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vlib/regex/README.md Normal file
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@ -0,0 +1,411 @@
# V RegEx (Regular expression) 0.9c
[TOC]
## introduction
Write here the introduction
## Basic assumption
In this release, during the writing of the code some assumption are made and are valid for all the features.
1. The matching stop at the end of the string not at the newline chars
2. The basic element of this regex engine are the tokens, in aquery string a simple char is a token. The token is the atomic unit of this regex engine.
## Match positional limiter
The module supports the following features:
- `$` `^` delimiter
`^` (Caret.) Matches the start of the string
`?` Matches the end of the string
## Tokens
The token are the atomic unit used by this regex engine and can be one of the following:
### Simple char
this token is a simple single character like `a`.
### Char class (cc)
The cc match all the char specified in its inside, it is delimited by square brackets `[ ]`
the sequence of chars in the class is evaluated with an OR operation.
For example the following cc `[abc]` match any char that is or `a` or `b` or `c` but doesn't match `C` or `z`.
Inside a cc is possible to specify a "range" of chars, for example `[ad-f]` is equivalent to write `[adef]`.
A cc can have different ranges in the same like `[a-zA-z0-9]` that match all the lowercase,uppercase and numeric chars.
It is possible negate the cc using the caret char at the start of the cc like: `[^abc]` that match every char that is not `a` or `b` or `c`.
A cc can contain meta-chars like: `[a-z\d]` that match all the lowercase latin chars `a-z` and all the digits `\d`.
It is possible to mix all the properties of the char class together.
### Meta-chars
A meta-char is specified by a back slash before a char like `\w` in this case the meta-char is `w`.
A meta-char can match different type of chars.
* `\w` match an alphanumeric char `[a-zA-Z0-9]`
* `\W` match a non alphanumeric char
* `\d` match a digit `[0-9]`
* `\D` match a non digit
* `\s`match a space char, one of `[' ','\t','\n','\r','\v','\f']`
* `\S` match a non space char
* `\a` match only a lowercase char `[a-z]`
* `\A` match only an uppercase char `[A-Z]`
### Quantifier
Each token can have a quantifier that specify how many times the char can or must be matched.
**Short quantifier**
- `?` match 0 or 1 time, `a?b` match both `ab` or `b`
- `+` match at minimum 1 time, `a+` match both `aaa` or `a`
- `*` match 0 or more time, `a*b` match both `aaab` or `ab` or `b`
**Long quantifier**
- `{x}` match exactly x time, `a{2}` match `aa` but doesn't match `aaa` or `a`
- `{min,}` match at minimum min time, `a{2,}` match `aaa` or `aa` bit doesn't march `a`
- `{,max}` match at least 1 and maximum max time, `a{,2}` match `a` and `aa` but doesn't match `aaa`
- `{min,max}` match from min times to max times, `a{2,3}` match `aa` and `aaa` but doesn't match `a` or `aaaa`
a long quantifier may have a `greedy` flag that is the `?` char after the brackets, `{2,4}?` means to match at the minimum possible tokens thus 2.
### dot char
the dot is a particular meta char that match "any char", is more simple explain it with an example:
supposed to have `abccc ddeef` as string to parse with regex, the following table show the query strings and the result of parsing source string.
| query string | result |
| ------------ | ------ |
| `.*c` | `abc` |
| `.*dd` | `abcc dd` |
| `ab.*e` | `abccc dde` |
| `ab.{3} .*e` | `abccc dde` |
the dot char match any char until the next token match is satisfied.
### OR token
the token `|` is an logic OR operation between two consecutive tokens, `a|b` match a char that is `a` or `b`.
The or token can work in a "chained way": `a|(b)|cd ` test first `a` if the char is not `a` the test the group `(b)` and if the group doesn't match test the token `c`.
**note: The OR work at token level! It doesn't work at concatenation level!**
A query string like `abc|bde` is not equal to `(abc)|(bde)`!!
The OR work only on `c|b` not at char concatenation level.
