segfault

[spir]

Hello D programmers,


I'm blocked by a mysterious segfault I seem to be unable to diagnose. There is probably some point of D I have not yet understood. Below relevant piece of code; "***" marks debug instructions.

The constructor works fine, assertions pass, and writeln writes:
    ([0-9]+ ("+" [0-9]+)*)
But when I call the method 'check', writeln writes
    (null null)
Which means that this.pattern's sub-patterns have disappeared. See line constructing this.pattern in constructor to have an idea (I even tried to replace sep & element by this.sep & this.element, but this does not help).

When matching with this.pattern later in check(), I get a segfault because the code tries to recursively match its sub-patterns (the null items).


Denis


class List : Pattern {
    // ...
    Pattern element;
    Pattern sep;
    Tuple pattern;
    uint min;
    
    this (Pattern element, Pattern sep, uint min=2) {
        this.min = min;
        // for output
        this.element = element;
        this.sep = sep;
        // construct pattern
        this.pattern = new Tuple(
            element, 
            new ZeroOrMore(new Tuple(sep,element))
            );
        assert ((this.element !is null) && (this.sep !is null));    // ***
        assert (this.pattern !is null);                             // ***
        writeln(this.pattern);                                      // ***
    }
    
    override Result check (Source source) {
        assert (this.pattern !is null);                             // ***
        writeln(this.pattern);                                      // ***
        // ...

-- -- -- -- -- -- --
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