Getting ready for AppImage downloading

appimg/Tag.go

@@ -0,0 +1,117 @@
+package appimg
+
+import "strings"
+
+//Tag is a bbCode tag that is properly processed.
+type Tag struct {
+	typ    string
+	end    bool
+	params map[string]string
+	index  [2]int
+}
+
+//Value returns the value of a parameter of the bbCode tag. Starting parameters
+//is under "starting". Parameter names are always in lowercase
+func (t *Tag) Value(param string) string {
+	return t.params[param]
+}
+
+func (t *Tag) setValue(param, value string) {
+	if t.params == nil {
+		t.params = make(map[string]string)
+	}
+	t.params[strings.TrimSpace(strings.ToLower(param))] = strings.TrimSpace(value)
+}
+
+func (t *Tag) process(bbtag string) {
+	if strings.HasPrefix(bbtag, "/") {
+		t.end = true
+		t.typ = strings.ToLower(strings.TrimPrefix(bbtag[:len(bbtag)-1], "/"))
+		return
+	}
+	for i, v := range bbtag {
+		if v == '=' || v == ' ' || v == '>' {
+			t.typ = strings.ToLower(bbtag[:i])
+			switch v {
+			case '=':
+				if qt := bbtag[i+1]; qt == '\'' || qt == '"' {
+					for j := i + 2; j < len(bbtag); j++ {
+						if bbtag[j] == qt {
+							t.setValue("starting", bbtag[i+2:j])
+							bbtag = bbtag[j+1:]
+							break
+						} else if bbtag[j] == '>' {
+							t.setValue("starting", bbtag[i+2:j])
+							return
+						}
+					}
+				} else {
+					for j := i + 1; j < len(bbtag); j++ {
+						if bbtag[j] == '>' {
+							t.setValue("starting", bbtag[i+1:j])
+							return
+						} else if bbtag[j] == ' ' {
+							t.setValue("starting", bbtag[i+1:j])
+							bbtag = bbtag[j+1:]
+							break
+						}
+					}
+				}
+			case '>':
+				return
+			case ' ':
+				bbtag = bbtag[i:]
+			}
+			break
+		}
+	}
+	t.processFurther(bbtag)
+}
+
+func (t *Tag) processFurther(further string) {
+	further = strings.TrimSpace(further)
+	for i := 0; i < len(further); i++ {
+		switch further[i] {
+		case ' ':
+			t.setValue(strings.ToLower(further[:i]), further[:i])
+			further = strings.TrimSpace(further[i:])
+			i = -1
+		case '=':
+			if qt := further[i+1]; qt == '\'' || qt == '"' {
+			outloopqt:
+				for j := i + 2; j < len(further); j++ {
+					switch further[j] {
+					case '>':
+						t.setValue(strings.ToLower(further[:i]), further[i+2:j])
+						return
+					case qt:
+						t.setValue(strings.ToLower(further[:i]), further[i+2:j])
+						further = strings.TrimSpace(further[j+1:])
+						i = -1
+						break outloopqt
+					}
+				}
+			} else {
+			outloop:
+				for j := i + 1; j < len(further); j++ {
+					switch further[j] {
+					case '>':
+						t.setValue(strings.ToLower(further[:i]), further[i+1:j])
+						return
+					case ' ':
+						t.setValue(strings.ToLower(further[:i]), further[i+1:j])
+						further = strings.TrimSpace(further[j:])
+						i = -1
+						break outloop
+					}
+				}
+			}
+		case '>':
+			if i != 0 {
+				t.setValue(strings.ToLower(further[:i]), further[:i])
+				return
+			}
+			return
+		}
+	}
+}