module walker import v.ast // Visitor defines a visit method which is invoked by the walker in each node it encounters. pub interface Visitor { visit(node ast.Node) ? } pub type InspectorFn = fn (node ast.Node, data voidptr) bool struct Inspector { inspector_callback InspectorFn mut: data voidptr } pub fn (i &Inspector) visit(node ast.Node) ? { if i.inspector_callback(node, i.data) { return } return error('') } // inspect traverses and checks the AST node on a depth-first order and based on the data given pub fn inspect(node ast.Node, data voidptr, inspector_callback InspectorFn) { walk(Inspector{inspector_callback, data}, node) } // walk traverses the AST using the given visitor pub fn walk(visitor Visitor, node ast.Node) { visitor.visit(node) or { return } children := node.children() for child_node in children { walk(visitor, &child_node) } }