vscode-codeql/extensions/ql-vscode/syntaxes/ql.tmLanguage.yml

---
# This file is transformed into the equivalent JSON TextMate grammar, with the following additional
# features available:
#
# The `regexOptions` Property
# A top-level property named `regexOptions` may be defined with a string value. This string
# represents the set of regular expression options to apply to all regular expressions throughout
# the file.
#
# Macros
# The `macros` element defines a map of macro names to replacement text. When a `match`, `begin`, or
# `end` property has a value that is a single-key map, the value is replaced with the value of the
# macro named by the key, with any use of `(?#)` in the macro text replaced with the text of the
# value of the key, surrounded by a non-capturing group (`(?:)`). For example:
#
# The `beginPattern` and `endPattern` Properties
# A rule can have a `beginPattern` or `endPattern` property whose value is a reference to another
# rule (e.g. `#other-rule`). The `beginPattern` property is replaced as follows:
#
# my-rule:
#   beginPattern: '#other-rule'
#
# would be transformed to
#
# my-rule:
#   begin: '(?#other-rule)'
#   beginCaptures:
#     '0':
#       patterns:
#       - include: '#other-rule'
#
# An `endPattern` property is transformed similary.
#
# macros:
#   repeat: '(?#)*'
# repository:
#   multi-letter:
#     match:
#       repeat: '[A-Za-z]'
#     name: scope.multi-letter
# 
# would be transformed to
#
# repository:
#   multi-letter:
#     match: '(?:[A-Za-z])*'
#     name: scope.multi-letter
#
# Reference Expansion
# Any comment of the form `(?#ref-id)` in a `match`, `begin`, or `end` property will be replaced
# with the match text of the rule named "ref-id". If the rule named "ref-id" consists of just a
# `patterns` property with a list of `include` directives, the replacement pattern is the
# disjunction of the match patterns of all of the included rules.

name: QL
scopeName: source.ql
fileTypes: [ql, qll]
uuid: 7F6926BF-1C6C-468A-A7AA-215EBAC86A4E
regexOptions: 'x' # Ignore pattern whitespace

# Macros are parameterized patterns that can be used as a match elsewhere in the file.
# To use a macro, replace the string for a `match`, `begin`, or `end` property with a single-element
# map whose key is the name of the macro to invoke, and whose value is a string to be substituted for
# any usage of `(?#)` in the macro pattern definition.
macros:
  keyword: '\b(?#)(?#end-of-id)'

patterns:
- include: '#module-member'

repository:
  # A character that can appear somewhere in an identifier.
  id-character:
    match: '[0-9A-Za-z_]'

  # Matches a position containing a non-identifier character. Used to ensure we do not match partial
  # identifiers/keywords in other rules.
  end-of-id:
    match: '(?!(?#id-character))'

  # A QL "simple identifier", which can begin with either an uppercase or a lowercase letter.
  simple-id:
    match: '\b [A-Za-z][0-9A-Za-z_]* (?#end-of-id)'

  # An identifier beginning with a lowercase letter.
  lower-id: 
    match: '\b [a-z][0-9A-Za-z_]* (?#end-of-id)'

  # An identifier beginning with an uppercase letter.
  upper-id:
    match: '\b [A-Z][0-9A-Za-z_]* (?#end-of-id)'

  # An identifier beginning with an `@` followed by a lowercase letter. Used to represent database
  # types.
  at-lower-id:
    match: '@[a-z][0-9A-Za-z_]* (?#end-of-id)'

  # A pattern that can start a comment.
  comment-start:
    match: '// | /\*'

  # A pattern that can start a run of whitespace or a comment.
  # Commonly used as a negative lookahead in the `end` regex of a nonterminal, when searching for
  # tokens that can't start a child of that nonterminal.
  whitespace-or-comment-start:
    match: '\s | $ | (?#comment-start)'

  # All tokens that can appear in any context.
  non-context-sensitive:
    patterns:
    - include: '#comment'
    - include: '#literal'
    - include: '#operator-or-punctuation'
    - include: '#keyword'

