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-rw-r--r--source/luametatex/source/luacore/luapeg/lptree.c1305
1 files changed, 1305 insertions, 0 deletions
diff --git a/source/luametatex/source/luacore/luapeg/lptree.c b/source/luametatex/source/luacore/luapeg/lptree.c
new file mode 100644
index 000000000..345ca69e3
--- /dev/null
+++ b/source/luametatex/source/luacore/luapeg/lptree.c
@@ -0,0 +1,1305 @@
+/*
+** $Id: lptree.c $
+** Copyright 2013, Lua.org & PUC-Rio (see 'lpeg.html' for license)
+*/
+
+#include <ctype.h>
+#include <limits.h>
+#include <string.h>
+
+
+#include "lua.h"
+#include "lauxlib.h"
+
+#include "lptypes.h"
+#include "lpcap.h"
+#include "lpcode.h"
+#include "lpprint.h"
+#include "lptree.h"
+
+
+/* number of siblings for each tree */
+const byte numsiblings[] = {
+ 0, 0, 0, /* char, set, any */
+ 0, 0, /* true, false */
+ 1, /* rep */
+ 2, 2, /* seq, choice */
+ 1, 1, /* not, and */
+ 0, 0, 2, 1, /* call, opencall, rule, grammar */
+ 1, /* behind */
+ 1, 1 /* capture, runtime capture */
+};
+
+
+static TTree *newgrammar (lua_State *L, int arg);
+
+
+/*
+** returns a reasonable name for value at index 'idx' on the stack
+*/
+static const char *val2str (lua_State *L, int idx) {
+ const char *k = lua_tostring(L, idx);
+ if (k != NULL)
+ return lua_pushfstring(L, "%s", k);
+ else
+ return lua_pushfstring(L, "(a %s)", luaL_typename(L, idx));
+}
+
+
+/*
+** Fix a TOpenCall into a TCall node, using table 'postable' to
+** translate a key to its rule address in the tree. Raises an
+** error if key does not exist.
+*/
+static void fixonecall (lua_State *L, int postable, TTree *g, TTree *t) {
+ int n;
+ lua_rawgeti(L, -1, t->key); /* get rule's name */
+ lua_gettable(L, postable); /* query name in position table */
+ n = lua_tonumber(L, -1); /* get (absolute) position */
+ lua_pop(L, 1); /* remove position */
+ if (n == 0) { /* no position? */
+ lua_rawgeti(L, -1, t->key); /* get rule's name again */
+ luaL_error(L, "rule '%s' undefined in given grammar", val2str(L, -1));
+ }
+ t->tag = TCall;
+ t->u.ps = n - (t - g); /* position relative to node */
+ assert(sib2(t)->tag == TRule);
+ sib2(t)->key = t->key; /* fix rule's key */
+}
+
+
+/*
+** Transform left associative constructions into right
+** associative ones, for sequence and choice; that is:
+** (t11 + t12) + t2 => t11 + (t12 + t2)
+** (t11 * t12) * t2 => t11 * (t12 * t2)
+** (that is, Op (Op t11 t12) t2 => Op t11 (Op t12 t2))
+*/
+static void correctassociativity (TTree *tree) {
+ TTree *t1 = sib1(tree);
+ assert(tree->tag == TChoice || tree->tag == TSeq);
+ while (t1->tag == tree->tag) {
+ int n1size = tree->u.ps - 1; /* t1 == Op t11 t12 */
+ int n11size = t1->u.ps - 1;
+ int n12size = n1size - n11size - 1;
+ memmove(sib1(tree), sib1(t1), n11size * sizeof(TTree)); /* move t11 */
+ tree->u.ps = n11size + 1;
+ sib2(tree)->tag = tree->tag;
+ sib2(tree)->u.ps = n12size + 1;
+ }
+}
+
+
+/*
+** Make final adjustments in a tree. Fix open calls in tree 't',
+** making them refer to their respective rules or raising appropriate
+** errors (if not inside a grammar). Correct associativity of associative
+** constructions (making them right associative). Assume that tree's
+** ktable is at the top of the stack (for error messages).
+*/
+static void finalfix (lua_State *L, int postable, TTree *g, TTree *t) {
+ tailcall:
+ switch (t->tag) {
+ case TGrammar: /* subgrammars were already fixed */
+ return;
+ case TOpenCall: {
+ if (g != NULL) /* inside a grammar? */
+ fixonecall(L, postable, g, t);
+ else { /* open call outside grammar */
+ lua_rawgeti(L, -1, t->key);
+ luaL_error(L, "rule '%s' used outside a grammar", val2str(L, -1));
+ }
+ break;
+ }
+ case TSeq: case TChoice:
+ correctassociativity(t);
+ break;
+ }
+ switch (numsiblings[t->tag]) {
+ case 1: /* finalfix(L, postable, g, sib1(t)); */
+ t = sib1(t); goto tailcall;
+ case 2:
+ finalfix(L, postable, g, sib1(t));
+ t = sib2(t); goto tailcall; /* finalfix(L, postable, g, sib2(t)); */
+ default: assert(numsiblings[t->tag] == 0); break;
+ }
+}
+
+
+
+/*
+** {===================================================================
+** KTable manipulation
+**
+** - The ktable of a pattern 'p' can be shared by other patterns that
+** contain 'p' and no other constants. Because of this sharing, we
+** should not add elements to a 'ktable' unless it was freshly created
+** for the new pattern.
+**
+** - The maximum index in a ktable is USHRT_MAX, because trees and
+** patterns use unsigned shorts to store those indices.
+** ====================================================================
+*/
+
+/*
+** Create a new 'ktable' to the pattern at the top of the stack.
+*/
+static void newktable (lua_State *L, int n) {
+ lua_createtable(L, n, 0); /* create a fresh table */
+ lua_setuservalue(L, -2); /* set it as 'ktable' for pattern */
+}
+
+
+/*
+** Add element 'idx' to 'ktable' of pattern at the top of the stack;
+** Return index of new element.
