// parseConstants finds constant definitions and references to them. // It replaces the references with the nodes denoting the value of // the respective constants. func parseConstants(ast *parser.AST, list []parser.Node) (out []parser.Node, err error) { var instr *parser.Instruction var expr *parser.Expression var name *parser.Name var ok bool consts := make(map[string][]parser.Node) for i := 0; i < len(list); i++ { if instr, ok = list[i].(*parser.Instruction); !ok { continue } name = instr.Children()[0].(*parser.Name) if name.Data != "equ" { continue } expr = instr.Children()[1].(*parser.Expression) name = expr.Children()[0].(*parser.Name) if _, ok = consts[name.Data]; ok { return nil, NewBuildError( ast.Files[instr.File()], instr.Line(), instr.Col(), "Duplicate constant %q.", name.Data) } expr = instr.Children()[2].(*parser.Expression) consts[name.Data] = expr.Children() // Remove constant node from AST. copy(list[i:], list[i+1:]) list = list[:len(list)-1] i-- } for k, v := range consts { list = replaceConstantRef(list, k, v) } return list, nil }
func (sw *SourceWriter) writeExpression(n *parser.Expression) { sw.writeList(n.Children()) }