From 7ae4c5a1abff7ca4f7360ea7ee4a9192e16689da Mon Sep 17 00:00:00 2001
From: Manuel Barrio Linares <mbarriolinares@gmail.com>
Date: Mon, 16 Feb 2026 17:27:43 -0300
Subject: [PATCH] some refactoring of io formatter internals

extracted logic for hex-buffers (%h), string-padding (%s), hex-floats
(%a), and collection printing into helper functions.
---
 lib/std/io/formatter.c3         | 295 ++++++++++++++------------------
 lib/std/io/formatter_private.c3 | 136 ++++++++-------
 2 files changed, 203 insertions(+), 228 deletions(-)

diff --git a/lib/std/io/formatter.c3 b/lib/std/io/formatter.c3
index 7571133c1..8909b3a93 100644
--- a/lib/std/io/formatter.c3
+++ b/lib/std/io/formatter.c3
@@ -139,6 +139,47 @@ fn usz? Formatter.out_unknown(&self, String category, any arg) @private
 {
 	return self.out_substr("<") + self.out_substr(category) + self.out_substr(" type:") + self.ntoa((iptr)arg.type, false, 16) + self.out_substr(", addr:") + self.ntoa((iptr)arg.ptr, false, 16) + self.out_substr(">");
 }
+fn usz? Formatter.out_collection(&self, any arg, String open, String close) @private
+{
+	typeid inner = arg.type.inner;
+	if (inner == void.typeid) inner = char.typeid;
+	usz size = inner.sizeof;
+
+	usz alen;
+	void* data_ptr;
+	if (arg.type.kindof == SLICE)
+	{
+		String* temp = arg.ptr;
+		data_ptr = temp.ptr;
+		alen = temp.len;
+	}
+	else
+	{
+		data_ptr = arg.ptr;
+		alen = arg.type.len;
+	}
+
+	PrintFlags flags = self.flags;
+	uint width = self.width;
+	defer
+	{
+		self.flags = flags;
+		self.width = width;
+	}
+	self.flags = {};
+	self.width = 0;
+
+	usz len = self.out_substr(open)!;
+	for (usz i = 0; i < alen; i++)
+	{
+		if (i != 0) len += self.out_substr(", ")!;
+		len += self.out_str(any_make(data_ptr, inner))!;
+		data_ptr += size;
+	}
+	len += self.out_substr(close)!;
+	return len;
+}
+
 fn usz? Formatter.out_str(&self, any arg) @private
 {
 	switch (arg.type.kindof)
@@ -158,17 +199,9 @@ fn usz? Formatter.out_str(&self, any arg) @private
 			unreachable();
 		case SIGNED_INT:
 		case UNSIGNED_INT:
-			PrintFlags flags = self.flags;
-			uint width = self.width;
-			defer
-			{
-				self.flags = flags;
-				self.width = width;
-			}
-			self.flags = {};
-			self.width = 0;
-			return self.ntoa_any(arg, 10) ?? self.out_substr("<INVALID>");
 		case FLOAT:
+		case FUNC:
+		case POINTER:
 			PrintFlags flags = self.flags;
 			uint width = self.width;
 			defer
@@ -178,7 +211,27 @@ fn usz? Formatter.out_str(&self, any arg) @private
 			}
 			self.flags = {};
 			self.width = 0;
-			return self.ftoa(float_from_any(arg)) ?? self.out_substr("ERR");
+			switch (arg.type.kindof)
+			{
+				case SIGNED_INT:
+				case UNSIGNED_INT:
+					return self.ntoa_any(arg, 10) ?? self.out_substr("<INVALID>");
+				case FLOAT:
+					return self.ftoa(float_from_any(arg)) ?? self.out_substr("ERR");
+				case FUNC:
+				case POINTER:
+					if (arg.type.kindof == POINTER && arg.type.inner != void.typeid)
+					{
+						void** pointer = arg.ptr;
+						any deref = any_make(*pointer, arg.type.inner);
+						usz? n = self.print_with_function((Printable)deref);
+						if (try n) return n;
+						if (@catch(n) != NOT_FOUND) n!;
+					}
+					return self.out_substr("0x")! + self.ntoa_any(arg, 16);
+				default:
+					unreachable();
+			}
 		case BOOL:
 			return self.out_substr(*(bool*)arg.ptr ? "true" : "false");
 		default:
