/* $Id: strscan.c 11708 2007-02-12 23:01:19Z shyouhei $ Copyright (c) 1999-2006 Minero Aoki This program is free software. You can distribute/modify this program under the terms of the Ruby License. For details, see the file COPYING. */ #include #include #define STRSCAN_VERSION "0.7.0" /* ======================================================================= Data Type Definitions ======================================================================= */ static VALUE StringScanner; static VALUE ScanError; struct strscanner { /* multi-purpose flags */ unsigned long flags; #define FLAG_MATCHED (1 << 0) /* the string to scan */ VALUE str; /* scan pointers */ long prev; /* legal only when MATCHED_P(s) */ long curr; /* always legal */ /* the regexp register; legal only when MATCHED_P(s) */ struct re_registers regs; }; #define MATCHED_P(s) ((s)->flags & FLAG_MATCHED) #define MATCHED(s) (s)->flags |= FLAG_MATCHED #define CLEAR_MATCH_STATUS(s) (s)->flags &= ~FLAG_MATCHED #define S_PBEG(s) (RSTRING((s)->str)->ptr) #define S_LEN(s) (RSTRING((s)->str)->len) #define S_PEND(s) (S_PBEG(s) + S_LEN(s)) #define CURPTR(s) (S_PBEG(s) + (s)->curr) #define S_RESTLEN(s) (S_LEN(s) - (s)->curr) #define EOS_P(s) ((s)->curr >= RSTRING(p->str)->len) #define GET_SCANNER(obj,var) do {\ Data_Get_Struct(obj, struct strscanner, var);\ if (NIL_P(var->str)) rb_raise(rb_eArgError, "uninitialized StringScanner object");\ } while (0) /* ======================================================================= Function Prototypes ======================================================================= */ static VALUE infect _((VALUE str, struct strscanner *p)); static VALUE extract_range _((struct strscanner *p, long beg_i, long end_i)); static VALUE extract_beg_len _((struct strscanner *p, long beg_i, long len)); static void check_strscan _((VALUE obj)); static void strscan_mark _((struct strscanner *p)); static void strscan_free _((struct strscanner *p)); static VALUE strscan_s_allocate _((VALUE klass)); static VALUE strscan_initialize _((int argc, VALUE *argv, VALUE self)); static VALUE strscan_init_copy _((VALUE vself, VALUE vorig)); static VALUE strscan_s_mustc _((VALUE self)); static VALUE strscan_terminate _((VALUE self)); static VALUE strscan_clear _((VALUE self)); static VALUE strscan_get_string _((VALUE self)); static VALUE strscan_set_string _((VALUE self, VALUE str)); static VALUE strscan_concat _((VALUE self, VALUE str)); static VALUE strscan_get_pos _((VALUE self)); static VALUE strscan_set_pos _((VALUE self, VALUE pos)); static VALUE strscan_do_scan _((VALUE self, VALUE regex, int succptr, int getstr, int headonly)); static VALUE strscan_scan _((VALUE self, VALUE re)); static VALUE strscan_match_p _((VALUE self, VALUE re)); static VALUE strscan_skip _((VALUE self, VALUE re)); static VALUE strscan_check _((VALUE self, VALUE re)); static VALUE strscan_scan_full _((VALUE self, VALUE re, VALUE succp, VALUE getp)); static VALUE strscan_scan_until _((VALUE self, VALUE re)); static VALUE strscan_skip_until _((VALUE self, VALUE re)); static VALUE strscan_check_until _((VALUE self, VALUE re)); static VALUE strscan_search_full _((VALUE self, VALUE re, VALUE succp, VALUE getp)); static void adjust_registers_to_matched _((struct strscanner *p)); static VALUE strscan_getch _((VALUE self)); static VALUE strscan_get_byte _((VALUE self)); static VALUE strscan_getbyte _((VALUE self)); static VALUE strscan_peek _((VALUE self, VALUE len)); static VALUE strscan_peep _((VALUE self, VALUE len)); static VALUE strscan_unscan _((VALUE self)); static VALUE strscan_bol_p _((VALUE self)); static VALUE strscan_eos_p _((VALUE self)); static VALUE strscan_empty_p _((VALUE self)); static VALUE strscan_rest_p _((VALUE self)); static VALUE strscan_matched_p _((VALUE self)); static VALUE strscan_matched _((VALUE self)); static VALUE strscan_matched_size _((VALUE self)); static VALUE strscan_aref _((VALUE self, VALUE idx)); static VALUE