### Groups
Groups are a method to create complex patterns with repetition of blocks of token.
The groups a delimited by round brackets `( )`, groups can be nested and can have a quantifier as all the tokens.
`c(pa)+z` match `cpapaz` or `cpaz` or `cpapapaz` .
`(c(pa)+z ?)+` match `cpaz cpapaz cpapapaz` or `cpapaz`
let analyze this last case, first we have the group 0 that are the most outer round brackets `(...)+`, this group has a quantifier that say to match its content at least one time `+`.
After we have a simple char token `c` and a second group that is the number 1 `(pa)+`, this group try to match the sequence `pa` at least one time as specified by the `+` quantifier.
After we have another simple token `z` and another simple token ` ?` that is the space char (ascii code 32) with the `?` quantifier that say to capture this char or 0 or 1 time
This explain because the `(c(pa)+z ?)+` query string can match `cpaz cpapaz cpapapaz` .
In this implementation the groups are capturing groups that means that the last result for each group can be retrieved from the `RE` struct.
The captured groups are store as couple of index in the field `groups` that is an `[]int` each captured group
**example:**
```v
text := "cpaz cpapaz cpapapaz"
query:= r"(c(pa)+z ?)+"
re, _, _ := regex.regex(query)
println(re.get_query())
// #0(c#1(pa)+z ?)+ // #0 and #1 are the ids of the groups, are shown if re.debug is 1 or 2
start, end := re.match_string(text)
// [start=0, end=20] match => [cpaz cpapaz cpapapaz]
mut gi := 0
for gi < re.groups.len {
if re.groups[gi] >= 0 {
println("${gi/2} :[${text[re.groups[gi]..re.groups[gi+1]]}]")
}
gi += 2
}
// groups captured
// 0 :[cpapapaz]
// 1 :[pa]
```
**note:** *to show the `group id number` in the result of the `get_query()` the flag `debug` of the RE object must be `1` or `2`*
## Flags
It is possible to set some flag in the regex parser that change the behavior of the parser itself.
```v
// example of flag settings
mut re := regex.new_regex()
re.flag = regex.F_BIN
```
- `F_BIN`: parse a string as bytes, utf-8 management disabled.
- `F_EFM`: exit on the first char match in the query, used by the find function
- `F_MS`: match only if the index of the start match is 0, same as `^` at the start of query string
- `F_ME`: match only if the end index of the match is the last char of the input string, same as `$` end of query string
- `F_NL`: stop the matching if found a new line char `\n` or `\r`
## Functions
### Initializer
These function are helper that create the `RE` struct, the struct can be manually create if you need it
**Simplified initializer**
```v
// regex create a regex object from the query string and compile it
pub fn regex(in_query string) (RE,int,int)
```
**Base initializer**
```v
// new_regex create a REgex of small size, usually sufficient for ordinary use
pub fn new_regex() RE
// 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
```
After the base initializer use the regex expression must be compiled with:
```v
// 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)
```
### Functions
These are the operative functions
```v
// match_string try to match the input string, return start and end index if found else start is -1
pub fn (re mut RE) match_string(in_txt string) (int,int)
// find try to find the first match in the input string, return start and end index if found else start is -1
pub fn (re mut RE) find(in_txt string) (int,int)
// find all the non overlapping occurrences of the match pattern, return a list of start end indexes
pub fn (re mut RE) find_all(in_txt string) []int
// replace return a string where the matches are replaced with the replace string, only non overlapped match are used
pub fn (re mut RE) replace(in_txt string, repl string) string
```
## Debugging
This module has few small utilities to help the writing of regex expressions.
**Syntax errors highlight**
the following example code show how to visualize the syntax errors in the compiling pahse:
```v
query:= r"ciao da ab[ab-]" // there is an error, a range not closed
mut re := new_regex()
// re_err ==> is the return value, if < 0 it is an error
// re_pos ==> if re_err < 0, re_pos is the error index in the query string
re_err, err_pos := re.compile(query)
// print the error if one happen
if re_err != COMPILE_OK {
println("query: $query")
lc := "-".repeat(err_pos)
println("err : $lc^")
err_str := re.get_parse_error_string(re_err) // get the error string
println("ERROR: $err_str")
}
// output!!
