Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1957 insertions, 0 deletions

diff --git a/intl/l10n/FluentSyntax.jsm b/intl/l10n/FluentSyntax.jsm
new file mode 100644
index 0000000000..ec60dd5283
--- /dev/null
+++ b/intl/l10n/FluentSyntax.jsm
@@ -0,0 +1,1957 @@
+/* vim: set ts=2 et sw=2 tw=80 filetype=javascript: */
+
+/* Copyright 2019 Mozilla Foundation and others
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+/* fluent-syntax@0.12.0 */
+
+/*
+ * Base class for all Fluent AST nodes.
+ *
+ * All productions described in the ASDL subclass BaseNode, including Span and
+ * Annotation.
+ *
+ */
+class BaseNode {
+  constructor() {}
+
+  equals(other, ignoredFields = ["span"]) {
+    const thisKeys = new Set(Object.keys(this));
+    const otherKeys = new Set(Object.keys(other));
+    if (ignoredFields) {
+      for (const fieldName of ignoredFields) {
+        thisKeys.delete(fieldName);
+        otherKeys.delete(fieldName);
+      }
+    }
+    if (thisKeys.size !== otherKeys.size) {
+      return false;
+    }
+    for (const fieldName of thisKeys) {
+      if (!otherKeys.has(fieldName)) {
+        return false;
+      }
+      const thisVal = this[fieldName];
+      const otherVal = other[fieldName];
+      if (typeof thisVal !== typeof otherVal) {
+        return false;
+      }
+      if (thisVal instanceof Array) {
+        if (thisVal.length !== otherVal.length) {
+          return false;
+        }
+        for (let i = 0; i < thisVal.length; ++i) {
+          if (!scalarsEqual(thisVal[i], otherVal[i], ignoredFields)) {
+            return false;
+          }
+        }
+      } else if (!scalarsEqual(thisVal, otherVal, ignoredFields)) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  clone() {
+    function visit(value) {
+      if (value instanceof BaseNode) {
+        return value.clone();
+      }
+      if (Array.isArray(value)) {
+        return value.map(visit);
+      }
+      return value;
+    }
+    const clone = Object.create(this.constructor.prototype);
+    for (const prop of Object.keys(this)) {
+      clone[prop] = visit(this[prop]);
+    }
+    return clone;
+  }
+}
+
+function scalarsEqual(thisVal, otherVal, ignoredFields) {
+  if (thisVal instanceof BaseNode) {
+    return thisVal.equals(otherVal, ignoredFields);
+  }
+  return thisVal === otherVal;
+}
+
+/*
+ * Base class for AST nodes which can have Spans.
+ */
+class SyntaxNode extends BaseNode {
+  addSpan(start, end) {
+    this.span = new Span(start, end);
+  }
+}
+
+class Resource extends SyntaxNode {
+  constructor(body = []) {
+    super();
+    this.type = "Resource";
+    this.body = body;
+  }
+}
+
+/*
+ * An abstract base class for useful elements of Resource.body.
+ */
+class Entry extends SyntaxNode {}
+
+class Message extends Entry {
+  constructor(id, value = null, attributes = [], comment = null) {
+    super();
+    this.type = "Message";
+    this.id = id;
+    this.value = value;
+    this.attributes = attributes;
+    this.comment = comment;
+  }
+}
+
+class Term extends Entry {
+  constructor(id, value, attributes = [], comment = null) {
+    super();
+    this.type = "Term";
+    this.id = id;
+    this.value = value;
+    this.attributes = attributes;
+    this.comment = comment;
+  }
+}
+
+class Pattern extends SyntaxNode {
+  constructor(elements) {
+    super();
+    this.type = "Pattern";
+    this.elements = elements;
+  }
+}
+
+/*
+ * An abstract base class for elements of Patterns.
+ */
+class PatternElement extends SyntaxNode {}
+
+class TextElement extends PatternElement {
+  constructor(value) {
+    super();
+    this.type = "TextElement";
+    this.value = value;
+  }
+}
+
+class Placeable extends PatternElement {
+  constructor(expression) {
+    super();
+    this.type = "Placeable";
+    this.expression = expression;
+  }
+}
+
+/*
+ * An abstract base class for expressions.
+ */
+class Expression extends SyntaxNode {}
+
+// An abstract base class for Literals.
+class Literal extends Expression {
+  constructor(value) {
+    super();
+    // The "value" field contains the exact contents of the literal,
+    // character-for-character.
+    this.value = value;
+  }
+
+  parse() {
+    return {value: this.value};
+  }
+}
+
+class StringLiteral extends Literal {
+  constructor(value) {
+    super(value);
+    this.type = "StringLiteral";
+  }
+
+  parse() {
+    // Backslash backslash, backslash double quote, uHHHH, UHHHHHH.
+    const KNOWN_ESCAPES =
+      /(?:\\\\|\\"|\\u([0-9a-fA-F]{4})|\\U([0-9a-fA-F]{6}))/g;
+
+    function from_escape_sequence(match, codepoint4, codepoint6) {
+      switch (match) {
+        case "\\\\":
+          return "\\";
+        case "\\\"":
+          return "\"";
+        default:
+          let codepoint = parseInt(codepoint4 || codepoint6, 16);
+          if (codepoint <= 0xD7FF || 0xE000 <= codepoint) {
+            // It's a Unicode scalar value.
+            return String.fromCodePoint(codepoint);
+          }
+          // Escape sequences reresenting surrogate code points are
+          // well-formed but invalid in Fluent. Replace them with U+FFFD
+          // REPLACEMENT CHARACTER.
