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authorIndrajith K L2022-12-03 17:00:20 +0530
committerIndrajith K L2022-12-03 17:00:20 +0530
commitf5c4671bfbad96bf346bd7e9a21fc4317b4959df (patch)
tree2764fc62da58f2ba8da7ed341643fc359873142f /v_windows/v/vlib/strconv/atoi.v
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Adds most of the toolsHEADmaster
Diffstat (limited to 'v_windows/v/vlib/strconv/atoi.v')
-rw-r--r--v_windows/v/vlib/strconv/atoi.v261
1 files changed, 261 insertions, 0 deletions
diff --git a/v_windows/v/vlib/strconv/atoi.v b/v_windows/v/vlib/strconv/atoi.v
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+module strconv
+
+// Copyright (c) 2019-2021 Alexander Medvednikov. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+// TODO: use optionals, or some way to return default with error.
+const (
+ // int_size is the size in bits of an int or uint value.
+ // int_size = 32 << (~u32(0) >> 63)
+ // max_u64 = u64(u64(1 << 63) - 1)
+ int_size = 32
+ max_u64 = u64(18446744073709551615) // as u64 // use this until we add support
+)
+
+pub fn byte_to_lower(c byte) byte {
+ return c | (`x` - `X`)
+}
+
+// common_parse_uint is called by parse_uint and allows the parsing
+// to stop on non or invalid digit characters and return with an error
+pub fn common_parse_uint(s string, _base int, _bit_size int, error_on_non_digit bool, error_on_high_digit bool) ?u64 {
+ result, err := common_parse_uint2(s, _base, _bit_size)
+ // TODO: error_on_non_digit and error_on_high_digit have no difference
+ if err != 0 && (error_on_non_digit || error_on_high_digit) {
+ match err {
+ -1 { return error('common_parse_uint: wrong base $_base for $s') }
+ -2 { return error('common_parse_uint: wrong bit size $_bit_size for $s') }
+ -3 { return error('common_parse_uint: integer overflow $s') }
+ else { return error('common_parse_uint: syntax error $s') }
+ }
+ }
+ return result
+}
+
+// the first returned value contains the parsed value,
+// the second returned value contains the error code (0 = OK, >1 = index of first non-parseable character + 1, -1 = wrong base, -2 = wrong bit size, -3 = overflow)
+pub fn common_parse_uint2(s string, _base int, _bit_size int) (u64, int) {
+ mut bit_size := _bit_size
+ mut base := _base
+ if s.len < 1 || !underscore_ok(s) {
+ // return error('parse_uint: syntax error $s')
+ return u64(0), 1
+ }
+ base0 := base == 0
+ mut start_index := 0
+ if 2 <= base && base <= 36 {
+ // valid base; nothing to do
+ } else if base == 0 {
+ // Look for octal, hex prefix.
+ base = 10
+ if s[0] == `0` {
+ if s.len >= 3 && byte_to_lower(s[1]) == `b` {
+ base = 2
+ start_index += 2
+ } else if s.len >= 3 && byte_to_lower(s[1]) == `o` {
+ base = 8
+ start_index += 2
+ } else if s.len >= 3 && byte_to_lower(s[1]) == `x` {
+ base = 16
+ start_index += 2
+ }
+ // manage leading zeros in decimal base's numbers
+ else if s.len >= 2 && (s[1] >= `0` && s[1] <= `9`) {
+ base = 10
+ start_index++
+ } else {
+ base = 8
+ start_index++
+ }
+ }
+ } else {
+ // return error('parse_uint: base error $s - $base')
+ return u64(0), -1
+ }
+ if bit_size == 0 {
+ bit_size = strconv.int_size
+ } else if bit_size < 0 || bit_size > 64 {
+ // return error('parse_uint: bitsize error $s - $bit_size')
+ return u64(0), -2
+ }
+ // Cutoff is the smallest number such that cutoff*base > maxUint64.
+ // Use compile-time constants for common cases.
+ cutoff := strconv.max_u64 / u64(base) + u64(1)
+ max_val := if bit_size == 64 { strconv.max_u64 } else { (u64(1) << u64(bit_size)) - u64(1) }
+ mut n := u64(0)
+ for i in start_index .. s.len {
+ c := s[i]
+ cl := byte_to_lower(c)
+ mut d := byte(0)
+ if c == `_` && base0 {
+ // underscore_ok already called
+ continue
+ } else if `0` <= c && c <= `9` {
+ d = c - `0`
+ } else if `a` <= cl && cl <= `z` {
+ d = cl - `a` + 10
+ } else {
+ return n, i + 1
+ }
+ if d >= byte(base) {
+ return n, i + 1
+ }
+ if n >= cutoff {
+ // n*base overflows
+ // return error('parse_uint: range error $s')
+ return max_val, -3
+ }
+ n *= u64(base)
+ n1 := n + u64(d)
+ if n1 < n || n1 > max_val {
+ // n+v overflows
+ // return error('parse_uint: range error $s')
+ return max_val, -3
+ }
+ n = n1
+ }
+ return n, 0
+}
+
+// parse_uint is like parse_int but for unsigned numbers.