//query: ciao da ab[ab-]
//err : ----------^
//ERROR: ERR_SYNTAX_ERROR
```
**Compiled code**
It is possible view the compiled code calling the function `get_query()` the result will something like this:
```
========================================
v RegEx compiler v 0.9c output:
PC: 0 ist: 7fffffff [a] query_ch { 1, 1}
PC: 1 ist: 7fffffff [b] query_ch { 1,MAX}
PC: 2 ist: 88000000 PROG_END { 0, 0}
========================================
```
`PC`:`int` is the program counter or step of execution, each single step is a token
`ist`:`hex` is the token instruction id
`[a]` is the char used by the token
`query_ch` is the type of token
`{m,n}` are the quantifier, the greedy flag `?` will be showed if present in the token
**Log debug**
The log debugger allow to print the status of the regex parser when the parser is running.
It is possible to have two different level of debug: 1 is normal while 2 is verbose.
here an example:
*normal*
list only the token instruction with the values
```
// re.flag = 1 // log level normal
flags: 00000000
# 2 s: ist_load PC: 0=>7fffffff i,ch,len:[ 0,'a',1] f.m:[ -1, -1] query_ch: [a]{1,1}:0 (#-1)
# 5 s: ist_load PC: 1=>7fffffff i,ch,len:[ 1,'b',1] f.m:[ 0, 0] query_ch: [b]{2,3}:0? (#-1)
# 7 s: ist_load PC: 1=>7fffffff i,ch,len:[ 2,'b',1] f.m:[ 0, 1] query_ch: [b]{2,3}:1? (#-1)
# 10 PROG_END
```
*verbose*
list all the instruction and states of the parser
```
flags: 00000000
# 0 s: start PC: NA
# 1 s: ist_next PC: NA
# 2 s: ist_load PC: 0=>7fffffff i,ch,len:[ 0,'a',1] f.m:[ -1, -1] query_ch: [a]{1,1}:0 (#-1)
# 3 s: ist_quant_p PC: 0=>7fffffff i,ch,len:[ 1,'b',1] f.m:[ 0, 0] query_ch: [a]{1,1}:1 (#-1)
# 4 s: ist_next PC: NA
# 5 s: ist_load PC: 1=>7fffffff i,ch,len:[ 1,'b',1] f.m:[ 0, 0] query_ch: [b]{2,3}:0? (#-1)
# 6 s: ist_quant_p PC: 1=>7fffffff i,ch,len:[ 2,'b',1] f.m:[ 0, 1] query_ch: [b]{2,3}:1? (#-1)
# 7 s: ist_load PC: 1=>7fffffff i,ch,len:[ 2,'b',1] f.m:[ 0, 1] query_ch: [b]{2,3}:1? (#-1)
# 8 s: ist_quant_p PC: 1=>7fffffff i,ch,len:[ 3,'b',1] f.m:[ 0, 2] query_ch: [b]{2,3}:2? (#-1)
# 9 s: ist_next PC: NA
# 10 PROG_END
# 11 PROG_END
```
the column have the following meaning:
`# 2` number of actual steps from the start of parsing
`s: ist_next` state of the present step
`PC: 1` program counter of the step
`=>7fffffff ` hex code of the instruction
`i,ch,len:[ 0,'a',1]` `i` index in the source string, `ch` the char parsed, `len` the length in byte of the char parsed
`f.m:[ 0, 1]` `f` index of the first match in the source string, `m` index that is actual matching
`query_ch: [b]` token in use and its char
`{2,3}:1?` quantifier `{min,max}`, `:1` is the actual counter of repetition, `?` is the greedy flag if present
## Example code
Here there is a simple code to perform some basically match of strings
```v
struct TestObj {
source string // source string to parse
query string // regex query string
s int // expected match start index
e int // expected match end index
}
const (
tests = [
TestObj{"this is a good.",r"this (\w+) a",0,9},
TestObj{"this,these,those. over",r"(th[eio]se?[,. ])+",0,17},
TestObj{"test1@post.pip.com, pera",r"[\w]+@([\w]+\.)+\w+",0,18},
TestObj{"cpapaz ole. pippo,",r".*c.+ole.*pi",0,14},
TestObj{"adce aabe",r"(a(ab)+)|(a(dc)+)e",0,4},
]
)
fn example() {
for c,tst in tests {
mut re := regex.new_regex()
re_err, err_pos := re.compile(tst.query)
if re_err == regex.COMPILE_OK {