+          return "�";
+      }
+    }
+
+    let value = this.value.replace(KNOWN_ESCAPES, from_escape_sequence);
+    return {value};
+  }
+}
+
+class NumberLiteral extends Literal {
+  constructor(value) {
+    super(value);
+    this.type = "NumberLiteral";
+  }
+
+  parse() {
+    let value = parseFloat(this.value);
+    let decimal_position = this.value.indexOf(".");
+    let precision = decimal_position > 0
+      ? this.value.length - decimal_position - 1
+      : 0;
+    return {value, precision};
+  }
+}
+
+class MessageReference extends Expression {
+  constructor(id, attribute = null) {
+    super();
+    this.type = "MessageReference";
+    this.id = id;
+    this.attribute = attribute;
+  }
+}
+
+class TermReference extends Expression {
+  constructor(id, attribute = null, args = null) {
+    super();
+    this.type = "TermReference";
+    this.id = id;
+    this.attribute = attribute;
+    this.arguments = args;
+  }
+}
+
+class VariableReference extends Expression {
+  constructor(id) {
+    super();
+    this.type = "VariableReference";
+    this.id = id;
+  }
+}
+
+class FunctionReference extends Expression {
+  constructor(id, args) {
+    super();
+    this.type = "FunctionReference";
+    this.id = id;
+    this.arguments = args;
+  }
+}
+
+class SelectExpression extends Expression {
+  constructor(selector, variants) {
+    super();
+    this.type = "SelectExpression";
+    this.selector = selector;
+    this.variants = variants;
+  }
+}
+
+class CallArguments extends SyntaxNode {
+  constructor(positional = [], named = []) {
+    super();
+    this.type = "CallArguments";
+    this.positional = positional;
+    this.named = named;
+  }
+}
+
+class Attribute extends SyntaxNode {
+  constructor(id, value) {
+    super();
+    this.type = "Attribute";
+    this.id = id;
+    this.value = value;
+  }
+}
+
+class Variant extends SyntaxNode {
+  constructor(key, value, def = false) {
+    super();
+    this.type = "Variant";
+    this.key = key;
+    this.value = value;
+    this.default = def;
+  }
+}
+
+class NamedArgument extends SyntaxNode {
+  constructor(name, value) {
+    super();
+    this.type = "NamedArgument";
+    this.name = name;
+    this.value = value;
+  }
+}
+
+class Identifier extends SyntaxNode {
+  constructor(name) {
+    super();
+    this.type = "Identifier";
+    this.name = name;
+  }
+}
+
+class BaseComment extends Entry {
+  constructor(content) {
+    super();
+    this.type = "BaseComment";
+    this.content = content;
+  }
+}
+
+class Comment extends BaseComment {
+  constructor(content) {
+    super(content);
+    this.type = "Comment";
+  }
+}
+
+class GroupComment extends BaseComment {
+  constructor(content) {
+    super(content);
+    this.type = "GroupComment";
+  }
+}
+class ResourceComment extends BaseComment {
+  constructor(content) {
+    super(content);
+    this.type = "ResourceComment";
+  }
+}
+
+class Junk extends SyntaxNode {
+  constructor(content) {
+    super();
+    this.type = "Junk";
+    this.annotations = [];
+    this.content = content;
+  }
+
+  addAnnotation(annot) {
+    this.annotations.push(annot);
+  }
+}
+
+class Span extends BaseNode {
+  constructor(start, end) {
+    super();
+    this.type = "Span";
+    this.start = start;
+    this.end = end;
+  }
+}
+
+class Annotation extends SyntaxNode {
+  constructor(code, args = [], message) {
+    super();
+    this.type = "Annotation";
+    this.code = code;
+    this.arguments = args;
+    this.message = message;
+  }
+}
+
+const ast = ({
+  BaseNode: BaseNode,
+  Resource: Resource,
+  Entry: Entry,
+  Message: Message,
+  Term: Term,
+  Pattern: Pattern,
+  PatternElement: PatternElement,
+  TextElement: TextElement,
+  Placeable: Placeable,
+  Expression: Expression,
+  Literal: Literal,
+  StringLiteral: StringLiteral,
+  NumberLiteral: NumberLiteral,
+  MessageReference: MessageReference,
+  TermReference: TermReference,
+  VariableReference: VariableReference,
+  FunctionReference: FunctionReference,
+  SelectExpression: SelectExpression,
+  CallArguments: CallArguments,
+  Attribute: Attribute,
+  Variant: Variant,
+  NamedArgument: NamedArgument,
+  Identifier: Identifier,
+  BaseComment: BaseComment,
+  Comment: Comment,
+  GroupComment: GroupComment,
+  ResourceComment: ResourceComment,
+  Junk: Junk,
+  Span: Span,
+  Annotation: Annotation
+});
+
+class ParseError extends Error {
+  constructor(code, ...args) {
+    super();
+    this.code = code;
+    this.args = args;
+    this.message = getErrorMessage(code, args);
+  }
+}
+
+/* eslint-disable complexity */
+function getErrorMessage(code, args) {
+  switch (code) {
+    case "E0001":
+      return "Generic error";
+    case "E0002":
+      return "Expected an entry start";
+    case "E0003": {
+      const [token] = args;
+      return `Expected token: "${token}"`;
+    }
+    case "E0004": {
+      const [range] = args;
+      return `Expected a character from range: "${range}"`;
+    }
+    case "E0005": {
+      const [id] = args;
+      return `Expected message "${id}" to have a value or attributes`;
+    }
+    case "E0006": {
+      const [id] = args;
+      return `Expected term "-${id}" to have a value`;
+    }
+    case "E0007":
+      return "Keyword cannot end with a whitespace";
+    case "E0008":
+      return "The callee has to be an upper-case identifier or a term";
+    case "E0009":
+      return "The argument name has to be a simple identifier";
+    case "E0010":
+      return "Expected one of the variants to be marked as default (*)";
+    case "E0011":
+      return 'Expected at least one variant after "->"';
+    case "E0012":
+      return "Expected value";
+    case "E0013":
+      return "Expected variant key";
+    case "E0014":
+      return "Expected literal";
+    case "E0015":
+      return "Only one variant can be marked as default (*)";
+    case "E0016":
+      return "Message references cannot be used as selectors";
+    case "E0017":
+      return "Terms cannot be used as selectors";
+    case "E0018":
+      return "Attributes of messages cannot be used as selectors";
+    case "E0019":
+      return "Attributes of terms cannot be used as placeables";
+    case "E0020":
+      return "Unterminated string expression";
+    case "E0021":
+      return "Positional arguments must not follow named arguments";
+    case "E0022":
+      return "Named arguments must be unique";
+    case "E0024":
+      return "Cannot access variants of a message.";
+    case "E0025": {
+      const [char] = args;
+      return `Unknown escape sequence: \\${char}.`;
+    }
+    case "E0026": {
+      const [sequence] = args;
+      return `Invalid Unicode escape sequence: ${sequence}.`;
+    }
+    case "E0027":
+      return "Unbalanced closing brace in TextElement.";
+    case "E0028":
+      return "Expected an inline expression";
+    default:
+      return code;
+  }
+}
+
+function includes(arr, elem) {
+  return arr.indexOf(elem) > -1;
+}
+
+/* eslint no-magic-numbers: "off" */
+
+class ParserStream {
+  constructor(string) {
+    this.string = string;
+    this.index = 0;
+    this.peekOffset = 0;
+  }
+
+  charAt(offset) {
+    // When the cursor is at CRLF, return LF but don't move the cursor.