@@ -200,16 +253,6 @@ fn usz? Formatter.out_str(&self, any arg) @private
 			return self.out_unknown("union", arg);
 		case BITSTRUCT:
 			return self.out_unknown("bitstruct", arg);
-		case FUNC:
-			PrintFlags flags = self.flags;
-			uint width = self.width;
-			defer
-			{
-				self.flags = flags;
-				self.width = width;
-			}
-			self.width = 0;
-			return self.out_substr("0x")! + self.ntoa_any(arg, 16);
 		case CONST_ENUM:
 		case DISTINCT:
 			if (arg.type == String.typeid)
@@ -225,102 +268,12 @@ fn usz? Formatter.out_str(&self, any arg) @private
 				return self.out_substr(*(DString*)arg ? ((DString*)arg).str_view() : "(null)");
 			}
 			return self.out_str(arg.as_inner());
-		case POINTER:
-			typeid inner = arg.type.inner;
-			void** pointer = arg.ptr;
-			if (arg.type.inner != void.typeid)
-			{
-				any deref = any_make(*pointer, inner);
-				n = self.print_with_function((Printable)deref);
-				if (try n) return n;
-				if (@catch(n) != NOT_FOUND) n!;
-			}
-			PrintFlags flags = self.flags;
-			uint width = self.width;
-			defer
-			{
-				self.flags = flags;
-				self.width = width;
-			}
-			self.width = 0;
-			return self.out_substr("0x")! + self.ntoa_any(arg, 16);
 		case ARRAY:
-			// this is SomeType[*] so grab the "SomeType"
-			PrintFlags flags = self.flags;
-			uint width = self.width;
-			defer
-			{
-				self.flags = flags;
-				self.width = width;
-			}
-			self.flags = {};
-			self.width = 0;
-			typeid inner = arg.type.inner;
-			usz size = inner.sizeof;
-			usz alen = arg.type.len;
-			// Pretend this is a String
-			void* ptr = (void*)arg.ptr;
-			usz len = self.out('[')!;
-			for (usz i = 0; i < alen; i++)
-			{
-				if (i != 0) len += self.out_substr(", ")!;
-				len += self.out_str(any_make(ptr, inner))!;
-				ptr += size;
-			}
-			len += self.out(']')!;
-			return len;
+			return self.out_collection(arg, "[", "]");
 		case VECTOR:
-			PrintFlags flags = self.flags;
-			uint width = self.width;
-			defer
-			{
-				self.flags = flags;
-				self.width = width;
-			}
-			self.flags = {};
-			self.width = 0;
-			// this is SomeType[*] so grab the "SomeType"
-			typeid inner = arg.type.inner;
-			usz size = inner.sizeof;
-			usz vlen = arg.type.len;
-			// Pretend this is a String
-			void* ptr = (void*)arg.ptr;
-			usz len = self.out_substr("[<")!;
-			for (usz i = 0; i < vlen; i++)
-			{
-				if (i != 0) len += self.out_substr(", ")!;
-				len += self.out_str(any_make(ptr, inner))!;
-				ptr += size;
-			}
-			len += self.out_substr(">]")!;
-			return len;
+			return self.out_collection(arg, "[<", ">]");
 		case SLICE:
-			// this is SomeType[] so grab the "SomeType"
-			typeid inner = arg.type.inner;
-			if (inner == void.typeid) inner = char.typeid;
-			PrintFlags flags = self.flags;
-			uint width = self.width;
-			defer
-			{
-				self.flags = flags;
-				self.width = width;
-			}
-			self.flags = {};
-			self.width = 0;
-			usz size = inner.sizeof;
-			// Pretend this is a String
-			String* temp = (void*)arg.ptr;
-			void* ptr = (void*)temp.ptr;
-			usz slen = temp.len;
-			usz len = self.out('[')!;
-			for (usz i = 0; i < slen; i++)
-			{
-				if (i != 0) len += self.out_substr(", ")!;
-				len += self.out_str(any_make(ptr, inner))!;
-				ptr += size;
-			}
-			len += self.out(']')!;
-			return len;
+			return self.out_collection(arg, "[", "]");
