diff options
| -rw-r--r-- | match.c | 14 | ||||
| -rw-r--r-- | txr.1 | 28 |
2 files changed, 40 insertions, 2 deletions
@@ -366,8 +366,14 @@ static val dest_bind(val spec, val bindings, val pattern, lisp_evaled = t; } - if (lisp_evaled) - return if3(tree_find(value, ret, swap_12_21(testfun)), bindings, t); + if (lisp_evaled) { + if (!opt_compat || opt_compat >= 184) + if (tree_find(ret, value, testfun)) + return bindings; + if (tree_find(value, ret, swap_12_21(testfun))) + return bindings; + return t; + } while (consp(piter) && consp(viter)) { @@ -386,6 +392,10 @@ static val dest_bind(val spec, val bindings, val pattern, return funcall2(testfun, piter, viter) ? bindings : t; } return bindings; + } else if ((!opt_compat || opt_compat >= 184) && + tree_find(pattern, value, testfun)) + { + return bindings; } else if (tree_find(value, pattern, swap_12_21(testfun))) { return bindings; } @@ -60685,6 +60685,34 @@ of these version values, the described behaviors are provided if is given an argument which is equal or lower. For instance .code "-C 103" selects the behaviors described below for version 105, but not those for 102. +.IP 183 +A value of 183 or lower restores an inconsistent behavior in the +.code "@(bind)" +directive and other places in the \*(TX pattern language where binding +takes place. Prior to version 184, a string tree match was only tried in +both directions when the left hand side of a binding (the "pattern") was a +variable. For non-variable pattern terms, such as Lisp expressions or atoms, +the string tree match was tried in one direction only: a string tree arising +out of the pattern could match a string atom value on the right side. +A string tree is a nested list structure whose leaves are strings: a list +of strings, a list of lists of strings, and so on, in any mixture. +Concretely, before \*(TX 184, +.cblk +@(bind "a" ("a" "b" "c")) +.cble +didn't match, but +.cblk +@(bind ("a" "b" "c") "a") +.cble +did. However, if the variable +.code a +contained +.strn a +then +.cblk +@(bind a ("a" "b" "c")) +.cble +did match: an inconsistency. .IP 177 A value of 177 or lower causes the emulation of a bug which was present in the .code rng |