+    // The cursor still points to the EOL position, which in this case is the
+    // beginning of the compound CRLF sequence. This ensures slices of
+    // [inclusive, exclusive) continue to work properly.
+    if (this.string[offset] === "\r"
+        && this.string[offset + 1] === "\n") {
+      return "\n";
+    }
+
+    return this.string[offset];
+  }
+
+  get currentChar() {
+    return this.charAt(this.index);
+  }
+
+  get currentPeek() {
+    return this.charAt(this.index + this.peekOffset);
+  }
+
+  next() {
+    this.peekOffset = 0;
+    // Skip over the CRLF as if it was a single character.
+    if (this.string[this.index] === "\r"
+        && this.string[this.index + 1] === "\n") {
+      this.index++;
+    }
+    this.index++;
+    return this.string[this.index];
+  }
+
+  peek() {
+    // Skip over the CRLF as if it was a single character.
+    if (this.string[this.index + this.peekOffset] === "\r"
+        && this.string[this.index + this.peekOffset + 1] === "\n") {
+      this.peekOffset++;
+    }
+    this.peekOffset++;
+    return this.string[this.index + this.peekOffset];
+  }
+
+  resetPeek(offset = 0) {
+    this.peekOffset = offset;
+  }
+
+  skipToPeek() {
+    this.index += this.peekOffset;
+    this.peekOffset = 0;
+  }
+}
+
+const EOL = "\n";
+const EOF = undefined;
+const SPECIAL_LINE_START_CHARS = ["}", ".", "[", "*"];
+
+class FluentParserStream extends ParserStream {
+  peekBlankInline() {
+    const start = this.index + this.peekOffset;
+    while (this.currentPeek === " ") {
+      this.peek();
+    }
+    return this.string.slice(start, this.index + this.peekOffset);
+  }
+
+  skipBlankInline() {
+    const blank = this.peekBlankInline();
+    this.skipToPeek();
+    return blank;
+  }
+
+  peekBlankBlock() {
+    let blank = "";
+    while (true) {
+      const lineStart = this.peekOffset;
+      this.peekBlankInline();
+      if (this.currentPeek === EOL) {
+        blank += EOL;
+        this.peek();
+        continue;
+      }
+      if (this.currentPeek === EOF) {
+        // Treat the blank line at EOF as a blank block.
+        return blank;
+      }
+      // Any other char; reset to column 1 on this line.
+      this.resetPeek(lineStart);
+      return blank;
+    }
+  }
+
+  skipBlankBlock() {
+    const blank = this.peekBlankBlock();
+    this.skipToPeek();
+    return blank;
+  }
+
+  peekBlank() {
+    while (this.currentPeek === " " || this.currentPeek === EOL) {
+      this.peek();
+    }
+  }
+
+  skipBlank() {
+    this.peekBlank();
+    this.skipToPeek();
+  }
+
+  expectChar(ch) {
+    if (this.currentChar === ch) {
+      this.next();
+      return true;
+    }
+
+    throw new ParseError("E0003", ch);
+  }
+
+  expectLineEnd() {
+    if (this.currentChar === EOF) {
+      // EOF is a valid line end in Fluent.
+      return true;
+    }
+
+    if (this.currentChar === EOL) {
+      this.next();
+      return true;
+    }
+
+    // Unicode Character 'SYMBOL FOR NEWLINE' (U+2424)
+    throw new ParseError("E0003", "\u2424");
+  }
+
+  takeChar(f) {
+    const ch = this.currentChar;
+    if (ch === EOF) {
+      return EOF;
+    }
+    if (f(ch)) {
+      this.next();
+      return ch;
+    }
+    return null;
+  }
+
+  isCharIdStart(ch) {
+    if (ch === EOF) {
+      return false;
+    }
+
+    const cc = ch.charCodeAt(0);
+    return (cc >= 97 && cc <= 122) || // a-z
+           (cc >= 65 && cc <= 90); // A-Z
+  }
+
+  isIdentifierStart() {
+    return this.isCharIdStart(this.currentPeek);
+  }
+
+  isNumberStart() {
+    const ch = this.currentChar === "-"
+      ? this.peek()
+      : this.currentChar;
+
+    if (ch === EOF) {
+      this.resetPeek();
+      return false;
+    }
+
+    const cc = ch.charCodeAt(0);
+    const isDigit = cc >= 48 && cc <= 57; // 0-9
+    this.resetPeek();
+    return isDigit;
+  }
+
+  isCharPatternContinuation(ch) {
+    if (ch === EOF) {
+      return false;
+    }
+
+    return !includes(SPECIAL_LINE_START_CHARS, ch);
+  }
+
+  isValueStart() {
+    // Inline Patterns may start with any char.
+    const ch = this.currentPeek;
+    return ch !== EOL && ch !== EOF;
+  }
+
+  isValueContinuation() {
+    const column1 = this.peekOffset;
+    this.peekBlankInline();
+
+    if (this.currentPeek === "{") {
+      this.resetPeek(column1);
+      return true;
+    }
+
+    if (this.peekOffset - column1 === 0) {
+      return false;
+    }
+
+    if (this.isCharPatternContinuation(this.currentPeek)) {
+      this.resetPeek(column1);
+      return true;
+    }
+
+    return false;
+  }
+
+  // -1 - any
+  //  0 - comment
+  //  1 - group comment
+  //  2 - resource comment
+  isNextLineComment(level = -1) {
+    if (this.currentChar !== EOL) {
+      return false;
+    }
+
+    let i = 0;
+
+    while (i <= level || (level === -1 && i < 3)) {
+      if (this.peek() !== "#") {
+        if (i <= level && level !== -1) {
+          this.resetPeek();
+          return false;
+        }
+        break;
+      }
+      i++;
+    }
+
+    // The first char after #, ## or ###.
