parsing c++ type identifiers rofl

kill me

ent/decoders.go

@@ -37,6 +37,8 @@ func newFieldDecoder(n *Namespace, f *Field) decoder {
 		return entityDecoder(f.class)
 	}
 
+	Debug.Printf("type spec: %v", parseTypeName(n, typeName))
+
 	switch {
 	case strings.HasPrefix(typeName, "CHandle"):
 		return decodeVarInt32

ent/type_spec.go

@@ -0,0 +1,112 @@
+package ent
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+const (
+	t_element  = iota // a known element class
+	t_object          // c++ object type that is not a known element class
+	t_array           // c++ array type
+	t_template        // c++ template type
+)
+
+// constant identifiers
+var cIdents = map[string]int{"MAX_ABILITY_DRAFT_ABILITIES": 48}
+
+type typeSpec struct {
+	name     string
+	kind     int
+	size     int
+	template string
+	member   *typeSpec
+}
+
+func (t typeSpec) String() string {
+	if t.member != nil {
+		return fmt.Sprintf("{%v %v %v %v %v}", t.name, t.kind, t.size, t.template, *t.member)
+	}
+	return fmt.Sprintf("{%v %v %v %v %v}", t.name, t.kind, t.size, t.template, t.member)
+}
+
+func parseTypeName(n *Namespace, s string) typeSpec {
+	s = strings.TrimSpace(s)
+	t := typeSpec{name: s}
+
+	if n.HasClass(s) {
+		t.kind = t_element
+		return t
+	}
+
+	// presumably this is some sort of array type
+	if strings.ContainsRune(s, '[') {
+		memName, count := parseArrayName(s)
+		t.kind = t_array
+		t.size = count
+		t.member = new(typeSpec)
+		*t.member = parseTypeName(n, memName)
+		return t
+	}
+
+	if strings.ContainsRune(s, '<') {
+		t.kind = t_template
+		template, member := parseTemplateName(s)
+		t.template = template
+		t.member = new(typeSpec)
+		*t.member = parseTypeName(n, member)
+		return t
+	}
+
+	t.kind = t_object
+	return t
+}
+
+func parseArrayName(s string) (string, int) {
+	runes := []rune(s)
+	if runes[len(runes)-1] != ']' {
+		panic("invalid array type name: " + s)
+	}
+	for i := len(runes) - 2; i >= 0; i-- {
+		if runes[i] == '[' {
+			ns := strings.TrimSpace(string(runes[i+1 : len(runes)-1]))
+			n, err := strconv.Atoi(ns)
+			if err != nil {
+				n = cIdents[ns]
+				if n == 0 {
+					panic("invalid array type name: " + err.Error())
+				}
+			}
+			return strings.TrimSpace(string(runes[:i])), n
+		}
+	}
+	panic("invalid array type name: " + s)
+}
+
+func parseTemplateName(s string) (string, string) {
+	if strings.ContainsRune(s, ',') {
+		panic("can't handle templates with multiple parameters")
+	}
+
+	runes := []rune(s)
+	template := ""
+	depth := 0
+	bracket_start := -1
+	for i, r := range runes {
+		if r == '<' {
+			if depth == 0 {
+				bracket_start = i
+				template = strings.TrimSpace(string(runes[:i]))
+			}
+			depth++
+		}
+		if r == '>' {
+			depth--
+			if depth == 0 {
+				return template, strings.TrimSpace(string(runes[bracket_start+1 : i]))
+			}
+		}
+	}
+	panic("invalid template type definition: " + s)
+}