// print the query parsed with the groups ids
re.debug = 1 // set debug on at minimum level
println("#${c:2d} query parsed: ${re.get_query()}")
re.debug = 0
// do the match
start, end := re.match_string(tst.source)
if start >= 0 && end > start {
println("#${c:2d} found in: [$start, $end] => [${tst.source[start..end]}]")
}
// print the groups
mut gi := 0
for gi < re.groups.len {
if re.groups[gi] >= 0 {
println("group ${gi/2:2d} :[${tst.source[re.groups[gi]..re.groups[gi+1]]}]")
}
gi += 2
}
println("")
} else {
// print the compile error
println("query: $tst.query")
lc := "-".repeat(err_pos-1)
println("err : $lc^")
err_str := re.get_parse_error_string(re_err)
println("ERROR: $err_str")
}
}
}
fn main() {
example()
}
```
more example code is available in the test code for the `regex` module `vlib\regex\regex_test.v`.

196
vlib/regex/regex.v
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@ -1,6 +1,6 @@
/**********************************************************************
*
* regex 0.9b
* regex 0.9c
*
* Copyright (c) 2019 Dario Deledda. All rights reserved.
* Use of this source code is governed by an MIT license
@ -18,7 +18,7 @@ module regex
import strings
pub const(
V_REGEX_VERSION = "0.9b" // regex module version
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
@ -47,7 +47,6 @@ const(
//*************************************
// regex program instructions
//*************************************
SIMPLE_CHAR_MASK = u32(0x80000000) // single char mask
IST_SIMPLE_CHAR = u32(0x7FFFFFFF) // single char instruction, 31 bit available to char
// char class 11 0100 AA xxxxxxxx
@ -88,9 +87,11 @@ fn utf8util_char_len(b byte) int {
// get_char get a char from position i and return an u32 with the unicode code
[inline]
fn get_char(in_txt string, i int) (u32,int) {
fn (re RE) get_char(in_txt string, i int) (u32,int) {
// ascii 8 bit
if in_txt.str[i] & 0x80 == 0 {
if (re.flag & F_BIN) !=0 ||
in_txt.str[i] & 0x80 == 0
{
return u32(in_txt.str[i]), 1
}
// unicode char
@ -106,9 +107,11 @@ fn get_char(in_txt string, i int) (u32,int) {
// get_charb get a char from position i and return an u32 with the unicode code
[inline]
fn get_charb(in_txt byteptr, i int) (u32,int) {
fn (re RE) get_charb(in_txt byteptr, i int) (u32,int) {
// ascii 8 bit
if in_txt[i] & 0x80 == 0 {
if (re.flag & F_BIN) !=0 ||
in_txt[i] & 0x80 == 0
{
return u32(in_txt[i]), 1
}
// unicode char
@ -215,8 +218,7 @@ fn utf8_str(ch u32) string {
// simple_log default log function
fn simple_log(txt string) {
C.fprintf(C.stdout, "%s",txt.str)
C.fflush(stdout)
print(txt)
}
/******************************************************************************
@ -228,9 +230,14 @@ 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
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
@ -240,15 +247,14 @@ mut:
// validator function pointer and control char
validator fn (byte) bool
v_ch u32 = u32(0) // debug, helper for recreate the query string
// 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
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
next_is_or bool = false // true if the next token is an OR
}
fn (tok mut Token) reset() {
@ -262,13 +268,14 @@ fn (tok mut Token) reset() {
******************************************************************************/
pub const (
//F_FND = 0x00000001 // check until the end of the input string, it act like a "find first match", not efficient!!