+** If new element is nil, does not add it to table (as it would be
+** useless) and returns 0, as ktable[0] is always nil.
+*/
+static int addtoktable (lua_State *L, int idx) {
+ if (lua_isnil(L, idx)) /* nil value? */
+ return 0;
+ else {
+ int n;
+ lua_getuservalue(L, -1); /* get ktable from pattern */
+ n = lua_rawlen(L, -1);
+ if (n >= USHRT_MAX)
+ luaL_error(L, "too many Lua values in pattern");
+ lua_pushvalue(L, idx); /* element to be added */
+ lua_rawseti(L, -2, ++n);
+ lua_pop(L, 1); /* remove 'ktable' */
+ return n;
+ }
+}
+
+
+/*
+** Return the number of elements in the ktable at 'idx'.
+** In Lua 5.2/5.3, default "environment" for patterns is nil, not
+** a table. Treat it as an empty table. In Lua 5.1, assumes that
+** the environment has no numeric indices (len == 0)
+*/
+static int ktablelen (lua_State *L, int idx) {
+ if (!lua_istable(L, idx)) return 0;
+ else return lua_rawlen(L, idx);
+}
+
+
+/*
+** Concatentate the contents of table 'idx1' into table 'idx2'.
+** (Assume that both indices are negative.)
+** Return the original length of table 'idx2' (or 0, if no
+** element was added, as there is no need to correct any index).
+*/
+static int concattable (lua_State *L, int idx1, int idx2) {
+ int i;
+ int n1 = ktablelen(L, idx1);
+ int n2 = ktablelen(L, idx2);
+ if (n1 + n2 > USHRT_MAX)
+ luaL_error(L, "too many Lua values in pattern");
+ if (n1 == 0) return 0; /* nothing to correct */
+ for (i = 1; i <= n1; i++) {
+ lua_rawgeti(L, idx1, i);
+ lua_rawseti(L, idx2 - 1, n2 + i); /* correct 'idx2' */
+ }
+ return n2;
+}
+
+
+/*
+** When joining 'ktables', constants from one of the subpatterns must
+** be renumbered; 'correctkeys' corrects their indices (adding 'n'
+** to each of them)
+*/
+static void correctkeys (TTree *tree, int n) {
+ if (n == 0) return; /* no correction? */
+ tailcall:
+ switch (tree->tag) {
+ case TOpenCall: case TCall: case TRunTime: case TRule: {
+ if (tree->key > 0)
+ tree->key += n;
+ break;
+ }
+ case TCapture: {
+ if (tree->key > 0 && tree->cap != Carg && tree->cap != Cnum)
+ tree->key += n;
+ break;
+ }
+ default: break;
+ }
+ switch (numsiblings[tree->tag]) {
+ case 1: /* correctkeys(sib1(tree), n); */
+ tree = sib1(tree); goto tailcall;
+ case 2:
+ correctkeys(sib1(tree), n);
+ tree = sib2(tree); goto tailcall; /* correctkeys(sib2(tree), n); */
+ default: assert(numsiblings[tree->tag] == 0); break;
+ }
+}
+
+
+/*
+** Join the ktables from p1 and p2 the ktable for the new pattern at the
+** top of the stack, reusing them when possible.
+*/
+static void joinktables (lua_State *L, int p1, TTree *t2, int p2) {
+ int n1, n2;
+ lua_getuservalue(L, p1); /* get ktables */
+ lua_getuservalue(L, p2);
+ n1 = ktablelen(L, -2);
+ n2 = ktablelen(L, -1);
+ if (n1 == 0 && n2 == 0) /* are both tables empty? */
+ lua_pop(L, 2); /* nothing to be done; pop tables */
+ else if (n2 == 0 || lp_equal(L, -2, -1)) { /* 2nd table empty or equal? */
+ lua_pop(L, 1); /* pop 2nd table */
+ lua_setuservalue(L, -2); /* set 1st ktable into new pattern */
+ }
+ else if (n1 == 0) { /* first table is empty? */
+ lua_setuservalue(L, -3); /* set 2nd table into new pattern */
+ lua_pop(L, 1); /* pop 1st table */
+ }
+ else {
+ lua_createtable(L, n1 + n2, 0); /* create ktable for new pattern */
+ /* stack: new p; ktable p1; ktable p2; new ktable */
+ concattable(L, -3, -1); /* from p1 into new ktable */
+ concattable(L, -2, -1); /* from p2 into new ktable */
+ lua_setuservalue(L, -4); /* new ktable becomes 'p' environment */
+ lua_pop(L, 2); /* pop other ktables */
+ correctkeys(t2, n1); /* correction for indices from p2 */
+ }
+}
+
+
+/*
+** copy 'ktable' of element 'idx' to new tree (on top of stack)
+*/
+static void copyktable (lua_State *L, int idx) {
+ lua_getuservalue(L, idx);
+ lua_setuservalue(L, -2);
+}
+
+
+/*
+** merge 'ktable' from 'stree' at stack index 'idx' into 'ktable'
+** from tree at the top of the stack, and correct corresponding
+** tree.
+*/
+static void mergektable (lua_State *L, int idx, TTree *stree) {
+ int n;
+ lua_getuservalue(L, -1); /* get ktables */
+ lua_getuservalue(L, idx);
+ n = concattable(L, -1, -2);
+ lua_pop(L, 2); /* remove both ktables */
+ correctkeys(stree, n);
+}
+
+
+/*
+** Create a new 'ktable' to the pattern at the top of the stack, adding
+** all elements from pattern 'p' (if not 0) plus element 'idx' to it.
+** Return index of new element.
+*/
+static int addtonewktable (lua_State *L, int p, int idx) {
+ newktable(L, 1);
+ if (p)
+ mergektable(L, p, NULL);
+ return addtoktable(L, idx);
+}
+
+/* }====================================================== */
+
+
+/*
+** {======================================================
+** Tree generation
+** =======================================================
+*/
+
+/*
+** In 5.2, could use 'luaL_testudata'...
