81 lines
2.7 KiB
V
81 lines
2.7 KiB
V
/**********************************************************************
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* regex samples
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*
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* Copyright (c) 2019-2021 Dario Deledda. All rights reserved.
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* Use of this source code is governed by an MIT license
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* that can be found in the LICENSE file.
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*
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* This file contains a collection of regex samples
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*
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**********************************************************************/
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import regex
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/*
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This simple function converts an HTML RGB value with 3 or 6 hex digits to a u32 value,
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this function is not optimized and it is only for didatical purpose
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example: #A0B0CC #A9F
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*/
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fn convert_html_rgb(in_col string) u32 {
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mut n_digit := if in_col.len == 4 { 1 } else { 2 }
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mut col_mul := if in_col.len == 4 { 4 } else { 0 }
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// this is the regex query, it uses V string interpolation to customize the regex query
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// NOTE: if you want use escaped code you must use the r"" (raw) strings,
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// *** please remember that V interpoaltion doesn't work on raw strings. ***
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query := '#([a-fA-F0-9]{$n_digit})([a-fA-F0-9]{$n_digit})([a-fA-F0-9]{$n_digit})'
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mut re := regex.regex_opt(query) or { panic(err) }
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start, end := re.match_string(in_col)
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println('start: $start, end: $end')
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mut res := u32(0)
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if start >= 0 {
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group_list := re.get_group_list()
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r := ('0x' + in_col[group_list[0].start..group_list[0].end]).int() << col_mul
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g := ('0x' + in_col[group_list[1].start..group_list[1].end]).int() << col_mul
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b := ('0x' + in_col[group_list[2].start..group_list[2].end]).int() << col_mul
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println('r: $r g: $g b: $b')
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res = u32(r) << 16 | u32(g) << 8 | u32(b)
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}
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return res
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}
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/*
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This function demonstrates the use of the named groups
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*/
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fn convert_html_rgb_n(in_col string) u32 {
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mut n_digit := if in_col.len == 4 { 1 } else { 2 }
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mut col_mul := if in_col.len == 4 { 4 } else { 0 }
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query := '#(?P<red>[a-fA-F0-9]{$n_digit})(?P<green>[a-fA-F0-9]{$n_digit})(?P<blue>[a-fA-F0-9]{$n_digit})'
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mut re := regex.regex_opt(query) or { panic(err) }
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start, end := re.match_string(in_col)
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println('start: $start, end: $end')
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mut res := u32(0)
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if start >= 0 {
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red_s, red_e := re.get_group_bounds_by_name('red')
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r := ('0x' + in_col[red_s..red_e]).int() << col_mul
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green_s, green_e := re.get_group_bounds_by_name('green')
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g := ('0x' + in_col[green_s..green_e]).int() << col_mul
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blue_s, blue_e := re.get_group_bounds_by_name('blue')
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b := ('0x' + in_col[blue_s..blue_e]).int() << col_mul
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println('r: $r g: $g b: $b')
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res = u32(r) << 16 | u32(g) << 8 | u32(b)
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}
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return res
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}
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fn main() {
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// convert HTML rgb color using groups
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println(convert_html_rgb('#A0b0Cc').hex())
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println(convert_html_rgb('#ABC').hex())
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// convert HTML rgb color using named groups
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println(convert_html_rgb_n('#A0B0CC').hex())
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println(convert_html_rgb_n('#ABC').hex())
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}
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