qmlls: completions in JS expressions

Implement completions for JS expressions, now that JS statements are mostly done.

List of expressions to complete:

done

to be done

do not do

in progress

• PrimaryExpressions (https://262.ecma-international.org/7.0/#sec-primary-expression)
      * this
      * Identifier
      * Literal (no completion for literals needed)
      * ArrayLiteral (complete values inside of array)
      * ObjectLiteral
      * FunctionExpression
      * ClassExpression (not needed for now)
      * GeneratorExpression
      * RegularExpressionLiteral
      * TemplateLiteral (complete inside the templated string stuff)
      * CoverParenthesizedExpressionAndArrowParameterList
  • this is being parsed as AST::FormalParameterList or
  • AST::NestedExpression for expressions inside of `()` brackets
• Left-Hand-Side expressions (https://262.ecma-international.org/7.0/#sec-left-hand-side-expressions)
  • Property Accessors
    • Bracket expressions (`id[something]`)
    • Field Member access (`id.field`)  {}
  • New expressions (`new Something ()`) (not needed for now)
  • Function calls

• • • inclusive ArgumentLists, passed to the calls
  • Template Literal
  • Super property (not needed for now)
  • Meta Property (new.target support) (not needed for now)
• UpdateExpressions (https://262.ecma-international.org/7.0/#sec-update-expressions)
  • pre/post increment/decrements
• Unary Operators (https://262.ecma-international.org/7.0/#sec-unary-operators)
  • delete/void/typeof/+/-/~/!
• BinaryExpressions:

• • Exponentiation operator (https://262.ecma-international.org/7.0/#sec-exp-operator )
  • Multiplicative operators (https://262.ecma-international.org/7.0/#sec-multiplicative-operators )
  • Additive Operators (https://262.ecma-international.org/7.0/#sec-additive-operators )
  • Bitwise Shifts (https://262.ecma-international.org/7.0/#sec-bitwise-shift-operators )
  • Relational operators (https://262.ecma-international.org/7.0/#sec-relational-operators )
  • Equality Operators ( https://262.ecma-international.org/7.0/#sec-equality-operators )
  • Binary bitwise operators (https://262.ecma-international.org/7.0/#sec-binary-bitwise-operators )
  • Binary logical operators (https://262.ecma-international.org/7.0/#sec-binary-logical-operators )
  • Assignment Operators (https://262.ecma-international.org/7.0/#sec-assignment-operators )
  • Comma operators (https://262.ecma-international.org/7.0/#sec-comma-operator )

• • • note: this is being parsed as an "AST::Expression"!!!
• Conditional operator (https://262.ecma-international.org/7.0/#sec-conditional-operator )