diff options
Diffstat (limited to 'trex.c')
| -rw-r--r-- | trex.c | 643 |
1 files changed, 643 insertions, 0 deletions
@@ -0,0 +1,643 @@ +/* see copyright notice in trex.h */ +#include <string.h> +#include <stdlib.h> +#include <ctype.h> +#include <setjmp.h> +#include "trex.h" + +#ifdef _UINCODE +#define scisprint iswprint +#define scstrlen wcslen +#define scprintf wprintf +#define _SC(x) L(x) +#else +#define scisprint isprint +#define scstrlen strlen +#define scprintf printf +#define _SC(x) (x) +#endif + +#ifdef _DEBUG +#include <stdio.h> + +static const TRexChar *g_nnames[] = +{ + _SC("NONE"),_SC("OP_GREEDY"), _SC("OP_OR"), + _SC("OP_EXPR"),_SC("OP_NOCAPEXPR"),_SC("OP_DOT"), _SC("OP_CLASS"), + _SC("OP_CCLASS"),_SC("OP_NCLASS"),_SC("OP_RANGE"),_SC("OP_CHAR"), + _SC("OP_EOL"),_SC("OP_BOL"),_SC("OP_WB") +}; + +#endif +#define OP_GREEDY (MAX_CHAR+1) // * + ? {n} +#define OP_OR (MAX_CHAR+2) +#define OP_EXPR (MAX_CHAR+3) //parentesis () +#define OP_NOCAPEXPR (MAX_CHAR+4) //parentesis (?:) +#define OP_DOT (MAX_CHAR+5) +#define OP_CLASS (MAX_CHAR+6) +#define OP_CCLASS (MAX_CHAR+7) +#define OP_NCLASS (MAX_CHAR+8) //negates class the [^ +#define OP_RANGE (MAX_CHAR+9) +#define OP_CHAR (MAX_CHAR+10) +#define OP_EOL (MAX_CHAR+11) +#define OP_BOL (MAX_CHAR+12) +#define OP_WB (MAX_CHAR+13) + +#define TREX_SYMBOL_ANY_CHAR ('.') +#define TREX_SYMBOL_GREEDY_ONE_OR_MORE ('+') +#define TREX_SYMBOL_GREEDY_ZERO_OR_MORE ('*') +#define TREX_SYMBOL_GREEDY_ZERO_OR_ONE ('?') +#define TREX_SYMBOL_BRANCH ('|') +#define TREX_SYMBOL_END_OF_STRING ('$') +#define TREX_SYMBOL_BEGINNING_OF_STRING ('^') +#define TREX_SYMBOL_ESCAPE_CHAR ('\\') + + +typedef int TRexNodeType; + +typedef struct tagTRexNode{ + TRexNodeType type; + int left; + int right; + int next; +}TRexNode; + +struct TRex{ + const TRexChar *_eol; + const TRexChar *_bol; + const TRexChar *_p; + int _first; + int _op; + TRexNode *_nodes; + int _nallocated; + int _nsize; + int _nsubexpr; + TRexMatch *_matches; + int _currsubexp; + void *_jmpbuf; + const TRexChar **_error; +}; + +static int trex_list(TRex *exp); + +static int trex_newnode(TRex *exp, TRexNodeType type) +{ + TRexNode n; + int newid; + n.type = type; + n.next = n.right = n.left = -1; + if(type == OP_EXPR) + n.right = exp->_nsubexpr++; + if(exp->_nallocated < (exp->_nsize + 1)) { + int oldsize = exp->_nallocated; + exp->_nallocated *= 2; + exp->_nodes = (TRexNode *)realloc(exp->_nodes, exp->_nallocated * sizeof(TRexNode)); + } + exp->_nodes[exp->_nsize++] = n; + newid = exp->_nsize - 1; + return (int)newid; +} + +static void trex_error(TRex *exp,const TRexChar *error) +{ + if(exp->_error) *exp->_error = error; + longjmp(*((jmp_buf*)exp->_jmpbuf),-1); +} + +static void trex_expect(TRex *exp, int n){ + if((*exp->_p) != n) + trex_error(exp, _SC("expected paren")); + exp->_p++; +} + +static TRexChar trex_escapechar(TRex *exp) +{ + if(*exp->_p == TREX_SYMBOL_ESCAPE_CHAR){ + exp->_p++; + switch(*exp->_p) { + case 'v': exp->_p++; return '\v'; + case 'n': exp->_p++; return '\n'; + case 't': exp->_p++; return '\t'; + case 'r': exp->_p++; return '\r'; + case 'f': exp->_p++; return '\f'; + default: return (*exp->_p++); + } + } else if(!scisprint(*exp->_p)) trex_error(exp,_SC("letter expected")); + return (*exp->_p++); +} + +static int trex_charclass(TRex *exp,int