PSON decoder example using namespaced imports

2025-06-14 23:41:30 +00:00 · 2017-12-30 05:11:58 +01:00
parent c67f87a988
commit 2888ba14ad
41 changed files with 1283 additions and 336 deletions
--- a/examples/pson/assembly/pson.ts
+++ b/examples/pson/assembly/pson.ts
@ -0,0 +1,156 @@
+const enum Token {
+  ZERO = 0x00,
+  MAX = 0xEF,
+  NULL = 0xf0,
+  TRUE = 0xf1,
+  FALSE = 0xf2,
+  EOBJECT = 0xf3,
+  EARRAY = 0xf4,
+  ESTRING = 0xf5,
+  OBJECT = 0xf6,
+  ARRAY = 0xf7,
+  INTEGER = 0xf8,
+  LONG = 0xf9,
+  FLOAT = 0xfa,
+  DOUBLE = 0xfb,
+  STRING = 0xfc,
+  STRING_ADD = 0xfd,
+  STRING_GET = 0xfe,
+  BINARY = 0xff
+}
+
+namespace pson {
+  export declare function onNull(): void;
+  export declare function onTrue(): void;
+  export declare function onFalse(): void;
+  export declare function onEObject(): void;
+  export declare function onEArray(): void;
+  export declare function onEString(): void;
+  export declare function onObject(size: u32): void;
+  export declare function onArray(size: u32): void;
+  export declare function onInteger(value: i32): void;
+  export declare function onLong(valueLow: i32, valueHigh: i32): void;
+  export declare function onFloat(value: f32): void;
+  export declare function onDouble(value: f64): void;
+  export declare function onString(offset: usize, length: u32): void;
+  export declare function onBinary(offset: usize, length: u32): void;
+  export declare function onTruncated(): void;
+}
+
+var offset: usize = 0;
+
+export function decode(length: usize): void {
+  offset = 0;
+  while (offset < length)
+    decodeValue();
+  if (offset != length)
+    pson.onTruncated();
+}
+
+function decodeValue(): void {
+  var token: u32 = load<u8>(offset++);
+  var size: u32;
+  var long: u64;
+  switch (token) {
+
+    case Token.NULL:
+      pson.onNull();
+      break;
+
+    case Token.TRUE:
+      pson.onTrue();
+      break;
+
+    case Token.FALSE:
+      pson.onFalse();
+      break;
+
+    case Token.EOBJECT:
+      pson.onEObject();
+      break;
+
+    case Token.EARRAY:
+      pson.onEArray();
+      break;
+
+    case Token.ESTRING:
+      pson.onEString();
+      break;
+
+    case Token.OBJECT:
+      pson.onObject(size = readVarint32());
+      while (size--) {
+        decodeValue();
+        decodeValue();
+      }
+      break;
+
+    case Token.ARRAY:
+      pson.onArray(size = readVarint32());
+      while (size--)
+        decodeValue();
+      break;
+
+    case Token.INTEGER:
+      pson.onInteger(((size = readVarint32()) >> 1) ^ -(size & 1));
+      break;
+
+    case Token.LONG:
+      long = ((long = readVarint64()) >> 1) ^ -(long & 1);
+      pson.onLong(<i32>long, <i32>(long >>> 32));
+      break;
+
+    case Token.FLOAT:
+      pson.onFloat(load<f32>(offset));
+      offset += 4;
+      break;
+
+    case Token.DOUBLE:
+      pson.onDouble(load<f64>(offset));
+      offset += 8;
+      break;
+
+    case Token.STRING:
+      size = readVarint32();
+      pson.onString(offset, size);
+      offset += size;
+      break;
+
+    case Token.STRING_ADD:
+    case Token.STRING_GET:
+      // could be implemented via imports as well, but isn't necessary for this example
+      throw new Error("not implemented");
+
+    case Token.BINARY:
+      size = readVarint32();
+      pson.onBinary(offset, size);
+      offset += size;
+      break;
+
+    default: // small integer?
+      if (token > Token.MAX)
+        throw new Error("unexpected token");
+      pson.onInteger((token >> 1) ^ -(token & 1));
+      break;
+  }
+}
+
+function readVarint32(): u32 {
+  var value: u32 = 0;
+  var shift: u32 = 0;
+  do {
+    var b = load<u8>(offset++);
+    value |= <u32>(b & 0x7f) << (7 * shift++);
+  } while (b & 0x80);
+  return value;
+}
+
+function readVarint64(): u64 {
+  var value: u64 = 0;
+  var shift: u64 = 0;
+  do {
+    var b = load<u8>(offset++);
+    value |= <u64>(b & 0x7f) << (7 * shift++);
+  } while (b & 0x80);
+  return value;
+}