+*/
+static int testpattern (lua_State *L, int idx) {
+ if (lua_touserdata(L, idx)) { /* value is a userdata? */
+ if (lua_getmetatable(L, idx)) { /* does it have a metatable? */
+ luaL_getmetatable(L, PATTERN_T);
+ if (lua_rawequal(L, -1, -2)) { /* does it have the correct mt? */
+ lua_pop(L, 2); /* remove both metatables */
+ return 1;
+ }
+ }
+ }
+ return 0;
+}
+
+
+static Pattern *getpattern (lua_State *L, int idx) {
+ return (Pattern *)luaL_checkudata(L, idx, PATTERN_T);
+}
+
+
+static int getsize (lua_State *L, int idx) {
+ return (lua_rawlen(L, idx) - sizeof(Pattern)) / sizeof(TTree) + 1;
+}
+
+
+static TTree *gettree (lua_State *L, int idx, int *len) {
+ Pattern *p = getpattern(L, idx);
+ if (len)
+ *len = getsize(L, idx);
+ return p->tree;
+}
+
+
+/*
+** create a pattern. Set its uservalue (the 'ktable') equal to its
+** metatable. (It could be any empty sequence; the metatable is at
+** hand here, so we use it.)
+*/
+static TTree *newtree (lua_State *L, int len) {
+ size_t size = (len - 1) * sizeof(TTree) + sizeof(Pattern);
+ Pattern *p = (Pattern *)lua_newuserdata(L, size);
+ luaL_getmetatable(L, PATTERN_T);
+ lua_pushvalue(L, -1);
+ lua_setuservalue(L, -3);
+ lua_setmetatable(L, -2);
+ p->code = NULL; p->codesize = 0;
+ return p->tree;
+}
+
+
+static TTree *newleaf (lua_State *L, int tag) {
+ TTree *tree = newtree(L, 1);
+ tree->tag = tag;
+ return tree;
+}
+
+
+static TTree *newcharset (lua_State *L) {
+ TTree *tree = newtree(L, bytes2slots(CHARSETSIZE) + 1);
+ tree->tag = TSet;
+ loopset(i, treebuffer(tree)[i] = 0);
+ return tree;
+}
+
+
+/*
+** add to tree a sequence where first sibling is 'sib' (with size
+** 'sibsize'); returns position for second sibling
+*/
+static TTree *seqaux (TTree *tree, TTree *sib, int sibsize) {
+ tree->tag = TSeq; tree->u.ps = sibsize + 1;
+ memcpy(sib1(tree), sib, sibsize * sizeof(TTree));
+ return sib2(tree);
+}
+
+
+/*
+** Build a sequence of 'n' nodes, each with tag 'tag' and 'u.n' got
+** from the array 's' (or 0 if array is NULL). (TSeq is binary, so it
+** must build a sequence of sequence of sequence...)
+*/
+static void fillseq (TTree *tree, int tag, int n, const char *s) {
+ int i;
+ for (i = 0; i < n - 1; i++) { /* initial n-1 copies of Seq tag; Seq ... */
+ tree->tag = TSeq; tree->u.ps = 2;
+ sib1(tree)->tag = tag;
+ sib1(tree)->u.n = s ? (byte)s[i] : 0;
+ tree = sib2(tree);
+ }
+ tree->tag = tag; /* last one does not need TSeq */
+ tree->u.n = s ? (byte)s[i] : 0;
+}
+
+
+/*
+** Numbers as patterns:
+** 0 == true (always match); n == TAny repeated 'n' times;
+** -n == not (TAny repeated 'n' times)
+*/
+static TTree *numtree (lua_State *L, int n) {
+ if (n == 0)
+ return newleaf(L, TTrue);
+ else {
+ TTree *tree, *nd;
+ if (n > 0)
+ tree = nd = newtree(L, 2 * n - 1);
+ else { /* negative: code it as !(-n) */
+ n = -n;
+ tree = newtree(L, 2 * n);
+ tree->tag = TNot;
+ nd = sib1(tree);
+ }
+ fillseq(nd, TAny, n, NULL); /* sequence of 'n' any's */
+ return tree;
+ }
+}
+
+
+/*
+** Convert value at index 'idx' to a pattern
+*/
+static TTree *getpatt (lua_State *L, int idx, int *len) {
+ TTree *tree;
+ switch (lua_type(L, idx)) {
+ case LUA_TSTRING: {
+ size_t slen;
+ const char *s = lua_tolstring(L, idx, &slen); /* get string */
+ if (slen == 0) /* empty? */
+ tree = newleaf(L, TTrue); /* always match */
+ else {
+ tree = newtree(L, 2 * ((int) slen - 1) + 1);
+ fillseq(tree, TChar, (int) slen, s); /* sequence of 'slen' chars */
+ }
+ break;
+ }
+ case LUA_TNUMBER: {
+ int n = lua_tointeger(L, idx);
+ tree = numtree(L, n);
+ break;
+ }
+ case LUA_TBOOLEAN: {
+ tree = (lua_toboolean(L, idx) ? newleaf(L, TTrue) : newleaf(L, TFalse));
+ break;
+ }
+ case LUA_TTABLE: {
+ tree = newgrammar(L, idx);
+ break;
+ }
+ case LUA_TFUNCTION: {
+ tree = newtree(L, 2);
+ tree->tag = TRunTime;
+ tree->key = addtonewktable(L, 0, idx);
+ sib1(tree)->tag = TTrue;
+ break;
+ }
+ default: {
+ return gettree(L, idx, len);
+ }
+ }
+ lua_replace(L, idx); /* put new tree into 'idx' slot */
+ if (len)
+ *len = getsize(L, idx);
+ return tree;
+}
+
+
+/*
+** create a new tree, whith a new root and one sibling.
+** Sibling must be on the Lua stack, at index 1.