# Operators and punctuation
  relational-operator:
    match: '<=|<|>=|>'
    name: keyword.operator.relational.ql
  
  comparison-operator:
    match: '=|\!\='
    name: keyword.operator.comparison.ql
  
  arithmetic-operator:
    match: '\+|-|\*|/|%'
    name: keyword.operator.arithmetic.ql

  comma:
    match: ','
    name: punctuation.separator.comma.ql
  
  semicolon:
    match: ';'
    name: punctuation.separator.statement.ql
  
  dot:
    match: '\.'
    name: punctuation.accessor.ql

  dotdot:
    match: '\.\.'
    name: punctuation.operator.range.ql
  
  pipe:
    match: '\|'
    name: punctuation.separator.pipe.ql

  open-paren:
    match: '\('
    name: punctuation.parenthesis.open.ql

  close-paren:
    match: '\)'
    name: punctuation.parenthesis.close.ql

  open-brace:
    match: '\{'
    name: punctuation.curlybrace.open.ql

  close-brace:
    match: '\}'
    name: punctuation.curlybrace.close.ql

  open-bracket:
    match: '\['
    name: punctuation.squarebracket.open.ql

  close-bracket:
    match: '\]'
    name: punctuation.squarebracket.close.ql

  operator-or-punctuation:
    patterns:
    - include: '#relational-operator'
    - include: '#comparison-operator'
    - include: '#arithmetic-operator'
    - include: '#comma'
    - include: '#semicolon'
    - include: '#dot'
    - include: '#dotdot'
    - include: '#pipe'
    - include: '#open-paren'
    - include: '#close-paren'
    - include: '#open-brace'
    - include: '#close-brace'
    - include: '#open-bracket'
    - include: '#close-bracket'

# Keywords
  dont-care:
    match:
      keyword: '_'
    name: variable.language.dont-care.ql
  
  and:
    match:
      keyword: 'and'
    name: keyword.other.and.ql

  any:
    match:
      keyword: 'any'
    name: keyword.quantifier.any.ql

  as:
    match:
      keyword: 'as'
    name: keyword.other.as.ql

  asc:
    match:
      keyword: 'asc'
    name: keyword.order.asc.ql
    
  avg:
    match:
      keyword: 'avg'
    name: keyword.aggregate.avg.ql
    
  boolean:
    match:
      keyword: 'boolean'
    name: keyword.type.boolean.ql

  by:
    match:
      keyword: 'by'
    name: keyword.order.by.ql

  class:
    match:
      keyword: 'class'
    name: keyword.other.class.ql

  concat:
    match:
      keyword: 'concat'
    name: keyword.aggregate.concat.ql

  count:
    match:
      keyword: 'count'
    name: keyword.aggregate.count.ql
    
  date:
    match:
      keyword: 'date'
    name: keyword.type.date.ql
    
  desc:
    match:
      keyword: 'desc'
    name: keyword.order.desc.ql
    
  else:
    match:
      keyword: 'else'
    name: keyword.other.else.ql

  exists:
    match:
      keyword: 'exists'
    name: keyword.quantifier.exists.ql
  
  extends:
    match:
      keyword: 'extends'
    name: keyword.other.extends.ql

  false:
    match:
      keyword: 'false'
    name: constant.language.boolean.false.ql

  float:
    match:
      keyword: 'float'
    name: keyword.type.float.ql

  forall:
    match:
      keyword: 'forall'
    name: keyword.quantifier.forall.ql

  forex:
    match:
      keyword: 'forex'
    name: keyword.quantifier.forex.ql

  from:
    match:
      keyword: 'from'
    name: keyword.other.from.ql

  if:
    match:
      keyword: 'if'
    name: keyword.other.if.ql
    
  implies:
    match:
      keyword: 'implies'
    name: keyword.other.implies.ql
    
  import:
    match:
      keyword: 'import'
    name: keyword.other.import.ql

  in:
    match:
      keyword: 'in'
    name: keyword.other.in.ql

  instanceof:
    match:
      keyword: 'instanceof'
    name: keyword.other.instanceof.ql

  int:
    match:
      keyword: 'int'
    name: keyword.type.int.ql
  
  max:
    match:
      keyword: 'max'
    name: keyword.aggregate.max.ql

  min:
    match:
      keyword: 'min'
    name: keyword.aggregate.min.ql

  module:
    match:
      keyword: 'module'
    name: keyword.other.module.ql
    
  newtype:
    match:
      keyword: 'newtype'
    name: keyword.other.newtype.ql

  none:
    match:
      keyword: 'none'
    name: keyword.quantifier.none.ql

  not:
    match:
      keyword: 'not'
    name: keyword.other.not.ql

  or:
    match:
      keyword: 'or'
    name: keyword.other.or.ql

  order:
    match:
      keyword: 'order'
    name: keyword.order.order.ql

  predicate:
    match:
      keyword: 'predicate'
    name: keyword.other.predicate.ql