strscan_pre_match _((VALUE self)); static VALUE strscan_post_match _((VALUE self)); static VALUE strscan_rest _((VALUE self)); static VALUE strscan_rest_size _((VALUE self)); static VALUE strscan_inspect _((VALUE self)); static VALUE inspect1 _((struct strscanner *p)); static VALUE inspect2 _((struct strscanner *p)); /* ======================================================================= Utils ======================================================================= */ static VALUE infect(VALUE str, struct strscanner *p) { OBJ_INFECT(str, p->str); return str; } static VALUE extract_range(struct strscanner *p, long beg_i, long end_i) { if (beg_i > S_LEN(p)) return Qnil; if (end_i > S_LEN(p)) end_i = S_LEN(p); return infect(rb_str_new(S_PBEG(p) + beg_i, end_i - beg_i), p); } static VALUE extract_beg_len(struct strscanner *p, long beg_i, long len) { if (beg_i > S_LEN(p)) return Qnil; if (beg_i + len > S_LEN(p)) len = S_LEN(p) - beg_i; return infect(rb_str_new(S_PBEG(p) + beg_i, len), p); } /* ======================================================================= Constructor ======================================================================= */ static void strscan_mark(struct strscanner *p) { rb_gc_mark(p->str); } static void strscan_free(struct strscanner *p) { re_free_registers(&(p->regs)); free(p); } static VALUE strscan_s_allocate(VALUE klass) { struct strscanner *p; p = ALLOC(struct strscanner); MEMZERO(p, struct strscanner, 1); CLEAR_MATCH_STATUS(p); MEMZERO(&(p->regs), struct re_registers, 1); p->str = Qnil; return Data_Wrap_Struct(klass, strscan_mark, strscan_free, p); } /* * call-seq: StringScanner.new(string, dup = false) * * Creates a new StringScanner object to scan over the given +string+. * +dup+ argument is obsolete and not used now. */ static VALUE strscan_initialize(int argc, VALUE *argv, VALUE self) { struct strscanner *p; VALUE str, need_dup; Data_Get_Struct(self, struct strscanner, p); rb_scan_args(argc, argv, "11", &str, &need_dup); StringValue(str); p->str = str; return self; } static void check_strscan(VALUE obj) { if (TYPE(obj) != T_DATA || RDATA(obj)->dmark != (RUBY_DATA_FUNC)strscan_mark) { rb_raise(rb_eTypeError, "wrong argument type %s (expected StringScanner)", rb_obj_classname(obj)); } } /* * call-seq: * dup * clone * * Duplicates a StringScanner object. */ static VALUE strscan_init_copy(VALUE vself, VALUE vorig) { struct strscanner *self, *orig; Data_Get_Struct(vself, struct strscanner, self); check_strscan(vorig); Data_Get_Struct(vorig, struct strscanner, orig); if (self != orig) { self->flags = orig->flags; self->str = orig->str; self->prev = orig->prev; self->curr = orig->curr; re_copy_registers(&self->regs, &orig->regs); } return vself; } /* ======================================================================= Instance Methods ======================================================================= */ /* * call-seq: StringScanner.must_C_version * * This method is defined for backward compatibility. */ static VALUE strscan_s_mustc(VALUE self) { return self; } /* * Reset the scan pointer (index 0) and clear matching data. */ static VALUE strscan_reset(VALUE self) { struct strscanner *p; GET_SCANNER(self, p); p->curr = 0; CLEAR_MATCH_STATUS(p); return self; } /* * call-seq: * terminate * clear * * Set the scan pointer to the end of the string and clear matching data. */ static VALUE strscan_terminate(VALUE self) { struct strscanner *p; GET_SCANNER(self, p); p->curr = S_LEN(p); CLEAR_MATCH_STATUS(p); return self; } /* * Equivalent to #terminate. * This method is obsolete; use #terminate instead. */ static VALUE strscan_clear(VALUE self) { rb_warning("StringScanner#clear is obsolete; use #terminate instead"); return strscan_terminate(self); } /* * Returns the string being scanned. */ static VALUE strscan_get_string(VALUE self) { struct strscanner *p; GET_SCANNER(self, p); return p->str; } /* * call-seq: string=(str) * * Changes the string being scanned to +str+ and resets the scanner. * Returns +str+. */ static VALUE strscan_set_string(VALUE self, VALUE str) { struct strscanner *p; Data_Get_Struct(self, struct strscanner, p); StringValue(str); p->str = rb_str_dup(str); rb_obj_freeze(p->str); p->curr = 0; CLEAR_MATCH_STATUS(p); return str; } /* * call-seq: * concat(str) * <<(str) * * Appends +str+ to the string being scanned. * This method does not affect scan pointer. * * s = StringScanner.new("Fri Dec 12 1975 14:39") * s.scan(/Fri /) * s << " +1000 GMT" * s.string # -> "Fri Dec 12 1975 14:39 +1000 GMT" * s.scan(/Dec/) # -> "Dec" */ static VALUE strscan_concat(VALUE self, VALUE str) { struct strscanner *p; GET_SCANNER(self, p); StringValue(str); rb_str_append(p->str, str); return self; } /* * Returns the position of the scan pointer. In the 'reset' position, this * value is zero. In the 'terminated' position (i.e. the string is exhausted), * this value is the length of the string. * * In short, it's a 0-based index into the string. * * s = StringScanner.new('test string') * s.pos # -> 0 * s.scan_until /str/ # -> "test str" * s.pos # -> 8 * s.terminate # -> # * s.pos # -> 11 */ static VALUE strscan_get_pos(VALUE self) { struct strscanner *p; GET_SCANNER(self, p); return INT2FIX(p->curr); } /* * call-seq: pos=(n) * * Modify the scan pointer. * * s = StringScanner.new('test string') * s.pos = 7 # -> 7 * s.rest # -> "ring" */ static VALUE strscan_set_pos(VALUE self, VALUE v) { struct strscanner *p; long i; GET_SCANNER(self, p); i = NUM2INT(v); if (i < 0) i += S_LEN(p); if (i < 0) rb_raise(rb_eRangeError, "index out of range"); if (i > S_LEN(p)) rb_raise(rb_eRangeError, "index out of range"); p->curr = i; return INT2NUM(i); } static VALUE strscan_do_scan(VALUE self, VALUE regex, int succptr, int getstr, int headonly) { struct strscanner *p; int ret; Check_Type(regex, T_REGEXP); GET_SCANNER(self, p); CLEAR_MATCH_STATUS(p); if (S_RESTLEN(p) < 0) { return Qnil; } rb_kcode_set_option(regex); if (headonly) { ret = re_match(RREGEXP(regex)->ptr, CURPTR(p), S_RESTLEN(p), 0, &(p->regs)); } else { ret = re_search(RREGEXP(regex)->ptr, CURPTR(p), S_RESTLEN(p), 0, S_RESTLEN(p), &(p->regs)); } rb_kcode_reset_option(); if (ret == -2) rb_raise(ScanError, "regexp buffer overflow"); if (ret < 0) { /* not matched */ return Qnil; } MATCHED(p); p->prev = p->curr; if (succptr) { p->curr += p->regs.end[0]; } if (getstr) { return extract_beg_len(p, p->prev, p->regs.end[0]); } else { return INT2FIX(p->regs.end[0]); } } /* * call-seq: scan(pattern) => String * * Tries to match with +pattern+ at the current position. If there's a match, * the scanner advances the "scan pointer" and returns the matched string. * Otherwise, the scanner returns +nil+. * * s = StringScanner.new('test string') * p s.scan(/\w+/) # -> "test" * p s.scan(/\w+/) # -> nil * p s.scan(/\s+/) # -> " " * p s.scan(/\w+/) # -> "string" * p s.scan(/./) # -> nil * */ static VALUE strscan_scan(VALUE self, VALUE re) { return strscan_do_scan(self, re, 1, 1, 1); } /* * call-seq: match?(pattern) * * Tests whether the given +pattern+ is matched from the current scan pointer. * Returns the length of the match, or +nil+. The scan pointer is not advanced. * * s = StringScanner.new('test string') * p s.match?(/\w+/) # -> 4 * p s.match?(/\w+/) # -> 4 * p s.match?(/\s+/) # -> nil */ static VALUE strscan_match_p(VALUE self, VALUE re) { return strscan_do_scan(self, re, 0, 0, 1); } /* * call-seq: skip(pattern) * * Attempts to skip over the given +pattern+ beginning with the scan pointer. * If it matches, the scan pointer is advanced to the end of the match, and the * length of the match is returned. Otherwise, +nil+ is returned. * * It's similar to #scan, but without returning the matched string. * * s = StringScanner.new('test string') * p s.skip(/\w+/) # -> 4 * p s.skip(/\w+/) # -> nil * p s.skip(/\s+/) # -> 1 * p s.skip(/\w+/) # -> 6 * p s.skip(/./) # -> nil * */ static VALUE strscan_skip(VALUE self, VALUE