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v/vlib/regex/regex.v
penguindark 15a63b5bcb regex fixes
2020-01-25 19:12:23 +01:00

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/**********************************************************************
*
* regex 0.9c
*
* Copyright (c) 2019-2020 Dario Deledda. All rights reserved.
* Use of this source code is governed by an MIT license
* that can be found in the LICENSE file.
*
* This file contains regex module
*
* Know limitation:
* - max 8 stacked groups
* - find is implemented in a trivial way
*
*
**********************************************************************/
module regex
import strings
pub const(
V_REGEX_VERSION = "0.9c" // regex module version
MAX_CODE_LEN = 256 // default small base code len for the regex programs
MAX_QUANTIFIER = 1073741824 // default max repetitions allowed for the quantifiers = 2^30
// spaces chars (here only westerns!!) TODO: manage all the spaces from unicode
SPACES = [` `, `\t`, `\n`, `\r`, `\v`, `\f`]
// new line chars for now only '\n'
NEW_LINE_LIST = [`\n`,`\r`]
// Results
NO_MATCH_FOUND = -1
// Errors
COMPILE_OK = 0 // the regex string compiled, all ok
ERR_CHAR_UNKNOWN = -2 // the char used is unknow to the system
ERR_UNDEFINED = -3 // the compiler symbol is undefined
ERR_INTERNAL_ERROR = -4 // Bug in the regex system!!
ERR_CC_ALLOC_OVERFLOW = -5 // memory for char class full!!
ERR_SYNTAX_ERROR = -6 // syntax error in regex compiling
ERR_GROUPS_OVERFLOW = -7 // max number of groups reached
ERR_GROUPS_MAX_NESTED = -8 // max number of nested group reached
ERR_GROUP_NOT_BALANCED = -9 // group not balanced
)
const(
//*************************************
// regex program instructions
//*************************************
IST_SIMPLE_CHAR = u32(0x7FFFFFFF) // single char instruction, 31 bit available to char
// char class 11 0100 AA xxxxxxxx
// AA = 00 regular class
// AA = 01 Negated class ^ char
IST_CHAR_CLASS = 0xD1000000 // MASK
IST_CHAR_CLASS_POS = 0xD0000000 // char class normal [abc]
IST_CHAR_CLASS_NEG = 0xD1000000 // char class negate [^abc]
// dot char 10 0110 xx xxxxxxxx
IST_DOT_CHAR = 0x98000000 // match any char except \n
// backslash chars 10 0100 xx xxxxxxxx
IST_BSLS_CHAR = 0x90000000 // backslash char
// OR | 10 010Y xx xxxxxxxx
IST_OR_BRANCH = 0x91000000 // OR case
// groups 10 010Y xx xxxxxxxx
IST_GROUP_START = 0x92000000 // group start (
IST_GROUP_END = 0x94000000 // group end )
// control instructions
IST_PROG_END = u32(0x88000000) //10 0010 xx xxxxxxxx
//*************************************
)
/******************************************************************************
*
* General Utilities
*
******************************************************************************/
// utf8util_char_len calculate the length in bytes of a utf8 char
[inline]
fn utf8util_char_len(b byte) int {
return (( 0xe5000000 >> (( b >> 3 ) & 0x1e )) & 3 ) + 1
}
// get_char get a char from position i and return an u32 with the unicode code
[inline]
fn (re RE) get_char(in_txt string, i int) (u32,int) {
// ascii 8 bit
if (re.flag & F_BIN) !=0 ||
in_txt.str[i] & 0x80 == 0
{
return u32(in_txt.str[i]), 1
}
// unicode char
char_len := utf8util_char_len(in_txt.str[i])
mut tmp := 0
mut ch := u32(0)
for tmp < char_len {
ch = (ch << 8) | in_txt.str[i+tmp]
tmp++
}
return ch,char_len
}
// get_charb get a char from position i and return an u32 with the unicode code
[inline]
fn (re RE) get_charb(in_txt byteptr, i int) (u32,int) {
// ascii 8 bit
if (re.flag & F_BIN) !=0 ||
in_txt[i] & 0x80 == 0
{
return u32(in_txt[i]), 1
}
// unicode char
char_len := utf8util_char_len(in_txt[i])
mut tmp := 0
mut ch := u32(0)
for tmp < char_len {
ch = (ch << 8) | in_txt[i+tmp]
tmp++
}
return ch,char_len
}
[inline]
fn is_alnum(in_char byte) bool {
mut tmp := in_char - `A`
if tmp >= 0x00 && tmp <= 25 { return true }
tmp = in_char - `a`
if tmp >= 0x00 && tmp <= 25 { return true }
tmp = in_char - `0`
if tmp >= 0x00 && tmp <= 9 { return true }
return false
}
[inline]
fn is_not_alnum(in_char byte) bool {
return !is_alnum(in_char)
}
[inline]
fn is_space(in_char byte) bool {
return in_char in SPACES
}
[inline]
fn is_not_space(in_char byte) bool {
return !is_space(in_char)
}
[inline]
fn is_digit(in_char byte) bool {
tmp := in_char - `0`
return tmp <= 0x09 && tmp >= 0
}
[inline]
fn is_not_digit(in_char byte) bool {
return !is_digit(in_char)
}
[inline]
fn is_wordchar(in_char byte) bool {
return is_alnum(in_char) || in_char == `_`
}
[inline]
fn is_not_wordchar(in_char byte) bool {
return !is_alnum(in_char)
}
[inline]
fn is_lower(in_char byte) bool {
tmp := in_char - `a`
return tmp >= 0x00 && tmp <= 25
}
[inline]
fn is_upper(in_char byte) bool {
tmp := in_char - `A`
return tmp >= 0x00 && tmp <= 25
}
pub fn (re RE) get_parse_error_string(err int) string {
match err {
COMPILE_OK { return "COMPILE_OK" }
NO_MATCH_FOUND { return "NO_MATCH_FOUND" }
ERR_CHAR_UNKNOWN { return "ERR_CHAR_UNKNOWN" }
ERR_UNDEFINED { return "ERR_UNDEFINED" }
ERR_INTERNAL_ERROR { return "ERR_INTERNAL_ERROR" }
ERR_CC_ALLOC_OVERFLOW { return "ERR_CC_ALLOC_OVERFLOW" }
ERR_SYNTAX_ERROR { return "ERR_SYNTAX_ERROR" }
ERR_GROUPS_OVERFLOW { return "ERR_GROUPS_OVERFLOW"}
ERR_GROUPS_MAX_NESTED { return "ERR_GROUPS_MAX_NESTED"}
ERR_GROUP_NOT_BALANCED { return "ERR_GROUP_NOT_BALANCED"}
else { return "ERR_UNKNOWN" }
}
}
// utf8_str convert and utf8 sequence to a printable string
[inline]
fn utf8_str(ch u32) string {
mut i := 4
mut res := ""
for i > 0 {
v := byte((ch >> ((i-1)*8)) & 0xFF)
if v != 0{
res += "${v:1c}"
}
i--
}
return res
}
// simple_log default log function
fn simple_log(txt string) {
print(txt)