//F_NL = 0x00000002 // end the match when find a new line symbol
//F_PM = 0x00000004 // partial match: if the source text finish and the match is positive until then return true
F_NL = 0x00000002 // end the match when find a new line symbol
F_MS = 0x00000008 // match true only if the match is at the start of the string
F_ME = 0x00000010 // match true only if the match is at the end of the string
F_EFM = 0x01000000 // exit on first token matched, used by search
F_BIN = 0x02000000 // work only on bytes, ignore utf-8
)
struct StateDotObj{
@ -364,7 +371,7 @@ fn (re RE) parse_bsls(in_txt string, in_i int) (int,int){
for i < in_txt.len {
// get our char
char_tmp,char_len := get_char(in_txt,i)
char_tmp,char_len := re.get_char(in_txt,i)
ch := byte(char_tmp)
if status == .start && ch == `\\` {
@ -512,7 +519,7 @@ fn (re mut RE) parse_char_class(in_txt string, in_i int) (int, int, u32) {
}
// get our char
char_tmp,char_len := get_char(in_txt,i)
char_tmp,char_len := re.get_char(in_txt,i)
ch := byte(char_tmp)
//C.printf("CC #%3d ch: %c\n",i,ch)
@ -614,11 +621,13 @@ enum Quant_parse_state {
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) {
// 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
@ -634,7 +643,7 @@ fn (re RE) parse_quantifier(in_txt string, in_i int) (int, int, int) {
// exit on no compatible char with {} quantifier
if utf8util_char_len(ch) != 1 {
return ERR_SYNTAX_ERROR,i,0
return ERR_SYNTAX_ERROR,i,0,false
}
// min parsing skip if comma present
@ -670,13 +679,17 @@ fn (re RE) parse_quantifier(in_txt string, in_i int) (int, int, int) {
// single value {4}
if status == .min_parse && ch == `}` {
q_max = q_min
return q_min, q_max, i-in_i+2
status = .greedy
continue
}
// end without max
if status == .comma_checked && ch == `}` {
q_max = MAX_QUANTIFIER
return q_min, q_max, i-in_i+2
status = .greedy
continue
}
// start max parsing
@ -696,17 +709,40 @@ fn (re RE) parse_quantifier(in_txt string, in_i int) (int, int, int) {
continue
}
// end the parsing
// finished the quantifier
if status == .max_parse && ch == `}` {
return q_min, q_max, i-in_i+2
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
return ERR_SYNTAX_ERROR, i, 0, false
}
// not a conform {} quantifier
return ERR_SYNTAX_ERROR,i,0
return ERR_SYNTAX_ERROR, i, 0, false
}
//
@ -733,7 +769,7 @@ pub fn (re mut RE) compile(in_txt string) (int,int) {
mut char_len := 0
//C.printf("i: %3d ch: %c\n", i, in_txt.str[i])
char_tmp,char_len = get_char(in_txt,i)
char_tmp,char_len = re.get_char(in_txt,i)
//
// check special cases: $ ^
@ -848,13 +884,14 @@ pub fn (re mut RE) compile(in_txt string) (int,int) {
}
`{` {
min,max,tmp := re.parse_quantifier(in_txt, i+1)
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]\n",min,max,in_txt[i..i+tmp])
//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 {
@ -879,7 +916,7 @@ pub fn (re mut RE) compile(in_txt string) (int,int) {
}
}
// IST_CHAR_CLASS
// 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)
@ -912,14 +949,14 @@ pub fn (re mut RE) compile(in_txt string) (int,int) {
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].v_ch = BSLS_VALIDATOR_ARRAY[bsls_index].ch
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 = get_char(in_txt,i)
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!)