re) { return strscan_do_scan(self, re, 1, 0, 1); } /* * call-seq: check(pattern) * * This returns the value that #scan would return, without advancing the scan * pointer. The match register is affected, though. * * s = StringScanner.new("Fri Dec 12 1975 14:39") * s.check /Fri/ # -> "Fri" * s.pos # -> 0 * s.matched # -> "Fri" * s.check /12/ # -> nil * s.matched # -> nil * * Mnemonic: it "checks" to see whether a #scan will return a value. */ static VALUE strscan_check(VALUE self, VALUE re) { return strscan_do_scan(self, re, 0, 1, 1); } /* * call-seq: scan_full(pattern, return_string_p, advance_pointer_p) * * Tests whether the given +pattern+ is matched from the current scan pointer. * Returns the matched string if +return_string_p+ is true. * Advances the scan pointer if +advance_pointer_p+ is true. * The match register is affected. * * "full" means "#scan with full parameters". */ static VALUE strscan_scan_full(VALUE self, VALUE re, VALUE s, VALUE f) { return strscan_do_scan(self, re, RTEST(s), RTEST(f), 1); } /* * call-seq: scan_until(pattern) * * Scans the string _until_ the +pattern+ is matched. Returns the substring up * to and including the end of the match, advancing the scan pointer to that * location. If there is no match, +nil+ is returned. * * s = StringScanner.new("Fri Dec 12 1975 14:39") * s.scan_until(/1/) # -> "Fri Dec 1" * s.pre_match # -> "Fri Dec " * s.scan_until(/XYZ/) # -> nil */ static VALUE strscan_scan_until(VALUE self, VALUE re) { return strscan_do_scan(self, re, 1, 1, 0); } /* * call-seq: exist?(pattern) * * Looks _ahead_ to see if the +pattern+ exists _anywhere_ in the string, * without advancing the scan pointer. This predicates whether a #scan_until * will return a value. * * s = StringScanner.new('test string') * s.exist? /s/ # -> 3 * s.scan /test/ # -> "test" * s.exist? /s/ # -> 6 * s.exist? /e/ # -> nil */ static VALUE strscan_exist_p(VALUE self, VALUE re) { return strscan_do_scan(self, re, 0, 0, 0); } /* * call-seq: skip_until(pattern) * * Advances the scan pointer until +pattern+ is matched and consumed. Returns * the number of bytes advanced, or +nil+ if no match was found. * * Look ahead to match +pattern+, and advance the scan pointer to the _end_ * of the match. Return the number of characters advanced, or +nil+ if the * match was unsuccessful. * * It's similar to #scan_until, but without returning the intervening string. * * s = StringScanner.new("Fri Dec 12 1975 14:39") * s.skip_until /12/ # -> 10 * s # */ static VALUE strscan_skip_until(VALUE self, VALUE re) { return strscan_do_scan(self, re, 1, 0, 0); } /* * call-seq: check_until(pattern) * * This returns the value that #scan_until would return, without advancing the * scan pointer. The match register is affected, though. * * s = StringScanner.new("Fri Dec 12 1975 14:39") * s.check_until /12/ # -> "Fri Dec 12" * s.pos # -> 0 * s.matched # -> 12 * * Mnemonic: it "checks" to see whether a #scan_until will return a value. */ static VALUE strscan_check_until(VALUE self, VALUE re) { return strscan_do_scan(self, re, 0, 1, 0); } /* * call-seq: search_full(pattern, return_string_p, advance_pointer_p) * * Scans the string _until_ the +pattern+ is matched. * Returns the matched string if +return_string_p+ is true, otherwise * returns the number of bytes advanced. * Advances the scan pointer if +advance_pointer_p+, otherwise not. * This method does affect the match register. */ static VALUE strscan_search_full(VALUE self, VALUE re, VALUE s, VALUE f) { return strscan_do_scan(self, re, RTEST(s), RTEST(f), 0); } /* DANGEROUS; need to synchronize with regex.c */ static void adjust_registers_to_matched(struct strscanner *p) { if (p->regs.allocated == 0) { p->regs.beg = ALLOC_N(int, RE_NREGS); p->regs.end = ALLOC_N(int, RE_NREGS); p->regs.allocated = RE_NREGS; } p->regs.num_regs = 1; p->regs.beg[0] = 0; p->regs.end[0] = p->curr - p->prev; } /* * Scans one character and returns it. * This method is multi-byte character