}
/******************************************************************************
*
* Token Structs
*
******************************************************************************/
struct Token{
mut:
ist u32 = u32(0)
// char
ch u32 = u32(0) // char of the token if any
ch_len byte = byte(0) // char len
// Quantifiers / branch
rep_min int = 0 // used also for jump next in the OR branch [no match] pc jump
rep_max int = 0 // used also for jump next in the OR branch [ match] pc jump
greedy bool = false // greedy quantifier flag
// Char class
cc_index int = -1
// counters for quantifier check (repetitions)
rep int = 0
// validator function pointer
validator fn (byte) bool
// groups variables
group_rep int = 0 // repetition of the group
group_id int = -1 // id of the group
goto_pc int = -1 // jump to this PC if is needed
// OR flag for the token
next_is_or bool = false // true if the next token is an OR
}
fn (tok mut Token) reset() {
tok.rep = 0
}
/******************************************************************************
*
* Regex struct
*
******************************************************************************/
pub const (
F_NL = 0x00000001 // end the match when find a new line symbol
F_MS = 0x00000002 // match true only if the match is at the start of the string
F_ME = 0x00000004 // match true only if the match is at the end of the string
F_EFM = 0x00000100 // exit on first token matched, used by search
F_BIN = 0x00000200 // work only on bytes, ignore utf-8
)
struct StateDotObj{
mut:
i int = -1 // char index in the input buffer
pc int = -1 // program counter saved
mi int = -1 // match_index saved
group_stack_index int = -1 // continuous save on capturing groups
}
pub
struct RE {
pub mut:
prog []Token
// char classes storage
cc []CharClass // char class list
cc_index int = 0 // index
// state index
state_stack_index int= -1
state_stack []StateDotObj
// groups
group_count int = 0 // number of groups in this regex struct
groups []int // groups index results
group_max_nested int = 3 // max nested group
group_max int = 8 // max allowed number of different groups
group_csave []int = []int // groups continuous save array
group_csave_index int= -1 // groups continuous save index
// flags
flag int = 0 // flag for optional parameters
// Debug/log
debug int = 0 // enable in order to have the unroll of the code 0 = NO_DEBUG, 1 = LIGHT 2 = VERBOSE
log_func fn (string) = simple_log // log function, can be customized by the user
query string = "" // query string
}
// Reset RE object
fn (re mut RE) reset(){
//re.group_count = 0
re.cc_index = 0
mut i := 0
for i < re.prog.len {
re.prog[i].group_rep = 0 // clear repetition of the group
re.prog[i].rep = 0 // clear repetition of the token
i++
}
re.groups = [-1].repeat(re.group_count*2)
re.state_stack_index = -1
// reset group_csave
if re.group_csave.len > 0 {
re.group_csave_index = 1
re.group_csave[0] = 0 // reset the capture count
}
}
/******************************************************************************
*
* Backslashes chars
*
******************************************************************************/
struct BslsStruct {
ch u32 // meta char
validator fn (byte) bool // validator function pointer
}
const(
BSLS_VALIDATOR_ARRAY = [
BslsStruct{`w`, is_alnum},
BslsStruct{`W`, is_not_alnum},
BslsStruct{`s`, is_space},
BslsStruct{`S`, is_not_space},
BslsStruct{`d`, is_digit},
BslsStruct{`D`, is_not_digit},
BslsStruct{`a`, is_lower},
BslsStruct{`A`, is_upper},
]
// these chars are escape if preceded by a \
BSLS_ESCAPE_LIST = [ `\\`,`|`,`.`,`*`,`+`,`{`,`}`,`[`,`]` ]
)
enum BSLS_parse_state {
start,
bsls_found,
bsls_char,
normal_char
}
// parse_bsls return (index, str_len) BSLS_VALIDATOR_ARRAY index, len of the backslash sequence if present
fn (re RE) parse_bsls(in_txt string, in_i int) (int,int){
mut status := BSLS_parse_state.start
mut i := in_i
for i < in_txt.len {
// get our char
char_tmp,char_len := re.get_char(in_txt,i)
ch := byte(char_tmp)
if status == .start && ch == `\\` {
status = .bsls_found
i += char_len
continue
}
// check if is our bsls char, for now only one length sequence
if status == .bsls_found {
for c,x in BSLS_VALIDATOR_ARRAY {
if x.ch == ch {
return c,i-in_i+1
}
}
status = .normal_char
continue
}
// no BSLS validator, manage as normal escape char char
if status == .normal_char {
if ch in BSLS_ESCAPE_LIST {
return NO_MATCH_FOUND,i-in_i+1
}
return ERR_SYNTAX_ERROR,i-in_i+1
}
// at the present time we manage only one char after the \
break
}
// not our bsls return KO
return ERR_SYNTAX_ERROR, i
}
/******************************************************************************
*
* Char class
*
******************************************************************************/
const(
CC_NULL = 0 // empty cc token
CC_CHAR = 1 // simple char: a
CC_INT = 2 // char interval: a-z
CC_BSLS = 3 // backslash char
CC_END = 4 // cc sequence terminator
)
struct CharClass {
mut:
cc_type int = CC_NULL // type of cc token
ch0 u32 = u32(0) // first char of the interval a-b a in this case
ch1 u32 = u32(0) // second char of the interval a-b b in this case
validator fn (byte) bool // validator function pointer
}
enum CharClass_parse_state {
start,
in_char,
in_bsls,
separator,
finish,
}
fn (re RE) get_char_class(pc int) string {
buf := [byte(0)].repeat(re.cc.len)
mut buf_ptr := *byte(&buf)
mut cc_i := re.prog[pc].cc_index
mut i := 0
mut tmp := 0
for cc_i >= 0 && cc_i < re.cc.len && re.cc[cc_i].cc_type != CC_END {
if re.cc[cc_i].cc_type == CC_BSLS {
buf_ptr[i++] = `\\`
buf_ptr[i++] = byte(re.cc[cc_i].ch0)
}
else if re.cc[cc_i].ch0 == re.cc[cc_i].ch1 {
tmp = 3
for tmp >= 0 {
