non-array types.
func (n *Node) ArrayOf() *Node {
dbg("ArrayOf()\n")
return n.stripAbstract("Array")
}
//IsArray returns true if the node is an array
func (n *Node) IsArray() bool {
return n.ArrayOf() != nil
}
func (n *Node) IsStruct() bool {
if n == nil || len(n.Children) < 1 {
return false
}
return n.Children[0].Kind == "Struct"
}
func (n *Node) IsFunction() bool {
if n == nil || len(n.Children) < 1 {
return false
}
return n.Children[len(n.Children)-1].Kind == "Function"
}
//BaseType strips off all layers of pointer indirection
func (n *Node) BaseType() *Node {
if n == nil {
return nil
}
if n2 := n.PointsTo(); n2 == nil {
return n
} else {
return n2.BaseType()
}
}