diff options
Diffstat (limited to 'src/compile.c')
| -rw-r--r-- | src/compile.c | 28 |
1 files changed, 11 insertions, 17 deletions
diff --git a/src/compile.c b/src/compile.c index 33a8e72c..bd0cb6d9 100644 --- a/src/compile.c +++ b/src/compile.c @@ -759,7 +759,7 @@ static void block_get_unbound_vars(block b, jv *vars) { /* Build wrappers around destructuring matchers so that we can chain them * when we have errors. The approach is as follows: - * FORK_OPT NEXT_MATCHER (unless last matcher) + * DESTRUCTURE_ALT NEXT_MATCHER (unless last matcher) * existing_matcher_block * JUMP BODY */ @@ -767,20 +767,18 @@ static block bind_alternation_matchers(block matchers, block body) { block preamble = {0}; block altmatchers = {0}; block mb = {0}; + block final_matcher = matchers; // Pass through the matchers to find all destructured names. - while (matchers.first && matchers.first->op == DESTRUCTURE_ALT) { - block_append(&altmatchers, inst_block(block_take(&matchers))); + while (final_matcher.first && final_matcher.first->op == DESTRUCTURE_ALT) { + block_append(&altmatchers, inst_block(block_take(&final_matcher))); } // We don't have any alternations here, so we can use the simplest case. if (altmatchers.first == NULL) { - return bind_matcher(matchers, body); + return bind_matcher(final_matcher, body); } - // The final matcher needs to strip the error from the previous FORK_OPT - block final_matcher = BLOCK(gen_op_simple(POP), gen_op_simple(DUP), matchers); - // Collect var names jv all_vars = jv_object(); block_get_unbound_vars(altmatchers, &all_vars); @@ -800,16 +798,11 @@ static block bind_alternation_matchers(block matchers, block body) { for (inst *i = altmatchers.first; i; i = i->next) { block submatcher = i->subfn; - // Get rid of the error from the previous matcher - if (mb.first != NULL) { - submatcher = BLOCK(gen_op_simple(POP), gen_op_simple(DUP), submatcher); - } - // If we're successful, jump to the end of the matchers submatcher = BLOCK(submatcher, gen_op_target(JUMP, final_matcher)); - // FORK_OPT to the end of this submatcher so we can skip to the next one on error - mb = BLOCK(mb, gen_op_target(FORK_OPT, submatcher), submatcher); + // DESTRUCTURE_ALT to the end of this submatcher so we can skip to the next one on error + mb = BLOCK(mb, gen_op_target(DESTRUCTURE_ALT, submatcher), submatcher); // We're done with this inst and we don't want it anymore // But we can't let it free the submatcher block. @@ -1003,12 +996,13 @@ block gen_destructure(block var, block matchers, block body) { if (body.first && body.first->op == TOP) top = inst_block(block_take(&body)); - if (matchers.first && matchers.first->op == DESTRUCTURE_ALT && !block_is_noop(var)) { + if (matchers.first && matchers.first->op == DESTRUCTURE_ALT) { block_append(&var, gen_op_simple(DUP)); - block_append(&matchers, gen_op_simple(POP)); + } else { + top = BLOCK(top, gen_op_simple(DUP)); } - return BLOCK(top, gen_op_simple(DUP), gen_subexp(var), gen_op_simple(POP), bind_alternation_matchers(matchers, body)); + return BLOCK(top, gen_subexp(var), gen_op_simple(POP), bind_alternation_matchers(matchers, body)); } // Like gen_var_binding(), but bind `break`'s wildcard unbound variable |