sensitive. * See also #get_byte. * * s = StringScanner.new('ab') * s.getch # => "a" * s.getch # => "b" * s.getch # => nil * * $KCODE = 'EUC' * s = StringScanner.new("\244\242") * s.getch # => "\244\242" # Japanese hira-kana "A" in EUC-JP * s.getch # => nil */ static VALUE strscan_getch(VALUE self) { struct strscanner *p; long len; GET_SCANNER(self, p); CLEAR_MATCH_STATUS(p); if (EOS_P(p)) return Qnil; len = mbclen(*CURPTR(p)); if (p->curr + len > S_LEN(p)) { len = S_LEN(p) - p->curr; } p->prev = p->curr; p->curr += len; MATCHED(p); adjust_registers_to_matched(p); return extract_range(p, p->prev + p->regs.beg[0], p->prev + p->regs.end[0]); } /* * Scans one byte and returns it. * This method is NOT multi-byte character sensitive. * See also #getch. * * s = StringScanner.new('ab') * s.get_byte # => "a" * s.get_byte # => "b" * s.get_byte # => nil * * s = StringScanner.new("\244\242") * s.get_byte # => "\244" * s.get_byte # => "\242" * s.get_byte # => nil */ static VALUE strscan_get_byte(VALUE self) { struct strscanner *p; GET_SCANNER(self, p); CLEAR_MATCH_STATUS(p); if (EOS_P(p)) { return Qnil; } p->prev = p->curr; p->curr++; MATCHED(p); adjust_registers_to_matched(p); return extract_range(p, p->prev + p->regs.beg[0], p->prev + p->regs.end[0]); } /* * Equivalent to #get_byte. * This method is obsolete; use #get_byte instead. */ static VALUE strscan_getbyte(VALUE self) { rb_warning("StringScanner#getbyte is obsolete; use #get_byte instead"); return strscan_get_byte(self); } /* * call-seq: peek(len) * * Extracts a string corresponding to string[pos,len], without * advancing the scan pointer. * * s = StringScanner.new('test string') * s.peek(7) # => "test st" * s.peek(7) # => "test st" * */ static VALUE strscan_peek(VALUE self, VALUE vlen) { struct strscanner *p; long len; GET_SCANNER(self, p); len = NUM2LONG(vlen); if (EOS_P(p)) { return infect(rb_str_new("", 0), p); } if (p->curr + len > S_LEN(p)) { len = S_LEN(p) - p->curr; } return extract_beg_len(p, p->curr, len); } /* * Equivalent to #peek. * This method is obsolete; use #peek instead. */ static VALUE strscan_peep(VALUE self, VALUE vlen) { rb_warning("StringScanner#peep is obsolete; use #peek instead"); return strscan_peek(self, vlen); } /* * Set the scan pointer to the previous position. Only one previous position is * remembered, and it changes with each scanning operation. * * s = StringScanner.new('test string') * s.scan(/\w+/) # => "test" * s.unscan * s.scan(/../) # => "te" * s.scan(/\d/) # => nil * s.unscan # ScanError: unscan failed: previous match had failed */ static VALUE strscan_unscan(VALUE self) { struct strscanner *p; GET_SCANNER(self, p); if (! MATCHED_P(p)) { rb_raise(ScanError, "unscan failed: previous match had failed"); } p->curr = p->prev; CLEAR_MATCH_STATUS(p); return self; } /* * Returns +true+ iff the scan pointer is at the beginning of the line. * * s = StringScanner.new("test\ntest\n") * s.bol? # => true * s.scan(/te/) * s.bol? # => false * s.scan(/st\n/) * s.bol? # => true * s.terminate * s.bol? # => true */ static VALUE strscan_bol_p(VALUE self) { struct strscanner *p; GET_SCANNER(self, p); if (CURPTR(p) > S_PEND(p)) return Qnil; if (p->curr == 0) return Qtrue; return (*(CURPTR(p) - 1) == '\n') ? Qtrue : Qfalse; } /* * Returns +true+ if the scan pointer is at the end of the string. * * s = StringScanner.new('test string') * p s.eos? # => false * s.scan(/test/) * p s.eos? # => false * s.terminate * p s.eos? # => true */ static VALUE strscan_eos_p(VALUE self) { struct strscanner *p; GET_SCANNER(self, p); return EOS_P(p) ? Qtrue : Qfalse; } /* * Equivalent to #eos?. * This method is obsolete, use #eos? instead. */ static VALUE strscan_empty_p(VALUE self) { rb_warning("StringScanner#empty? is obsolete; use #eos? instead"); return strscan_eos_p(self); } /* * Returns true iff there is more data in the string. See #eos?. * This method is obsolete; use #eos? instead. * * s = StringScanner.new('test string') * s.eos? # These two * s.rest? # are opposites. */ static VALUE strscan_rest_p(VALUE self) { struct strscanner *p; GET_SCANNER(self, p); return EOS_P(p) ? Qfalse : Qtrue; } /* * Returns +true+ iff the last match was successful. * * s = StringScanner.new('test string') * s.match?