generate: Decode arrays (but don't validate their length yet)

generate/generate.go

@@ -555,17 +555,88 @@ func (this *Generator) generateDecodeBranch(hash [16]byte, typ Type) (n int, err
 	n += nn; if err != nil { return n, err }
 	nn, err = this.printf(" decoder *tape.Decoder, tag tape.Tag) (nn int, err error) \n{")
 	n += nn; if err != nil { return n, err }
+	this.push()
 	
-	switch typ := typ.(type) {
+		nn, err = this.iprintf("var nn int\n")
-	case TypeArray:
+		n += nn; if err != nil { return n, err }
-		// OTA: <length: UN> <elementTag: tape.Tag> <values>*
 		
-	case TypeTableDefined:
+		switch typ := typ.(type) {
-		// KTV: <length: UN> (<key: U16> <tag: Tag> <value>)*
+		case TypeArray:
-		// TODO
+			// OTA: <length: UN> <elementTag: tape.Tag> <values>*
-	default: return n, fmt.Errorf("unexpected type: %T", typ)
+			// read header
-	}
+			lengthVar := this.newTemporaryVar("length")
-	
+			nn, err := this.iprintf("var %s uint64\n", lengthVar)
+			n += nn; if err != nil { return n, err }
+			nn, err = this.iprintf("%s, nn, err = decoder.ReadUintN(int(tag.CN()))\n", lengthVar)
+			n += nn; if err != nil { return n, err }
+			nn, err = this.generateErrorCheck()
+			n += nn; if err != nil { return n, err }
+			elementTagVar := this.newTemporaryVar("elementTag")
+			nn, err = this.iprintf("var %s uint64\n", lengthVar)
+			n += nn; if err != nil { return n, err }
+			nn, err = this.iprintf("%s, nn, err = decoder.ReadTag()\n", elementTagVar)
+			n += nn; if err != nil { return n, err }
+			nn, err = this.generateErrorCheck()
+			n += nn; if err != nil { return n, err }
+
+			// abort macro
+			abort := func() (n int, err error) {
+				// skim entire array
+				nn, err = this.iprintf("for _ = range %s {\n", lengthVar)
+				n += nn; if err != nil { return n, err }
+				this.push()
+					nn, err = this.iprintf("nn, err = tape.Skim(decoder, tag)")
+					n += nn; if err != nil { return n, err }
+					nn, err = this.generateErrorCheck()
+					n += nn; if err != nil { return n, err }
+				this.pop()
+				nn, err = this.iprintf("}\n")
+				n += nn; if err != nil { return n, err }
+				nn, err = this.iprintf("return n, nil")
+				n += nn; if err != nil { return n, err }
+				return n, nil
+			}
+
+			// validate header
+			// TODO: here, validate that length is less than the
+			// max, whatever that is configured to be. the reason we
+			// want to read it here is that we would have to skip
+			// the tag anyway so why not.
+			nn, err = this.iprintf("if %s != ", elementTagVar)
+			n += nn; if err != nil { return n, err }
+			nn, err = this.generateTag(typ.Element, "(*this)")
+			n += nn; if err != nil { return n, err }
+			nn, err = this.printf(" {\n")
+			n += nn; if err != nil { return n, err }
+			this.push()
+				nn, err = abort()
+				n += nn; if err != nil { return n, err }
+			this.pop()
+			nn, err = this.iprintf("}\n")
+			n += nn; if err != nil { return n, err }
+
+			// decode payloads
+			nn, err = this.iprintf("*this = make(")
+			n += nn; if err != nil { return n, err }
+			nn, err = this.generateType(typ)
+			n += nn; if err != nil { return n, err }
+			nn, err = this.printf(", %s)\n", lengthVar)
+			n += nn; if err != nil { return n, err }
+			nn, err = this.iprintf("for index := range %s {\n", lengthVar)
+			n += nn; if err != nil { return n, err }
+			this.push()
+				nn, err = this.generateDecodeValue(typ.Element, "(*this)[index]", elementTagVar)
+				n += nn; if err != nil { return n, err }
+			this.pop()
+			nn, err = this.iprintf("}\n")
+			n += nn; if err != nil { return n, err }
+		case TypeTableDefined:
+			// KTV: <length: UN> (<key: U16> <tag: Tag> <value>)*
+			// TODO
+		default: return n, fmt.Errorf("unexpected type: %T", typ)
+		}
+
+	this.pop()
 	nn, err = this.iprintf("}")
 	n += nn; if err != nil { return n, err }
 	return n, nil