WIP - add extractor, generate snippet_data

node_modules/@webassemblyjs/wast-parser/esm/string-literals.js

@@ -0,0 +1,88 @@
+// string literal characters cannot contain control codes
+var CONTROL_CODES = [0, // null
+7, // bell
+8, // backspace
+9, // horizontal
+10, // line feed
+11, // vertical tab
+12, // form feed
+13, // carriage return
+26, // Control-Z
+27, // escape
+127 // delete
+]; // escaped sequences can either be a two character hex value, or one of the
+// following single character codes
+
+function decodeControlCharacter(char) {
+  switch (char) {
+    case "t":
+      return 0x09;
+
+    case "n":
+      return 0x0a;
+
+    case "r":
+      return 0x0d;
+
+    case '"':
+      return 0x22;
+
+    case "′":
+      return 0x27;
+
+    case "\\":
+      return 0x5c;
+  }
+
+  return -1;
+}
+
+var ESCAPE_CHAR = 92; // backslash
+
+var QUOTE_CHAR = 34; // backslash
+// parse string as per the spec:
+// https://webassembly.github.io/spec/core/multipage/text/values.html#text-string
+
+export function parseString(value) {
+  var byteArray = [];
+  var index = 0;
+
+  while (index < value.length) {
+    var charCode = value.charCodeAt(index);
+
+    if (CONTROL_CODES.indexOf(charCode) !== -1) {
+      throw new Error("ASCII control characters are not permitted within string literals");
+    }
+
+    if (charCode === QUOTE_CHAR) {
+      throw new Error("quotes are not permitted within string literals");
+    }
+
+    if (charCode === ESCAPE_CHAR) {
+      var firstChar = value.substr(index + 1, 1);
+      var decodedControlChar = decodeControlCharacter(firstChar);
+
+      if (decodedControlChar !== -1) {
+        // single character escaped values, e.g. \r
+        byteArray.push(decodedControlChar);
+        index += 2;
+      } else {
+        // hex escaped values, e.g. \2a
+        var hexValue = value.substr(index + 1, 2);
+
+        if (!/^[0-9A-F]{2}$/i.test(hexValue)) {
+          throw new Error("invalid character encoding");
+        }
+
+        byteArray.push(parseInt(hexValue, 16));
+        index += 3;
+      }
+    } else {
+      // ASCII encoded values
+      byteArray.push(charCode);
+      index++;
+    }
+  }
+
+  return byteArray;
+}