+*/
+static TTree *newroot1sib (lua_State *L, int tag) {
+ int s1;
+ TTree *tree1 = getpatt(L, 1, &s1);
+ TTree *tree = newtree(L, 1 + s1); /* create new tree */
+ tree->tag = tag;
+ memcpy(sib1(tree), tree1, s1 * sizeof(TTree));
+ copyktable(L, 1);
+ return tree;
+}
+
+
+/*
+** create a new tree, whith a new root and 2 siblings.
+** Siblings must be on the Lua stack, first one at index 1.
+*/
+static TTree *newroot2sib (lua_State *L, int tag) {
+ int s1, s2;
+ TTree *tree1 = getpatt(L, 1, &s1);
+ TTree *tree2 = getpatt(L, 2, &s2);
+ TTree *tree = newtree(L, 1 + s1 + s2); /* create new tree */
+ tree->tag = tag;
+ tree->u.ps = 1 + s1;
+ memcpy(sib1(tree), tree1, s1 * sizeof(TTree));
+ memcpy(sib2(tree), tree2, s2 * sizeof(TTree));
+ joinktables(L, 1, sib2(tree), 2);
+ return tree;
+}
+
+
+static int lp_P (lua_State *L) {
+ luaL_checkany(L, 1);
+ getpatt(L, 1, NULL);
+ lua_settop(L, 1);
+ return 1;
+}
+
+
+/*
+** sequence operator; optimizations:
+** false x => false, x true => x, true x => x
+** (cannot do x . false => false because x may have runtime captures)
+*/
+static int lp_seq (lua_State *L) {
+ TTree *tree1 = getpatt(L, 1, NULL);
+ TTree *tree2 = getpatt(L, 2, NULL);
+ if (tree1->tag == TFalse || tree2->tag == TTrue)
+ lua_pushvalue(L, 1); /* false . x == false, x . true = x */
+ else if (tree1->tag == TTrue)
+ lua_pushvalue(L, 2); /* true . x = x */
+ else
+ newroot2sib(L, TSeq);
+ return 1;
+}
+
+
+/*
+** choice operator; optimizations:
+** charset / charset => charset
+** true / x => true, x / false => x, false / x => x
+** (x / true is not equivalent to true)
+*/
+static int lp_choice (lua_State *L) {
+ Charset st1, st2;
+ TTree *t1 = getpatt(L, 1, NULL);
+ TTree *t2 = getpatt(L, 2, NULL);
+ if (tocharset(t1, &st1) && tocharset(t2, &st2)) {
+ TTree *t = newcharset(L);
+ loopset(i, treebuffer(t)[i] = st1.cs[i] | st2.cs[i]);
+ }
+ else if (nofail(t1) || t2->tag == TFalse)
+ lua_pushvalue(L, 1); /* true / x => true, x / false => x */
+ else if (t1->tag == TFalse)
+ lua_pushvalue(L, 2); /* false / x => x */
+ else
+ newroot2sib(L, TChoice);
+ return 1;
+}
+
+
+/*
+** p^n
+*/
+static int lp_star (lua_State *L) {
+ int size1;
+ int n = (int)luaL_checkinteger(L, 2);
+ TTree *tree1 = getpatt(L, 1, &size1);
+ if (n >= 0) { /* seq tree1 (seq tree1 ... (seq tree1 (rep tree1))) */
+ TTree *tree = newtree(L, (n + 1) * (size1 + 1));
+ if (nullable(tree1))
+ luaL_error(L, "loop body may accept empty string");
+ while (n--) /* repeat 'n' times */
+ tree = seqaux(tree, tree1, size1);
+ tree->tag = TRep;
+ memcpy(sib1(tree), tree1, size1 * sizeof(TTree));
+ }
+ else { /* choice (seq tree1 ... choice tree1 true ...) true */
+ TTree *tree;
+ n = -n;
+ /* size = (choice + seq + tree1 + true) * n, but the last has no seq */
+ tree = newtree(L, n * (size1 + 3) - 1);
+ for (; n > 1; n--) { /* repeat (n - 1) times */
+ tree->tag = TChoice; tree->u.ps = n * (size1 + 3) - 2;
+ sib2(tree)->tag = TTrue;
+ tree = sib1(tree);
+ tree = seqaux(tree, tree1, size1);
+ }
+ tree->tag = TChoice; tree->u.ps = size1 + 1;
+ sib2(tree)->tag = TTrue;
+ memcpy(sib1(tree), tree1, size1 * sizeof(TTree));
+ }
+ copyktable(L, 1);
+ return 1;
+}
+
+
+/*
+** #p == &p
+*/
+static int lp_and (lua_State *L) {
+ newroot1sib(L, TAnd);
+ return 1;
+}
+
+
+/*
+** -p == !p
+*/
+static int lp_not (lua_State *L) {
+ newroot1sib(L, TNot);
+ return 1;
+}
+
+
+/*
+** [t1 - t2] == Seq (Not t2) t1
+** If t1 and t2 are charsets, make their difference.
