chore: add go doc

Signed-off-by: Caio Ferreira <[email protected]>

value.go

@@ -405,6 +405,10 @@ type Decimal int64
 // DecimalPrecision is the precision of a Decimal.
 const DecimalPrecision = 10000
 
+// ParseDecimal takes a string representation of a decimal number and converts it into a Decimal type.
+// The function handles optional negative sign and ensures that the decimal part of the number does not exceed four digits.
+// It returns an error if the string is empty, contains non-digit characters, missing decimal point, or if the number overflows.
+// The function also handles the case of negative numbers correctly to avoid overflow.
 func ParseDecimal(s string) (Decimal, error) {
 	// Check for empty string.
 	if len(s) == 0 {
@@ -576,6 +580,10 @@ func (v Decimal) deepClone() Value { return v }
 // The value can represent an individual address or a range of addresses.
 type IPAddr netip.Prefix
 
+// ParseIPAddr takes a string representation of an IP address and converts it into an IPAddr type.
+// The function handles both IPv4 and IPv6 addresses, and can also handle IP ranges.
+// It disallows IPv4-mapped IPv6 addresses in dotted notation.
+// The function returns an error if the string cannot be parsed into an IP address or IP range.
 func ParseIPAddr(s string) (IPAddr, error) {
 	// We disallow IPv4-mapped IPv6 addresses in dotted notation because Cedar does.
 	if strings.Count(s, ":") >= 2 && strings.Count(s, ".") >= 2 {