func goLinksFor()

in internal/texthtml/ast.go [55:165]
82 lines of code
34 McCabe index (conditional complexity)

func goLinksFor(node ast.Node) (links []goLink) {
	// linkMap tracks link information for each ast.Ident node. Entries may
	// be created out of source order (for example, when we visit a parent
	// definition node). These links are appended to the returned slice when
	// their ast.Ident nodes are visited.
	linkMap := make(map[*ast.Ident]goLink)

	ast.Inspect(node, func(node ast.Node) bool {
		switch n := node.(type) {
		case *ast.Field:
			for _, n := range n.Names {
				linkMap[n] = goLink{}
			}
		case *ast.ImportSpec:
			if name := n.Name; name != nil {
				linkMap[name] = goLink{}
			}
		case *ast.ValueSpec:
			for _, n := range n.Names {
				linkMap[n] = goLink{name: n.Name, isVal: true}
			}
		case *ast.FuncDecl:
			linkMap[n.Name] = goLink{}
		case *ast.TypeSpec:
			linkMap[n.Name] = goLink{}
		case *ast.AssignStmt:
			// Short variable declarations only show up if we apply
			// this code to all source code (as opposed to exported
			// declarations only).
			if n.Tok == token.DEFINE {
				// Some of the lhs variables may be re-declared,
				// so technically they are not defs. We don't
				// care for now.
				for _, x := range n.Lhs {
					// Each lhs expression should be an
					// ident, but we are conservative and check.
					if n, _ := x.(*ast.Ident); n != nil {
						linkMap[n] = goLink{isVal: true}
					}
				}
			}
		case *ast.SelectorExpr:
			// Detect qualified identifiers of the form pkg.ident.
			// If anything fails we return true and collect individual
			// identifiers instead.
			if x, _ := n.X.(*ast.Ident); x != nil {
				// Create links only if x is a qualified identifier.
				if obj := x.Obj; obj != nil && obj.Kind == ast.Pkg {
					if spec, _ := obj.Decl.(*ast.ImportSpec); spec != nil {
						// spec.Path.Value is the import path
						if path, err := strconv.Unquote(spec.Path.Value); err == nil {
							// Register two links, one for the package
							// and one for the qualified identifier.
							linkMap[x] = goLink{path: path}
							linkMap[n.Sel] = goLink{path: path, name: n.Sel.Name}
						}
					}
				}
			}
		case *ast.CompositeLit:
			// Detect field names within composite literals. These links should
			// be prefixed by the type name.
			fieldPath := ""
			prefix := ""
			switch typ := n.Type.(type) {
			case *ast.Ident:
				prefix = typ.Name + "."
			case *ast.SelectorExpr:
				if x, _ := typ.X.(*ast.Ident); x != nil {
					// Create links only if x is a qualified identifier.
					if obj := x.Obj; obj != nil && obj.Kind == ast.Pkg {
						if spec, _ := obj.Decl.(*ast.ImportSpec); spec != nil {
							// spec.Path.Value is the import path
							if path, err := strconv.Unquote(spec.Path.Value); err == nil {
								// Register two links, one for the package
								// and one for the qualified identifier.
								linkMap[x] = goLink{path: path}
								linkMap[typ.Sel] = goLink{path: path, name: typ.Sel.Name}
								fieldPath = path
								prefix = typ.Sel.Name + "."
							}
						}
					}
				}
			}
			for _, e := range n.Elts {
				if kv, ok := e.(*ast.KeyValueExpr); ok {
					if k, ok := kv.Key.(*ast.Ident); ok {
						// Note: there is some syntactic ambiguity here. We cannot determine
						// if this is a struct literal or a map literal without type
						// information. We assume struct literal.
						name := prefix + k.Name
						linkMap[k] = goLink{path: fieldPath, name: name}
					}
				}
			}
		case *ast.Ident:
			if l, ok := linkMap[n]; ok {
				links = append(links, l)
			} else {
				l := goLink{name: n.Name}
				if n.Obj == nil && doc.IsPredeclared(n.Name) {
					l.path = "builtin"
				}
				links = append(links, l)
			}
		}
		return true
	})
	return
}