+    const ch = this.peek();
+    if (ch === " " || ch === EOL) {
+      this.resetPeek();
+      return true;
+    }
+
+    this.resetPeek();
+    return false;
+  }
+
+  isVariantStart() {
+    const currentPeekOffset = this.peekOffset;
+    if (this.currentPeek === "*") {
+      this.peek();
+    }
+    if (this.currentPeek === "[") {
+      this.resetPeek(currentPeekOffset);
+      return true;
+    }
+    this.resetPeek(currentPeekOffset);
+    return false;
+  }
+
+  isAttributeStart() {
+    return this.currentPeek === ".";
+  }
+
+  skipToNextEntryStart(junkStart) {
+    let lastNewline = this.string.lastIndexOf(EOL, this.index);
+    if (junkStart < lastNewline) {
+      // Last seen newline is _after_ the junk start. It's safe to rewind
+      // without the risk of resuming at the same broken entry.
+      this.index = lastNewline;
+    }
+    while (this.currentChar) {
+      // We're only interested in beginnings of line.
+      if (this.currentChar !== EOL) {
+        this.next();
+        continue;
+      }
+
+      // Break if the first char in this line looks like an entry start.
+      const first = this.next();
+      if (this.isCharIdStart(first) || first === "-" || first === "#") {
+        break;
+      }
+    }
+  }
+
+  takeIDStart() {
+    if (this.isCharIdStart(this.currentChar)) {
+      const ret = this.currentChar;
+      this.next();
+      return ret;
+    }
+
+    throw new ParseError("E0004", "a-zA-Z");
+  }
+
+  takeIDChar() {
+    const closure = ch => {
+      const cc = ch.charCodeAt(0);
+      return ((cc >= 97 && cc <= 122) || // a-z
+              (cc >= 65 && cc <= 90) || // A-Z
+              (cc >= 48 && cc <= 57) || // 0-9
+               cc === 95 || cc === 45); // _-
+    };
+
+    return this.takeChar(closure);
+  }
+
+  takeDigit() {
+    const closure = ch => {
+      const cc = ch.charCodeAt(0);
+      return (cc >= 48 && cc <= 57); // 0-9
+    };
+
+    return this.takeChar(closure);
+  }
+
+  takeHexDigit() {
+    const closure = ch => {
+      const cc = ch.charCodeAt(0);
+      return (cc >= 48 && cc <= 57) // 0-9
+        || (cc >= 65 && cc <= 70) // A-F
+        || (cc >= 97 && cc <= 102); // a-f
+    };
+
+    return this.takeChar(closure);
+  }
+}
+
+/*  eslint no-magic-numbers: [0]  */
+
+
+const trailingWSRe = /[ \t\n\r]+$/;
+
+
+function withSpan(fn) {
+  return function(ps, ...args) {
+    if (!this.withSpans) {
+      return fn.call(this, ps, ...args);
+    }
+
+    const start = ps.index;
+    const node = fn.call(this, ps, ...args);
+
+    // Don't re-add the span if the node already has it. This may happen when
+    // one decorated function calls another decorated function.
+    if (node.span) {
+      return node;
+    }
+
+    const end = ps.index;
+    node.addSpan(start, end);
+    return node;
+  };
+}
+
+
+class FluentParser {
+  constructor({
+    withSpans = true,
+  } = {}) {
+    this.withSpans = withSpans;
+
+    // Poor man's decorators.
+    const methodNames = [
+      "getComment", "getMessage", "getTerm", "getAttribute", "getIdentifier",
+      "getVariant", "getNumber", "getPattern", "getTextElement",
+      "getPlaceable", "getExpression", "getInlineExpression",
+      "getCallArgument", "getCallArguments", "getString", "getLiteral",
+    ];
+    for (const name of methodNames) {
+      this[name] = withSpan(this[name]);
+    }
+  }
+
+  parse(source) {
+    const ps = new FluentParserStream(source);
+    ps.skipBlankBlock();
+
+    const entries = [];
+    let lastComment = null;
+
+    while (ps.currentChar) {
+      const entry = this.getEntryOrJunk(ps);
+      const blankLines = ps.skipBlankBlock();
+
+      // Regular Comments require special logic. Comments may be attached to
+      // Messages or Terms if they are followed immediately by them. However
+      // they should parse as standalone when they're followed by Junk.
+      // Consequently, we only attach Comments once we know that the Message
+      // or the Term parsed successfully.
+      if (entry.type === "Comment"
+          && blankLines.length === 0
+          && ps.currentChar) {
+        // Stash the comment and decide what to do with it in the next pass.
+        lastComment = entry;
+        continue;
+      }
+
+      if (lastComment) {
+        if (entry.type === "Message" || entry.type === "Term") {
+          entry.comment = lastComment;
+          if (this.withSpans) {
+            entry.span.start = entry.comment.span.start;
+          }
+        } else {
+          entries.push(lastComment);
+        }
+        // In either case, the stashed comment has been dealt with; clear it.
+        lastComment = null;
+      }
+
+      // No special logic for other types of entries.
+      entries.push(entry);
+    }
+
+    const res = new Resource(entries);
+
+    if (this.withSpans) {
+      res.addSpan(0, ps.index);
+    }
+
+    return res;
+  }
+
+  /*
+   * Parse the first Message or Term in `source`.
+   *
+   * Skip all encountered comments and start parsing at the first Message or
+   * Term start. Return Junk if the parsing is not successful.
+   *
+   * Preceding comments are ignored unless they contain syntax errors
+   * themselves, in which case Junk for the invalid comment is returned.
+   */
+  parseEntry(source) {
+    const ps = new FluentParserStream(source);
+    ps.skipBlankBlock();
+
+    while (ps.currentChar === "#") {
+      const skipped = this.getEntryOrJunk(ps);
+      if (skipped.type === "Junk") {
+        // Don't skip Junk comments.
+        return skipped;
+      }
+      ps.skipBlankBlock();
+    }
+
+    return this.getEntryOrJunk(ps);
+  }
+
+  getEntryOrJunk(ps) {
+    const entryStartPos = ps.index;
+
+    try {
+      const entry = this.getEntry(ps);
+      ps.expectLineEnd();
+      return entry;
+    } catch (err) {
+      if (!(err instanceof ParseError)) {
+        throw err;
+      }
+
+      let errorIndex = ps.index;
+      ps.skipToNextEntryStart(entryStartPos);
+      const nextEntryStart = ps.index;
+      if (nextEntryStart < errorIndex) {
+        // The position of the error must be inside of the Junk's span.