classid) +{ + int n = trex_newnode(exp,OP_CCLASS); + exp->_nodes[n].left = classid; + return n; +} + +static int trex_charnode(TRex *exp,TRexBool isclass) +{ + TRexChar t; + if(*exp->_p == TREX_SYMBOL_ESCAPE_CHAR) { + exp->_p++; + switch(*exp->_p) { + case 'n': exp->_p++; return trex_newnode(exp,'\n'); + case 't': exp->_p++; return trex_newnode(exp,'\t'); + case 'r': exp->_p++; return trex_newnode(exp,'\r'); + case 'f': exp->_p++; return trex_newnode(exp,'\f'); + case 'v': exp->_p++; return trex_newnode(exp,'\v'); + case 'a': case 'A': case 'w': case 'W': case 's': case 'S': + case 'd': case 'D': case 'x': case 'X': case 'c': case 'C': + case 'p': case 'P': case 'l': case 'u': + { + t = *exp->_p; exp->_p++; + return trex_charclass(exp,t); + } + case 'b': + case 'B': + if(!isclass) { + int node = trex_newnode(exp,OP_WB); + exp->_nodes[node].left = *exp->_p; + exp->_p++; + return node; + } //else default + default: + t = *exp->_p; exp->_p++; + return trex_newnode(exp,t); + } + } + else if(!scisprint(*exp->_p)) { + + trex_error(exp,_SC("letter expected")); + } + t = *exp->_p; exp->_p++; + return trex_newnode(exp,t); +} +static int trex_class(TRex *exp) +{ + int ret = -1; + int first = -1,chain; + if(*exp->_p == TREX_SYMBOL_BEGINNING_OF_STRING){ + ret = trex_newnode(exp,OP_NCLASS); + exp->_p++; + }else ret = trex_newnode(exp,OP_CLASS); + + if(*exp->_p == ']') trex_error(exp,_SC("empty class")); + chain = ret; + while(*exp->_p != ']' && exp->_p != exp->_eol) { + if(*exp->_p == '-' && first != -1){ + int r,t; + if(*exp->_p++ == ']') trex_error(exp,_SC("unfinished range")); + r = trex_newnode(exp,OP_RANGE); + if(first>*exp->_p) trex_error(exp,_SC("invalid range")); + if(exp->_nodes[first].type == OP_CCLASS) trex_error(exp,_SC("cannot use character classes in ranges")); + exp->_nodes[r].left = exp->_nodes[first].type; + t = trex_escapechar(exp); + exp->_nodes[r].right = t; + exp->_nodes[chain].next = r; + chain = r; + first = -1; + } + else{ + if(first!=-1){ + int c = first; + exp->_nodes[chain].next = c; + chain = c; + first = trex_charnode(exp,TRex_True); + } + else{ + first = trex_charnode(exp,TRex_True); + } + } + } + if(first!=-1){ + int c = first; + exp->_nodes[chain].next = c; + chain = c; + first = -1; + } + /* hack? */ + exp->_nodes[ret].left = exp->_nodes[ret].next; + exp->_nodes[ret].next = -1; + return ret; +} + +static int trex_parsenumber(TRex *exp) +{ + int ret = *exp->_p-'0'; + int positions = 10; + exp->_p++; + while(isdigit(*exp->_p)) { + ret = ret*10+(*exp->_p++-'0'); + if(positions==1000000000) trex_error(exp,_SC("overflow in numeric constant")); + positions *= 10; + }; + return ret; +} + +static int trex_element(TRex *exp) +{ + int ret = -1; + switch(*exp->_p) + { + case '(': { + int expr,newn; + exp->_p++; + + + if(*exp->_p =='?') { + exp->_p++; + trex_expect(exp,':'); + expr = trex_newnode(exp,OP_NOCAPEXPR); + } + else + expr = trex_newnode(exp,OP_EXPR); + newn = trex_list(exp); + exp->_nodes[expr].left = newn; + ret = expr; + trex_expect(exp,')'); + } + break; + case '[': + exp->_p++; + ret = trex_class(exp); + trex_expect(exp,']'); + break; + case TREX_SYMBOL_END_OF_STRING: exp->_p++; ret = trex_newnode(exp,OP_EOL);break; + case TREX_SYMBOL_ANY_CHAR: exp->_p++; ret = trex_newnode(exp,OP_DOT);break; + default: + ret = trex_charnode(exp,TRex_False); + break; + } + + { + int op; + TRexBool isgreedy = TRex_False; + unsigned short p0 = 0, p1 = 0; + switch(*exp->_p){ + case TREX_SYMBOL_GREEDY_ZERO_OR_MORE: p0 = 0; p1 = 0xFFFF; exp->_p++; isgreedy = TRex_True; break; + case TREX_SYMBOL_GREEDY_ONE_OR_MORE: p0 = 1; p1 = 0xFFFF; exp->_p++; isgreedy = TRex_True; break; + case TREX_SYMBOL_GREEDY_ZERO_OR_ONE: p0 = 0; p1 = 1; exp->_p++; isgreedy = TRex_True; break; + case '{': + exp->_p++; + if(!isdigit(*exp->_p)) trex_error(exp,_SC("number expected")); + p0 = (unsigned short)trex_parsenumber(exp); + /*******************************/ + switch(*exp->_p) { + case '}': + p1 = p0; exp->_p++; + break; + case ',': + exp->_p++; + p1 = 0xFFFF; + if(isdigit(*exp->_p)){ + p1 = (unsigned short)trex_parsenumber(exp); + } + trex_expect(exp,'}'); + break; + default: + trex_error(exp,_SC(", or } expected")); + } + /*******************************/ + isgreedy = TRex_True; + break; + + } + if(isgreedy) { + int nnode = trex_newnode(exp,OP_GREEDY); + op = OP_GREEDY; + exp->_nodes[nnode].left = ret; + exp->_nodes[nnode].right = ((p0)<<16)|p1; + ret = nnode; + } + } + if((*exp->_p != TREX_SYMBOL_BRANCH) && (*exp->_p != ')') && (*exp->_p != TREX_SYMBOL_GREEDY_ZERO_OR_MORE) && (*exp->_p != TREX_SYMBOL_GREEDY_ONE_OR_MORE) && (*exp->_p != '\0')) { + int nnode = trex_element(exp); + exp->_nodes[ret].next = nnode; + } + + return ret; +} + +static int trex_list(TRex *exp) +{ + int ret=-1,e; + if(*exp->_p == TREX_SYMBOL_BEGINNING_OF_STRING) { + exp->_p++; + ret = trex_newnode(exp,OP_BOL); + } + e = trex_element(exp); + if(ret != -1) { + exp->_nodes[ret].next = e; + } + else ret = e; + + if(*exp->_p == TREX_SYMBOL_BRANCH) { + int temp,tright; + exp->_p++; + temp = trex_newnode(exp,OP_OR); + exp->_nodes[temp].left = ret; + tright = trex_list(exp); + exp->_nodes[temp].right = tright; + ret = temp; + } + return ret; +} + +static TRexBool trex_matchcclass(int cclass,TRexChar c) +{ + switch(cclass) { + case 'a': return isalpha(c)?TRex_True:TRex_False; + case 'A': return !isalpha(c)?TRex_True:TRex_False; + case 'w': return (isalnum(c) || c == '_')?TRex_True:TRex_False; + case 'W': return (!isalnum(c) && c != '_')?TRex_True:TRex_False; + case 's': return isspace(c)?TRex_True:TRex_False; + case 'S': return !isspace(c)?TRex_True:TRex_False; + case 'd': return isdigit(c)?TRex_True:TRex_False; + case 'D': return !isdigit(c)?TRex_True:TRex_False; + case 'x': return isxdigit(c)?TRex_True:TRex_False; + case 'X': return !isxdigit(c)?TRex_True:TRex_False; + case 'c': return iscntrl(c)?TRex_True:TRex_False; + case 'C': return !iscntrl(c)?TRex_True:TRex_False; + case 'p': return ispunct(c)?TRex_True:TRex_False; + case 'P': return !ispunct(c)?TRex_True:TRex_False; + case 'l': return islower(c)?TRex_True:TRex_False; + case 'u': return isupper(c)?TRex_True:TRex_False; + } + return TRex_False; /*cannot happen*/ +} + +static TRexBool trex_matchclass(TRex* exp,TRexNode *node,TRexChar c) +{ + do { + switch(node->type) { + case OP_RANGE: + if(c >= node->left && c <= node->right) return TRex_True; + break; + case OP_CCLASS: + if(trex_matchcclass(node->left,c)) return TRex_True; + break; + default: + if(c == node->type)return TRex_True; + } + } while((node->next != -1) && (node = &exp->_nodes[node->next])); + return TRex_False; +} + +static const