  rank:
    match:
      keyword: 'rank'
    name: keyword.aggregate.rank.ql

  result:
    match:
      keyword: 'result'
    name: variable.language.result.ql

  select:
    match:
      keyword: 'select'
    name: keyword.query.select.ql

  strictconcat:
    match:
      keyword: 'strictconcat'
    name: keyword.aggregate.strictconcat.ql

  strictcount:
    match:
      keyword: 'strictcount'
    name: keyword.aggregate.strictcount.ql

  strictsum:
    match:
      keyword: 'strictsum'
    name: keyword.aggregate.strictsum.ql

  string:
    match:
      keyword: 'string'
    name: keyword.type.string.ql
  
  sum:
    match:
      keyword: 'sum'
    name: keyword.aggregate.sum.ql

  super:
    match:
      keyword: 'super'
    name: variable.language.super.ql
  
  then:
    match:
      keyword: 'then'
    name: keyword.other.then.ql

  this:
    match:
      keyword: 'this'
    name: variable.language.this.ql

  true:
    match:
      keyword: 'true'
    name: constant.language.boolean.true.ql

  unique:
    match:
      keyword: 'unique'
    name: keyword.aggregate.unique.ql

  where:
    match:
      keyword: 'where'
    name: keyword.query.where.ql

  # Any "true" keyword (not including annotations).
  keyword:
    patterns:
    - include: '#dont-care'
    - include: '#and'
    - include: '#any'
    - include: '#as'
    - include: '#asc'
    - include: '#avg'
    - include: '#boolean'
    - include: '#by'
    - include: '#class'
    - include: '#concat'
    - include: '#count'
    - include: '#date'
    - include: '#desc'
    - include: '#else'
    - include: '#exists'
    - include: '#extends'
    - include: '#false'
    - include: '#float'
    - include: '#forall'
    - include: '#forex'
    - include: '#from'
    - include: '#if'
    - include: '#implies'
    - include: '#import'
    - include: '#in'
    - include: '#instanceof'
    - include: '#int'
    - include: '#max'
    - include: '#min'
    - include: '#module'
    - include: '#newtype'
    - include: '#none'
    - include: '#not'
    - include: '#or'
    - include: '#order'
    - include: '#predicate'
    - include: '#rank'
    - include: '#result'
    - include: '#select'
    - include: '#strictconcat'
    - include: '#strictcount'
    - include: '#strictsum'
    - include: '#string'
    - include: '#sum'
    - include: '#super'
    - include: '#then'
    - include: '#this'
    - include: '#true'
    # `unique` is not really a keyword, but we'll highlight it as if it is.
    - include: '#unique'
    - include: '#where'

  # A keyword that can be the first token of a predicate declaration.
  predicate-start-keyword:
    patterns:
    - include: '#boolean'
    - include: '#date'
    - include: '#float'
    - include: '#int'
    - include: '#predicate'
    - include: '#string'

# Annotation keywords
  abstract:
    match:
      keyword: 'abstract'
    name: storage.modifier.abstract.ql
  
  bindingset:
    match:
      keyword: 'bindingset'
    name: storage.modifier.bindingset.ql

  cached:
    match:
      keyword: 'cached'
    name: storage.modifier.cached.ql
  
  deprecated:
    match:
      keyword: 'deprecated'
    name: storage.modifier.deprecated.ql
    
  external:
    match:
      keyword: 'external'
    name: storage.modifier.external.ql
  
  final:
    match:
      keyword: 'final'
    name: storage.modifier.final.ql
    
  language:
    match:
      keyword: 'language'
    name: storage.modifier.language.ql

  library:
    match:
      keyword: 'library'
    name: storage.modifier.library.ql
  
  override:
    match:
      keyword: 'override'
    name: storage.modifier.override.ql
  
  pragma:
    match:
      keyword: 'pragma'
    name: storage.modifier.pragma.ql

  private:
    match:
      keyword: 'private'
    name: storage.modifier.private.ql

  query:
    match:
      keyword: 'query'
    name: storage.modifier.query.ql

  transient:
    match:
      keyword: 'transient'
    name: storage.modifier.transient.ql

  annotation-keyword:
    patterns:
    - include: '#abstract'
    - include: '#bindingset'
    - include: '#cached'
    - include: '#deprecated'
    - include: '#external'
    - include: '#final'
    - include: '#language'
    - include: '#library'
    - include: '#override'
    - include: '#pragma'
    - include: '#private'
    - include: '#query'
    - include: '#transient'