+        errorIndex = nextEntryStart;
+      }
+
+      // Create a Junk instance
+      const slice = ps.string.substring(entryStartPos, nextEntryStart);
+      const junk = new Junk(slice);
+      if (this.withSpans) {
+        junk.addSpan(entryStartPos, nextEntryStart);
+      }
+      const annot = new Annotation(err.code, err.args, err.message);
+      annot.addSpan(errorIndex, errorIndex);
+      junk.addAnnotation(annot);
+      return junk;
+    }
+  }
+
+  getEntry(ps) {
+    if (ps.currentChar === "#") {
+      return this.getComment(ps);
+    }
+
+    if (ps.currentChar === "-") {
+      return this.getTerm(ps);
+    }
+
+    if (ps.isIdentifierStart()) {
+      return this.getMessage(ps);
+    }
+
+    throw new ParseError("E0002");
+  }
+
+  getComment(ps) {
+    // 0 - comment
+    // 1 - group comment
+    // 2 - resource comment
+    let level = -1;
+    let content = "";
+
+    while (true) {
+      let i = -1;
+      while (ps.currentChar === "#" && (i < (level === -1 ? 2 : level))) {
+        ps.next();
+        i++;
+      }
+
+      if (level === -1) {
+        level = i;
+      }
+
+      if (ps.currentChar !== EOL) {
+        ps.expectChar(" ");
+        let ch;
+        while ((ch = ps.takeChar(x => x !== EOL))) {
+          content += ch;
+        }
+      }
+
+      if (ps.isNextLineComment(level)) {
+        content += ps.currentChar;
+        ps.next();
+      } else {
+        break;
+      }
+    }
+
+    let Comment$$1;
+    switch (level) {
+      case 0:
+        Comment$$1 = Comment;
+        break;
+      case 1:
+        Comment$$1 = GroupComment;
+        break;
+      case 2:
+        Comment$$1 = ResourceComment;
+        break;
+    }
+    return new Comment$$1(content);
+  }
+
+  getMessage(ps) {
+    const id = this.getIdentifier(ps);
+
+    ps.skipBlankInline();
+    ps.expectChar("=");
+
+    const value = this.maybeGetPattern(ps);
+    const attrs = this.getAttributes(ps);
+
+    if (value === null && attrs.length === 0) {
+      throw new ParseError("E0005", id.name);
+    }
+
+    return new Message(id, value, attrs);
+  }
+
+  getTerm(ps) {
+    ps.expectChar("-");
+    const id = this.getIdentifier(ps);
+
+    ps.skipBlankInline();
+    ps.expectChar("=");
+
+    const value = this.maybeGetPattern(ps);
+    if (value === null) {
+      throw new ParseError("E0006", id.name);
+    }
+
+    const attrs = this.getAttributes(ps);
+    return new Term(id, value, attrs);
+  }
+
+  getAttribute(ps) {
+    ps.expectChar(".");
+
+    const key = this.getIdentifier(ps);
+
+    ps.skipBlankInline();
+    ps.expectChar("=");
+
+    const value = this.maybeGetPattern(ps);
+    if (value === null) {
+      throw new ParseError("E0012");
+    }
+
+    return new Attribute(key, value);
+  }
+
+  getAttributes(ps) {
+    const attrs = [];
+    ps.peekBlank();
+    while (ps.isAttributeStart()) {
+      ps.skipToPeek();
+      const attr = this.getAttribute(ps);
+      attrs.push(attr);
+      ps.peekBlank();
+    }
+    return attrs;
+  }
+
+  getIdentifier(ps) {
+    let name = ps.takeIDStart();
+
+    let ch;
+    while ((ch = ps.takeIDChar())) {
+      name += ch;
+    }
+
+    return new Identifier(name);
+  }
+
+  getVariantKey(ps) {
+    const ch = ps.currentChar;
+
+    if (ch === EOF) {
+      throw new ParseError("E0013");
+    }
+
+    const cc = ch.charCodeAt(0);
+
+    if ((cc >= 48 && cc <= 57) || cc === 45) { // 0-9, -
+      return this.getNumber(ps);
+    }
+
+    return this.getIdentifier(ps);
+  }
+
+  getVariant(ps, {hasDefault}) {
+    let defaultIndex = false;
+
+    if (ps.currentChar === "*") {
+      if (hasDefault) {
+        throw new ParseError("E0015");
+      }
+      ps.next();
+      defaultIndex = true;
+    }
+
+    ps.expectChar("[");
+
+    ps.skipBlank();
+
+    const key = this.getVariantKey(ps);
+
+    ps.skipBlank();
+    ps.expectChar("]");
+
+    const value = this.maybeGetPattern(ps);
+    if (value === null) {
+      throw new ParseError("E0012");
+    }
+
+    return new Variant(key, value, defaultIndex);
+  }
+
+  getVariants(ps) {
+    const variants = [];
+    let hasDefault = false;
+
+    ps.skipBlank();
+    while (ps.isVariantStart()) {
+      const variant = this.getVariant(ps, {hasDefault});
+
+      if (variant.default) {
+        hasDefault = true;
+      }
+
+      variants.push(variant);
+      ps.expectLineEnd();
+      ps.skipBlank();
+    }
+
+    if (variants.length === 0) {
+      throw new ParseError("E0011");
+    }
+
+    if (!hasDefault) {
+      throw new ParseError("E0010");
+    }
+
+    return variants;
+  }
+
+  getDigits(ps) {
+    let num = "";
+
+    let ch;
+    while ((ch = ps.takeDigit())) {
+      num += ch;
+    }
+
+    if (num.length === 0) {
+      throw new ParseError("E0004", "0-9");
+    }
+
+    return num;
+  }
+
+  getNumber(ps) {
+    let value = "";
+
+    if (ps.currentChar === "-") {
+      ps.next();
+      value += `-${this.getDigits(ps)}`;
+    } else {
+      value += this.getDigits(ps);
+    }
+
+    if (ps.currentChar === ".") {
+      ps.next();
+      value += `.${this.getDigits(ps)}`;
+    }
+
+    return new NumberLiteral(value);
+  }
+
+  // maybeGetPattern distinguishes between patterns which start on the same line
+  // as the identifier (a.k.a. inline signleline patterns and inline multiline
+  // patterns) and patterns which start on a new line (a.k.a. block multiline
+  // patterns). The distinction is important for the dedentation logic: the
+  // indent of the first line of a block pattern must be taken into account when
+  // calculating the maximum common indent.
