1 files changed, 71 insertions, 0 deletions
diff --git a/vendor/github.com/graph-gophers/graphql-go/internal/validation/suggestion.go b/vendor/github.com/graph-gophers/graphql-go/internal/validation/suggestion.go
new file mode 100644
index 00000000..9702b5f5
--- /dev/null
+++ b/vendor/github.com/graph-gophers/graphql-go/internal/validation/suggestion.go
@@ -0,0 +1,71 @@
+package validation
+
+import (
+	"fmt"
+	"sort"
+	"strconv"
+	"strings"
+)
+
+func makeSuggestion(prefix string, options []string, input string) string {
+	var selected []string
+	distances := make(map[string]int)
+	for _, opt := range options {
+		distance := levenshteinDistance(input, opt)
+		threshold := max(len(input)/2, max(len(opt)/2, 1))
+		if distance < threshold {
+			selected = append(selected, opt)
+			distances[opt] = distance
+		}
+	}
+
+	if len(selected) == 0 {
+		return ""
+	}
+	sort.Slice(selected, func(i, j int) bool {
+		return distances[selected[i]] < distances[selected[j]]
+	})
+
+	parts := make([]string, len(selected))
+	for i, opt := range selected {
+		parts[i] = strconv.Quote(opt)
+	}
+	if len(parts) > 1 {
+		parts[len(parts)-1] = "or " + parts[len(parts)-1]
+	}
+	return fmt.Sprintf(" %s %s?", prefix, strings.Join(parts, ", "))
+}
+
+func levenshteinDistance(s1, s2 string) int {
+	column := make([]int, len(s1)+1)
+	for y := range s1 {
+		column[y+1] = y + 1
+	}
+	for x, rx := range s2 {
+		column[0] = x + 1
+		lastdiag := x
+		for y, ry := range s1 {
+			olddiag := column[y+1]
+			if rx != ry {
+				lastdiag++
+			}
+			column[y+1] = min(column[y+1]+1, min(column[y]+1, lastdiag))
+			lastdiag = olddiag
+		}
+	}
+	return column[len(s1)]
+}
+
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}
+
+func max(a, b int) int {
+	if a > b {
+		return a
+	}
+	return b
+}