  # A QL comment, regardless of form.
  comment:
    patterns:
      # A QLDoc (`/** */`) comment.
    - begin: '/\*\*'
      end: '\*/'
      name: comment.block.documentation.ql
      # Highlight tag names within the QLDoc.
      patterns:
      - begin: '(?<=/\*\*)([^*]|\*(?!/))*$'
        while: '(^|\G)\s*([^*]|\*(?!/))(?=([^*]|[*](?!/))*$)'
        patterns:
        - include: 'text.html.markdown#fenced_code_block'
        - include: 'text.html.markdown#lists'
        - include: 'text.html.markdown#inline'
        - match: '\G\s* (@\S+)'
          name: keyword.tag.ql
      # A block (`/* */`) comment.
    - begin: '/\*'
      end: '\*/'
      name: comment.block.ql
      # A single line (`//`) comment.
    - match: //.*$
      name: comment.line.double-slash.ql

  # List of rules that can be matched within the body of a module, including at file scope.
  module-member:
    patterns:
    - include: '#import-directive'
    - include: '#import-as-clause'
    - include: '#module-declaration'
    - include: '#newtype-declaration'
    # See the comment on newtype-declaration for why we include these next three nonterminals at the
    # module-member level instead of as part of the newtype-declaration.
    - include: '#newtype-branch-name-with-prefix'
    - include: '#predicate-parameter-list'
    - include: '#predicate-body'
    - include: '#class-declaration'
    - include: '#select-clause'
    - include: '#predicate-or-field-declaration'
    - include: '#non-context-sensitive'
    - include: '#annotation'

  # An `import` directive. Note that we parse the optional `as` clause as a separate top-level
  # directive, because otherwise it's too hard to figure out where the `import` directive ends.
  import-directive:
    beginPattern: '#import'
    # Ends with a simple-id that is not followed by a `.` or a `::`. This does not handle comments or
    # line breaks between the simple-id and the `.` or `::`. 
    end: '(?#simple-id) (?!\s*(\.|\:\:))'
    endCaptures:
      '0':
        name: entity.name.type.namespace.ql
    name: meta.block.import-directive.ql
    patterns:
    - include: '#non-context-sensitive'
    - match: '(?#simple-id)'
      name: entity.name.type.namespace.ql

  # The end pattern for an `as` clause, whether on an `import` directive, in an aggregate, or on a
  # `select`.
  end-of-as-clause:
    match: '(?: (?<=(?#id-character)) (?!(?#id-character)) (?<!(?<!(?#id-character))as)) |
            (?=\s* (?!(?#comment-start) | (?#simple-id)) \S) |
            (?=\s* (?#keyword))' 

  # The `as` clause of an `import` directive. We treat this as a separate module-scope directive.
  import-as-clause:
    # Start at the `as` keyword.
    beginPattern: '#as'
    # The end pattern is tricky.
    # We want to allow an aribtrary amount of whitespace and comments, followed by a single
    # simple-id. To do this, we end when one of the following matches:
    # - We are at the end of an identifier, and that identifier is not `as`.
    # - The next non-whitespace character is not the start of a comment or a simple-id.
    # - The next non-whitespace character is a keyword.
    end:  '(?#end-of-as-clause)'
    name: meta.block.import-as-clause.ql
    patterns:
    - include: '#non-context-sensitive'
    - match: '(?#simple-id)'
      name: entity.name.type.namespace.ql

  # A `module` declaration, whether a module definition or an alias declaration.
  module-declaration:
    # Starts with the `module` keyword.
    beginPattern: '#module'
    # Ends after a `}` or `;`
    end: '(?<=\}|;)'
    name: meta.block.module-declaration.ql
    patterns:
    - include: '#module-body'
    - include: '#non-context-sensitive'
      # Any simple-id within a module head is part of a module name.
    - match: '(?#simple-id)'
      name: entity.name.type.namespace.ql

