v/vlib/toml/ast/walker/walker.v

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2021-09-24 20:13:52 +02:00
module walker
import toml.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) ?
struct Inspector {
inspector_callback InspectorFn
mut:
data voidptr
}
pub fn (i &Inspector) visit(node &ast.Node) ? {
i.inspector_callback(node, i.data) or { return err }
}
// 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) ? {
if node is map[string]ast.Node {
n := node as map[string]ast.Node
for _, nn in n {
walk(visitor, &nn) ?
}
} else {
visitor.visit(node) ?
}
}