#348 Chapter 9 and positional patterns

[Josep Maria Blasco]

The docs are incoherent regarding what can be specified between parentheses. The interpreter accepts expressions in all cases, but, in the docs, this depends on the paragraph. See, for example,

• (9.3): "An expression in parentheses with an equal sign before the left parenthesis. (See Section 9.4,
  “Parsing with Variable Patterns” for details on variable positional patterns.)", which is OK, but when we refer to 9.4, we find:
• "If no equal, plus sign, minus sign, >, or < precedes the parenthesis that is before the variable name, the character string value of the variable is then treated as a string pattern" ("variable name" and "variable" should be substituted by "expression").

Similar incoherences occur in the whole section. At some point, the language accepted only variables, and then it was extended to accept expressions, but some of these updates escaped the docs.