@ -930,8 +967,9 @@ pub fn (re mut RE) compile(in_txt string) (int,int) {
}
// IST_SIMPLE_CHAR
tmp_code = (tmp_code | char_tmp) & IST_SIMPLE_CHAR
re.prog[pc].ist = tmp_code
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)
@ -1044,7 +1082,7 @@ pub fn (re RE) get_code() string {
res.write(" ")
ist :=re.prog[pc1].ist
if ist == IST_BSLS_CHAR {
res.write("[\\${re.prog[pc1].v_ch:1c}] BSLS")
res.write("[\\${re.prog[pc1].ch:1c}] BSLS")
} else if ist == IST_PROG_END {
res.write("PROG_END")
stop_flag = true
@ -1060,8 +1098,8 @@ pub fn (re RE) get_code() string {
res.write("( GROUP_START #:${re.prog[pc1].group_id}")
} else if ist == IST_GROUP_END {
res.write(") GROUP_END #:${re.prog[pc1].group_id}")
} else if ist & SIMPLE_CHAR_MASK == 0 {
res.write("[${ist & IST_SIMPLE_CHAR:1c}] query_ch")
} else if ist == IST_SIMPLE_CHAR {
res.write("[${re.prog[pc1].ch:1c}] query_ch")
}
if re.prog[pc1].rep_max == MAX_QUANTIFIER {
@ -1072,6 +1110,9 @@ pub fn (re RE) get_code() string {
} else {
res.write(" {${re.prog[pc1].rep_min:3d},${re.prog[pc1].rep_max:3d}}")
}
if re.prog[pc1].greedy == true {
res.write("?")
}
}
res.write("\n")
if stop_flag {
@ -1136,7 +1177,7 @@ pub fn (re RE) get_query() string {
// bsls char
if ch == IST_BSLS_CHAR {
res.write("\\${re.prog[i].v_ch:1c}")
res.write("\\${re.prog[i].ch:1c}")
}
// IST_DOT_CHAR
@ -1145,11 +1186,11 @@ pub fn (re RE) get_query() string {
}
// char alone
if ch & SIMPLE_CHAR_MASK == 0 {
if ch == IST_SIMPLE_CHAR {
if byte(ch) in BSLS_ESCAPE_LIST {
res.write("\\")
}
res.write("${re.prog[i].ist:c}")
res.write("${re.prog[i].ch:c}")
}
// quantifier
@ -1166,6 +1207,9 @@ pub fn (re RE) get_query() string {
} else {
res.write("{${re.prog[i].rep_min},${re.prog[i].rep_max}}")
}
if re.prog[i].greedy == true {
res.write("?")
}
}
}
@ -1187,10 +1231,11 @@ enum match_state{
start = 0,
stop,
end,
new_line,
ist_load, // load and execute istruction
ist_next, // go to next istruction
ist_next_ks, // go to next istruction without clenaning the state
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
@ -1202,6 +1247,7 @@ fn state_str(s match_state) string {
.start { return "start" }
.stop { return "stop" }
.end { return "end" }
.new_line { return "new line" }
.ist_load { return "ist_load" }
.ist_next { return "ist_next" }
@ -1277,7 +1323,7 @@ pub fn (re mut RE) match_base(in_txt byteptr, in_txt_len int ) (int,int) {
re.log_func(buf2.str())
}else{
// print only the exe istruction
// print only the exe instruction
if (re.debug == 1 && m_state == .ist_load) ||
re.debug == 2
{
@ -1287,23 +1333,17 @@ pub fn (re mut RE) match_base(in_txt byteptr, in_txt_len int ) (int,int) {
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 = get_charb(in_txt,i)
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},${state.match_index:3d}] ")
if ist & SIMPLE_CHAR_MASK == 0 {
if char_len < 4 {
tmp_c := ist & IST_SIMPLE_CHAR
buf2.write("query_ch: [${tmp_c:1c}]")
} else {
tmp_c := ist | IST_SIMPLE_CHAR
buf2.write("query_ch: [${tmp_c:1c}]")
}
if ist == IST_SIMPLE_CHAR {
buf2.write("query_ch: [${re.prog[pc].ch:1c}]")
} else {
if ist == IST_BSLS_CHAR {