  # The body of a `module` definition.
  module-body:
    beginPattern: '#open-brace'
    endPattern: '#close-brace'
    name: meta.block.module-body.ql
    patterns:
    - include: '#module-member'

  # A simple-id followed by a `::` is a module qualifier.
  module-qualifier:
    match: '(?#simple-id) (?=\s*\:\:)'
    name: entity.name.type.namespace.ql

  # The declaration of a predicate or field.
  predicate-or-field-declaration:
    # Starts with one of the following:
    # - A simpleId that is neither a keyword nor an annotation keyword.
    # - A keyword that can start a predicate (e.g. a primitive type, or `predicate`).
    # = An atLowerId.
    begin: '(?:(?=(?#simple-id))(?!(?#keyword)|(?#annotation-keyword))) |
            (?=(?#predicate-start-keyword)) |
            (?=(?#at-lower-id))'
    # Ends after a `}` or `;`
    end: '(?<=\}|;)'
    name: meta.block.predicate-or-field-declaration.ql
    patterns:
    - include: '#predicate-parameter-list'
    - include: '#predicate-body'
    - include: '#non-context-sensitive'
      # An identifier followed by a `::` is a module.
    - include: '#module-qualifier'
      # A lower-id followed by a `;` is a field name.
    - match: '(?#lower-id)(?=\s*;)'
      name: variable.field.ql
      # Any other lower-id is assumed to be a predicate name.
    - match: '(?#lower-id)'
      name: entity.name.function.ql
      # Any other upper-id or at-lower-id is a type name.
    - match: '(?#upper-id)|(?#at-lower-id)'
      name: entity.name.type.ql

  # The parenthesized parameter list of a predicate.
  predicate-parameter-list:
    beginPattern: '#open-paren'
    endPattern: '#close-paren'
    name: meta.block.predicate-parameter-list.ql
    # Figuring out which kind of identifier we're looking at is tricky in a parameter declaration,
    # because variable names can be upper-ids or lower-ids. We'll use some heuristics.
    patterns:
    - include: '#non-context-sensitive'
      # An upper-id followed by a `,` or a `)` is assumed to be a variable name.
    - match: '(?#upper-id)(?=\s*(?:,|\)))'
      name: variable.parameter.ql
      # A simple-id followed by a `::` is a module qualifier.
    - include: '#module-qualifier'
      # Any other upper-id is assumed to be part of a type name.
    - match: '(?#upper-id)|(?#at-lower-id)'
      name: entity.name.type.ql
      # Any other lower-id is assumed to be a variable name.
    - match: '(?#lower-id)'
      name: variable.parameter.ql

  # An `as` clause in an aggregate or `select`.
  expr-as-clause:
    # Start at the `as` keyword.
    beginPattern: '#as'
    end:  '(?#end-of-as-clause)'
    name: meta.block.expr-as-clause.ql
    patterns:
    - include: '#non-context-sensitive'
    - match: '(?#simple-id)'
      name: variable.other.ql

  # The contents of a predicate body.
  predicate-body-contents:
    patterns:
    - include: '#expr-as-clause'
    - include: '#non-context-sensitive'
      # A simple-id followed by a `::` is a module qualifier.
    - include: '#module-qualifier'
      # Any lower-id followed by a `(`, optionally with a `*` or `+` in between,
      # is a predicate name.
    - match: '(?#lower-id)\s*(?:\*|\+)?\s*(?=\()'
      name: entity.name.function.ql
      # Any other lower-id is assumed to be a variable name.
    - match: '(?#lower-id)'
      name: variable.other.ql
      # Any other upper-id is assumed to be part of a type name.
    - match: '(?#upper-id)|(?#at-lower-id)'
      name: entity.name.type.ql

  # The brace-enclosed body of a predicate definition.
  predicate-body:
    beginPattern: '#open-brace'
    endPattern: '#close-brace'
    name: meta.block.predicate-body.ql
    patterns:
    - include: '#predicate-body-contents'

  # An annotation on a declaration.
  annotation:
    patterns:
    - include: '#bindingset-annotation'
    - include: '#language-annotation'
    - include: '#pragma-annotation'
    - include: '#annotation-keyword'

  # A `pragma` annotation, including its arguments.
  bindingset-annotation:
    beginPattern: '#bindingset'
    # Ends after the next `]`, or when we encounter something other than a `[`.
    end: '(?! (?#whitespace-or-comment-start) | \[ ) |
          (?<=\])'
    name: meta.block.bindingset-annotation.ql
    patterns:
    - include: '#bindingset-annotation-body'
    - include: '#non-context-sensitive'