TRexChar *trex_matchnode(TRex* exp,TRexNode *node,const TRexChar *str,TRexNode *next) +{ + + TRexNodeType type = node->type; + switch(type) { + case OP_GREEDY: { + //TRexNode *greedystop = (node->next != -1) ? &exp->_nodes[node->next] : NULL; + TRexNode *greedystop = NULL; + int p0 = (node->right >> 16)&0x0000FFFF, p1 = node->right&0x0000FFFF, nmaches = 0; + const TRexChar *s=str, *good = str; + + if(node->next != -1) { + greedystop = &exp->_nodes[node->next]; + } + else { + greedystop = next; + } + + while((nmaches == 0xFFFF || nmaches < p1)) { + + const TRexChar *stop; + if(!(s = trex_matchnode(exp,&exp->_nodes[node->left],s,greedystop))) + break; + nmaches++; + good=s; + if(greedystop) { + //checks that 0 matches satisfy the expression(if so skips) + //if not would always stop(for instance if is a '?') + if(greedystop->type != OP_GREEDY || + (greedystop->type == OP_GREEDY && ((greedystop->right >> 16)&0x0000FFFF) != 0)) + { + TRexNode *gnext = NULL; + if(greedystop->next != -1) { + gnext = &exp->_nodes[greedystop->next]; + }else if(next && next->next != -1){ + gnext = &exp->_nodes[next->next]; + } + stop = trex_matchnode(exp,greedystop,s,gnext); + if(stop) { + //if satisfied stop it + if(p0 == p1 && p0 == nmaches) break; + else if(nmaches >= p0 && p1 == 0xFFFF) break; + else if(nmaches >= p0 && nmaches <= p1) break; + } + } + } + + if(s >= exp->_eol) + break; + } + if(p0 == p1 && p0 == nmaches) return good; + else if(nmaches >= p0 && p1 == 0xFFFF) return good; + else if(nmaches >= p0 && nmaches <= p1) return good; + return NULL; + } + case OP_OR: { + const TRexChar *asd = str; + TRexNode *temp=&exp->_nodes[node->left]; + while( (asd = trex_matchnode(exp,temp,asd,NULL)) ) { + if(temp->next != -1) + temp = &exp->_nodes[temp->next]; + else + return asd; + } + asd = str; + temp = &exp->_nodes[node->right]; + while( (asd = trex_matchnode(exp,temp,asd,NULL)) ) { + if(temp->next != -1) + temp = &exp->_nodes[temp->next]; + else + return asd; + } + return NULL; + break; + } + case OP_EXPR: + case OP_NOCAPEXPR:{ + TRexNode *n = &exp->_nodes[node->left]; + const TRexChar *cur = str; + int capture = -1; + if(node->type != OP_NOCAPEXPR && node->right == exp->_currsubexp) { + capture = exp->_currsubexp; + exp->_matches[capture].begin = cur; + exp->_currsubexp++; + } + + do { + TRexNode *subnext = NULL; + if(n->next != -1) { + subnext = &exp->_nodes[n->next]; + }else { + subnext = next; + } + if(!(cur = trex_matchnode(exp,n,cur,subnext))) { + if(capture != -1){ + exp->_matches[capture].begin = 0; + exp->_matches[capture].len = 0; + } + return NULL; + } + } while((n->next != -1) && (n = &exp->_nodes[n->next])); + + if(capture != -1) + exp->_matches[capture].len = cur - exp->_matches[capture].begin; + return cur; + } + case OP_WB: + if(str == exp->_bol && !isspace(*str) + || (str == exp->_eol && !isspace(*(str-1))) + || (!isspace(*str) && isspace(*(str+1))) + || (isspace(*str) && !isspace(*(str+1))) ) { + return (node->left == 'b')?str:NULL; + } + return (node->left == 'b')?NULL:str; + case OP_BOL: + if(str == exp->_bol) return str; + return NULL; + case OP_EOL: + if(str == exp->_eol) return str; + return NULL; + case OP_DOT:{ + *str++; + } + return str; + case OP_NCLASS: + case OP_CLASS: + if(trex_matchclass(exp,&exp->_nodes[node->left],*str)?