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| 1 | namespace Syntax.Parsers.Variables is | |
| 2 | use Source | |
| 3 | use Logging | |
| 4 | ||
| 5 | class LIST(variable_parser: Parser[Trees.Variables.VARIABLE]): Base[Trees.Variables.LIST] is | |
| 6 | allow_empty: bool | |
| 7 | ||
| 8 | super() | |
| 9 | ||
| 10 | parse(context: CONTEXT) -> Trees.Variables.LIST is | |
| 11 | let start = context.location | |
| 12 | let end mut = context.location | |
| 13 | let variables = Collections.LIST[Trees.Variables.VARIABLE]() | |
| 14 | ||
| 15 | if | |
| 16 | context.current_token == Lexical.TOKEN.IDENTIFIER \/ | |
| 17 | context.current_token == Lexical.TOKEN.PAREN_OPEN \/ | |
| 18 | (context.current.token == Lexical.TOKEN.OPERATOR /\ context.current.value_string =~ "..") \/ | |
| 19 | (context.in_formal_arguments /\ context.current_token == Lexical.TOKEN.AT) \/ | |
| 20 | !allow_empty | |
| 21 | then | |
| 22 | do | |
| 23 | let variable: Trees.Variables.VARIABLE? mut | |
| 24 | ||
| 25 | variable = variable_parser.parse(context) | |
| 26 | ||
| 27 | if variable? /\ variable.is_variable then | |
| 28 | // FIXME: parsing destructure list within an argument list probably | |
| 29 | // makes this more fragile, and we don't support it anyway - should | |
| 30 | // disable destructure list parsing in in the variable list parser | |
| 31 | // when parsing an argument list | |
| 32 | ||
| 33 | // A `(` straight after a variable on the same line | |
| 34 | // means its name was probably absorbed from a | |
| 35 | // following function declaration; recover below. A | |
| 36 | // line-start `(` is not that mistake - it opens the | |
| 37 | // next statement, and the variable is complete. | |
| 38 | if | |
| 39 | context.current.token == Lexical.TOKEN.PAREN_OPEN /\ | |
| 40 | !context.current.first_on_line | |
| 41 | then | |
| 42 | if variable.is_explicit_type then | |
| 43 | // we've probably just absorbed the name of a following | |
| 44 | // function declaration | |
| 45 | ||
| 46 | // exclude the type from the variable's location | |
| 47 | // to stop the error message running on into | |
| 48 | // the following function declaration | |
| 49 | let name_location = variable.name!.location | |
| 50 | ||
| 51 | end = name_location | |
| 52 | ||
| 53 | // clear the type expression so we don't report a spurious error | |
| 54 | // about it being undefined | |
| 55 | variable.set_type_expression(Trees.TypeExpressions.INFER(name_location)) | |
| 56 | ||
| 57 | variables.add(variable) | |
| 58 | else | |
| 59 | context.expect_token(Lexical.TOKEN.COLON) | |
| 60 | fi | |
| 61 | ||
| 62 | break | |
| 63 | fi | |
| 64 | ||
| 65 | end = variable.location | |
| 66 | ||
| 67 | variables.add(variable) | |
| 68 | ||
| 69 | // An identifier hard on the heels of a variable is | |
| 70 | // probably another variable missing its comma - but | |
| 71 | // only on the same line. One that opens a new line is | |
| 72 | // the next statement, ended by the line break. | |
| 73 | if | |
| 74 | context.current.token == Lexical.TOKEN.IDENTIFIER /\ | |
| 75 | !context.current.first_on_line /\ | |
| 76 | context.location.start_column > variable.location.end_column | |
| 77 | then | |
| 78 | context.expect_token(Lexical.TOKEN.COMMA) | |
| 79 | elif context.is_end_of_file \/ context.current.token != Lexical.TOKEN.COMMA then | |
| 80 | break | |
| 81 | else | |
| 82 | end = context.location | |
| 83 | context.next_token() | |
| 84 | ||
| 85 | // Trailing comma: stop when what follows | |
| 86 | // can't start another variable. Permits | |
| 87 | // formal-argument lists, let-statement | |
| 88 | // variable lists, and destructuring | |
| 89 | // patterns to end with a comma. | |
| 90 | if | |
| 91 | context.current.token != Lexical.TOKEN.IDENTIFIER /\ | |
| 92 | context.current.token != Lexical.TOKEN.PAREN_OPEN /\ | |
| 93 | !(context.current.token == Lexical.TOKEN.OPERATOR /\ context.current.value_string =~ "..") /\ | |
| 94 | !(context.in_formal_arguments /\ context.current.token == Lexical.TOKEN.AT) | |
| 95 | then | |
| 96 | break | |
| 97 | fi | |
| 98 | fi | |
| 99 | ||
| 100 | else | |
| 101 | break | |
| 102 | fi | |
| 103 | od | |
| 104 | fi | |
| 105 | ||
| 106 | return Trees.Variables.LIST(start::end, variables) | |
| 107 | si | |
| 108 | si | |
| 109 | si |