 		case ANY:
 		case INTERFACE:
 			unreachable("Already handled");
@@ -361,6 +314,63 @@ macro usz? @wrap_bad(Formatter* f, #action)
 	return len;
 }
 
+fn usz? Formatter.out_hex_buffer(&self, any arg) @private @inline
+{
+	char[] out @noinit;
+	switch (arg.type)
+	{
+		case char[]:
+		case ichar[]:
+			out = *(char[]*)arg;
+		default:
+			if (arg.type.kindof == ARRAY && (arg.type.inner == char.typeid || arg.type.inner == ichar.typeid))
+			{
+				out = ((char*)arg.ptr)[:arg.type.sizeof];
+				break;
+			}
+			if (arg.type.kindof == POINTER)
+			{
+				// Maybe there is a more idiomatic way here
+				out = ((*(char**)arg.ptr))[:arg.type.inner.sizeof];
+				break;
+			}
+			return self.out_substr("<INVALID>");
+	}
+	usz len = out.len * 2;
+	usz total;
+	if (self.flags.left)
+	{
+		total += print_hex_chars(self, out, self.flags.uppercase)!;
+		total += self.pad(' ', self.width, (isz)total)!;
+	}
+	else
+	{
+		if (self.width) total += self.pad(' ', self.width, (isz)len)!;
+		total += print_hex_chars(self, out, self.flags.uppercase)!;
+	}
+	return total;
+}
+
+fn usz? Formatter.out_str_pad(&self, any arg) @private @inline
+{
+	usz total;
+	if (self.width && !self.flags.left)
+	{
+		OutputFn out_fn = self.out_fn;
+		self.out_fn = (OutputFn)&out_null_fn;
+		usz len = self.out_str(arg)!;
+		self.out_fn = out_fn;
+		total += self.pad(' ', self.width, (isz)len)!;
+	}
+	usz len = self.out_str(arg)!;
+	total += len;
+	if (self.flags.left)
+	{
+		total += self.pad(' ', self.width, (isz)len)!;
+	}
+	return total;
+}
+
 fn usz? Formatter.vprintf(&self, String format, any[] anys)
 {
 	self.first_fault = {};
@@ -415,7 +425,7 @@ fn usz? Formatter.vprintf(&self, String format, any[] anys)
 			self.flags.left = true;
 			w = -w;
 		}
-		self.width = w;
+		self.width = (uint)w;
 		// evaluate precision field
 		self.prec = 0;
 		if (c == '.')
@@ -424,7 +434,7 @@ fn usz? Formatter.vprintf(&self, String format, any[] anys)
 			if (++i >= format_len) return @report_fault(self, "<BAD FORMAT>");
 			int? prec = printf_parse_format_field(anys.ptr, anys.len, &variant_index, format.ptr, format.len, &i);
 			if (catch prec) return @report_fault(self, "<BAD FORMAT>");
-			self.prec = prec < 0 ? 0 : prec;
+			self.prec = (uint)(prec < 0 ? 0 : prec);
 			c = format[i];
 		}
 
@@ -488,56 +498,10 @@ fn usz? Formatter.vprintf(&self, String format, any[] anys)
 				self.flags.uppercase = true;
 				nextcase;
 			case 'h':
-				char[] out @noinit;
-				switch (current.type)
-				{
-					case char[]:
-					case ichar[]:
-						out = *(char[]*)current;
-					default:
-						if (current.type.kindof == ARRAY && (current.type.inner == char.typeid || current.type.inner == ichar.typeid))
-						{
-							out = ((char*)current.ptr)[:current.type.sizeof];
-							break;
-						}
-						if (current.type.kindof == POINTER)
-						{
-							out = ((*(char**)current.ptr))[:current.type.inner.sizeof];
-							break;
-						}
-						total_len += self.out_substr("<INVALID>")!;
-						continue;
-				}
-				if (self.flags.left)
-				{
-					usz len = print_hex_chars(self, out, self.flags.uppercase)!;
-					total_len += len;
-					total_len += self.pad(' ', self.width, len)!;
-					continue;
-				}
-				if (self.width)
-				{
-					total_len += self.pad(' ', self.width, out.len * 2)!;
-				}
-				total_len += print_hex_chars(self, out, self.flags.uppercase)!;
