refactor(deps): Manage deps with goven

third_party/launchpad.net/goyaml/resolve.go

@@ -0,0 +1,155 @@
+package goyaml
+
+import (
+	"math"
+	"strconv"
+	"strings"
+)
+
+// TODO: merge, timestamps, base 60 floats, omap.
+
+type resolveMapItem struct {
+	value interface{}
+	tag   string
+}
+
+var resolveTable = make([]byte, 256)
+var resolveMap = make(map[string]resolveMapItem)
+
+func init() {
+	t := resolveTable
+	t[int('+')] = 'S' // Sign
+	t[int('-')] = 'S'
+	for _, c := range "0123456789" {
+		t[int(c)] = 'D' // Digit
+	}
+	for _, c := range "yYnNtTfFoO~" {
+		t[int(c)] = 'M' // In map
+	}
+	t[int('.')] = '.' // Float (potentially in map)
+	t[int('<')] = '<' // Merge
+
+	var resolveMapList = []struct {
+		v   interface{}
+		tag string
+		l   []string
+	}{
+		{true, "!!bool", []string{"y", "Y", "yes", "Yes", "YES"}},
+		{true, "!!bool", []string{"true", "True", "TRUE"}},
+		{true, "!!bool", []string{"on", "On", "ON"}},
+		{false, "!!bool", []string{"n", "N", "no", "No", "NO"}},
+		{false, "!!bool", []string{"false", "False", "FALSE"}},
+		{false, "!!bool", []string{"off", "Off", "OFF"}},
+		{nil, "!!null", []string{"~", "null", "Null", "NULL"}},
+		{math.NaN(), "!!float", []string{".nan", ".NaN", ".NAN"}},
+		{math.Inf(+1), "!!float", []string{".inf", ".Inf", ".INF"}},
+		{math.Inf(+1), "!!float", []string{"+.inf", "+.Inf", "+.INF"}},
+		{math.Inf(-1), "!!float", []string{"-.inf", "-.Inf", "-.INF"}},
+	}
+
+	m := resolveMap
+	for _, item := range resolveMapList {
+		for _, s := range item.l {
+			m[s] = resolveMapItem{item.v, item.tag}
+		}
+	}
+}
+
+const longTagPrefix = "tag:yaml.org,2002:"
+
+func shortTag(tag string) string {
+	if strings.HasPrefix(tag, longTagPrefix) {
+		return "!!" + tag[len(longTagPrefix):]
+	}
+	return tag
+}
+
+func resolvableTag(tag string) bool {
+	switch tag {
+	case "", "!!str", "!!bool", "!!int", "!!float", "!!null":
+		return true
+	}
+	return false
+}
+
+func resolve(tag string, in string) (rtag string, out interface{}) {
+	tag = shortTag(tag)
+	if !resolvableTag(tag) {
+		return tag, in
+	}
+
+	defer func() {
+		if tag != "" && tag != rtag {
+			panic("Can't decode " + rtag + " '" + in + "' as a " + tag)
+		}
+	}()
+
+	if in == "" {
+		return "!!null", nil
+	}
+
+	c := resolveTable[in[0]]
+	if c == 0 {
+		// It's a string for sure. Nothing to do.
+		return "!!str", in
+	}
+
+	// Handle things we can lookup in a map.
+	if item, ok := resolveMap[in]; ok {
+		return item.tag, item.value
+	}
+
+	switch c {
+	case 'M':
+		// We've already checked the map above.
+
+	case '.':
+		// Not in the map, so maybe a normal float.
+		floatv, err := strconv.ParseFloat(in, 64)
+		if err == nil {
+			return "!!float", floatv
+		}
+	// XXX Handle base 60 floats here (WTF!)
+
+	case 'D', 'S':
+		// Int, float, or timestamp.
+		for i := 0; i != len(in); i++ {
+			if in[i] == '_' {
+				in = strings.Replace(in, "_", "", -1)
+				break
+			}
+		}
+		intv, err := strconv.ParseInt(in, 0, 64)
+		if err == nil {
+			if intv == int64(int(intv)) {
+				return "!!int", int(intv)
+			} else {
+				return "!!int", intv
+			}
+		}
+		floatv, err := strconv.ParseFloat(in, 64)
+		if err == nil {
+			return "!!float", floatv
+		}
+		if strings.HasPrefix(in, "0b") {
+			intv, err := strconv.ParseInt(in[2:], 2, 64)
+			if err == nil {
+				return "!!int", int(intv)
+			}
+		} else if strings.HasPrefix(in, "-0b") {
+			intv, err := strconv.ParseInt(in[3:], 2, 64)
+			if err == nil {
+				return "!!int", -int(intv)
+			}
+		}
+	// XXX Handle timestamps here.
+
+	case '<':
+		// XXX Handle merge (<<) here.
+
+	default:
+		panic("resolveTable item not yet handled: " +
+			string([]byte{c}) + " (with " + in + ")")
+	}
+	return "!!str", in
+}