x := byte((re.cc[cc_i].ch0 >> (tmp*8)) & 0xFF)
if x != 0 {
buf_ptr[i++] = x
}
tmp--
}
}
else {
tmp = 3
for tmp >= 0 {
x := byte((re.cc[cc_i].ch0 >> (tmp*8)) & 0xFF)
if x != 0 {
buf_ptr[i++] = x
}
tmp--
}
buf_ptr[i++] = `-`
tmp = 3
for tmp >= 0 {
x := byte((re.cc[cc_i].ch1 >> (tmp*8)) & 0xFF)
if x != 0 {
buf_ptr[i++] = x
}
tmp--
}
}
cc_i++
}
buf_ptr[i] = byte(0)
return tos_clone( buf_ptr )
}
fn (re RE) check_char_class(pc int, ch u32) bool {
mut cc_i := re.prog[pc].cc_index
for cc_i >= 0 && cc_i < re.cc.len && re.cc[cc_i].cc_type != CC_END {
if re.cc[cc_i].cc_type == CC_BSLS {
if re.cc[cc_i].validator(byte(ch)) {
return true
}
}
else if ch >= re.cc[cc_i].ch0 && ch <= re.cc[cc_i].ch1 {
return true
}
cc_i++
}
return false
}
// parse_char_class return (index, str_len, cc_type) of a char class [abcm-p], char class start after the [ char
fn (re mut RE) parse_char_class(in_txt string, in_i int) (int, int, u32) {
mut status := CharClass_parse_state.start
mut i := in_i
mut tmp_index := re.cc_index
res_index := re.cc_index
mut cc_type := u32(IST_CHAR_CLASS_POS)
for i < in_txt.len {
// check if we are out of memory for char classes
if tmp_index >= re.cc.len {
return ERR_CC_ALLOC_OVERFLOW,0,u32(0)
}
// get our char
char_tmp,char_len := re.get_char(in_txt,i)
ch := byte(char_tmp)
//C.printf("CC #%3d ch: %c\n",i,ch)
// negation
if status == .start && ch == `^` {
cc_type = u32(IST_CHAR_CLASS_NEG)
i += char_len
continue
}
// bsls
if (status == .start || status == .in_char) && ch == `\\` {
//C.printf("CC bsls.\n")
status = .in_bsls
i += char_len
continue
}
if status == .in_bsls {
//C.printf("CC bsls validation.\n")
for c,x in BSLS_VALIDATOR_ARRAY {
if x.ch == ch {
//C.printf("CC bsls found \\%c.\n",ch)
re.cc[tmp_index].cc_type = CC_BSLS
re.cc[tmp_index].ch0 = BSLS_VALIDATOR_ARRAY[c].ch
re.cc[tmp_index].ch1 = BSLS_VALIDATOR_ARRAY[c].ch
re.cc[tmp_index].validator = BSLS_VALIDATOR_ARRAY[c].validator
i += char_len
tmp_index++
status = .in_char
break
}
}
if status == .in_bsls {
//C.printf("CC bsls not found \\%c.\n",ch)
status = .in_char
}else {
continue
}
}
// simple char
if (status == .start || status == .in_char) &&
ch != `-` && ch != `]`
{
status = .in_char
re.cc[tmp_index].cc_type = CC_CHAR
re.cc[tmp_index].ch0 = char_tmp
re.cc[tmp_index].ch1 = char_tmp
i += char_len
tmp_index++
continue
}
// check range separator
if status == .in_char && ch == `-` {
status = .separator
i += char_len
continue
}
// check range end
if status == .separator && ch != `]` && ch != `-` {
status = .in_char
re.cc[tmp_index-1].cc_type = CC_INT
re.cc[tmp_index-1].ch1 = char_tmp
i += char_len
continue
}
// char class end
if status == .in_char && ch == `]` {
re.cc[tmp_index].cc_type = CC_END
re.cc[tmp_index].ch0 = 0
re.cc[tmp_index].ch1 = 0
re.cc_index = tmp_index+1
return res_index, i-in_i+2, cc_type
}
i++
}
return ERR_SYNTAX_ERROR,0,u32(0)
}
/******************************************************************************
*
* Re Compiler
*
******************************************************************************/
//
// Quantifier
//
enum Quant_parse_state {
start,
min_parse,
comma_checked,
max_parse,
greedy,
gredy_parse,
finish
}
// parse_quantifier return (min, max, str_len) of a {min,max}? quantifier starting after the { char
fn (re RE) parse_quantifier(in_txt string, in_i int) (int, int, int, bool) {
mut status := Quant_parse_state.start
mut i := in_i
mut q_min := 0 // default min in a {} quantifier is 1
mut q_max := 0 // deafult max in a {} quantifier is MAX_QUANTIFIER
mut ch := byte(0)
for i < in_txt.len {
ch = in_txt.str[i]
//C.printf("%c status: %d\n",ch,status)
// exit on no compatible char with {} quantifier
if utf8util_char_len(ch) != 1 {
return ERR_SYNTAX_ERROR,i,0,false
}
// min parsing skip if comma present
if status == .start && ch == `,` {
q_min = 0 // default min in a {} quantifier is 0
status = .comma_checked
i++
continue
}
if status == .start && is_digit( ch ) {
status = .min_parse
q_min *= 10
q_min += int(ch - `0`)
i++
continue
}
if status == .min_parse && is_digit( ch ) {
q_min *= 10
q_min += int(ch - `0`)
i++
continue
}
// we have parsed the min, now check the max
if status == .min_parse && ch == `,` {
status = .comma_checked
i++
continue
}
// single value {4}
if status == .min_parse && ch == `}` {
q_max = q_min
status = .greedy
continue
}
// end without max
if status == .comma_checked && ch == `}` {
q_max = MAX_QUANTIFIER
status = .greedy
continue
}
// start max parsing
if status == .comma_checked && is_digit( ch ) {
status = .max_parse
q_max *= 10
q_max += int(ch - `0`)
i++
continue
}
// parse the max
if status == .max_parse && is_digit( ch ) {
q_max *= 10
q_max += int(ch - `0`)
i++
continue
}
// finished the quantifier
if status == .max_parse && ch == `}` {
status = .greedy
continue
}
// check if greedy flag char ? is present
if status == .greedy {
if i+1 < in_txt.len {
i++
status = .gredy_parse
continue
}
return q_min, q_max, i-in_i+2, false
}
// check the greedy flag
if status == .gredy_parse {
if ch == `?` {
return q_min, q_max, i-in_i+2, true
} else {
i--
return q_min, q_max, i-in_i+2, false
}
}
// not a {} quantifier, exit
return ERR_SYNTAX_ERROR, i, 0, false
}
// not a conform {} quantifier
return ERR_SYNTAX_ERROR, i, 0, false
}
//
// main compiler
//
// compile return (return code, index) where index is the index of the error in the query string if return code is an error code
pub fn (re mut RE) compile(in_txt string) (int,int) {
mut i := 0 // input string index
mut pc := 0 // program counter
mut tmp_code := u32(0)
// group management variables
mut group_count := -1
mut group_stack := [0 ].repeat(re.group_max_nested)