buf2.write("BSLS [\\${re.prog[pc].v_ch:1c}]")
buf2.write("BSLS [\\${re.prog[pc].ch:1c}]")
} else if ist == IST_PROG_END {
buf2.write("PROG_END")
} else if ist == IST_OR_BRANCH {
@ -1327,6 +1367,9 @@ pub fn (re mut RE) match_base(in_txt byteptr, in_txt_len int ) (int,int) {
} 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())
@ -1338,7 +1381,7 @@ pub fn (re mut RE) match_base(in_txt byteptr, in_txt_len int ) (int,int) {
//******************************************
// we're out of text, manage it
if i >= in_txt_len {
if i >= in_txt_len || m_state == .new_line {
// manage groups
if group_index >= 0 && state.match_index >= 0 {
@ -1376,7 +1419,7 @@ pub fn (re mut RE) match_base(in_txt byteptr, in_txt_len int ) (int,int) {
// manage IST_DOT_CHAR
if re.state_stack_index >= 0 {
//C.printf("DOT CHAR text end management!\n")
// if DOT CHAR is not the last istruction and we are still going, then no match!!
// if DOT CHAR is not the last instruction and we are still going, then no match!!
if pc < re.prog.len && re.prog[pc+1].ist != IST_PROG_END {
return NO_MATCH_FOUND,0
}
@ -1395,7 +1438,7 @@ pub fn (re mut RE) match_base(in_txt byteptr, in_txt_len int ) (int,int) {
continue
}
// ist_next, next istruction reseting its state
// ist_next, next instruction reseting its state
if m_state == .ist_next {
pc = pc + 1
re.prog[pc].reset()
@ -1408,7 +1451,7 @@ pub fn (re mut RE) match_base(in_txt byteptr, in_txt_len int ) (int,int) {
continue
}
// ist_next_ks, next istruction keeping its state
// 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
@ -1421,7 +1464,13 @@ pub fn (re mut RE) match_base(in_txt byteptr, in_txt_len int ) (int,int) {
}
// load the char
ch, char_len = get_charb(in_txt,i)
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 {
@ -1547,7 +1596,7 @@ pub fn (re mut RE) match_base(in_txt byteptr, in_txt_len int ) (int,int) {
m_state = .ist_next
continue
}
// IST_DOT_CHAR is the last istruction, get all
// IST_DOT_CHAR is the last instruction, get all
else {
//C.printf("We are the last one!\n")
pc--
@ -1613,12 +1662,11 @@ pub fn (re mut RE) match_base(in_txt byteptr, in_txt_len int ) (int,int) {
}
// simple char IST
else if ist & IST_SIMPLE_CHAR != 0 {
else if ist == IST_SIMPLE_CHAR {
//C.printf("IST_SIMPLE_CHAR\n")
state.match_flag = false
if (char_len<4 && ist == ch) ||
(char_len == 4 && (ist | SIMPLE_CHAR_MASK) == ch )
if re.prog[pc].ch == ch
{
state.match_flag = true
@ -1749,6 +1797,15 @@ pub fn (re mut RE) match_base(in_txt byteptr, in_txt_len int ) (int,int) {
}
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
@ -1832,6 +1889,13 @@ pub fn (re mut RE) match_base(in_txt byteptr, in_txt_len int ) (int,int) {
// 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
}

1
vlib/regex/regex_test.v
View File

@ -65,6 +65,7 @@ match_test_suite = [
TestItem{"cpapaz ole. pippo,",r".*c.+ole.*pi",0,14},
TestItem{"cpapaz ole. pipipo,",r".*c.+ole.*p([ip])+o",0,18},
TestItem{"cpapaz ole. pipipo",r"^.*c.+ol?e.*p([ip])+o$",0,18},
TestItem{"abbb",r"ab{2,3}?",0,3},
// negative
TestItem{"zthis ciao",r"((t[hieo]+se?)\s*)+",-1,0},