  # The bracket-enclosed body of a `bindingset` annotation.
  bindingset-annotation-body:
    beginPattern: '#open-bracket'
    endPattern: '#close-bracket'
    name: meta.block.bindingset-annotation-body.ql
    patterns:
    - include: '#non-context-sensitive'
    - match: '(?#simple-id)'
      name: variable.parameter.ql

  # A `language` annotation, including its arguments.
  language-annotation:
    beginPattern: '#language'
    # Ends after the next `]`, or when we encounter something other than a `[`.
    end: '(?! (?#whitespace-or-comment-start) | \[ ) |
          (?<=\])'
    name: meta.block.language-annotation.ql
    patterns:
    - include: '#language-annotation-body'
    - include: '#non-context-sensitive'

  # The bracket-enclosed body of a `language` annotation.
  language-annotation-body:
    beginPattern: '#open-bracket'
    endPattern: '#close-bracket'
    name: meta.block.language-annotation-body.ql
    patterns:
    - include: '#non-context-sensitive'
    - match:
        keyword: 'monotonicAggregates'
      name: storage.modifier.ql

  # A `pragma` annotation, including its arguments.
  pragma-annotation:
    beginPattern: '#pragma'
    # Ends after the next `]`, or when we encounter something other than a `[`.
    end: '(?! (?#whitespace-or-comment-start) | \[ ) |
          (?<=\])'
    name: meta.block.pragma-annotation.ql
    patterns:
    - include: '#pragma-annotation-body'
    - include: '#non-context-sensitive'

  # The bracket-enclosed body of a `pragma` annotation.
  pragma-annotation-body:
    beginPattern: '#open-bracket'
    endPattern: '#close-bracket'
    name: meta.block.pragma-annotation-body.ql
    patterns:
    - match: '\b(?:inline|noinline|nomagic|noopt)\b'
      name: storage.modifier.ql

  # The declaration of an IPA type.
  # This only includes the `newtype` keyword and the identifier for the IPA type itself. The
  # branches of the IPA type are modeled as separate nonterminals contained directly in the module
  # body. This is kind of hacky, but without it, we don't seem to have a way to get TextMate to
  # handle this:
  # ```ql
  # newtype TRoot =
  #   TBranch1(int x) {
  #     x = 5
  #   } or
  #   TBranch2()  // No body
  #
  # TOther getOther() { any() }
  # ```
  # If the branches are within the newtype declaration node, it's very hard to get the upper-id for
  # the name of the IPA type to be included in the newtype declaration node, without also including
  # the `TOther` upper-id in the declaration node.
  newtype-declaration:
    beginPattern: '#newtype'
    # We're expecting a newtype-declaration-without-keyword immediately after the `newtype` keyword,
    # so end if we see anything other than the upper-id that starts it, or whitespace, or a comment.
    # An upper-id can't start anything else at module scope, so once we see the rest of this
    # newtype-declaration, whatever comes next should end this block.
    end: '(?#upper-id)'
    endCaptures:
      '0':
        name: entity.name.type.ql
    name: meta.block.newtype-declaration.ql
    patterns:
    - include: '#non-context-sensitive'

  # A branch of an IPA type, including just the `=` or `or` prefix and the name of the branch.
  # The parameter list and body are separate nonterminals contained directly within the module body.
  # See the comment for newtype-declaration for why.
  newtype-branch-name-with-prefix:
    begin: '\= | (?#or)'
    beginCaptures:
      '0':
        patterns:
        - include: '#or'
        - include: '#comparison-operator'
    end: '(?#upper-id)'
    endCaptures:
      '0':
        name: entity.name.type.ql
    name: meta.block.newtype-branch-name-with-prefix.ql
    patterns:
    - include: '#non-context-sensitive'

  # The declaration of a class, include an alias.
  class-declaration:
    beginPattern: '#class'
    # Ends after a `}` or `;`.
    end: '(?<= \} | ; )'
    name: meta.block.class-declaration.ql
    patterns:
    - include: '#class-body'
    - include: '#extends-clause'
    - include: '#non-context-sensitive'
    - match: '(?#upper-id)'
      name: entity.name.type.class.ql