mut group_stack_txt_index := [-1].repeat(re.group_max_nested)
mut group_stack_index := -1
re.query = in_txt // save the query string
i = 0
for i < in_txt.len {
tmp_code = u32(0)
mut char_tmp := u32(0)
mut char_len := 0
//C.printf("i: %3d ch: %c\n", i, in_txt.str[i])
char_tmp,char_len = re.get_char(in_txt,i)
//
// check special cases: $ ^
//
if char_len == 1 && i == 0 && byte(char_tmp) == `^` {
re.flag = F_MS
i = i + char_len
continue
}
if char_len == 1 && i == (in_txt.len-1) && byte(char_tmp) == `$` {
re.flag = F_ME
i = i + char_len
continue
}
// IST_GROUP_START
if char_len == 1 && pc >= 0 && byte(char_tmp) == `(` {
//check max groups allowed
if group_count > re.group_max {
return ERR_GROUPS_OVERFLOW,i+1
}
group_stack_index++
// check max nested groups allowed
if group_stack_index > re.group_max_nested {
return ERR_GROUPS_MAX_NESTED,i+1
}
group_count++
group_stack_txt_index[group_stack_index] = i
group_stack[group_stack_index] = pc
re.prog[pc].ist = u32(0) | IST_GROUP_START
re.prog[pc].group_id = group_count
re.prog[pc].rep_min = 1
re.prog[pc].rep_max = 1
pc = pc + 1
i = i + char_len
continue
}
// IST_GROUP_END
if char_len==1 && pc > 0 && byte(char_tmp) == `)` {
if group_stack_index < 0 {
return ERR_GROUP_NOT_BALANCED,i+1
}
goto_pc := group_stack[group_stack_index]
group_stack_index--
re.prog[pc].ist = u32(0) | IST_GROUP_END
re.prog[pc].rep_min = 1
re.prog[pc].rep_max = 1
re.prog[pc].goto_pc = goto_pc // PC where to jump if a group need
re.prog[pc].group_id = re.prog[goto_pc].group_id // id of this group, used for storing data
re.prog[goto_pc].goto_pc = pc // start goto point to the end group pc
//re.prog[goto_pc].group_id = group_count // id of this group, used for storing data
pc = pc + 1
i = i + char_len
continue
}
// IST_DOT_CHAR match any char except the following token
if char_len==1 && pc >= 0 && byte(char_tmp) == `.` {
re.prog[pc].ist = u32(0) | IST_DOT_CHAR
re.prog[pc].rep_min = 1
re.prog[pc].rep_max = 1
pc = pc + 1
i = i + char_len
continue
}
// OR branch
if char_len==1 && pc > 0 && byte(char_tmp) == `|` {
// two consecutive IST_DOT_CHAR are an error
if pc > 0 && re.prog[pc-1].ist == IST_OR_BRANCH {
return ERR_SYNTAX_ERROR,i
}
re.prog[pc].ist = u32(0) | IST_OR_BRANCH
pc = pc + 1
i = i + char_len
continue
}
// Quantifiers
if char_len==1 && pc > 0{
mut quant_flag := true
match byte(char_tmp) {
`?` {
//C.printf("q: %c\n",char_tmp)
re.prog[pc-1].rep_min = 0
re.prog[pc-1].rep_max = 1
}
`+` {
//C.printf("q: %c\n",char_tmp)
re.prog[pc-1].rep_min = 1
re.prog[pc-1].rep_max = MAX_QUANTIFIER
}
`*` {
//C.printf("q: %c\n",char_tmp)
re.prog[pc-1].rep_min = 0
re.prog[pc-1].rep_max = MAX_QUANTIFIER
}
`{` {
min, max, tmp, greedy := re.parse_quantifier(in_txt, i+1)
// it is a quantifier
if min >= 0 {
//C.printf("{%d,%d}\n str:[%s] greedy: %d\n", min, max, in_txt[i..i+tmp], greedy)
i = i + tmp
re.prog[pc-1].rep_min = min
re.prog[pc-1].rep_max = max
re.prog[pc-1].greedy = greedy
continue
}
else {
return min,i
}
// TODO: decide if the open bracket can be conform without the close bracket
/*
// no conform, parse as normal char
else {
quant_flag = false
}
*/
}
else{
quant_flag = false
}
}
if quant_flag {
i = i + char_len
continue
}
}
// IST_CHAR_CLASS_*
if char_len==1 && pc >= 0{
if byte(char_tmp) == `[` {
cc_index,tmp,cc_type := re.parse_char_class(in_txt, i+1)
if cc_index >= 0 {
//C.printf("index: %d str:%s\n",cc_index,in_txt[i..i+tmp])
i = i + tmp
re.prog[pc].ist = u32(0) | cc_type
re.prog[pc].cc_index = cc_index
re.prog[pc].rep_min = 1
re.prog[pc].rep_max = 1
pc = pc + 1
continue
}
// cc_class vector memory full
else if cc_index < 0 {
return cc_index, i
}
}
}
// IST_BSLS_CHAR
if char_len==1 && pc >= 0{
if byte(char_tmp) == `\\` {
bsls_index,tmp := re.parse_bsls(in_txt,i)
//C.printf("index: %d str:%s\n",bsls_index,in_txt[i..i+tmp])
if bsls_index >= 0 {
i = i + tmp
re.prog[pc].ist = u32(0) | IST_BSLS_CHAR
re.prog[pc].rep_min = 1
re.prog[pc].rep_max = 1
re.prog[pc].validator = BSLS_VALIDATOR_ARRAY[bsls_index].validator
re.prog[pc].ch = BSLS_VALIDATOR_ARRAY[bsls_index].ch
pc = pc + 1
continue
}
// this is an escape char, skip the bsls and continue as a normal char
else if bsls_index == NO_MATCH_FOUND {
i += char_len
char_tmp,char_len = re.get_char(in_txt,i)
// continue as simple char
}
// if not an escape or a bsls char then it is an error (at least for now!)
else {
return bsls_index,i+tmp
}
}
}
// IST_SIMPLE_CHAR
re.prog[pc].ist = IST_SIMPLE_CHAR
re.prog[pc].ch = char_tmp
re.prog[pc].ch_len = char_len
re.prog[pc].rep_min = 1
re.prog[pc].rep_max = 1
//C.printf("char: %c\n",char_tmp)
pc = pc +1
i+=char_len
}
// add end of the program
re.prog[pc].ist = IST_PROG_END
// check for unbalanced groups
if group_stack_index != -1 {
return ERR_GROUP_NOT_BALANCED, group_stack_txt_index[group_stack_index]+1
}
// check for OR at the end of the program
if pc > 0 && re.prog[pc-1].ist == IST_OR_BRANCH {
return ERR_SYNTAX_ERROR,in_txt.len
}
// store the number of groups in the query
re.group_count = group_count+1
//******************************************
// Post processing
//******************************************
// count IST_DOT_CHAR to set the size of the state stack
mut pc1 := 0
mut tmp_count := 0
for pc1 < pc {
if re.prog[pc1].ist == IST_DOT_CHAR {
tmp_count++
}
pc1++
}
// init the state stack
re.state_stack = [StateDotObj{}].repeat(tmp_count+1)
// OR branch
// a|b|cd
// d exit point
// a,b,c branches
// set the jump in the right places
pc1 = 0
for pc1 < pc-2 {
// two consecutive OR are a syntax error
if re.prog[pc1+1].ist == IST_OR_BRANCH && re.prog[pc1+2].ist == IST_OR_BRANCH {
return ERR_SYNTAX_ERROR, i
}
// manange a|b chains like a|(b)|c|d...