+pub fn parse_uint(s string, _base int, _bit_size int) ?u64 {
+ return common_parse_uint(s, _base, _bit_size, true, true)
+}
+
+// common_parse_int is called by parse int and allows the parsing
+// to stop on non or invalid digit characters and return with an error
+pub fn common_parse_int(_s string, base int, _bit_size int, error_on_non_digit bool, error_on_high_digit bool) ?i64 {
+ mut s := _s
+ mut bit_size := _bit_size
+ if s.len < 1 {
+ // return error('parse_int: syntax error $s')
+ return i64(0)
+ }
+ // Pick off leading sign.
+ mut neg := false
+ if s[0] == `+` {
+ s = s[1..]
+ } else if s[0] == `-` {
+ neg = true
+ s = s[1..]
+ }
+ // Convert unsigned and check range.
+ // un := parse_uint(s, base, bit_size) or {
+ // return i64(0)
+ // }
+ un := common_parse_uint(s, base, bit_size, error_on_non_digit, error_on_high_digit) ?
+ if un == 0 {
+ return i64(0)
+ }
+ if bit_size == 0 {
+ bit_size = strconv.int_size
+ }
+ // TODO: check should u64(bit_size-1) be size of int (32)?
+ cutoff := u64(1) << u64(bit_size - 1)
+ if !neg && un >= cutoff {
+ // return error('parse_int: range error $s0')
+ return i64(cutoff - u64(1))
+ }
+ if neg && un > cutoff {
+ // return error('parse_int: range error $s0')
+ return -i64(cutoff)
+ }
+ return if neg { -i64(un) } else { i64(un) }
+}
+
+// parse_int interprets a string s in the given base (0, 2 to 36) and
+// bit size (0 to 64) and returns the corresponding value i.
+//
+// If the base argument is 0, the true base is implied by the string's
+// prefix: 2 for "0b", 8 for "0" or "0o", 16 for "0x", and 10 otherwise.
+// Also, for argument base 0 only, underscore characters are permitted
+// as defined by the Go syntax for integer literals.
+//
+// The bitSize argument specifies the integer type
+// that the result must fit into. Bit sizes 0, 8, 16, 32, and 64
+// correspond to int, int8, int16, int32, and int64.
+// If bitSize is below 0 or above 64, an error is returned.
+pub fn parse_int(_s string, base int, _bit_size int) ?i64 {
+ return common_parse_int(_s, base, _bit_size, true, true)
+}
+
+// atoi is equivalent to parse_int(s, 10, 0), converted to type int.
+pub fn atoi(s string) ?int {
+ if s == '' {
+ return error('strconv.atoi: parsing "$s": invalid syntax ')
+ }
+ if (strconv.int_size == 32 && (0 < s.len && s.len < 10))
+ || (strconv.int_size == 64 && (0 < s.len && s.len < 19)) {
+ // Fast path for small integers that fit int type.
+ mut start_idx := 0
+ if s[0] == `-` || s[0] == `+` {
+ start_idx++
+ if s.len - start_idx < 1 {
+ // return 0, &NumError{fnAtoi, s0, ErrSyntax}
+ return error('strconv.atoi: parsing "$s": invalid syntax ')
+ }
+ }
+ mut n := 0
+ for i in start_idx .. s.len {
+ ch := s[i] - `0`
+ if ch > 9 {
+ // return 0, &NumError{fnAtoi, s0, ErrSyntax}
+ return error('strconv.atoi: parsing "$s": invalid syntax ')
+ }
+ n = n * 10 + int(ch)
+ }
+ return if s[0] == `-` { -n } else { n }
+ }
+ // Slow path for invalid, big, or underscored integers.
+ int64 := parse_int(s, 10, 0) ?
+ return int(int64)
+}
+
+// underscore_ok reports whether the underscores in s are allowed.
+// Checking them in this one function lets all the parsers skip over them simply.
+// Underscore must appear only between digits or between a base prefix and a digit.
+fn underscore_ok(s string) bool {
+ // saw tracks the last character (class) we saw:
+ // ^ for beginning of number,
+ // 0 for a digit or base prefix,
+ // _ for an underscore,
+ // ! for none of the above.
+ mut saw := `^`
+ mut i := 0
+ // Optional sign.
+ if s.len >= 1 && (s[0] == `-` || s[0] == `+`) {
+ i++
+ }
+ // Optional base prefix.
+ mut hex := false
+ if s.len - i >= 2 && s[i] == `0` && (byte_to_lower(s[i + 1]) == `b`
+ || byte_to_lower(s[i + 1]) == `o` || byte_to_lower(s[i + 1]) == `x`) {
+ saw = `0` // base prefix counts as a digit for "underscore as digit separator"
+ hex = byte_to_lower(s[i + 1]) == `x`
+ i += 2
+ }
+ // Number proper.
+ for ; i < s.len; i++ {
+ // Digits are always okay.
+ if (`0` <= s[i] && s[i] <= `9`) || (hex && `a` <= byte_to_lower(s[i])
+ && byte_to_lower(s[i]) <= `f`) {
+ saw = `0`
+ continue
+ }
+ // Underscore must follow digit.
+ if s[i] == `_` {
+ if saw != `0` {
+ return false
+ }
+ saw = `_`
+ continue
+ }
+ // Underscore must also be followed by digit.
+ if saw == `_` {
+ return false
+ }
+ // Saw non-digit, non-underscore.
+ saw = `!`
+ }
+ return saw != `_`
+}