diff --git a/contrib/ltree/expected/ltree.out b/contrib/ltree/expected/ltree.out index 610cb6f3266..5d9102cb6c9 100644 --- a/contrib/ltree/expected/ltree.out +++ b/contrib/ltree/expected/ltree.out @@ -445,6 +445,12 @@ SELECT '1.*.4|3|2.*{1}'::lquery; 1.*.4|3|2.*{1} (1 row) +SELECT 'foo.bar{,}.!a*|b{1,}.c{,44}.d{3,4}'::lquery; + lquery +------------------------------------ + foo.bar{,}.!a*|b{1,}.c{,44}.d{3,4} +(1 row) + SELECT 'qwerty%@*.tu'::lquery; lquery -------------- @@ -727,7 +733,7 @@ SELECT 'a.b.c.d.e'::ltree ~ '*.a.*.d.*'; SELECT 'a.b.c.d.e'::ltree ~ '*.!d.*'; ?column? ---------- - f + t (1 row) SELECT 'a.b.c.d.e'::ltree ~ '*.!d'; @@ -757,7 +763,7 @@ SELECT 'a.b.c.d.e'::ltree ~ '*.!e'; SELECT 'a.b.c.d.e'::ltree ~ '*.!e.*'; ?column? ---------- - f + t (1 row) SELECT 'a.b.c.d.e'::ltree ~ 'a.*.!e'; @@ -775,7 +781,7 @@ SELECT 'a.b.c.d.e'::ltree ~ 'a.*.!d'; SELECT 'a.b.c.d.e'::ltree ~ 'a.*.!d.*'; ?column? ---------- - f + t (1 row) SELECT 'a.b.c.d.e'::ltree ~ 'a.*.!f.*'; @@ -793,7 +799,7 @@ SELECT 'a.b.c.d.e'::ltree ~ '*.a.*.!f.*'; SELECT 'a.b.c.d.e'::ltree ~ '*.a.*.!d.*'; ?column? ---------- - f + t (1 row) SELECT 'a.b.c.d.e'::ltree ~ '*.a.!d.*'; @@ -817,13 +823,13 @@ SELECT 'a.b.c.d.e'::ltree ~ 'a.!d.*'; SELECT 'a.b.c.d.e'::ltree ~ '*.a.*.!d.*'; ?column? ---------- - f + t (1 row) SELECT 'a.b.c.d.e'::ltree ~ '*.!b.*'; ?column? ---------- - f + t (1 row) SELECT 'a.b.c.d.e'::ltree ~ '*.!b.c.*'; @@ -835,7 +841,7 @@ SELECT 'a.b.c.d.e'::ltree ~ '*.!b.c.*'; SELECT 'a.b.c.d.e'::ltree ~ '*.!b.*.c.*'; ?column? ---------- - f + t (1 row) SELECT 'a.b.c.d.e'::ltree ~ '!b.*.c.*'; @@ -883,31 +889,31 @@ SELECT 'a.b.c.d.e'::ltree ~ '*{1}.!b.*.!c.*.e'; SELECT 'a.b.c.d.e'::ltree ~ '*{1}.!b.*{1}.!c.*.e'; ?column? ---------- - t + f (1 row) SELECT 'a.b.c.d.e'::ltree ~ 'a.!b.*{1}.!c.*.e'; ?column? ---------- - t + f (1 row) SELECT 'a.b.c.d.e'::ltree ~ '!b.*{1}.!c.*.e'; ?column? ---------- - t + f (1 row) SELECT 'a.b.c.d.e'::ltree ~ '*.!b.*{1}.!c.*.e'; ?column? ---------- - t + f (1 row) SELECT 'a.b.c.d.e'::ltree ~ '*.!b.*.!c.*.e'; ?column? ---------- - f + t (1 row) SELECT 'a.b.c.d.e'::ltree ~ '!b.!c.*'; @@ -937,19 +943,19 @@ SELECT 'a.b.c.d.e'::ltree ~ '*{1}.!b.*.!c.*'; SELECT 'a.b.c.d.e'::ltree ~ '*{1}.!b.*{1}.!c.*'; ?column? ---------- - t + f (1 row) SELECT 'a.b.c.d.e'::ltree ~ 'a.!b.*{1}.!c.*'; ?column? ---------- - t + f (1 row) SELECT 'a.b.c.d.e'::ltree ~ '!b.*{1}.!c.*'; ?column? ---------- - t + f (1 row) SELECT 'a.b.c.d.e'::ltree ~ '*.!b.*{1}.!c.*'; @@ -961,7 +967,7 @@ SELECT 'a.b.c.d.e'::ltree ~ '*.!b.*{1}.!c.*'; SELECT 'a.b.c.d.e'::ltree ~ '*.!b.*.!c.*'; ?column? ---------- - f + t (1 row) SELECT 'a.b.c.d.e'::ltree ~ 'a.*{2}.*{2}'; @@ -988,6 +994,78 @@ SELECT 'a.b.c.d.e'::ltree ~ 'a.*{5}.*'; f (1 row) +SELECT '5.0.1.0'::ltree ~ '5.!0.!0.0'; + ?column? +---------- + f +(1 row) + +SELECT 'a.b'::ltree ~ '!a.!a'; + ?column? +---------- + f +(1 row) + +SELECT 'a.b.c.d.e'::ltree ~ 'a{,}'; + ?column? +---------- + f +(1 row) + +SELECT 'a.b.c.d.e'::ltree ~ 'a{1,}.