// standard solution
if re.prog[pc1].ist != IST_OR_BRANCH &&
re.prog[pc1+1].ist == IST_OR_BRANCH &&
re.prog[pc1+2].ist != IST_OR_BRANCH
{
re.prog[pc1].next_is_or = true // set that the next token is an OR
re.prog[pc1+1].rep_min = pc1+2 // failed match jump
// match jump, if an OR chain the next token will be an OR token
mut pc2 := pc1+2
for pc2 < pc-1 {
ist := re.prog[pc2].ist
if ist == IST_GROUP_START {
re.prog[pc1+1].rep_max = re.prog[pc2].goto_pc + 1
break
}
if ist != IST_OR_BRANCH {
re.prog[pc1+1].rep_max = pc2 + 1
break
}
pc2++
}
//C.printf("Compile OR postproc. [%d,OR %d,%d]\n",pc1,pc1+1,pc2)
pc1 = pc2
continue
}
pc1++
}
//******************************************
// DEBUG PRINT REGEX GENERATED CODE
//******************************************
if re.debug > 0 {
re.log_func(re.get_code())
}
//******************************************
return COMPILE_OK, 0
}
// get_code return the compiled code as regex string, note: may be different from the source!
pub fn (re RE) get_code() string {
mut pc1 := 0
mut res := strings.new_builder(re.cc.len*2*re.prog.len)
res.write("========================================\nv RegEx compiler v $V_REGEX_VERSION output:\n")
mut stop_flag := false
for pc1 <= re.prog.len {
tk := re.prog[pc1]
res.write("PC:${pc1:3d}")
res.write(" ist: ")
res.write("${tk.ist:8x}".replace(" ","0") )
res.write(" ")
ist :=tk.ist
if ist == IST_BSLS_CHAR {
res.write("[\\${tk.ch:1c}] BSLS")
} else if ist == IST_PROG_END {
res.write("PROG_END")
stop_flag = true
} else if ist == IST_OR_BRANCH {
res.write("OR ")
} else if ist == IST_CHAR_CLASS_POS {
res.write("[${re.get_char_class(pc1)}] CHAR_CLASS_POS")
} else if ist == IST_CHAR_CLASS_NEG {
res.write("[^${re.get_char_class(pc1)}] CHAR_CLASS_NEG")
} else if ist == IST_DOT_CHAR {
res.write(". DOT_CHAR")
} else if ist == IST_GROUP_START {
res.write("( GROUP_START #:${tk.group_id}")
} else if ist == IST_GROUP_END {
res.write(") GROUP_END #:${tk.group_id}")
} else if ist == IST_SIMPLE_CHAR {
res.write("[${tk.ch:1c}] query_ch")
}
if tk.rep_max == MAX_QUANTIFIER {
res.write(" {${tk.rep_min:3d},MAX}")
}else{
if ist == IST_OR_BRANCH {
res.write(" if false go: ${tk.rep_min:3d} if true go: ${tk.rep_max:3d}")
} else {
res.write(" {${tk.rep_min:3d},${tk.rep_max:3d}}")
}
if tk.greedy == true {
res.write("?")
}
}
res.write("\n")
if stop_flag {
break
}
pc1++
}
res.write("========================================\n")
return res.str()
}
// get_query return a string with a reconstruction of the query starting from the regex program code
pub fn (re RE) get_query() string {
mut res := strings.new_builder(re.query.len*2)
if (re.flag & F_MS) != 0 {
res.write("^")
}
mut i := 0
for i < re.prog.len && re.prog[i].ist != IST_PROG_END && re.prog[i].ist != 0{
tk := &re.prog[i]
ch := tk.ist
// GROUP start
if ch == IST_GROUP_START {
if re.debug == 0 {
res.write("(")
} else {
res.write("#${tk.group_id}(")
}
i++
continue
}
// GROUP end
if ch == IST_GROUP_END {
res.write(")")
}
// OR branch
if ch == IST_OR_BRANCH {
res.write("|")
if re.debug > 0 {
res.write("{${tk.rep_min},${tk.rep_max}}")
}
i++
continue
}
// char class
if ch == IST_CHAR_CLASS_NEG || ch == IST_CHAR_CLASS_POS {
res.write("[")
if ch == IST_CHAR_CLASS_NEG {
res.write("^")
}
res.write("${re.get_char_class(i)}")
res.write("]")
}
// bsls char
if ch == IST_BSLS_CHAR {
res.write("\\${tk.ch:1c}")
}
// IST_DOT_CHAR
if ch == IST_DOT_CHAR {
res.write(".")
}
// char alone
if ch == IST_SIMPLE_CHAR {
if byte(ch) in BSLS_ESCAPE_LIST {
res.write("\\")
}
res.write("${tk.ch:c}")
}
// quantifier
if !(tk.rep_min == 1 && tk.rep_max == 1) {
if tk.rep_min == 0 && tk.rep_max == 1 {
res.write("?")
} else if tk.rep_min == 1 && tk.rep_max == MAX_QUANTIFIER {
res.write("+")
} else if tk.rep_min == 0 && tk.rep_max == MAX_QUANTIFIER {
res.write("*")
} else {
if tk.rep_max == MAX_QUANTIFIER {
res.write("{${tk.rep_min},MAX}")
} else {
res.write("{${tk.rep_min},${tk.rep_max}}")
}
if tk.greedy == true {
res.write("?")
}
}
}
i++
}
if (re.flag & F_ME) != 0 {
res.write("$")
}
return res.str()
}
/******************************************************************************
*
* Matching
*
******************************************************************************/
enum match_state{
start = 0,
stop,
end,
new_line,
ist_load, // load and execute instruction
ist_next, // go to next instruction
ist_next_ks, // go to next instruction without clenaning the state
ist_quant_p, // match positive ,quantifier check
ist_quant_n, // match negative, quantifier check
ist_quant_pg, // match positive ,group quantifier check
ist_quant_ng, // match negative ,group quantifier check
}
fn state_str(s match_state) string {
match s{
.start { return "start" }
.stop { return "stop" }
.end { return "end" }
.new_line { return "new line" }
.ist_load { return "ist_load" }
.ist_next { return "ist_next" }
.ist_next_ks { return "ist_next_ks" }
.ist_quant_p { return "ist_quant_p" }
.ist_quant_n { return "ist_quant_n" }
.ist_quant_pg { return "ist_quant_pg" }
.ist_quant_ng { return "ist_quant_ng" }
else { return "UNKN" }
}
}
struct StateObj {
pub mut:
match_flag bool = false
match_index int = -1
match_first int = -1
}
pub fn (re mut RE) match_base(in_txt byteptr, in_txt_len int ) (int,int) {
// result status
mut result := NO_MATCH_FOUND // function return
mut first_match := -1 //index of the first match
mut i := 0 // source string index
mut ch := u32(0) // examinated char
mut char_len := 0 // utf8 examinated char len
mut m_state := match_state.start // start point for the matcher FSM
mut pc := -1 // program counter
mut state := StateObj{} // actual state
mut ist := u32(0) // actual instruction
mut l_ist := u32(0) // last matched instruction
mut group_stack := [-1].repeat(re.group_max)
