package yaml
import (
"encoding/base64"
"fmt"
"reflect"
"regexp"
"strconv"
"strings"
"time"
"github.com/zclconf/go-cty/cty"
)
type resolveMapItem struct {
value cty.Value
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)
var resolveMapList = []struct {
v cty.Value
tag string
l []string
}{
{cty.True, yaml_BOOL_TAG, []string{"y", "Y", "yes", "Yes", "YES"}},
{cty.True, yaml_BOOL_TAG, []string{"true", "True", "TRUE"}},
{cty.True, yaml_BOOL_TAG, []string{"on", "On", "ON"}},
{cty.False, yaml_BOOL_TAG, []string{"n", "N", "no", "No", "NO"}},
{cty.False, yaml_BOOL_TAG, []string{"false", "False", "FALSE"}},
{cty.False, yaml_BOOL_TAG, []string{"off", "Off", "OFF"}},
{cty.NullVal(cty.DynamicPseudoType), yaml_NULL_TAG, []string{"", "~", "null", "Null", "NULL"}},
{cty.PositiveInfinity, yaml_FLOAT_TAG, []string{".inf", ".Inf", ".INF"}},
{cty.PositiveInfinity, yaml_FLOAT_TAG, []string{"+.inf", "+.Inf", "+.INF"}},
{cty.NegativeInfinity, yaml_FLOAT_TAG, []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 {
// TODO This can easily be made faster and produce less garbage.
if strings.HasPrefix(tag, longTagPrefix) {
return "!!" + tag[len(longTagPrefix):]
}
return tag
}
func longTag(tag string) string {
if strings.HasPrefix(tag, "!!") {
return longTagPrefix + tag[2:]
}
return tag
}
func resolvableTag(tag string) bool {
switch tag {
case "", yaml_STR_TAG, yaml_BOOL_TAG, yaml_INT_TAG, yaml_FLOAT_TAG, yaml_NULL_TAG, yaml_TIMESTAMP_TAG, yaml_BINARY_TAG:
return true
}
return false
}
var yamlStyleFloat = regexp.MustCompile(`^[-+]?(\.[0-9]+|[0-9]+(\.[0-9]*)?)([eE][-+]?[0-9]+)?$`)
func (c *Converter) resolveScalar(tag string, src string, style yaml_scalar_style_t) (cty.Value, error) {
if !resolvableTag(tag) {
return cty.NilVal, fmt.Errorf("unsupported tag %q", tag)
}
// Any data is accepted as a !!str or !!binary.
// Otherwise, the prefix is enough of a hint about what it might be.
hint := byte('N')
if src != "" {
hint = resolveTable[src[0]]
}
if hint != 0 && tag != yaml_STR_TAG && tag != yaml_BINARY_TAG {
if style == yaml_SINGLE_QUOTED_SCALAR_STYLE || style == yaml_DOUBLE_QUOTED_SCALAR_STYLE {
return cty.StringVal(src), nil
}
// Handle things we can lookup in a map.
if item, ok := resolveMap[src]; ok {
return item.value, nil
}
if tag == "" {
for _, nan := range []string{".nan", ".NaN", ".NAN"} {
if src == nan {
// cty cannot represent NaN, so this is an error
return cty.NilVal, fmt.Errorf("floating point NaN is not supported")
}
}
}
// Base 60 floats are intentionally not supported.
switch hint {
case 'M':
// We've already checked the map above.
case '.':
// Not in the map, so maybe a normal float.
if numberVal, err := cty.ParseNumberVal(src); err == nil {
return numberVal, nil
}
case 'D', 'S':
// Int, float, or timestamp.
// Only try values as a timestamp if the value is unquoted or there's an explicit
// !!timestamp tag.
if tag == "" || tag == yaml_TIMESTAMP_TAG {
t, ok := parseTimestamp(src)
if ok {
// cty has no timestamp type, but its functions stdlib
// conventionally uses strings in an RFC3339 encoding
// to represent time, so we'll follow that convention here.
return cty.StringVal(t.Format(time.RFC3339)), nil
}
}
plain := strings.Replace(src, "_", "", -1)
if numberVal, err := cty.ParseNumberVal(plain); err == nil {
return numberVal, nil
}
if strings.HasPrefix(plain, "0b") || strings.HasPrefix(plain, "-0b") {
tag = yaml_INT_TAG // will handle parsing below in our tag switch
}
default:
panic(fmt.Sprintf("cannot resolve tag %q with source %q", tag, src))
}
}
if tag == "" && src == "<<" {
return mergeMappingVal, nil
}
switch tag {
case yaml_STR_TAG, yaml_BINARY_TAG:
// If it's binary then we want to keep the base64 representation, because
// cty has no binary type, but we will check that it's actually base64.