+*/
+static int lp_sub (lua_State *L) {
+ Charset st1, st2;
+ int s1, s2;
+ TTree *t1 = getpatt(L, 1, &s1);
+ TTree *t2 = getpatt(L, 2, &s2);
+ if (tocharset(t1, &st1) && tocharset(t2, &st2)) {
+ TTree *t = newcharset(L);
+ loopset(i, treebuffer(t)[i] = st1.cs[i] & ~st2.cs[i]);
+ }
+ else {
+ TTree *tree = newtree(L, 2 + s1 + s2);
+ tree->tag = TSeq; /* sequence of... */
+ tree->u.ps = 2 + s2;
+ sib1(tree)->tag = TNot; /* ...not... */
+ memcpy(sib1(sib1(tree)), t2, s2 * sizeof(TTree)); /* ...t2 */
+ memcpy(sib2(tree), t1, s1 * sizeof(TTree)); /* ... and t1 */
+ joinktables(L, 1, sib1(tree), 2);
+ }
+ return 1;
+}
+
+
+static int lp_set (lua_State *L) {
+ size_t l;
+ const char *s = luaL_checklstring(L, 1, &l);
+ TTree *tree = newcharset(L);
+ while (l--) {
+ setchar(treebuffer(tree), (byte)(*s));
+ s++;
+ }
+ return 1;
+}
+
+
+static int lp_range (lua_State *L) {
+ int arg;
+ int top = lua_gettop(L);
+ TTree *tree = newcharset(L);
+ for (arg = 1; arg <= top; arg++) {
+ int c;
+ size_t l;
+ const char *r = luaL_checklstring(L, arg, &l);
+ luaL_argcheck(L, l == 2, arg, "range must have two characters");
+ for (c = (byte)r[0]; c <= (byte)r[1]; c++)
+ setchar(treebuffer(tree), c);
+ }
+ return 1;
+}
+
+
+/*
+** Look-behind predicate
+*/
+static int lp_behind (lua_State *L) {
+ TTree *tree;
+ TTree *tree1 = getpatt(L, 1, NULL);
+ int n = fixedlen(tree1);
+ luaL_argcheck(L, n >= 0, 1, "pattern may not have fixed length");
+ luaL_argcheck(L, !hascaptures(tree1), 1, "pattern have captures");
+ luaL_argcheck(L, n <= MAXBEHIND, 1, "pattern too long to look behind");
+ tree = newroot1sib(L, TBehind);
+ tree->u.n = n;
+ return 1;
+}
+
+
+/*
+** Create a non-terminal
+*/
+static int lp_V (lua_State *L) {
+ TTree *tree = newleaf(L, TOpenCall);
+ luaL_argcheck(L, !lua_isnoneornil(L, 1), 1, "non-nil value expected");
+ tree->key = addtonewktable(L, 0, 1);
+ return 1;
+}
+
+
+/*
+** Create a tree for a non-empty capture, with a body and
+** optionally with an associated Lua value (at index 'labelidx' in the
+** stack)
+*/
+static int capture_aux (lua_State *L, int cap, int labelidx) {
+ TTree *tree = newroot1sib(L, TCapture);
+ tree->cap = cap;
+ tree->key = (labelidx == 0) ? 0 : addtonewktable(L, 1, labelidx);
+ return 1;
+}
+
+
+/*
+** Fill a tree with an empty capture, using an empty (TTrue) sibling.
+** (The 'key' field must be filled by the caller to finish the tree.)
+*/
+static TTree *auxemptycap (TTree *tree, int cap) {
+ tree->tag = TCapture;
+ tree->cap = cap;
+ sib1(tree)->tag = TTrue;
+ return tree;
+}
+
+
+/*
+** Create a tree for an empty capture.
+*/
+static TTree *newemptycap (lua_State *L, int cap, int key) {
+ TTree *tree = auxemptycap(newtree(L, 2), cap);
+ tree->key = key;
+ return tree;
+}
+
+
+/*
+** Create a tree for an empty capture with an associated Lua value.
+*/
+static TTree *newemptycapkey (lua_State *L, int cap, int idx) {
+ TTree *tree = auxemptycap(newtree(L, 2), cap);
+ tree->key = addtonewktable(L, 0, idx);
+ return tree;
+}
+
+
+/*
+** Captures with syntax p / v
+** (function capture, query capture, string capture, or number capture)
+*/
+static int lp_divcapture (lua_State *L) {
+ switch (lua_type(L, 2)) {
+ case LUA_TFUNCTION: return capture_aux(L, Cfunction, 2);
+ case LUA_TTABLE: return capture_aux(L, Cquery, 2);
+ case LUA_TSTRING: return capture_aux(L, Cstring, 2);
+ case LUA_TNUMBER: {
+ int n = lua_tointeger(L, 2);
+ TTree *tree = newroot1sib(L, TCapture);
+ luaL_argcheck(L, 0 <= n && n <= SHRT_MAX, 1, "invalid number");
+ tree->cap = Cnum;
+ tree->key = n;
+ return 1;
+ }
+ default: return luaL_argerror(L, 2, "invalid replacement value");
+ }
+}
+
+
+static int lp_substcapture (lua_State *L) {
+ return capture_aux(L, Csubst, 0);
+}
+
+
+static int lp_tablecapture (lua_State *L) {
+ return capture_aux(L, Ctable, 0);
+}
+
+
+static int lp_groupcapture (lua_State *L) {
+ if (lua_isnoneornil(L, 2))
+ return capture_aux(L, Cgroup, 0);
+ else
+ return capture_aux(L, Cgroup, 2);
+}
+
+
+static int lp_foldcapture (lua_State *L) {
+ luaL_checktype(L, 2, LUA_TFUNCTION);
+ return capture_aux(L, Cfold, 2);
+}
+
+
+static int lp_simplecapture (lua_State *L) {
+ return capture_aux(L, Csimple, 0);
+}
+
+
+static int lp_poscapture (lua_State *L) {
+ newemptycap(L, Cposition, 0);
+ return 1;
+}
+
+
+static int lp_argcapture (lua_State *L) {
+ int n = (int)luaL_checkinteger(L, 1);
+ luaL_argcheck(L, 0 < n && n <= SHRT_MAX, 1, "invalid argument index");
+ newemptycap(L, Carg, n);
+ return 1;
+}
+
+
+static int lp_backref (lua_State *L) {
+ luaL_checkany(L, 1);
+ newemptycapkey(L, Cbackref, 1);
+ return 1;
+}
+
+
+/*
+** Constant capture
+*/
+static int lp_constcapture (lua_State *L) {
+ int i;
+ int n = lua_gettop(L); /* number of values */
+ if (n == 0) /* no values? */
+ newleaf(L, TTrue); /* no capture */
+ else if (n == 1)
+ newemptycapkey(L, Cconst, 1); /* single constant capture */
+ else { /* create a group capture with all values */
+ TTree *tree = newtree(L, 1 + 3 * (n - 1) + 2);
+ newktable(L, n); /* create a 'ktable' for new tree */
+ tree->tag = TCapture;
+ tree->cap = Cgroup;
+ tree->key = 0;
+ tree = sib1(tree);
+ for (i = 1; i <= n - 1; i++) {
+ tree->tag = TSeq;
+ tree->u.ps = 3; /* skip TCapture and its sibling */
+ auxemptycap(sib1(tree), Cconst);
+ sib1(tree)->key = addtoktable(L, i);
+ tree = sib2(tree);
+ }
+ auxemptycap(tree, Cconst);
+ tree->key = addtoktable(L, i);
+ }
+ return 1;
+}
+
+
+static int lp_matchtime (lua_State *L) {
+ TTree *tree;
+ luaL_checktype(L, 2, LUA_TFUNCTION);
+ tree = newroot1sib(L, TRunTime);
+ tree->key = addtonewktable(L, 1, 2);
+ return 1;
+}
+
+/* }====================================================== */
+
+
+/*
+** {======================================================
+** Grammar - Tree generation
+** =======================================================
+*/
+
+/*
+** push on the stack the index and the pattern for the
+** initial rule of grammar at index 'arg' in the stack;
+** also add that index into position table.