mut group_data := [-1].repeat(re.group_max)
mut group_index := -1 // group id used to know how many groups are open
mut step_count := 0 // stats for debug
mut dbg_line := 0 // count debug line printed
re.reset()
if re.debug>0 {
// print header
mut h_buf := strings.new_builder(32)
h_buf.write("flags: ")
h_buf.write("${re.flag:8x}".replace(" ","0"))
h_buf.write("\n")
re.log_func(h_buf.str())
}
for m_state != .end {
if pc >= 0 && pc < re.prog.len {
ist = re.prog[pc].ist
}else if pc >= re.prog.len {
//C.printf("ERROR!! PC overflow!!\n")
return ERR_INTERNAL_ERROR, i
}
//******************************************
// DEBUG LOG
//******************************************
if re.debug>0 {
mut buf2 := strings.new_builder(re.cc.len+128)
// print all the instructions
// end of the input text
if i >= in_txt_len {
buf2.write("# ${step_count:3d} END OF INPUT TEXT\n")
re.log_func(buf2.str())
}else{
// print only the exe instruction
if (re.debug == 1 && m_state == .ist_load) ||
re.debug == 2
{
if ist == IST_PROG_END {
buf2.write("# ${step_count:3d} PROG_END\n")
}
else if ist == 0 || m_state in [.start,.ist_next,.stop] {
buf2.write("# ${step_count:3d} s: ${state_str(m_state):12s} PC: NA\n")
}else{
ch, char_len = re.get_charb(in_txt,i)
buf2.write("# ${step_count:3d} s: ${state_str(m_state):12s} PC: ${pc:3d}=>")
buf2.write("${ist:8x}".replace(" ","0"))
buf2.write(" i,ch,len:[${i:3d},'${utf8_str(ch)}',${char_len}] f.m:[${first_match:3d},${state.match_index:3d}] ")
if ist == IST_SIMPLE_CHAR {
buf2.write("query_ch: [${re.prog[pc].ch:1c}]")
} else {
if ist == IST_BSLS_CHAR {
buf2.write("BSLS [\\${re.prog[pc].ch:1c}]")
} else if ist == IST_PROG_END {
buf2.write("PROG_END")
} else if ist == IST_OR_BRANCH {
buf2.write("OR")
} else if ist == IST_CHAR_CLASS_POS {
buf2.write("CHAR_CLASS_POS[${re.get_char_class(pc)}]")
} else if ist == IST_CHAR_CLASS_NEG {
buf2.write("CHAR_CLASS_NEG[${re.get_char_class(pc)}]")
} else if ist == IST_DOT_CHAR {
buf2.write("DOT_CHAR")
} else if ist == IST_GROUP_START {
tmp_gi :=re.prog[pc].group_id
tmp_gr := re.prog[re.prog[pc].goto_pc].group_rep
buf2.write("GROUP_START #:${tmp_gi} rep:${tmp_gr} ")
} else if ist == IST_GROUP_END {
buf2.write("GROUP_END #:${re.prog[pc].group_id} deep:${group_index}")
}
}
if re.prog[pc].rep_max == MAX_QUANTIFIER {
buf2.write("{${re.prog[pc].rep_min},MAX}:${re.prog[pc].rep}")
} else {
buf2.write("{${re.prog[pc].rep_min},${re.prog[pc].rep_max}}:${re.prog[pc].rep}")
}
if re.prog[pc].greedy == true {
buf2.write("?")
}
buf2.write(" (#${group_index})\n")
}
re.log_func(buf2.str())
}
}
step_count++
dbg_line++
}
//******************************************
// we're out of text, manage it
if i >= in_txt_len || m_state == .new_line {
// manage groups
if group_index >= 0 && state.match_index >= 0 {
//C.printf("End text with open groups!\n")
// close the groups
for group_index >= 0 {
tmp_pc := group_data[group_index]
re.prog[tmp_pc].group_rep++
/*
C.printf("Closing group %d {%d,%d}:%d\n",
group_index,
re.prog[tmp_pc].rep_min,
re.prog[tmp_pc].rep_max,
re.prog[tmp_pc].group_rep
)
*/
if re.prog[tmp_pc].group_rep >= re.prog[tmp_pc].rep_min{
start_i := group_stack[group_index]
group_stack[group_index]=-1
// save group results
g_index := re.prog[tmp_pc].group_id*2
if start_i >= 0 {
re.groups[g_index] = start_i
} else {
re.groups[g_index] = 0
}
re.groups[g_index+1] = i
// continuous save, save until we have space
if re.group_csave_index > 0 {
// check if we have space to save the record
if (re.group_csave_index + 3) < re.group_csave.len {
// incrment counter
re.group_csave[0]++
// save the record
re.group_csave[re.group_csave_index++] = g_index // group id
re.group_csave[re.group_csave_index++] = re.groups[g_index] // start
re.group_csave[re.group_csave_index++] = re.groups[g_index+1] // end
}
}
}
group_index--
}
}
// manage IST_DOT_CHAR
m_state == .end
break
//return NO_MATCH_FOUND,0
}
// starting and init
if m_state == .start {
pc = -1
i = 0
m_state = .ist_next
continue
}
// ist_next, next instruction reseting its state
if m_state == .ist_next {
pc = pc + 1
re.prog[pc].reset()
// check if we are in the program bounds
if pc < 0 || pc > re.prog.len {
//C.printf("ERROR!! PC overflow!!\n")
return ERR_INTERNAL_ERROR, i
}
m_state = .ist_load
continue
}
// ist_next_ks, next instruction keeping its state
if m_state == .ist_next_ks {
pc = pc + 1
// check if we are in the program bounds
if pc < 0 || pc > re.prog.len {
//C.printf("ERROR!! PC overflow!!\n")
return ERR_INTERNAL_ERROR, i
}
m_state = .ist_load
continue
}
// load the char
ch, char_len = re.get_charb(in_txt,i)
// check new line if flag F_NL enabled
if (re.flag & F_NL) != 0 && char_len == 1 && byte(ch) in NEW_LINE_LIST {
m_state = .new_line
continue
}
// check if stop
if m_state == .stop {
// if we are in restore state ,do it and restart
//C.printf("re.state_stack_index %d\n",re.state_stack_index )
if re.state_stack_index >=0 && re.state_stack[re.state_stack_index].pc >= 0 {
i = re.state_stack[re.state_stack_index].i
pc = re.state_stack[re.state_stack_index].pc
state.match_index = re.state_stack[re.state_stack_index].mi
group_index = re.state_stack[re.state_stack_index].group_stack_index
m_state = .ist_load
continue
}
if ist == IST_PROG_END {
return first_match,i
}
// exit on no match
return result,0
}
// ist_load
if m_state == .ist_load {
// program end
if ist == IST_PROG_END {
// if we are in match exit well
if group_index >= 0 && state.match_index >= 0 {
group_index = -1
}
// we have a DOT MATCH on going
//C.printf("IST_PROG_END l_ist: %08x\n", l_ist)
if re.state_stack_index>=0 && l_ist == IST_DOT_CHAR {
m_state = .stop
continue
}
re.state_stack_index = -1
m_state = .stop
continue
}
// check GROUP start, no quantifier is checkd for this token!!