(/\w+/) # => 4 * s.matched? # => true * s.match?(/\d+/) # => nil * s.matched? # => false */ static VALUE strscan_matched_p(VALUE self) { struct strscanner *p; GET_SCANNER(self, p); return MATCHED_P(p) ? Qtrue : Qfalse; } /* * Returns the last matched string. * * s = StringScanner.new('test string') * s.match?(/\w+/) # -> 4 * s.matched # -> "test" */ static VALUE strscan_matched(VALUE self) { struct strscanner *p; GET_SCANNER(self, p); if (! MATCHED_P(p)) return Qnil; return extract_range(p, p->prev + p->regs.beg[0], p->prev + p->regs.end[0]); } /* * Returns the size of the most recent match (see #matched), or +nil+ if there * was no recent match. * * s = StringScanner.new('test string') * s.check /\w+/ # -> "test" * s.matched_size # -> 4 * s.check /\d+/ # -> nil * s.matched_size # -> nil */ static VALUE strscan_matched_size(VALUE self) { struct strscanner *p; GET_SCANNER(self, p); if (! MATCHED_P(p)) return Qnil; return INT2NUM(p->regs.end[0] - p->regs.beg[0]); } /* * Equivalent to #matched_size. * This method is obsolete; use #matched_size instead. */ static VALUE strscan_matchedsize(VALUE self) { rb_warning("StringScanner#matchedsize is obsolete; use #matched_size instead"); return strscan_matched_size(self); } /* * call-seq: [](n) * * Return the n-th subgroup in the most recent match. * * s = StringScanner.new("Fri Dec 12 1975 14:39") * s.scan(/(\w+) (\w+) (\d+) /) # -> "Fri Dec 12 " * s[0] # -> "Fri Dec 12 " * s[1] # -> "Fri" * s[2] # -> "Dec" * s[3] # -> "12" * s.post_match # -> "1975 14:39" * s.pre_match # -> "" */ static VALUE strscan_aref(VALUE self, VALUE idx) { struct strscanner *p; long i; GET_SCANNER(self, p); if (! MATCHED_P(p)) return Qnil; i = NUM2LONG(idx); if (i < 0) i += p->regs.num_regs; if (i < 0) return Qnil; if (i >= p->regs.num_regs) return Qnil; if (p->regs.beg[i] == -1) return Qnil; return extract_range(p, p->prev + p->regs.beg[i], p->prev + p->regs.end[i]); } /* * Return the pre-match (in the regular expression sense) of the last scan. * * s = StringScanner.new('test string') * s.scan(/\w+/) # -> "test" * s.scan(/\s+/) # -> " " * s.pre_match # -> "test" * s.post_match # -> "string" */ static VALUE strscan_pre_match(VALUE self) { struct strscanner *p; GET_SCANNER(self, p); if (! MATCHED_P(p)) return Qnil; return extract_range(p, 0, p->prev + p->regs.beg[0]); } /* * Return the post-match (in the regular expression sense) of the last scan. * * s = StringScanner.new('test string') * s.scan(/\w+/) # -> "test" * s.scan(/\s+/) # -> " " * s.pre_match # -> "test" * s.post_match # -> "string" */ static VALUE strscan_post_match(VALUE self) { struct strscanner *p; GET_SCANNER(self, p); if (! MATCHED_P(p)) return Qnil; return extract_range(p, p->prev + p->regs.end[0], S_LEN(p)); } /* * Returns the "rest" of the string (i.e. everything after the scan pointer). * If there is no more data (eos? = true), it returns "". */ static VALUE strscan_rest(VALUE self) { struct strscanner *p; GET_SCANNER(self, p); if (EOS_P(p)) { return infect(rb_str_new("", 0), p); } return extract_range(p, p->curr, S_LEN(p)); } /* * s.rest_size is equivalent to s.rest.size. */ static VALUE strscan_rest_size(VALUE self) { struct strscanner *p; long i; GET_SCANNER(self, p); if (EOS_P(p)) { return INT2FIX(0); } i = S_LEN(p) - p->curr; return INT2FIX(i); } /* * s.restsize is equivalent to s.rest_size. * This method is obsolete; use #rest_size instead. */ static VALUE strscan_restsize(VALUE self) { rb_warning("StringScanner#restsize is obsolete; use #rest_size instead"); return strscan_rest_size(self); } #define INSPECT_LENGTH 5 #define BUFSIZE 256 /* * Returns a string that represents the StringScanner object, showing: * - the current