+  maybeGetPattern(ps) {
+    ps.peekBlankInline();
+    if (ps.isValueStart()) {
+      ps.skipToPeek();
+      return this.getPattern(ps, {isBlock: false});
+    }
+
+    ps.peekBlankBlock();
+    if (ps.isValueContinuation()) {
+      ps.skipToPeek();
+      return this.getPattern(ps, {isBlock: true});
+    }
+
+    return null;
+  }
+
+  getPattern(ps, {isBlock}) {
+    const elements = [];
+    if (isBlock) {
+      // A block pattern is a pattern which starts on a new line. Store and
+      // measure the indent of this first line for the dedentation logic.
+      const blankStart = ps.index;
+      const firstIndent = ps.skipBlankInline();
+      elements.push(this.getIndent(ps, firstIndent, blankStart));
+      var commonIndentLength = firstIndent.length;
+    } else {
+      commonIndentLength = Infinity;
+    }
+
+    let ch;
+    elements: while ((ch = ps.currentChar)) {
+      switch (ch) {
+        case EOL: {
+          const blankStart = ps.index;
+          const blankLines = ps.peekBlankBlock();
+          if (ps.isValueContinuation()) {
+            ps.skipToPeek();
+            const indent = ps.skipBlankInline();
+            commonIndentLength = Math.min(commonIndentLength, indent.length);
+            elements.push(this.getIndent(ps, blankLines + indent, blankStart));
+            continue elements;
+          }
+
+          // The end condition for getPattern's while loop is a newline
+          // which is not followed by a valid pattern continuation.
+          ps.resetPeek();
+          break elements;
+        }
+        case "{":
+          elements.push(this.getPlaceable(ps));
+          continue elements;
+        case "}":
+          throw new ParseError("E0027");
+        default:
+          const element = this.getTextElement(ps);
+          elements.push(element);
+      }
+    }
+
+    const dedented = this.dedent(elements, commonIndentLength);
+    return new Pattern(dedented);
+  }
+
+  // Create a token representing an indent. It's not part of the AST and it will
+  // be trimmed and merged into adjacent TextElements, or turned into a new
+  // TextElement, if it's surrounded by two Placeables.
+  getIndent(ps, value, start) {
+    return {
+      type: "Indent",
+      span: {start, end: ps.index},
+      value,
+    };
+  }
+
+  // Dedent a list of elements by removing the maximum common indent from the
+  // beginning of text lines. The common indent is calculated in getPattern.
+  dedent(elements, commonIndent) {
+    const trimmed = [];
+
+    for (let element of elements) {
+      if (element.type === "Placeable") {
+        trimmed.push(element);
+        continue;
+      }
+
+      if (element.type === "Indent") {
+        // Strip common indent.
+        element.value = element.value.slice(
+          0, element.value.length - commonIndent);
+        if (element.value.length === 0) {
+          continue;
+        }
+      }
+
+      let prev = trimmed[trimmed.length - 1];
+      if (prev && prev.type === "TextElement") {
+        // Join adjacent TextElements by replacing them with their sum.
+        const sum = new TextElement(prev.value + element.value);
+        if (this.withSpans) {
+          sum.addSpan(prev.span.start, element.span.end);
+        }
+        trimmed[trimmed.length - 1] = sum;
+        continue;
+      }
+
+      if (element.type === "Indent") {
+        // If the indent hasn't been merged into a preceding TextElement,
+        // convert it into a new TextElement.
+        const textElement = new TextElement(element.value);
+        if (this.withSpans) {
+          textElement.addSpan(element.span.start, element.span.end);
+        }
+        element = textElement;
+      }
+
+      trimmed.push(element);
+    }
+
+    // Trim trailing whitespace from the Pattern.
+    const lastElement = trimmed[trimmed.length - 1];
+    if (lastElement.type === "TextElement") {
+      lastElement.value = lastElement.value.replace(trailingWSRe, "");
+      if (lastElement.value.length === 0) {
+        trimmed.pop();
+      }
+    }
+
+    return trimmed;
+  }
+
+  getTextElement(ps) {
+    let buffer = "";
+
+    let ch;
+    while ((ch = ps.currentChar)) {
+      if (ch === "{" || ch === "}") {
+        return new TextElement(buffer);
+      }
+
+      if (ch === EOL) {
+        return new TextElement(buffer);
+      }
+
+      buffer += ch;
+      ps.next();
+    }
+
+    return new TextElement(buffer);
+  }
+
+  getEscapeSequence(ps) {
+    const next = ps.currentChar;
+
+    switch (next) {
+      case "\\":
+      case "\"":
+        ps.next();
+        return `\\${next}`;
+      case "u":
+        return this.getUnicodeEscapeSequence(ps, next, 4);
+      case "U":
+        return this.getUnicodeEscapeSequence(ps, next, 6);
+      default:
+        throw new ParseError("E0025", next);
+    }
+  }
+
+  getUnicodeEscapeSequence(ps, u, digits) {
+    ps.expectChar(u);
+
+    let sequence = "";
+    for (let i = 0; i < digits; i++) {
+      const ch = ps.takeHexDigit();
+
+      if (!ch) {
+        throw new ParseError(
+          "E0026", `\\${u}${sequence}${ps.currentChar}`);
+      }
+
+      sequence += ch;
+    }
+
+    return `\\${u}${sequence}`;
+  }
+
+  getPlaceable(ps) {
+    ps.expectChar("{");
+    ps.skipBlank();
+    const expression = this.getExpression(ps);
+    ps.expectChar("}");
+    return new Placeable(expression);
+  }
+
+  getExpression(ps) {
+    const selector = this.getInlineExpression(ps);
+    ps.skipBlank();
+
+    if (ps.currentChar === "-") {
+      if (ps.peek() !== ">") {
+        ps.resetPeek();
+        return selector;
+      }
+
+      if (selector.type === "MessageReference") {
+        if (selector.attribute === null) {
+          throw new ParseError("E0016");
+        } else {
+          throw new ParseError("E0018");
+        }
+      }
+
+      if (selector.type === "TermReference" && selector.attribute === null) {
+        throw new ParseError("E0017");
+      }
+
+      ps.next();
+      ps.next();
+
+      ps.skipBlankInline();
+      ps.expectLineEnd();
+
+      const variants = this.getVariants(ps);
+      return new SelectExpression(selector, variants);
+    }
+
+    if (selector.type === "TermReference" && selector.attribute !== null) {
+      throw new ParseError("E0019");
+    }
+
+    return selector;
+  }
+
+  getInlineExpression(ps) {
+    if (ps.currentChar === "{") {
+      return this.getPlaceable(ps);
+    }
+
+    if (ps.isNumberStart()) {
+      return this.getNumber(ps);
+    }
+
+    if (ps.currentChar === '"') {
+      return this.getString(ps);
+    }
+
+    if (ps.currentChar === "$") {
+      ps.next();
+      const id = this.getIdentifier(ps);
+      return new VariableReference(id);
+    }
+
+    if (ps.currentChar === "-") {
+      ps.next();
+      const id = this.getIdentifier(ps);
+
+      let attr;
+      if (ps.currentChar === ".") {
+        ps.next();
+        attr = this.getIdentifier(ps);
+      }
+
+      let args;
+      if (ps.currentChar === "(") {
+        args = this.getCallArguments(ps);
+      }
+
+      return new TermReference(id, attr, args);
+    }
+
+    if (ps.isIdentifierStart()) {
+      const id = this.getIdentifier(ps);
+
+      if (ps.currentChar === "(") {
+        // It's a Function. Ensure it's all upper-case.