+*/
+static void getfirstrule (lua_State *L, int arg, int postab) {
+ lua_rawgeti(L, arg, 1); /* access first element */
+ if (lua_isstring(L, -1)) { /* is it the name of initial rule? */
+ lua_pushvalue(L, -1); /* duplicate it to use as key */
+ lua_gettable(L, arg); /* get associated rule */
+ }
+ else {
+ lua_pushinteger(L, 1); /* key for initial rule */
+ lua_insert(L, -2); /* put it before rule */
+ }
+ if (!testpattern(L, -1)) { /* initial rule not a pattern? */
+ if (lua_isnil(L, -1))
+ luaL_error(L, "grammar has no initial rule");
+ else
+ luaL_error(L, "initial rule '%s' is not a pattern", lua_tostring(L, -2));
+ }
+ lua_pushvalue(L, -2); /* push key */
+ lua_pushinteger(L, 1); /* push rule position (after TGrammar) */
+ lua_settable(L, postab); /* insert pair at position table */
+}
+
+/*
+** traverse grammar at index 'arg', pushing all its keys and patterns
+** into the stack. Create a new table (before all pairs key-pattern) to
+** collect all keys and their associated positions in the final tree
+** (the "position table").
+** Return the number of rules and (in 'totalsize') the total size
+** for the new tree.
+*/
+static int collectrules (lua_State *L, int arg, int *totalsize) {
+ int n = 1; /* to count number of rules */
+ int postab = lua_gettop(L) + 1; /* index of position table */
+ int size; /* accumulator for total size */
+ lua_newtable(L); /* create position table */
+ getfirstrule(L, arg, postab);
+ size = 2 + getsize(L, postab + 2); /* TGrammar + TRule + rule */
+ lua_pushnil(L); /* prepare to traverse grammar table */
+ while (lua_next(L, arg) != 0) {
+ if (lua_tonumber(L, -2) == 1 ||
+ lp_equal(L, -2, postab + 1)) { /* initial rule? */
+ lua_pop(L, 1); /* remove value (keep key for lua_next) */
+ continue;
+ }
+ if (!testpattern(L, -1)) /* value is not a pattern? */
+ luaL_error(L, "rule '%s' is not a pattern", val2str(L, -2));
+ luaL_checkstack(L, LUA_MINSTACK, "grammar has too many rules");
+ lua_pushvalue(L, -2); /* push key (to insert into position table) */
+ lua_pushinteger(L, size);
+ lua_settable(L, postab);
+ size += 1 + getsize(L, -1); /* update size */
+ lua_pushvalue(L, -2); /* push key (for next lua_next) */
+ n++;
+ }
+ *totalsize = size + 1; /* TTrue to finish list of rules */
+ return n;
+}
+
+
+static void buildgrammar (lua_State *L, TTree *grammar, int frule, int n) {
+ int i;
+ TTree *nd = sib1(grammar); /* auxiliary pointer to traverse the tree */
+ for (i = 0; i < n; i++) { /* add each rule into new tree */
+ int ridx = frule + 2*i + 1; /* index of i-th rule */
+ int rulesize;
+ TTree *rn = gettree(L, ridx, &rulesize);
+ nd->tag = TRule;
+ nd->key = 0; /* will be fixed when rule is used */
+ nd->cap = i; /* rule number */
+ nd->u.ps = rulesize + 1; /* point to next rule */
+ memcpy(sib1(nd), rn, rulesize * sizeof(TTree)); /* copy rule */
+ mergektable(L, ridx, sib1(nd)); /* merge its ktable into new one */
+ nd = sib2(nd); /* move to next rule */
+ }
+ nd->tag = TTrue; /* finish list of rules */
+}
+
+
+/*
+** Check whether a tree has potential infinite loops
+*/
+static int checkloops (TTree *tree) {
+ tailcall:
+ if (tree->tag == TRep && nullable(sib1(tree)))
+ return 1;
+ else if (tree->tag == TGrammar)
+ return 0; /* sub-grammars already checked */
+ else {
+ switch (numsiblings[tree->tag]) {
+ case 1: /* return checkloops(sib1(tree)); */
+ tree = sib1(tree); goto tailcall;
+ case 2:
+ if (checkloops(sib1(tree))) return 1;
+ /* else return checkloops(sib2(tree)); */
+ tree = sib2(tree); goto tailcall;
+ default: assert(numsiblings[tree->tag] == 0); return 0;
+ }
+ }
+}
+
+
+/*
+** Give appropriate error message for 'verifyrule'. If a rule appears
+** twice in 'passed', there is path from it back to itself without
+** advancing the subject.
+*/
+static int verifyerror (lua_State *L, int *passed, int npassed) {
+ int i, j;
+ for (i = npassed - 1; i >= 0; i--) { /* search for a repetition */
+ for (j = i - 1; j >= 0; j--) {
+ if (passed[i] == passed[j]) {
+ lua_rawgeti(L, -1, passed[i]); /* get rule's key */
+ return luaL_error(L, "rule '%s' may be left recursive", val2str(L, -1));
+ }
+ }
+ }
+ return luaL_error(L, "too many left calls in grammar");
+}
+
+
+/*
+** Check whether a rule can be left recursive; raise an error in that
+** case; otherwise return 1 iff pattern is nullable.