position * - the size of the string * - the characters surrounding the scan pointer * * s = StringScanner.new("Fri Dec 12 1975 14:39") * s.inspect # -> '#' * s.scan_until /12/ # -> "Fri Dec 12" * s.inspect # -> '#' */ static VALUE strscan_inspect(VALUE self) { struct strscanner *p; char buf[BUFSIZE]; long len; VALUE a, b; Data_Get_Struct(self, struct strscanner, p); if (NIL_P(p->str)) { len = snprintf(buf, BUFSIZE, "#<%s (uninitialized)>", rb_class2name(CLASS_OF(self))); return infect(rb_str_new(buf, len), p); } if (EOS_P(p)) { len = snprintf(buf, BUFSIZE, "#<%s fin>", rb_class2name(CLASS_OF(self))); return infect(rb_str_new(buf, len), p); } if (p->curr == 0) { b = inspect2(p); len = snprintf(buf, BUFSIZE, "#<%s %ld/%ld @ %s>", rb_class2name(CLASS_OF(self)), p->curr, S_LEN(p), RSTRING(b)->ptr); return infect(rb_str_new(buf, len), p); } a = inspect1(p); b = inspect2(p); len = snprintf(buf, BUFSIZE, "#<%s %ld/%ld %s @ %s>", rb_class2name(CLASS_OF(self)), p->curr, S_LEN(p), RSTRING(a)->ptr, RSTRING(b)->ptr); return infect(rb_str_new(buf, len), p); } static VALUE inspect1(struct strscanner *p) { char buf[BUFSIZE]; char *bp = buf; long len; if (p->curr == 0) return rb_str_new2(""); if (p->curr > INSPECT_LENGTH) { strcpy(bp, "..."); bp += 3; len = INSPECT_LENGTH; } else { len = p->curr; } memcpy(bp, CURPTR(p) - len, len); bp += len; return rb_str_dump(rb_str_new(buf, bp - buf)); } static VALUE inspect2(struct strscanner *p) { char buf[BUFSIZE]; char *bp = buf; long len; if (EOS_P(p)) return rb_str_new2(""); len = S_LEN(p) - p->curr; if (len > INSPECT_LENGTH) { len = INSPECT_LENGTH; memcpy(bp, CURPTR(p), len); bp += len; strcpy(bp, "..."); bp += 3; } else { memcpy(bp, CURPTR(p), len); bp += len; } return rb_str_dump(rb_str_new(buf, bp - buf)); } /* ======================================================================= Ruby Interface ======================================================================= */ /* * Document-class: StringScanner * * StringScanner provides for lexical scanning operations on a String. Here is * an example of its usage: * * s = StringScanner.new('This is an example string') * s.eos? # -> false * * p s.scan(/\w+/) # -> "This" * p s.scan(/\w+/) # -> nil * p s.scan(/\s+/) # -> " " * p s.scan(/\s+/) # -> nil * p s.scan(/\w+/) # -> "is" * s.eos? # -> false * * p s.scan(/\s+/) # -> " " * p s.scan(/\w+/) # -> "an" * p s.scan(/\s+/) # -> " " * p s.scan(/\w+/) # -> "example" * p s.scan(/\s+/) # -> " " * p s.scan(/\w+/) # -> "string" * s.eos? # -> true * * p s.scan(/\s+/) # -> nil * p s.scan(/\w+/) # -> nil * * Scanning a string means remembering the position of a scan pointer, * which is just an index. The point of scanning is to move forward a bit at * a time, so matches are sought after the scan pointer; usually immediately * after it. * * Given the string "test string", here are the pertinent scan pointer * positions: * * t e s t s t r i n g * 0 1 2 ... 1 * 0 * * When you #scan for a pattern (a regular expression), the match must occur * at the character after the scan pointer. If you use #scan_until, then the * match can occur anywhere after the scan pointer. In both cases, the scan * pointer moves just beyond the last character of the match, ready to * scan again from the next character onwards. This is demonstrated by the * example above. * * == Method Categories * * There are other methods besides the plain scanners. You can look ahead in * the string without actually scanning. You can access the most recent match. * You can modify the string being scanned, reset or terminate the scanner, * find out or change the position of the scan pointer, skip ahead, and so on. * * === Advancing the Scan Pointer * * - #getch * - #get_byte * - #scan * - #scan_until * - #skip * - #skip_until * * === Looking Ahead * * - #check * - #check_until * - #exist? * - #match? * - #peek * * === Finding Where we Are * * - #beginning_of_line? (#bol?) * - #eos? * - #rest? * - #rest_size * - #pos * * === Setting Where we Are * * - #reset * - #terminate * - #pos= * * === Match Data * * - #matched * - #matched? * - #matched_size * - [] * - #pre_match * - #post_match * * === Miscellaneous * * - << * - #concat * - #string * - #string= * - #unscan * * There are aliases to several of the methods. */ void Init_strscan(void) { ID id_scanerr = rb_intern("ScanError"); VALUE tmp; StringScanner = rb_define_class("StringScanner", rb_cObject); ScanError = rb_define_class_under(StringScanner, "Error", rb_eStandardError); if (!rb_const_defined(rb_cObject, id_scanerr)) { rb_const_set(rb_cObject, id_scanerr, ScanError); } tmp = rb_str_new2(STRSCAN_VERSION); rb_obj_freeze(tmp); rb_const_set(StringScanner, rb_intern("Version"), tmp); tmp = rb_str_new2("$Id: strscan.c 11708 2007-02-12 23:01:19Z shyouhei $"); rb_obj_freeze(tmp); rb_const_set(StringScanner, rb_intern("Id"), tmp); rb_define_alloc_func(StringScanner, strscan_s_allocate); rb_define_private_method(StringScanner, "initialize", strscan_initialize, -1); rb_define_private_method(StringScanner, "initialize_copy", strscan_init_copy, 1); rb_define_singleton_method(StringScanner, "must_C_version", strscan_s_mustc, 0); rb_define_method(StringScanner, "reset", strscan_reset, 0); rb_define_method(StringScanner, "terminate", strscan_terminate, 0); rb_define_method(StringScanner, "clear", strscan_clear, 0); rb_define_method(StringScanner, "string", strscan_get_string, 0); rb_define_method(StringScanner, "string=", strscan_set_string, 1); rb_define_method(StringScanner, "concat", strscan_concat, 1); rb_define_method(StringScanner, "<<", strscan_concat, 1); rb_define_method(StringScanner, "pos", strscan_get_pos, 0); rb_define_method(StringScanner, "pos=", strscan_set_pos, 1); rb_define_method(StringScanner, "pointer", strscan_get_pos, 0); rb_define_method(StringScanner, "pointer=", strscan_set_pos, 1); rb_define_method(StringScanner, "scan", strscan_scan, 1); rb_define_method(StringScanner, "skip", strscan_skip, 1); rb_define_method(StringScanner, "match?", strscan_match_p, 1); rb_define_method(StringScanner, "check", strscan_check, 1); rb_define_method(StringScanner, "scan_full", strscan_scan_full, 3); rb_define_method(StringScanner, "scan_until", strscan_scan_until, 1); rb_define_method(StringScanner, "skip_until", strscan_skip_until, 1); rb_define_method(StringScanner, "exist?", strscan_exist_p, 1); rb_define_method(StringScanner, "check_until", strscan_check_until, 1); rb_define_method(StringScanner, "search_full", strscan_search_full, 3); rb_define_method(StringScanner, "getch", strscan_getch, 0); rb_define_method(StringScanner, "get_byte", strscan_get_byte, 0); rb_define_method(StringScanner, "getbyte", strscan_getbyte, 0); rb_define_method(StringScanner, "peek", strscan_peek, 1); rb_define_method(StringScanner, "peep", strscan_peep, 1); rb_define_method(StringScanner, "unscan", strscan_unscan, 0); rb_define_method(StringScanner, "beginning_of_line?", strscan_bol_p, 0); rb_alias(StringScanner, rb_intern("bol?"), rb_intern("beginning_of_line?")); rb_define_method(StringScanner, "eos?", strscan_eos_p, 0); rb_define_method(StringScanner, "empty?", strscan_empty_p, 0); rb_define_method(StringScanner, "rest?", strscan_rest_p, 0); rb_define_method(StringScanner, "matched?", strscan_matched_p, 0); rb_define_method(StringScanner, "matched", strscan_matched, 0); rb_define_method(StringScanner, "matched_size", strscan_matched_size, 0); rb_define_method(StringScanner, "matchedsize", strscan_matchedsize, 0); rb_define_method(StringScanner, "[]", strscan_aref, 1); rb_define_method(StringScanner, "pre_match", strscan_pre_match, 0); rb_define_method(StringScanner, "post_match", strscan_post_match, 0); rb_define_method(StringScanner, "rest", strscan_rest, 0); rb_define_method(StringScanner, "rest_size", strscan_rest_size, 0); rb_define_method(StringScanner, "restsize", strscan_restsize, 0); rb_define_method(StringScanner, "inspect", strscan_inspect, 0); }