*'; + ?column? +---------- + t +(1 row) + +SELECT 'a.b.c.d.e'::ltree ~ 'a{,}.!a{,}'; + ?column? +---------- + t +(1 row) + +SELECT 'a.b.c.d.a'::ltree ~ 'a{,}.!a{,}'; + ?column? +---------- + f +(1 row) + +SELECT 'a.b.c.d.a'::ltree ~ 'a{,2}.!a{1,}'; + ?column? +---------- + f +(1 row) + +SELECT 'a.b.c.d.e'::ltree ~ 'a{,2}.!a{1,}'; + ?column? +---------- + t +(1 row) + +SELECT 'a.b.c.d.e'::ltree ~ '!x{,}'; + ?column? +---------- + t +(1 row) + +SELECT 'a.b.c.d.e'::ltree ~ '!c{,}'; + ?column? +---------- + f +(1 row) + +SELECT 'a.b.c.d.e'::ltree ~ '!c{0,3}.!a{2,}'; + ?column? +---------- + t +(1 row) + +SELECT 'a.b.c.d.e'::ltree ~ '!c{0,3}.!d{2,}.*'; + ?column? +---------- + t +(1 row) + SELECT 'QWER_TY'::ltree ~ 'q%@*'; ?column? ---------- diff --git a/contrib/ltree/lquery_op.c b/contrib/ltree/lquery_op.c index 5c7afe5d541..ef86046fc4b 100644 --- a/contrib/ltree/lquery_op.c +++ b/contrib/ltree/lquery_op.c @@ -9,6 +9,7 @@ #include "catalog/pg_collation.h" #include "ltree.h" +#include "miscadmin.h" #include "utils/formatting.h" PG_FUNCTION_INFO_V1(ltq_regex); @@ -19,16 +20,6 @@ PG_FUNCTION_INFO_V1(lt_q_rregex); #define NEXTVAL(x) ( (lquery*)( (char*)(x) + INTALIGN( VARSIZE(x) ) ) ) -typedef struct -{ - lquery_level *q; - int nq; - ltree_level *t; - int nt; - int posq; - int post; -} FieldNot; - static char * getlexeme(char *start, char *end, int *len) { @@ -99,238 +90,125 @@ ltree_strncasecmp(const char *a, const char *b, size_t s) } /* - * See if a (non-star) lquery_level matches an ltree_level + * See if an lquery_level matches an ltree_level * - * Does not consider level's possible LQL_NOT flag. + * This accounts for all flags including LQL_NOT, but does not + * consider repetition counts. */ static bool checkLevel(lquery_level *curq, ltree_level *curt) { - int (*cmpptr) (const char *, const char *, size_t); lquery_variant *curvar = LQL_FIRST(curq); - int i; + bool success; - for (i = 0; i < curq->numvar; i++) + success = (curq->flag & LQL_NOT) ? false : true; + + /* numvar == 0 means '*' which matches anything */ + if (curq->numvar == 0) + return success; + + for (int i = 0; i < curq->numvar; i++) { + int (*cmpptr) (const char *, const char *, size_t); + cmpptr = (curvar->flag & LVAR_INCASE) ? ltree_strncasecmp : strncmp; if (curvar->flag & LVAR_SUBLEXEME) { - if (compare_subnode(curt, curvar->name, curvar->len, cmpptr, (curvar->flag & LVAR_ANYEND))) - return true; + if (compare_subnode(curt, curvar->name, curvar->len, cmpptr, + (curvar->flag & LVAR_ANYEND))) + return success; } else if ((curvar->len == curt->len || (curt->len > curvar->len && (curvar->flag & LVAR_ANYEND))) && (*cmpptr) (curvar->name, curt->name, curvar->len) == 0) - { + return success; - return true; - } curvar = LVAR_NEXT(curvar); } - return false; + return !success; } /* -void -printFieldNot(FieldNot *fn ) { - while(fn->q) { - elog(NOTICE,"posQ:%d lenQ:%d posT:%d lenT:%d", fn->posq,fn->nq,fn->post,fn->nt); - fn++; - } -} -*/ - -/* - * Try to match an lquery (of query_numlevel items) to an ltree (of - * tree_numlevel items) - * - * If the query contains any NOT flags, "ptr" must point to a FieldNot - * workspace initialized with ptr->q == NULL. Otherwise it can be NULL. - * (LQL_NOT flags will be ignored if ptr == NULL.) - * - * high_pos is the last ltree position the first lquery item is allowed - * to match at; it should be zero for external calls. - * - * force_advance must be false except in internal recursive calls. + * Try to match an lquery (of qlen items) to an ltree (of tlen items) */ static bool -checkCond(lquery_level *curq, int query_numlevel, - ltree_level *curt, int tree_numlevel, - FieldNot *ptr, - uint32 high_pos, - bool force_advance) +checkCond(lquery_level *curq, int qlen, + ltree_level *curt, int tlen) { - uint32 low_pos = 0, /* first allowed ltree position for match */ - cur_tpos = 0; /* ltree position of curt */ - int tlen = tree_numlevel, /* counts of remaining items */ - qlen = query_numlevel; - lquery_level *prevq = NULL; + /* Since this function recurses, it could be driven to stack overflow */ + check_stack_depth(); - /* advance curq (setting up prevq) if requested */ - if (force_advance) - { - Assert(qlen > 0); - prevq = curq; - curq = LQL_NEXT(curq); - qlen--; - } + /* Pathological patterns could take awhile, too */ + CHECK_FOR_INTERRUPTS(); - while (tlen > 0 && qlen > 0) - { - if (curq->numvar) - { - /* Current query item is not '*' */ - ltree_level *prevt = curt; - - /* skip tree items that must be ignored due to prior * items */ - while (cur_tpos < low_pos) - { - curt = LEVEL_NEXT(curt); - tlen--; - cur_tpos++; - if (tlen == 0) - return false; - if (ptr && ptr->q) - ptr->nt++; - } - - if (ptr && (curq->flag & LQL_NOT)) - { - /* Deal with a NOT item */ - if (!(prevq && prevq->numvar == 0)) - prevq = curq; - if (ptr->q == NULL) - { - ptr->t = prevt; - ptr->q = prevq; - ptr->nt = 1; - ptr->nq = 1 + ((prevq == curq) ? 0 : 1); - ptr->posq = query_numlevel - qlen - ((prevq == curq) ? 0 : 1); - ptr->post = cur_tpos; - } - else - { - ptr->nt++; - ptr->nq++; - } - - if (qlen == 1 && ptr->q->numvar == 0) - ptr->nt = tree_numlevel - ptr->post; - curt = LEVEL_NEXT(curt); - tlen--; - cur_tpos++; - if (high_pos < cur_tpos) - high_pos++; - } - else - { - /* Not a NOT item, check for normal match */ - bool isok = false; - - while (cur_tpos <= high_pos && tlen > 0 && !isok) - { - isok = checkLevel(curq, curt); - curt = LEVEL_NEXT(curt); - tlen--; - cur_tpos++; - if (isok && prevq && prevq->numvar == 0 && - tlen > 0 && cur_tpos <= high_pos) - { - FieldNot tmpptr; - - if (ptr) - memcpy(&tmpptr, ptr, sizeof(FieldNot)); - if (checkCond(prevq, qlen + 1, - curt, tlen, - (ptr) ? &tmpptr : NULL, - high_pos - cur_tpos, - true)) - return true; - } - if (!isok && ptr && ptr->q) - ptr->nt++; - } - if (!isok) - return false; - - if (ptr && ptr->q) - { - if (checkCond(ptr->q, ptr->nq, - ptr->t, ptr->nt, - NULL, - 0, - false)) - return false; - ptr->q = NULL; - } - low_pos = cur_tpos; - high_pos = cur_tpos; - } - } - else - { - /* Current query item is '*' */ - low_pos += curq->low; - - if (low_pos > tree_numlevel) - return false; - - high_pos = Min(high_pos + curq->high, tree_numlevel); - - if (ptr && ptr->q) - { - ptr->nq++; - if (qlen == 1) - ptr->nt = tree_numlevel - ptr->post; - } - } - - prevq = curq; - curq = LQL_NEXT(curq); - qlen--; - } - - /* Fail if we've already run out of ltree items */ - if (low_pos > tree_numlevel || tree_numlevel > high_pos) - return false; - - /* Remaining lquery items must be NOT or '*' items */ + /* Loop while we have query items to consider */ while (qlen > 0) { - if (curq->numvar) - { - if (!(curq->flag & LQL_NOT)) - return false; - } + int low, + high; + lquery_level *nextq; + + /* + * Get min and max repetition counts for this query item, dealing with + * the backwards-compatibility hack that the low/high fields aren't + * meaningful for non-'*' items unless LQL_COUNT is set. + */ + if ((curq->flag & LQL_COUNT) || curq->numvar == 0) + low = curq->low, high = curq->high; else - { - low_pos += curq->low; + low = high = 1; - if (low_pos > tree_numlevel) + /* + * We may limit "high" to the remaining text length; this avoids + * separate tests below. + */ + if (high > tlen) + high = tlen; + + /* Fail if a match of required number of items is impossible */ + if (high < low) + return false; + + /* + * Recursively check the rest of the pattern against each possible + * start point following some of this item's match(es). + */ + nextq = LQL_NEXT(curq); + qlen--; + + for (int matchcnt = 0; matchcnt < high; matchcnt++) + { + /* + * If we've consumed an acceptable number of matches of this item, + * and the rest of the pattern matches beginning here, we're good. + */ + if (matchcnt >= low && checkCond(nextq, qlen, curt, tlen)) + return true; + + /* + * Otherwise, try to match one more text item to this query item. + */ + if (!checkLevel(curq, curt)) return false; - high_pos = Min(high_pos + curq->high, tree_numlevel); + curt = LEVEL_NEXT(curt); + tlen--; } - curq = LQL_NEXT(curq); - qlen--; + /* + * Once we've consumed "high" matches, we can succeed only if the rest + * of the pattern matches beginning here. Loop around (if you prefer, + * think of this as tail recursion). + */ + curq = nextq; } - /* Fail if trailing '*'s require more ltree items than we have */ - if (low_pos > tree_numlevel || tree_numlevel > high_pos) - return false; - - /* Finish pending NOT check, if any */ - if (ptr && ptr->q && - checkCond(ptr->q, ptr->nq, - ptr->t, ptr->nt, - NULL, - 0, - false)) - return false; - - return true; + /* + * Once we're out of query items, we match only if there's no remaining + * text either. + */ + return (tlen == 0); } Datum @@ -338,28 +216,10 @@ ltq_regex(PG_FUNCTION_ARGS) { ltree *tree = PG_GETARG_LTREE_P(0); lquery *query = PG_GETARG_LQUERY_P(1); - bool res = false; + bool res; - if (query->flag & LQUERY_HASNOT) - { - FieldNot fn; - - fn.q = NULL; - - res = checkCond(LQUERY_FIRST(query), query->numlevel, - LTREE_FIRST(tree), tree->numlevel, - &fn, - 0, - false); - } - else - { - res = checkCond(LQUERY_FIRST(query), query->numlevel, - LTREE_FIRST(tree), tree->numlevel, - NULL, - 0, - false); - } + res = checkCond(LQUERY_FIRST(query), query->numlevel, + LTREE_FIRST(tree), tree->numlevel); PG_FREE_IF_COPY(tree, 0); PG_FREE_IF_COPY(query, 1); diff --git a/contrib/ltree/ltree.h b/contrib/ltree/ltree.h index 429cdc81317..7eac7c94528 100644 --- a/contrib/ltree/ltree.h +++ b/contrib/ltree/ltree.h @@ -65,14 +65,20 @@ typedef struct /* * In an lquery_level, "flag" contains the union of the variants' flags * along with possible LQL_xxx flags; so those bit sets can't overlap. + * + * "low" and "high" are nominally the minimum and maximum number of matches. + * However, for backwards compatibility with pre-v13 on-disk lqueries, + * non-'*' levels (those with numvar > 0) only have valid low/high if the + * LQL_COUNT flag is set; otherwise those fields are zero, but the behavior + * is as if they were both 1. */ typedef struct { uint16 totallen; /* total length of this level, in bytes */ uint16 flag; /* see LQL_xxx and LVAR_xxx flags */ uint16 numvar; /* number of variants; 0 means '*' */ - uint16 low; /* minimum repeat count for '*' */ - uint16 high; /* maximum repeat count for '*' */ + uint16 low; /* minimum repeat count */ + uint16 high; /* maximum repeat count */ /* Array of maxalign'd lquery_variant structs follows: */ char variants[FLEXIBLE_ARRAY_MEMBER]; } lquery_level; @@ -82,6 +88,7 @@ typedef struct #define LQL_FIRST(x) ( (lquery_variant*)( ((char*)(x))+LQL_HDRSIZE ) ) #define LQL_NOT 0x10 /* level has '!' (NOT) prefix */ +#define LQL_COUNT 0x20 /* level is non-'*' and has repeat counts */ #ifdef LOWER_NODE #define FLG_CANLOOKSIGN(x) ( ( (x) & ( LQL_NOT | LVAR_ANYEND | LVAR_SUBLEXEME ) ) == 0 ) diff --git a/contrib/ltree/ltree_io.c b/contrib/ltree/ltree_io.c index e806a144960..c6ea5dec8c9 100644 --- a/contrib/ltree/ltree_io.c +++ b/contrib/ltree/ltree_io.c @@ -317,6 +317,23 @@ lquery_in(PG_FUNCTION_ARGS) state = LQPRS_WAITVAR; } + else if (charlen == 1 && t_iseq(ptr, '{')) + { + lptr->len = ptr - lptr->start - + ((lptr->flag & LVAR_SUBLEXEME) ? 1 : 0) - + ((lptr->flag & LVAR_INCASE) ? 1 : 0) - + ((lptr->flag & LVAR_ANYEND) ? 