+** The return value is used to check sequences, where the second pattern
+** is only relevant if the first is nullable.
+** Parameter 'nb' works as an accumulator, to allow tail calls in
+** choices. ('nb' true makes function returns true.)
+** Parameter 'passed' is a list of already visited rules, 'npassed'
+** counts the elements in 'passed'.
+** Assume ktable at the top of the stack.
+*/
+static int verifyrule (lua_State *L, TTree *tree, int *passed, int npassed,
+ int nb) {
+ tailcall:
+ switch (tree->tag) {
+ case TChar: case TSet: case TAny:
+ case TFalse:
+ return nb; /* cannot pass from here */
+ case TTrue:
+ case TBehind: /* look-behind cannot have calls */
+ return 1;
+ case TNot: case TAnd: case TRep:
+ /* return verifyrule(L, sib1(tree), passed, npassed, 1); */
+ tree = sib1(tree); nb = 1; goto tailcall;
+ case TCapture: case TRunTime:
+ /* return verifyrule(L, sib1(tree), passed, npassed, nb); */
+ tree = sib1(tree); goto tailcall;
+ case TCall:
+ /* return verifyrule(L, sib2(tree), passed, npassed, nb); */
+ tree = sib2(tree); goto tailcall;
+ case TSeq: /* only check 2nd child if first is nb */
+ if (!verifyrule(L, sib1(tree), passed, npassed, 0))
+ return nb;
+ /* else return verifyrule(L, sib2(tree), passed, npassed, nb); */
+ tree = sib2(tree); goto tailcall;
+ case TChoice: /* must check both children */
+ nb = verifyrule(L, sib1(tree), passed, npassed, nb);
+ /* return verifyrule(L, sib2(tree), passed, npassed, nb); */
+ tree = sib2(tree); goto tailcall;
+ case TRule:
+ if (npassed >= MAXRULES)
+ return verifyerror(L, passed, npassed);
+ else {
+ passed[npassed++] = tree->key;
+ /* return verifyrule(L, sib1(tree), passed, npassed); */
+ tree = sib1(tree); goto tailcall;
+ }
+ case TGrammar:
+ return nullable(tree); /* sub-grammar cannot be left recursive */
+ default: assert(0); return 0;
+ }
+}
+
+
+static void verifygrammar (lua_State *L, TTree *grammar) {
+ int passed[MAXRULES];
+ TTree *rule;
+ /* check left-recursive rules */
+ for (rule = sib1(grammar); rule->tag == TRule; rule = sib2(rule)) {
+ if (rule->key == 0) continue; /* unused rule */
+ verifyrule(L, sib1(rule), passed, 0, 0);
+ }
+ assert(rule->tag == TTrue);
+ /* check infinite loops inside rules */
+ for (rule = sib1(grammar); rule->tag == TRule; rule = sib2(rule)) {
+ if (rule->key == 0) continue; /* unused rule */
+ if (checkloops(sib1(rule))) {
+ lua_rawgeti(L, -1, rule->key); /* get rule's key */
+ luaL_error(L, "empty loop in rule '%s'", val2str(L, -1));
+ }
+ }
+ assert(rule->tag == TTrue);
+}
+
+
+/*
+** Give a name for the initial rule if it is not referenced
+*/
+static void initialrulename (lua_State *L, TTree *grammar, int frule) {
+ if (sib1(grammar)->key == 0) { /* initial rule is not referenced? */
+ int n = lua_rawlen(L, -1) + 1; /* index for name */
+ lua_pushvalue(L, frule); /* rule's name */
+ lua_rawseti(L, -2, n); /* ktable was on the top of the stack */
+ sib1(grammar)->key = n;
+ }
+}
+
+
+static TTree *newgrammar (lua_State *L, int arg) {
+ int treesize;
+ int frule = lua_gettop(L) + 2; /* position of first rule's key */
+ int n = collectrules(L, arg, &treesize);
+ TTree *g = newtree(L, treesize);
+ luaL_argcheck(L, n <= MAXRULES, arg, "grammar has too many rules");
+ g->tag = TGrammar; g->u.n = n;
+ lua_newtable(L); /* create 'ktable' */
+ lua_setuservalue(L, -2);
+ buildgrammar(L, g, frule, n);
+ lua_getuservalue(L, -1); /* get 'ktable' for new tree */
+ finalfix(L, frule - 1, g, sib1(g));
+ initialrulename(L, g, frule);
+ verifygrammar(L, g);
+ lua_pop(L, 1); /* remove 'ktable' */
+ lua_insert(L, -(n * 2 + 2)); /* move new table to proper position */
+ lua_pop(L, n * 2 + 1); /* remove position table + rule pairs */
+ return g; /* new table at the top of the stack */
+}
+
+/* }====================================================== */
+
+
+static Instruction *prepcompile (lua_State *L, Pattern *p, int idx) {
+ lua_getuservalue(L, idx); /* push 'ktable' (may be used by 'finalfix') */
+ finalfix(L, 0, NULL, p->tree);
+ lua_pop(L, 1); /* remove 'ktable' */
+ return compile(L, p);
+}
+
+
+static int lp_printtree (lua_State *L) {
+ TTree *tree = getpatt(L, 1, NULL);
+ int c = lua_toboolean(L, 2);
+ if (c) {
+ lua_getuservalue(L, 1); /* push 'ktable' (may be used by 'finalfix') */
+ finalfix(L, 0, NULL, tree);
+ lua_pop(L, 1); /* remove 'ktable' */
+ }
+ printktable(L, 1);
+ printtree(tree, 0);
+ return 0;
+}
+
+
+static int lp_printcode (lua_State *L) {