(type == OP_CLASS?TRex_True:TRex_False):(type == OP_NCLASS?TRex_True:TRex_False)) { + *str++; + return str; + } + return NULL; + case OP_CCLASS: + if(trex_matchcclass(node->left,*str)) { + *str++; + return str; + } + return NULL; + default: /* char */ + if(*str != node->type) return NULL; + *str++; + return str; + } + return NULL; +} + +/* public api */ +TRex *trex_compile(const TRexChar *pattern,const TRexChar **error) +{ + TRex *exp = (TRex *)malloc(sizeof(TRex)); + exp->_eol = exp->_bol = NULL; + exp->_p = pattern; + exp->_nallocated = (int)scstrlen(pattern) * sizeof(TRexChar); + exp->_nodes = (TRexNode *)malloc(exp->_nallocated * sizeof(TRexNode)); + exp->_nsize = 0; + exp->_matches = 0; + exp->_nsubexpr = 0; + exp->_first = trex_newnode(exp,OP_EXPR); + exp->_error = error; + exp->_jmpbuf = malloc(sizeof(jmp_buf)); + if(setjmp(*((jmp_buf*)exp->_jmpbuf)) == 0) { + int res = trex_list(exp); + exp->_nodes[exp->_first].left = res; + if(*exp->_p!='\0') + trex_error(exp,_SC("unexpected character")); +#ifdef _DEBUG + { + int nsize,i; + TRexNode *t; + nsize = exp->_nsize; + t = &exp->_nodes[0]; + scprintf(_SC("\n")); + for(i = 0;i < nsize; i++) { + if(exp->_nodes[i].type>MAX_CHAR) + scprintf(_SC("[%02d] %10s "),i,g_nnames[exp->_nodes[i].type-MAX_CHAR]); + else + scprintf(_SC("[%02d] %10c "),i,exp->_nodes[i].type); + scprintf(_SC("left %02d right %02d next %02d\n"),exp->_nodes[i].left,exp->_nodes[i].right,exp->_nodes[i].next); + } + scprintf(_SC("\n")); + } +#endif + exp->_matches = (TRexMatch *) malloc(exp->_nsubexpr * sizeof(TRexMatch)); + memset(exp->_matches,0,exp->_nsubexpr * sizeof(TRexMatch)); + } + else{ + trex_free(exp); + return NULL; + } + return exp; +} + +void trex_free(TRex *exp) +{ + if(exp) { + if(exp->_nodes) free(exp->_nodes); + if(exp->_jmpbuf) free(exp->_jmpbuf); + if(exp->_matches) free(exp->_matches); + free(exp); + } +} + +TRexBool trex_match(TRex* exp,const TRexChar* text) +{ + const TRexChar* res = NULL; + exp->_bol = text; + exp->_eol = text + scstrlen(text); + exp->_currsubexp = 0; + res = trex_matchnode(exp,exp->_nodes,text,NULL); + if(res == NULL || res != exp->_eol) + return TRex_False; + return TRex_True; +} + +TRexBool trex_searchrange(TRex* exp,const TRexChar* text_begin,const TRexChar* text_end,const TRexChar** out_begin, const TRexChar** out_end) +{ + const TRexChar *cur = NULL; + int node = exp->_first; + if(text_begin >= text_end) return TRex_False; + exp->_bol = text_begin; + exp->_eol = text_end; + do { + cur = text_begin; + while(node != -1) { + exp->_currsubexp = 0; + cur = trex_matchnode(exp,&exp->_nodes[node],cur,NULL); + if(!cur) + break; + node = exp->_nodes[node].next; + } + *text_begin++; + } while(cur == NULL && text_begin != text_end); + + if(cur == NULL) + return TRex_False; + + --text_begin; + + if(out_begin) *out_begin = text_begin; + if(out_end) *out_end = cur; + return TRex_True; +} + +TRexBool trex_search(TRex* exp,const TRexChar* text, const TRexChar** out_begin, const TRexChar** out_end) +{ + return trex_searchrange(exp,text,text + scstrlen(text),out_begin,out_end); +} + +int trex_getsubexpcount(TRex* exp) +{ + return exp->_nsubexpr; +} + +TRexBool trex_getsubexp(TRex* exp, int n, TRexMatch *subexp) +{ + if( n<0 || n >= exp->_nsubexpr) return TRex_False; + *subexp = exp->_matches[n]; + return TRex_True; +} + |