+        if (!/^[A-Z][A-Z0-9_-]*$/.test(id.name)) {
+          throw new ParseError("E0008");
+        }
+
+        let args = this.getCallArguments(ps);
+        return new FunctionReference(id, args);
+      }
+
+      let attr;
+      if (ps.currentChar === ".") {
+        ps.next();
+        attr = this.getIdentifier(ps);
+      }
+
+      return new MessageReference(id, attr);
+    }
+
+
+    throw new ParseError("E0028");
+  }
+
+  getCallArgument(ps) {
+    const exp = this.getInlineExpression(ps);
+
+    ps.skipBlank();
+
+    if (ps.currentChar !== ":") {
+      return exp;
+    }
+
+    if (exp.type === "MessageReference" && exp.attribute === null) {
+      ps.next();
+      ps.skipBlank();
+
+      const value = this.getLiteral(ps);
+      return new NamedArgument(exp.id, value);
+    }
+
+    throw new ParseError("E0009");
+  }
+
+  getCallArguments(ps) {
+    const positional = [];
+    const named = [];
+    const argumentNames = new Set();
+
+    ps.expectChar("(");
+    ps.skipBlank();
+
+    while (true) {
+      if (ps.currentChar === ")") {
+        break;
+      }
+
+      const arg = this.getCallArgument(ps);
+      if (arg.type === "NamedArgument") {
+        if (argumentNames.has(arg.name.name)) {
+          throw new ParseError("E0022");
+        }
+        named.push(arg);
+        argumentNames.add(arg.name.name);
+      } else if (argumentNames.size > 0) {
+        throw new ParseError("E0021");
+      } else {
+        positional.push(arg);
+      }
+
+      ps.skipBlank();
+
+      if (ps.currentChar === ",") {
+        ps.next();
+        ps.skipBlank();
+        continue;
+      }
+
+      break;
+    }
+
+    ps.expectChar(")");
+    return new CallArguments(positional, named);
+  }
+
+  getString(ps) {
+    ps.expectChar("\"");
+    let value = "";
+
+    let ch;
+    while ((ch = ps.takeChar(x => x !== '"' && x !== EOL))) {
+      if (ch === "\\") {
+        value += this.getEscapeSequence(ps);
+      } else {
+        value += ch;
+      }
+    }
+
+    if (ps.currentChar === EOL) {
+      throw new ParseError("E0020");
+    }
+
+    ps.expectChar("\"");
+
+    return new StringLiteral(value);
+  }
+
+  getLiteral(ps) {
+    if (ps.isNumberStart()) {
+      return this.getNumber(ps);
+    }
+
+    if (ps.currentChar === '"') {
+      return this.getString(ps);
+    }
+
+    throw new ParseError("E0014");
+  }
+}
+
+function indent(content) {
+  return content.split("\n").join("\n    ");
+}
+
+function includesNewLine(elem) {
+  return elem.type === "TextElement" && includes(elem.value, "\n");
+}
+
+function isSelectExpr(elem) {
+  return elem.type === "Placeable"
+    && elem.expression.type === "SelectExpression";
+}
+
+const HAS_ENTRIES = 1;
+
+class FluentSerializer {
+  constructor({ withJunk = false } = {}) {
+    this.withJunk = withJunk;
+  }
+
+  serialize(resource) {
+    if (resource.type !== "Resource") {
+      throw new Error(`Unknown resource type: ${resource.type}`);
+    }
+
+    let state = 0;
+    const parts = [];
+
+    for (const entry of resource.body) {
+      if (entry.type !== "Junk" || this.withJunk) {
+        parts.push(this.serializeEntry(entry, state));
+        if (!(state & HAS_ENTRIES)) {
+          state |= HAS_ENTRIES;
+        }
+      }
+    }
+
+    return parts.join("");
+  }
+
+  serializeEntry(entry, state = 0) {
+    switch (entry.type) {
+      case "Message":
+        return serializeMessage(entry);
+      case "Term":
+        return serializeTerm(entry);
+      case "Comment":
+        if (state & HAS_ENTRIES) {
+          return `\n${serializeComment(entry, "#")}\n`;
+        }
+        return `${serializeComment(entry, "#")}\n`;
+      case "GroupComment":
+        if (state & HAS_ENTRIES) {
+          return `\n${serializeComment(entry, "##")}\n`;
+        }
+        return `${serializeComment(entry, "##")}\n`;
+      case "ResourceComment":
+        if (state & HAS_ENTRIES) {
+          return `\n${serializeComment(entry, "###")}\n`;
+        }
+        return `${serializeComment(entry, "###")}\n`;
+      case "Junk":
+        return serializeJunk(entry);
+      default :
+        throw new Error(`Unknown entry type: ${entry.type}`);
+    }
+  }
+}
+
+
+function serializeComment(comment, prefix = "#") {
+  const prefixed = comment.content.split("\n").map(
+    line => line.length ? `${prefix} ${line}` : prefix
+  ).join("\n");
+  // Add the trailing newline.