if tag == yaml_BINARY_TAG {
_, err := base64.StdEncoding.DecodeString(src)
if err != nil {
return cty.NilVal, fmt.Errorf("cannot parse %q as %s: not valid base64", src, tag)
}
}
return cty.StringVal(src), nil
case yaml_BOOL_TAG:
item, ok := resolveMap[src]
if !ok || item.tag != yaml_BOOL_TAG {
return cty.NilVal, fmt.Errorf("cannot parse %q as %s", src, tag)
}
return item.value, nil
case yaml_FLOAT_TAG, yaml_INT_TAG:
// Note: We don't actually check that a value tagged INT is a whole
// number here. We could, but cty generally doesn't care about the
// int/float distinction, so we'll just be generous and accept it.
plain := strings.Replace(src, "_", "", -1)
if numberVal, err := cty.ParseNumberVal(plain); err == nil { // handles decimal integers and floats
return numberVal, nil
}
if intv, err := strconv.ParseInt(plain, 0, 64); err == nil { // handles 0x and 00 prefixes
return cty.NumberIntVal(intv), nil
}
if uintv, err := strconv.ParseUint(plain, 0, 64); err == nil { // handles 0x and 00 prefixes
return cty.NumberUIntVal(uintv), nil
}
if strings.HasPrefix(plain, "0b") {
intv, err := strconv.ParseInt(plain[2:], 2, 64)
if err == nil {
return cty.NumberIntVal(intv), nil
}
uintv, err := strconv.ParseUint(plain[2:], 2, 64)
if err == nil {
return cty.NumberUIntVal(uintv), nil
}
} else if strings.HasPrefix(plain, "-0b") {
intv, err := strconv.ParseInt("-"+plain[3:], 2, 64)
if err == nil {
return cty.NumberIntVal(intv), nil
}
}
return cty.NilVal, fmt.Errorf("cannot parse %q as %s", src, tag)
case yaml_TIMESTAMP_TAG:
t, ok := parseTimestamp(src)
if ok {
// cty has no timestamp type, but its functions stdlib
// conventionally uses strings in an RFC3339 encoding
// to represent time, so we'll follow that convention here.
return cty.StringVal(t.Format(time.RFC3339)), nil
}
return cty.NilVal, fmt.Errorf("cannot parse %q as %s", src, tag)
case yaml_NULL_TAG:
return cty.NullVal(cty.DynamicPseudoType), nil
case "":
return cty.StringVal(src), nil
default:
return cty.NilVal, fmt.Errorf("unsupported tag %q", tag)
}
}
// encodeBase64 encodes s as base64 that is broken up into multiple lines
// as appropriate for the resulting length.
func encodeBase64(s string) string {
const lineLen = 70
encLen := base64.StdEncoding.EncodedLen(len(s))
lines := encLen/lineLen + 1
buf := make([]byte, encLen*2+lines)
in := buf[0:encLen]
out := buf[encLen:]
base64.StdEncoding.Encode(in, []byte(s))
k := 0
for i := 0; i < len(in); i += lineLen {
j := i + lineLen
if j > len(in) {
j = len(in)
}
k += copy(out[k:], in[i:j])
if lines > 1 {
out[k] = '\n'
k++
}
}
return string(out[:k])
}
// This is a subset of the formats allowed by the regular expression
// defined at http://yaml.org/type/timestamp.html.
var allowedTimestampFormats = []string{
"2006-1-2T15:4:5.999999999Z07:00", // RCF3339Nano with short date fields.
"2006-1-2t15:4:5.999999999Z07:00", // RFC3339Nano with short date fields and lower-case "t".
"2006-1-2 15:4:5.999999999", // space separated with no time zone
"2006-1-2", // date only
// Notable exception: time.Parse cannot handle: "2001-12-14 21:59:43.10 -5"
// from the set of examples.
}
// parseTimestamp parses s as a timestamp string and
// returns the timestamp and reports whether it succeeded.
// Timestamp formats are defined at http://yaml.org/type/timestamp.html
func parseTimestamp(s string) (time.Time, bool) {
// TODO write code to check all the formats supported by
// http://yaml.org/type/timestamp.html instead of using time.Parse.
// Quick check: all date formats start with YYYY-.
i := 0
for ; i < len(s); i++ {
if c := s[i]; c < '0' || c > '9' {
break
}
}
if i != 4 || i == len(s) || s[i] != '-' {
return time.Time{}, false
}
for _, format := range allowedTimestampFormats {
if t, err := time.Parse(format, s); err == nil {
return t, true
}
}
return time.Time{}, false
}
type mergeMapping struct{}
var mergeMappingTy = cty.Capsule("merge mapping", reflect.TypeOf(mergeMapping{}))
var mergeMappingVal = cty.CapsuleVal(mergeMappingTy, &mergeMapping{})