+				total_len += self.out_hex_buffer(current)!;
 				continue;
 			case 's':
-				if (self.flags.left)
-				{
-					usz len = self.out_str(current)!;
-					total_len += len;
-					total_len += self.pad(' ', self.width, len)!;
-					continue;
-				}
-				if (self.width)
-				{
-					OutputFn out_fn = self.out_fn;
-					self.out_fn = (OutputFn)&out_null_fn;
-					usz len = self.out_str(current)!;
-					self.out_fn = out_fn;
-					total_len += self.pad(' ', self.width, len)!;
-				}
-				total_len += self.out_str(current)!;
+				total_len += self.out_str_pad(current)!;
 				continue;
 			case 'p':
 				self.flags.zeropad = true;
@@ -559,10 +523,7 @@ fn usz? Formatter.vprintf(&self, String format, any[] anys)
 		bool is_neg;
 		total_len += @wrap_bad(self, self.ntoa(int_from_any(current, &is_neg), is_neg, base))!;
 	}
-	// termination
-	//	out((char)0, buffer, idx < maxlen ? idx : maxlen - 1U, maxlen);
 
-	// return written chars without terminating \0
 	if (self.first_fault) return self.first_fault~;
 	return total_len;
 }
diff --git a/lib/std/io/formatter_private.c3 b/lib/std/io/formatter_private.c3
index 82cae987a..9de436709 100644
--- a/lib/std/io/formatter_private.c3
+++ b/lib/std/io/formatter_private.c3
@@ -208,6 +208,70 @@ fn usz? Formatter.ftoa(&self, double y) => self.floatformat(FLOAT, y);
 fn usz? Formatter.gtoa(&self, double y) => self.floatformat(ADAPTIVE, y);
 fn usz? Formatter.atoa(&self, double y) => self.floatformat(HEX, y);
 
+fn usz? Formatter.floatformat_hex(&self, double y, bool is_neg, isz pl, isz p) @private @inline
+{
+	double round = 8.0;
+	// 0x / 0X
+	pl += 2;
+	if (p > 0 && p < math::DOUBLE_MANT_DIG / 4 - 1)
+	{
+		int re = math::DOUBLE_MANT_DIG / 4 - 1 - (int)p;
+		round *= 1 << (math::DOUBLE_MANT_DIG % 4);
+		while (re--) round *= 16;
+		if (is_neg)
+		{
+			y = -y;
+			y -= round;
+			y += round;
+			y = -y;
+		}
+		else
+		{
+			y += round;
+			y -= round;
+		}
+	}
+	int e2;
+	y = math::frexp(y, &e2) * 2;
+	if (y) e2--;
+	char[12] ebuf0;
+	char* ebuf = &ebuf0[0] + 12;
+	char[9 + math::DOUBLE_MANT_DIG / 4] buf_array;
+	char* buf = &buf_array[0];
+
+	// Reverse print
+	char* estr = fmt_u(e2 < 0 ? (int128)-e2 : (int128)e2, ebuf);
+	if (estr == ebuf) *--estr = '0';
+	*--estr = (e2 < 0 ? '-' : '+');
+	*--estr = self.flags.uppercase ? 'P' : 'p';
+	char* s = buf;
+	char* xdigits = self.flags.uppercase ? &XDIGITS_H : &XDIGITS_L;
+	do
+	{
+		int x = (int)y;
+		*s++ = xdigits[x];
+		y = 16 * (y - x);
+		if (s - buf == 1 && (y || p > 0 || self.flags.hash)) *s++ = '.';
+		if (p >= 0 && (s - buf) >= (2 + p)) break;
+	} while (y);
+	isz outlen = s - buf;
+	isz explen = ebuf - estr;
+	if (p > int.max - 2 - explen - pl) return INTERNAL_BUFFER_EXCEEDED~;
+	usz len;
+	usz l = (usz)(p && outlen - 2 < p
+			? p + 2 + explen
+			: outlen + explen);
+	if (!self.flags.left && !self.flags.zeropad) len += self.pad(' ', self.width, pl + l)!;
+	if (is_neg || self.flags.plus) len += self.out(is_neg ? '-' : '+')!;
+	len += self.out_chars(self.flags.uppercase ? "0X" : "0x")!;
+	if (self.flags.zeropad) len += self.pad('0', self.width, pl + l)!;
+	len += self.out_chars(buf[:outlen])!;
+	len += self.pad('0', (isz)l - outlen - explen, 0)!;
+	len += self.out_chars(estr[:explen])!;
+	if (self.flags.left) len += self.pad(' ', self.width, pl + (isz)l)!;
+	return len;
+}
+