+  return `${prefixed}\n`;
+}
+
+
+function serializeJunk(junk) {
+  return junk.content;
+}
+
+
+function serializeMessage(message) {
+  const parts = [];
+
+  if (message.comment) {
+    parts.push(serializeComment(message.comment));
+  }
+
+  parts.push(`${message.id.name} =`);
+
+  if (message.value) {
+    parts.push(serializePattern(message.value));
+  }
+
+  for (const attribute of message.attributes) {
+    parts.push(serializeAttribute(attribute));
+  }
+
+  parts.push("\n");
+  return parts.join("");
+}
+
+
+function serializeTerm(term) {
+  const parts = [];
+
+  if (term.comment) {
+    parts.push(serializeComment(term.comment));
+  }
+
+  parts.push(`-${term.id.name} =`);
+  parts.push(serializePattern(term.value));
+
+  for (const attribute of term.attributes) {
+    parts.push(serializeAttribute(attribute));
+  }
+
+  parts.push("\n");
+  return parts.join("");
+}
+
+
+function serializeAttribute(attribute) {
+  const value = indent(serializePattern(attribute.value));
+  return `\n    .${attribute.id.name} =${value}`;
+}
+
+
+function serializePattern(pattern) {
+  const content = pattern.elements.map(serializeElement).join("");
+  const startOnNewLine =
+    pattern.elements.some(isSelectExpr) ||
+    pattern.elements.some(includesNewLine);
+
+  if (startOnNewLine) {
+    return `\n    ${indent(content)}`;
+  }
+
+  return ` ${content}`;
+}
+
+
+function serializeElement(element) {
+  switch (element.type) {
+    case "TextElement":
+      return element.value;
+    case "Placeable":
+      return serializePlaceable(element);
+    default:
+      throw new Error(`Unknown element type: ${element.type}`);
+  }
+}
+
+
+function serializePlaceable(placeable) {
+  const expr = placeable.expression;
+  switch (expr.type) {
+    case "Placeable":
+      return `{${serializePlaceable(expr)}}`;
+    case "SelectExpression":
+      // Special-case select expression to control the whitespace around the
+      // opening and the closing brace.
+      return `{ ${serializeExpression(expr)}}`;
+    default:
+      return `{ ${serializeExpression(expr)} }`;
+  }
+}
+
+
+function serializeExpression(expr) {
+  switch (expr.type) {
+    case "StringLiteral":
+      return `"${expr.value}"`;
+    case "NumberLiteral":
+      return expr.value;
+    case "VariableReference":
+      return `$${expr.id.name}`;
+    case "TermReference": {
+      let out = `-${expr.id.name}`;
+      if (expr.attribute) {
+        out += `.${expr.attribute.name}`;
+      }
+      if (expr.arguments) {
+        out += serializeCallArguments(expr.arguments);
+      }
+      return out;
+    }
+    case "MessageReference": {
+      let out = expr.id.name;
+      if (expr.attribute) {
+        out += `.${expr.attribute.name}`;
+      }
+      return out;
+    }
+    case "FunctionReference":
+      return `${expr.id.name}${serializeCallArguments(expr.arguments)}`;
+    case "SelectExpression": {
+      let out = `${serializeExpression(expr.selector)} ->`;
+      for (let variant of expr.variants) {
+        out += serializeVariant(variant);
+      }
+      return `${out}\n`;
+    }
+    case "Placeable":
+      return serializePlaceable(expr);
+    default:
+      throw new Error(`Unknown expression type: ${expr.type}`);
+  }
+}
+
+
+function serializeVariant(variant) {
+  const key = serializeVariantKey(variant.key);
+  const value = indent(serializePattern(variant.value));
+
+  if (variant.default) {
+    return `\n   *[${key}]${value}`;
+  }
+
+  return `\n    [${key}]${value}`;
+}
+
+
+function serializeCallArguments(expr) {
+  const positional = expr.positional.map(serializeExpression).join(", ");
+  const named = expr.named.map(serializeNamedArgument).join(", ");
+  if (expr.positional.length > 0 && expr.named.length > 0) {
+    return `(${positional}, ${named})`;
+  }
+  return `(${positional || named})`;
+}
+
+
+function serializeNamedArgument(arg) {
+  const value = serializeExpression(arg.value);
+  return `${arg.name.name}: ${value}`;
+}
+
+
+function serializeVariantKey(key) {
+  switch (key.type) {
+    case "Identifier":
+      return key.name;
+    case "NumberLiteral":
+      return key.value;
+    default:
+      throw new Error(`Unknown variant key type: ${key.type}`);
+  }
+}
+
+/*
+ * Abstract Visitor pattern
+ */
+class Visitor {
+  visit(node) {
+    if (Array.isArray(node)) {
+      node.forEach(child => this.visit(child));
+      return;
+    }
+    if (!(node instanceof BaseNode)) {
+      return;
+    }
+    const visit = this[`visit${node.type}`] || this.genericVisit;
+    visit.call(this, node);
+  }
+
+  genericVisit(node) {
+    for (const propname of Object.keys(node)) {
+      this.visit(node[propname]);
+    }
+  }
+}
+
+/*
+ * Abstract Transformer pattern
+ */
+class Transformer extends Visitor {
+  visit(node) {
+    if (!(node instanceof BaseNode)) {
+      return node;
+    }
+    const visit = this[`visit${node.type}`] || this.genericVisit;
+    return visit.call(this, node);
+  }
+
+  genericVisit(node) {
+    for (const propname of Object.keys(node)) {
+      const propvalue = node[propname];
+      if (Array.isArray(propvalue)) {
+        const newvals = propvalue
+          .map(child => this.visit(child))
+          .filter(newchild => newchild !== undefined);
+        node[propname] = newvals;
+      }
+      if (propvalue instanceof BaseNode) {
+        const new_val = this.visit(propvalue);
+        if (new_val === undefined) {
+          delete node[propname];
+        } else {
+          node[propname] = new_val;
+        }
+      }
+    }
+    return node;
+  }
+}
+
+const visitor = ({
+  Visitor: Visitor,
+  Transformer: Transformer
+});
+
+/* eslint object-shorthand: "off",
+          comma-dangle: "off",
+          no-labels: "off" */
+
+this.EXPORTED_SYMBOLS = [
+  ...Object.keys({
+    FluentParser,
+    FluentSerializer,
+  }),
+  ...Object.keys(ast),
+  ...Object.keys(visitor),
+];