77 lines
1.3 KiB
Go
77 lines
1.3 KiB
Go
package cli
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import (
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"fmt"
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"io"
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"gogs.inhome.blapointe.com/ana-ledger/src/ledger"
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)
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type Query struct{}
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func BuildQuery(args args) (ledger.Like, error) {
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likes := make(ledger.Likes, 0)
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for _, ok := args.peek(); ok; _, ok = args.peek() {
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like, err := buildOneQuery(args)
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if err != nil {
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return nil, err
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}
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likes = append(likes, like)
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}
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return likes.Any, nil
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}
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func buildOneQuery(args args) (ledger.Like, error) {
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word, ok := args.peek()
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if !ok {
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return nil, io.EOF
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}
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likes := make(ledger.Likes, 0)
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for _, ok := args.peek(); ok; _, ok = args.peek() {
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switch word {
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case "and":
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if len(likes) == 0 {
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return nil, fmt.Errorf("and without predicate")
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}
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args.pop()
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like, err := buildOneQuery(args)
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if err != nil {
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return nil, err
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}
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likes = append(likes, like)
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case "not":
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args.pop()
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like, err := buildOneQuery(args)
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if err != nil {
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return nil, err
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}
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likes = append(likes, like)
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default:
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return nil, io.EOF
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if next, _ := args.peek(); next != "and" {
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return likes.All, nil
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}
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}
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}
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return nil, io.EOF
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}
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type args []string
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func (args *args) pop() string {
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first := (*args)[0]
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*args = (*args)[1:]
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return first
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}
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func (args *args) peek() (string, bool) {
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if len(*args) == 0 {
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return "", false
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}
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return (*args)[0], true
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}
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