else if ist == IST_GROUP_START {
group_index++
group_data[group_index] = re.prog[pc].goto_pc // save where is IST_GROUP_END, we will use it for escape
group_stack[group_index]=i // index where we start to manage
//C.printf("group_index %d rep %d\n", group_index, re.prog[re.prog[pc].goto_pc].group_rep)
m_state = .ist_next
continue
}
// check GROUP end
else if ist == IST_GROUP_END {
// we are in matching streak
if state.match_index >= 0 {
// restore txt index stack and save the group data
//C.printf("g.id: %d group_index: %d\n", re.prog[pc].group_id, group_index)
if group_index >= 0 {
start_i := group_stack[group_index]
//group_stack[group_index]=-1
// save group results
g_index := re.prog[pc].group_id*2
if start_i >= 0 {
re.groups[g_index] = start_i
} else {
re.groups[g_index] = 0
}
re.groups[g_index+1] = i
//C.printf("GROUP %d END [%d, %d]\n", re.prog[pc].group_id, re.groups[g_index], re.groups[g_index+1])
// continuous save, save until we have space
if re.group_csave_index > 0 {
// check if we have space to save the record
if (re.group_csave_index + 3) < re.group_csave.len {
// incrment counter
re.group_csave[0]++
// save the record
re.group_csave[re.group_csave_index++] = g_index // group id
re.group_csave[re.group_csave_index++] = re.groups[g_index] // start
re.group_csave[re.group_csave_index++] = re.groups[g_index+1] // end
}
}
}
re.prog[pc].group_rep++ // increase repetitions
//C.printf("GROUP %d END %d\n", group_index, re.prog[pc].group_rep)
m_state = .ist_quant_pg
continue
}
m_state = .ist_quant_ng
continue
}
// check OR
else if ist == IST_OR_BRANCH {
if state.match_index >= 0 {
pc = re.prog[pc].rep_max
//C.printf("IST_OR_BRANCH True pc: %d\n", pc)
}else{
pc = re.prog[pc].rep_min
//C.printf("IST_OR_BRANCH False pc: %d\n", pc)
}
re.prog[pc].reset()
m_state == .ist_load
continue
}
// check IST_DOT_CHAR
else if ist == IST_DOT_CHAR {
//C.printf("IST_DOT_CHAR rep: %d\n", re.prog[pc].rep)
state.match_flag = true
l_ist = u32(IST_DOT_CHAR)
if first_match < 0 {
first_match = i
}
state.match_index = i
re.prog[pc].rep++
//if re.prog[pc].rep >= re.prog[pc].rep_min && re.prog[pc].rep <= re.prog[pc].rep_max {
if re.prog[pc].rep >= 0 && re.prog[pc].rep <= re.prog[pc].rep_max {
//C.printf("DOT CHAR save state : %d\n", re.state_stack_index)
// save the state
// manage first dot char
if re.state_stack_index < 0 {
re.state_stack_index++
}
re.state_stack[re.state_stack_index].pc = pc
re.state_stack[re.state_stack_index].mi = state.match_index
re.state_stack[re.state_stack_index].group_stack_index = group_index
} else {
re.state_stack[re.state_stack_index].pc = -1
re.state_stack[re.state_stack_index].mi = -1
re.state_stack[re.state_stack_index].group_stack_index = -1
}
if re.prog[pc].rep >= 1 && re.state_stack_index >= 0 {
re.state_stack[re.state_stack_index].i = i + char_len
}
// manage * and {0,} quantifier
if re.prog[pc].rep_min > 0 {
i += char_len // next char
l_ist = u32(IST_DOT_CHAR)
}
m_state = .ist_next
continue
}
// char class IST
else if ist == IST_CHAR_CLASS_POS || ist == IST_CHAR_CLASS_NEG {
state.match_flag = false
mut cc_neg := false
if ist == IST_CHAR_CLASS_NEG {
cc_neg = true
}
mut cc_res := re.check_char_class(pc,ch)
if cc_neg {
cc_res = !cc_res
}
if cc_res {
state.match_flag = true
l_ist = u32(IST_CHAR_CLASS_POS)
if first_match < 0 {
first_match = i
}
state.match_index = i
re.prog[pc].rep++ // increase repetitions
i += char_len // next char
m_state = .ist_quant_p
continue
}
m_state = .ist_quant_n
continue
}
// check bsls
else if ist == IST_BSLS_CHAR {
state.match_flag = false
tmp_res := re.prog[pc].validator(byte(ch))
//C.printf("BSLS in_ch: %c res: %d\n", ch, tmp_res)
if tmp_res {
state.match_flag = true
l_ist = u32(IST_BSLS_CHAR)
if first_match < 0 {
first_match = i
}
state.match_index = i
re.prog[pc].rep++ // increase repetitions
i += char_len // next char
m_state = .ist_quant_p
continue
}
m_state = .ist_quant_n
continue
}
// simple char IST
else if ist == IST_SIMPLE_CHAR {
//C.printf("IST_SIMPLE_CHAR\n")
state.match_flag = false
if re.prog[pc].ch == ch
{
state.match_flag = true
l_ist = u32(IST_SIMPLE_CHAR)
if first_match < 0 {
first_match = i
}
//C.printf("state.match_index: %d\n", state.match_index)
state.match_index = i
re.prog[pc].rep++ // increase repetitions
i += char_len // next char
m_state = .ist_quant_p
continue
}
m_state = .ist_quant_n
continue
}
/* UNREACHABLE */
//C.printf("PANIC2!! state: %d\n", m_state)
return ERR_INTERNAL_ERROR, i
}
/***********************************
* Quantifier management
***********************************/
// ist_quant_ng
if m_state == .ist_quant_ng {
// we are finished here
if group_index < 0 {
//C.printf("Early stop!\n")
result = NO_MATCH_FOUND
m_state = .stop
continue
}
tmp_pc := group_data[group_index] // PC to the end of the group token
rep := re.prog[tmp_pc].group_rep // use a temp variable
re.prog[tmp_pc].group_rep = 0 // clear the repetitions
//C.printf(".ist_quant_ng group_pc_end: %d rep: %d\n", tmp_pc,rep)
if rep >= re.prog[tmp_pc].rep_min {
//C.printf("ist_quant_ng GROUP CLOSED OK group_index: %d\n", group_index)
i = group_stack[group_index]
pc = tmp_pc
group_index--
m_state = .ist_next
continue
}
else if re.prog[tmp_pc].next_is_or {
//C.printf("ist_quant_ng OR Negative branch\n")
i = group_stack[group_index]
pc = re.prog[tmp_pc+1].rep_min -1
group_index--
m_state = .ist_next
continue
}
else if rep>0 && rep < re.prog[tmp_pc].rep_min {
//C.printf("ist_quant_ng UNDER THE MINIMUM g.i: %d\n", group_index)
// check if we are inside a group, if yes exit from the nested groups
if group_index > 0{
group_index--
pc = tmp_pc
m_state = .ist_quant_ng //.ist_next
continue
}
if group_index == 0 {
group_index--
pc = tmp_pc // TEST
m_state = .ist_next
continue
}
result = NO_MATCH_FOUND
m_state = .stop
continue
}
else if rep==0 && rep < re.prog[tmp_pc].rep_min {
//C.printf("ist_quant_ng ZERO UNDER THE MINIMUM g.i: %d\n", group_index)
if group_index > 0{
group_index--
pc = tmp_pc
m_state = .ist_quant_ng //.ist_next
continue
}
result = NO_MATCH_FOUND
m_state = .stop
continue
}
//C.printf("DO NOT STAY HERE!! {%d,%d}:%d\n", re.prog[tmp_pc].rep_min, re.prog[tmp_pc].rep_max, rep)
/* UNREACHABLE */
return ERR_INTERNAL_ERROR, i
}
// ist_quant_pg
else if m_state == .ist_quant_pg {
//C.printf(".ist_quant_pg\n")
mut tmp_pc := pc
if group_index >= 0 {
tmp_pc = group_data[group_index]
}
rep := re.prog[tmp_pc].group_rep
if rep < re.prog[tmp_pc].rep_min {
//C.printf("ist_quant_pg UNDER RANGE\n")
pc = re.prog[tmp_pc].goto_pc
m_state = .ist_next
continue
}
else if rep == re.prog[tmp_pc].rep_max {
//C.printf("ist_quant_pg MAX RANGE\n")
re.prog[tmp_pc].group_rep = 0 // clear the repetitions
group_index--
m_state = .ist_next
continue
}
else if rep >= re.prog[tmp_pc].rep_min {
//C.printf("ist_quant_pg IN RANGE group_index:%d\n", group_index)
// check greedy flag, if true exit on minimum
if re.prog[tmp_pc].greedy == true {
re.prog[tmp_pc].group_rep = 0 // clear the repetitions
group_index--
m_state = .ist_next
continue
}
pc = re.prog[tmp_pc].goto_pc - 1
group_index--
m_state = .ist_next
continue
}
/* UNREACHABLE */
//C.printf("PANIC3!! state: %d\n", m_state)
return ERR_INTERNAL_ERROR, i
}
// ist_quant_n
else if m_state == .ist_quant_n {
rep := re.prog[pc].rep
//C.printf("Here!! PC %d is_next_or: %d \n", pc, re.prog[pc].next_is_or)
// zero quantifier * or ?
