Initial project import

tools/v/vlib/strconv/format.v

@@ -0,0 +1,104 @@
+module strconv
+
+import strings
+
+/*
+printf/sprintf V implementation
+
+Copyright (c) 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 the printf/sprintf functions
+*/
+
+// Align_text is used to describe the different ways to align a text - left, right and center
+pub enum Align_text {
+	right = 0
+	left
+	center
+}
+
+// Float conversion utility
+
+// rounding value
+const dec_round = [
+	f64(0.5),
+	0.05,
+	0.005,
+	0.0005,
+	0.00005,
+	0.000005,
+	0.0000005,
+	0.00000005,
+	0.000000005,
+	0.0000000005,
+	0.00000000005,
+	0.000000000005,
+	0.0000000000005,
+	0.00000000000005,
+	0.000000000000005,
+	0.0000000000000005,
+	0.00000000000000005,
+	0.000000000000000005,
+	0.0000000000000000005,
+	0.00000000000000000005,
+	0.000000000000000000005,
+	0.0000000000000000000005,
+	0.00000000000000000000005,
+	0.000000000000000000000005,
+	0.0000000000000000000000005,
+	0.00000000000000000000000005,
+	0.000000000000000000000000005,
+	0.0000000000000000000000000005,
+	0.00000000000000000000000000005,
+	0.000000000000000000000000000005,
+	0.0000000000000000000000000000005,
+	0.00000000000000000000000000000005,
+	0.000000000000000000000000000000005,
+	0.0000000000000000000000000000000005,
+	0.00000000000000000000000000000000005,
+	0.000000000000000000000000000000000005,
+]!
+
+// Single format functions
+
+// BF_param is used for describing the formatting options for a single interpolated value
+pub struct BF_param {
+pub mut:
+	pad_ch       u8   = u8(` `) // padding char
+	len0         int  = -1      // default len for whole the number or string
+	len1         int  = 6       // number of decimal digits, if needed
+	positive     bool = true    // mandatory: the sign of the number passed
+	sign_flag    bool // flag for print sign as prefix in padding
+	align        Align_text = .right // alignment of the string
+	rm_tail_zero bool // remove the tail zeros from floats
+}
+
+// format_str returns the `s` formatted, according to the options set in `p`.
+@[manualfree]
+pub fn format_str(s string, p BF_param) string {
+	if p.len0 <= 0 {
+		return s.clone()
+	}
+	dif := p.len0 - utf8_str_visible_length(s)
+	if dif <= 0 {
+		return s.clone()
+	}
+	mut res := strings.new_builder(s.len + dif)
+	defer {
+		unsafe { res.free() }
+	}
+	if p.align == .right {
+		for i1 := 0; i1 < dif; i1++ {
+			res.write_u8(p.pad_ch)
+		}
+	}
+	res.write_string(s)
+	if p.align == .left {
+		for i1 := 0; i1 < dif; i1++ {
+			res.write_u8(p.pad_ch)
+		}
+	}
+	return res.str()
+}