1 : 0); + if (lptr->wlen > LTREE_LABEL_MAX_CHARS) + ereport(ERROR, + (errcode(ERRCODE_NAME_TOO_LONG), + errmsg("label string is too long"), + errdetail("Label length is %d, must be at most %d, at character %d.", + lptr->wlen, LTREE_LABEL_MAX_CHARS, + pos))); + + curqlevel->flag |= LQL_COUNT; + state = LQPRS_WAITFNUM; + } else if (charlen == 1 && t_iseq(ptr, '.')) { lptr->len = ptr - lptr->start - @@ -348,6 +365,7 @@ lquery_in(PG_FUNCTION_ARGS) state = LQPRS_WAITFNUM; else if (charlen == 1 && t_iseq(ptr, '.')) { + /* We only get here for '*', so these are correct defaults */ curqlevel->low = 0; curqlevel->high = LTREE_MAX_LEVELS; curqlevel = NEXTLEV(curqlevel); @@ -567,7 +585,11 @@ lquery_out(PG_FUNCTION_ARGS) { totallen++; if (curqlevel->numvar) + { totallen += 1 + (curqlevel->numvar * 4) + curqlevel->totallen; + if (curqlevel->flag & LQL_COUNT) + totallen += 2 * 11 + 3; + } else totallen += 2 * 11 + 4; curqlevel = LQL_NEXT(curqlevel); @@ -618,27 +640,38 @@ lquery_out(PG_FUNCTION_ARGS) } } else + { + *ptr = '*'; + ptr++; + } + + if ((curqlevel->flag & LQL_COUNT) || curqlevel->numvar == 0) { if (curqlevel->low == curqlevel->high) { - sprintf(ptr, "*{%d}", curqlevel->low); + sprintf(ptr, "{%d}", curqlevel->low); } else if (curqlevel->low == 0) { if (curqlevel->high == LTREE_MAX_LEVELS) { - *ptr = '*'; - *(ptr + 1) = '\0'; + if (curqlevel->numvar == 0) + { + /* This is default for '*', so print nothing */ + *ptr = '\0'; + } + else + sprintf(ptr, "{,}"); } else - sprintf(ptr, "*{,%d}", curqlevel->high); + sprintf(ptr, "{,%d}", curqlevel->high); } else if (curqlevel->high == LTREE_MAX_LEVELS) { - sprintf(ptr, "*{%d,}", curqlevel->low); + sprintf(ptr, "{%d,}", curqlevel->low); } else - sprintf(ptr, "*{%d,%d}", curqlevel->low, curqlevel->high); + sprintf(ptr, "{%d,%d}", curqlevel->low, curqlevel->high); ptr = strchr(ptr, '\0'); } diff --git a/contrib/ltree/sql/ltree.sql b/contrib/ltree/sql/ltree.sql index f6d73b8aa65..0cf3dd61366 100644 --- a/contrib/ltree/sql/ltree.sql +++ b/contrib/ltree/sql/ltree.sql @@ -87,6 +87,7 @@ SELECT '1.*.4|3|2.*{1,4}'::lquery; SELECT '1.*.4|3|2.*{,4}'::lquery; SELECT '1.*.4|3|2.*{1,}'::lquery; SELECT '1.*.4|3|2.*{1}'::lquery; +SELECT 'foo.bar{,}.!a*|b{1,}.c{,44}.d{3,4}'::lquery; SELECT 'qwerty%@*.tu'::lquery; SELECT nlevel('1.2.3.4'); @@ -184,6 +185,19 @@ SELECT 'a.b.c.d.e'::ltree ~ 'a.*{2}.*{2}'; SELECT 'a.b.c.d.e'::ltree ~ 'a.*{1}.*{2}.e'; SELECT 'a.b.c.d.e'::ltree ~ 'a.*{1}.*{4}'; SELECT 'a.b.c.d.e'::ltree ~ 'a.*{5}.*'; +SELECT '5.0.1.0'::ltree ~ '5.!0.!0.0'; +SELECT 'a.b'::ltree ~ '!a.!a'; + +SELECT 'a.b.c.d.e'::ltree ~ 'a{,}'; +SELECT 'a.b.c.d.e'::ltree ~ 'a{1,}.*'; +SELECT 'a.b.c.d.e'::ltree ~ 'a{,}.!a{,}'; +SELECT 'a.b.c.d.a'::ltree ~ 'a{,}.!a{,}'; +SELECT 'a.b.c.d.a'::ltree ~ 'a{,2}.!a{1,}'; +SELECT 'a.b.c.d.e'::ltree ~ 'a{,2}.!a{1,}'; +SELECT 'a.b.c.d.e'::ltree ~ '!x{,}'; +SELECT 'a.b.c.d.e'::ltree ~ '!c{,}'; +SELECT 'a.b.c.d.e'::ltree ~ '!c{0,3}.!a{2,}'; +SELECT 'a.b.c.d.e'::ltree ~ '!c{0,3}.!d{2,}.