+ Pattern *p = getpattern(L, 1);
+ printktable(L, 1);
+ if (p->code == NULL) /* not compiled yet? */
+ prepcompile(L, p, 1);
+ printpatt(p->code, p->codesize);
+ return 0;
+}
+
+
+/*
+** Get the initial position for the match, interpreting negative
+** values from the end of the subject
+*/
+static size_t initposition (lua_State *L, size_t len) {
+ lua_Integer ii = luaL_optinteger(L, 3, 1);
+ if (ii > 0) { /* positive index? */
+ if ((size_t)ii <= len) /* inside the string? */
+ return (size_t)ii - 1; /* return it (corrected to 0-base) */
+ else return len; /* crop at the end */
+ }
+ else { /* negative index */
+ if ((size_t)(-ii) <= len) /* inside the string? */
+ return len - ((size_t)(-ii)); /* return position from the end */
+ else return 0; /* crop at the beginning */
+ }
+}
+
+
+/*
+** Main match function
+*/
+static int lp_match (lua_State *L) {
+ Capture capture[INITCAPSIZE];
+ const char *r;
+ size_t l;
+ Pattern *p = (getpatt(L, 1, NULL), getpattern(L, 1));
+ Instruction *code = (p->code != NULL) ? p->code : prepcompile(L, p, 1);
+ const char *s = luaL_checklstring(L, SUBJIDX, &l);
+ size_t i = initposition(L, l);
+ int ptop = lua_gettop(L);
+ lua_pushnil(L); /* initialize subscache */
+ lua_pushlightuserdata(L, capture); /* initialize caplistidx */
+ lua_getuservalue(L, 1); /* initialize penvidx */
+ r = match(L, s, s + i, s + l, code, capture, ptop);
+ if (r == NULL) {
+ lua_pushnil(L);
+ return 1;
+ }
+ return getcaptures(L, s, r, ptop);
+}
+
+
+
+/*
+** {======================================================
+** Library creation and functions not related to matching
+** =======================================================
+*/
+
+/* maximum limit for stack size */
+#define MAXLIM (INT_MAX / 100)
+
+static int lp_setmax (lua_State *L) {
+ lua_Integer lim = luaL_checkinteger(L, 1);
+ luaL_argcheck(L, 0 < lim && lim <= MAXLIM, 1, "out of range");
+ lua_settop(L, 1);
+ lua_setfield(L, LUA_REGISTRYINDEX, MAXSTACKIDX);
+ return 0;
+}
+
+
+static int lp_version (lua_State *L) {
+ lua_pushstring(L, VERSION);
+ return 1;
+}
+
+
+static int lp_type (lua_State *L) {
+ if (testpattern(L, 1))
+ lua_pushliteral(L, "pattern");
+ else
+ lua_pushnil(L);
+ return 1;
+}
+
+
+int lp_gc (lua_State *L) {
+ Pattern *p = getpattern(L, 1);
+ realloccode(L, p, 0); /* delete code block */
+ return 0;
+}
+
+
+static void createcat (lua_State *L, const char *catname, int (catf) (int)) {
+ TTree *t = newcharset(L);
+ int i;
+ for (i = 0; i <= UCHAR_MAX; i++)
+ if (catf(i)) setchar(treebuffer(t), i);
+ lua_setfield(L, -2, catname);
+}
+
+
+static int lp_locale (lua_State *L) {
+ if (lua_isnoneornil(L, 1)) {
+ lua_settop(L, 0);
+ lua_createtable(L, 0, 12);
+ }
+ else {
+ luaL_checktype(L, 1, LUA_TTABLE);
+ lua_settop(L, 1);
+ }
+ createcat(L, "alnum", isalnum);
+ createcat(L, "alpha", isalpha);
+ createcat(L, "cntrl", iscntrl);
+ createcat(L, "digit", isdigit);
+ createcat(L, "graph", isgraph);
+ createcat(L, "lower", islower);
+ createcat(L, "print", isprint);
+ createcat(L, "punct", ispunct);
+ createcat(L, "space", isspace);
+ createcat(L, "upper", isupper);
+ createcat(L, "xdigit", isxdigit);
+ return 1;
+}
+
+
+static struct luaL_Reg pattreg[] = {
+ {"ptree", lp_printtree},
+ {"pcode", lp_printcode},
+ {"match", lp_match},
+ {"B", lp_behind},
+ {"V", lp_V},
+ {"C", lp_simplecapture},
+ {"Cc", lp_constcapture},
+ {"Cmt", lp_matchtime},
+ {"Cb", lp_backref},
+ {"Carg", lp_argcapture},
+ {"Cp", lp_poscapture},
+ {"Cs", lp_substcapture},
+ {"Ct", lp_tablecapture},
+ {"Cf", lp_foldcapture},
+ {"Cg", lp_groupcapture},
+ {"P", lp_P},
+ {"S", lp_set},
+ {"R", lp_range},
+ {"locale", lp_locale},
+ {"version", lp_version},
+ {"setmaxstack", lp_setmax},
+ {"type", lp_type},
+ {NULL, NULL}
+};
+
+
+static struct luaL_Reg metareg[] = {
+ {"__mul", lp_seq},
+ {"__add", lp_choice},
+ {"__pow", lp_star},
+ {"__gc", lp_gc},
+ {"__len", lp_and},
+ {"__div", lp_divcapture},
+ {"__unm", lp_not},
+ {"__sub", lp_sub},
+ {NULL, NULL}
+};
+
+
+int luaopen_lpeg (lua_State *L);
+int luaopen_lpeg (lua_State *L) {
+ luaL_newmetatable(L, PATTERN_T);
+ lua_pushnumber(L, MAXBACK); /* initialize maximum backtracking */
+ lua_setfield(L, LUA_REGISTRYINDEX, MAXSTACKIDX);
+ luaL_setfuncs(L, metareg, 0);
+ luaL_newlib(L, pattreg);
+ lua_pushvalue(L, -1);
+ lua_setfield(L, -3, "__index");
+ return 1;
+}
+
+/* }====================================================== */
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-15 03:52:24 +0000