if rep == 0 && re.prog[pc].rep_min == 0 {
//C.printf("ist_quant_n ZERO RANGE MIN\n")
m_state = .ist_next // go to next ist
continue
}
// match + or *
else if rep >= re.prog[pc].rep_min {
//C.printf("ist_quant_n MATCH RANGE\n")
m_state = .ist_next
continue
}
// check the OR if present
if re.prog[pc].next_is_or {
//C.printf("OR present on failing\n")
state.match_index = -1
m_state = .ist_next
continue
}
// we are in a group manage no match from here
if group_index >= 0 {
//C.printf("ist_quant_n FAILED insied a GROUP group_index:%d\n", group_index)
m_state = .ist_quant_ng
continue
}
// no other options
//C.printf("ist_quant_n NO_MATCH_FOUND\n")
result = NO_MATCH_FOUND
m_state = .stop
continue
//return NO_MATCH_FOUND, 0
}
// ist_quant_p
else if m_state == .ist_quant_p {
// exit on first match
if (re.flag & F_EFM) != 0 {
return i,i+1
}
rep := re.prog[pc].rep
// under range
if rep > 0 && rep < re.prog[pc].rep_min {
//C.printf("ist_quant_p UNDER RANGE\n")
m_state = .ist_load // continue the loop
continue
}
// range ok, continue loop
else if rep >= re.prog[pc].rep_min && rep < re.prog[pc].rep_max {
//C.printf("ist_quant_p IN RANGE\n")
// check greedy flag, if true exit on minimum
if re.prog[pc].greedy == true {
m_state = .ist_next
continue
}
m_state = .ist_load
continue
}
// max reached
else if rep == re.prog[pc].rep_max {
//C.printf("ist_quant_p MAX RANGE\n")
m_state = .ist_next
continue
}
}
/* UNREACHABLE */
//C.printf("PANIC4!! state: %d\n", m_state)
return ERR_INTERNAL_ERROR, i
}
// Check the results
if state.match_index >= 0 {
if group_index < 0 {
//C.printf("OK match,natural end [%d,%d]\n", first_match, i)
return first_match, i
} else {
//C.printf("Skip last group\n")
return first_match,group_stack[group_index--]
}
}
//C.printf("NO_MATCH_FOUND, natural end\n")
return NO_MATCH_FOUND, 0
}
/******************************************************************************
*
* Public functions
*
******************************************************************************/
//
// Inits
//
// regex create a regex object from the query string
pub fn regex(in_query string) (RE,int,int){
mut re := RE{}
re.prog = [Token{}].repeat(in_query.len+1)
re.cc = [CharClass{}].repeat(in_query.len+1)
re.group_max_nested = 8
re_err,err_pos := re.compile(in_query)
return re, re_err, err_pos
}
// new_regex create a REgex of small size, usually sufficient for ordinary use
pub fn new_regex() RE {
return new_regex_by_size(1)
}
// new_regex_by_size create a REgex of large size, mult specify the scale factor of the memory that will be allocated
pub fn new_regex_by_size(mult int) RE {
mut re := RE{}
re.prog = [Token{}].repeat(MAX_CODE_LEN*mult) // max program length, default 256 istructions
re.cc = [CharClass{}].repeat(MAX_CODE_LEN*mult) // char class list
re.group_max_nested = 3*mult // max nested group
return re
}
//
// Matchers
//
pub fn (re mut RE) match_string(in_txt string) (int,int) {
start, end := re.match_base(in_txt.str,in_txt.len)
if start >= 0 && end > start {
if (re.flag & F_MS) != 0 && start > 0 {
return NO_MATCH_FOUND, 0
}
if (re.flag & F_ME) != 0 && end < in_txt.len {
if in_txt[end] in NEW_LINE_LIST {
return start, end
}
return NO_MATCH_FOUND, 0
}
return start, end
}
return start, end
}
//
// Finders
//
// find try to find the first match in the input string
pub fn (re mut RE) find(in_txt string) (int,int) {
mut i := 0
mut start := -1
mut end := -1
old_flag := re.flag
for i < in_txt.len {
// test only the first part of the query string
re.flag |= F_EFM // set to exit on the first token match
mut tmp_end := i+re.query.len
if tmp_end > in_txt.len { tmp_end = in_txt.len }
tmp_txt := string{ str: in_txt.str+i, len: tmp_end-i }
start, end = re.match_base(tmp_txt.str, tmp_txt.len)
if start >= 0 && end > start {
// test a complete match
re.flag = old_flag
tmp_txt1 := string{ str: in_txt.str+i , len: in_txt.len-i }
start, end = re.match_base(tmp_txt1.str, tmp_txt1.len)
if start >= 0 && end > start {
if (re.flag & F_MS) != 0 && (i+start) > 0 {
return NO_MATCH_FOUND, 0
}
if (re.flag & F_ME) != 0 && (i+end) < in_txt.len {
return NO_MATCH_FOUND, 0
}
return i+start, i+end
}
}
i++
if re.flag == F_MS && i>0 {
return NO_MATCH_FOUND, 0
}
}
return NO_MATCH_FOUND, 0
}
// find all the non overlapping occurrences of the match pattern
pub fn (re mut RE) find_all(in_txt string) []int {
mut i := 0
mut res := []int
mut ls := -1
for i < in_txt.len {
s,e := re.find(in_txt[i..])
if s >= 0 && e > s && i+s > ls {
//println("find match in: ${i+s},${i+e} [${in_txt[i+s..i+e]}] ls:$ls")
res << i+s
res << i+e
ls = i+s
i = i+e
continue
} else {
i++
}
}
return res
}
// replace return a string where the matches are replaced with the replace string
pub fn (re mut RE) replace(in_txt string, repl string) string {
pos := re.find_all(in_txt)
if pos.len > 0 {
mut res := ""
mut i := 0
mut s1 := 0
mut e1 := in_txt.len
for i < pos.len {
e1 = pos[i]
res += in_txt[s1..e1] + repl
s1 = pos[i+1]
i += 2
}
res += in_txt[s1..]
return res
}
return in_txt
}
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