*'; SELECT 'QWER_TY'::ltree ~ 'q%@*'; SELECT 'QWER_TY'::ltree ~ 'Q_t%@*'; diff --git a/doc/src/sgml/ltree.sgml b/doc/src/sgml/ltree.sgml index ae4b33ec85e..d7dd55540a8 100644 --- a/doc/src/sgml/ltree.sgml +++ b/doc/src/sgml/ltree.sgml @@ -60,7 +60,8 @@ lquery represents a regular-expression-like pattern for matching ltree values. A simple word matches that label within a path. A star symbol (*) matches zero - or more labels. For example: + or more labels. These can be joined with dots to form a pattern that + must match the whole label path. For example: foo Match the exact label path foo *.foo.* Match any label path containing the label foo @@ -69,19 +70,25 @@ foo Match the exact label path foo - Star symbols can also be quantified to restrict how many labels - they can match: + Both star symbols and simple words can be quantified to restrict how many + labels they can match: *{n} Match exactly n labels *{n,} Match at least n labels *{n,m} Match at least n but not more than m labels -*{,m} Match at most m labels — same as *{0,m} +*{,m} Match at most m labels — same as *{0,m} +foo{n,m} Match at least n but not more than m occurrences of foo +foo{,} Match any number of occurrences of foo, including zero + In the absence of any explicit quantifier, the default for a star symbol + is to match any number of labels (that is, {,}) while + the default for a non-star item is to match exactly once (that + is, {1}). There are several modifiers that can be put at the end of a non-star - label in lquery to make it match more than just the exact match: + lquery item to make it match more than just the exact match: @ Match case-insensitively, for example a@ matches A * Match any label with this prefix, for example foo* matches foobar @@ -97,17 +104,20 @@ foo Match the exact label path foo - Also, you can write several possibly-modified labels separated with - | (OR) to match any of those labels, and you can put - ! (NOT) at the start to match any label that doesn't - match any of the alternatives. + Also, you can write several possibly-modified non-star items separated with + | (OR) to match any of those items, and you can put + ! (NOT) at the start of a non-star group to match any + label that doesn't match any of the alternatives. A quantifier, if any, + goes at the end of the group; it means some number of matches for the + group as a whole (that is, some number of labels matching or not matching + any of the alternatives). Here's an annotated example of lquery: -Top.*{0,2}.sport*@.!football|tennis.Russ*|Spain -a. b. c. d. e. +Top.*{0,2}.sport*@.!football|tennis{1,}.Russ*|Spain +a. b. c. d. e. This query will match any label path that: @@ -129,8 +139,8 @@ a. b. c. d. e. - then a label not matching football nor - tennis + then has one or more labels, none of which + match football nor tennis @@ -632,7 +642,7 @@ ltreetest=> SELECT path FROM test WHERE path ~ '*.Astronomy.*'; Top.Collections.Pictures.Astronomy.Astronauts (7 rows) -ltreetest=> SELECT path FROM test WHERE path ~ '*.!pictures@.*.Astronomy.*'; +ltreetest=> SELECT path FROM test WHERE path ~ '*.!pictures@.Astronomy.*'; path ------------------------------------ Top.Science.Astronomy