  # The `extends` clause of a class definition.
  extends-clause:
    beginPattern: '#extends'
    # Ends at the first `{`.
    # REVIEW: This could be any token not allowed in a type.
    end: '(?= \{ )'
    name: meta.block.extends-clause.ql
    patterns:
    - include: '#non-context-sensitive'
    - match: '(?#simple-id)|(?#at-lower-id)'
      name: entity.name.type.ql

  # The body of a class definition.
  class-body:
    beginPattern: '#open-brace'
    endPattern: '#close-brace'
    name: meta.block.class-body.ql
    patterns:
    - include: '#class-member'

  # A declaration within a class definition.
  class-member:
    patterns:
    - include: '#predicate-or-field-declaration'
    - include: '#annotation'
    - include: '#non-context-sensitive'

  # An entire `select` clause, including the `from`, `where`, and `select` sections.
  select-clause:
    # Starts just before the `from`, `where`, or `select` keyword.
    begin: '(?=(?#from)|(?#where)|(?#select))'
    # Ends when we encounter anything other than `from`, `where`, or `select`.
    end: '(?!(?#from)|(?#where)|(?#select))'
    name: meta.block.select-clause.ql
    patterns:
    - include: '#from-section'
    - include: '#where-section'
    - include: '#select-section'

  # The `from` section of a `select` clause.
  from-section:
    # Starts just before the `from` keyword.
    beginPattern: '#from'
    # Ends at the subsequent `select` or `where` keyword.
    end: '(?= (?#select) | (?#where) )'
    name: meta.block.from-section.ql
    # Figuring out which kind of identifier we're looking at is tricky in a `from` section,
    # because variable names can be upper-ids or lower-ids. We'll use some heuristics.
    patterns:
    - include: '#non-context-sensitive'
      # An upper-id followed by a `,`, `where`, `select`, or newline is assumed to be a variable
      # name.
    - match: '(?#upper-id)(?=\s*(?:,|(?#where)|(?#select)|$))'
      name: variable.parameter.ql
      # A simple-id followed by a `::` is a module qualifier.
    - include: '#module-qualifier'
      # Any other upper-id is assumed to be part of a type name.
    - match: '(?#upper-id)|(?#at-lower-id)'
      name: entity.name.type.ql
      # Any other lower-id is assumed to be a variable name.
    - match: '(?#lower-id)'
      name: variable.parameter.ql

  # The `where` section of a `select` clause.
  where-section:
    beginPattern: '#where'
    end: '(?=(?#select))'
    name: meta.block.where-section.ql
    patterns:
    - include: '#predicate-body-contents'

  # The `select` section of a `select` clause.
  select-section:
    beginPattern: '#select'
    # REVIEW: It's hard to figure out where the `select` section ends, but we should be able to do
    # bettern than this.
    end: '(?=\n)'
    name: meta.block.select-section.ql
    patterns:
    - include: '#predicate-body-contents'
    - include: '#select-as-clause'

  # The `as` clause within a `select` expression.
  select-as-clause:
    beginPattern: '#as'
    # Ends after the first identifier we encounter.
    # REVIEW: Make similar to import-as-clause.
    end: '(?<=(?#id-character)(?#end-of-id))'
    match: meta.block.select-as-clause.ql
    patterns:
    - include: '#non-context-sensitive'
    - match: '(?#simple-id)'
      name: variable.other.ql
  
  # A literal (not including Boolean literals, which are keywords).
  literal:
    patterns:
    - include: '#float-literal'
    - include: '#int-literal'
    - include: '#string-literal'

  # An integer literal.
  int-literal:
    match: '-?[0-9]+(?![0-9])'
    name: constant.numeric.decimal.ql

  # A float literal.
  float-literal:
    match: '-?[0-9]+\.[0-9]+(?![0-9])'
    name: constant.numeric.decimal.ql

  # A string literal.
  string-literal:
    name: string.quoted.double.ql
    begin: '"'
    beginCaptures:
      '0': { name: punctuation.definition.string.begin.ql }
    end: '(") | ((?:[^\\\n])$)'
    endCaptures:
      '1': { name: punctuation.definition.string.end.ql }
      '2': { name: invalid.illegal.newline.ql }
    patterns:
    - include: '#string-escape'

  # An escape sequence in a string.
  string-escape:
    match: '\\["\\nrt]'
    name: constant.character.escape.ql