 fn usz? Formatter.floatformat(&self, FloatFormatting formatting, double y) @private
 {
 	// This code is heavily based on musl's printf code
@@ -234,70 +298,15 @@ fn usz? Formatter.floatformat(&self, FloatFormatting formatting, double y) @priv
 		if (self.flags.left) len += self.pad(' ', self.width, 3 + pl)!;
 		return len;
 	}
+
+	isz p = self.flags.precision ? self.prec : -1;
+	if (formatting == HEX) return self.floatformat_hex(y, is_neg, pl, p);
+
 	// Rescale
 	int e2;
-
 	y = math::frexp(y, &e2) * 2;
 	if (y) e2--;
-	char[12] ebuf0;
-	char* ebuf = 12 + (char*)&ebuf0;
-	char[9 + math::DOUBLE_MANT_DIG / 4] buf_array;
-	char* buf = &buf_array;
-	isz p = self.flags.precision ? self.prec : -1;
-	if (formatting == HEX)
-	{
-		double round = 8.0;
-		// 0x / 0X
-		pl += 2;
-		if (p > 0 && p < math::DOUBLE_MANT_DIG / 4 - 1)
-		{
-			int re = math::DOUBLE_MANT_DIG / 4 - 1 - (int)p;
-			round *= 1 << (math::DOUBLE_MANT_DIG % 4);
-			while (re--) round *= 16;
-			if (is_neg)
-			{
-				y = -y;
-				y -= round;
-				y += round;
-				y = -y;
-			}
-			else
-			{
-				y += round;
-				y -= round;
-			}
-		}
-		// Reverse print
-		char* estr = fmt_u(e2 < 0 ? (int128)-e2 : (int128)e2, ebuf);
-		if (estr == ebuf) *--estr = '0';
-		*--estr = (e2 < 0 ? '-' : '+');
-		*--estr = self.flags.uppercase ? 'P' : 'p';
-		char* s = buf;
-		char* xdigits = self.flags.uppercase ? &XDIGITS_H : &XDIGITS_L;
-		do
-		{
-			int x = (int)y;
-			*s++ = xdigits[x];
-			y = 16 * (y - x);
-			if (s - buf == 1 && (y || p > 0 || self.flags.hash)) *s++ = '.';
-		} while (y);
-		isz outlen = s - buf;
-		isz explen = ebuf - estr;
-		if (p > int.max - 2 - explen - pl) return INTERNAL_BUFFER_EXCEEDED~;
-		usz len;
-		usz l = p && outlen - 2 < p
-				? p + 2 + explen
-				: outlen + explen;
-		if (!self.flags.left && !self.flags.zeropad) len += self.pad(' ', self.width, pl + l)!;
-		if (is_neg || self.flags.plus) len += self.out(is_neg ? '-' : '+')!;
-		len += self.out_chars(self.flags.uppercase ? "0X" : "0x")!;
-		if (self.flags.zeropad) len += self.pad('0', self.width, pl + l)!;
-		len += self.out_chars(buf[:outlen])!;
-		len += self.pad('0', l - outlen - explen, 0)!;
-		len += self.out_chars(estr[:explen])!;
-		if (self.flags.left) len += self.pad(' ', self.width, pl + l)!;
-		return len;
-	}
+
 	if (p < 0) p = 6;
 	if (y)
 	{
@@ -344,7 +353,6 @@ fn usz? Formatter.floatformat(&self, FloatFormatting formatting, double y) @priv
 		int need = (int)(1 + (p + math::DOUBLE_MANT_DIG / 3u + 8) / 9);
 		for (uint* d = a; d < z; d++)
 		{
-			// CHECK THIS
 			uint rm = *d & ((1 << sh) - 1);
 			*d = (*d >> sh) + carry;
 			carry = (1000000000 >> sh) * rm;
@@ -456,6 +464,8 @@ fn usz? Formatter.floatformat(&self, FloatFormatting formatting, double y) @priv
 	}
 	if (p > int.max - 1 - (isz)(p || self.flags.hash)) return INTERNAL_BUFFER_EXCEEDED~;
 	int l = (int)(1 + p + (isz)(p || self.flags.hash));
+	char[12] ebuf0;
+	char* ebuf = &ebuf0[0] + 12;
 	char* estr @noinit;
 	if (formatting == FLOAT)
 	{
@@ -476,6 +486,10 @@ fn usz? Formatter.floatformat(&self, FloatFormatting formatting, double y) @priv
 	if (!self.flags.left && !self.flags.zeropad) len += self.pad(' ', self.width, pl + l)!;
 	if (is_neg || self.flags.plus) len += self.out(is_neg ? '-' : '+')!;
 	if (self.flags.zeropad) len += self.pad('0', self.width, pl + l)!;
+
+	char[9] buf_array;
+	char* buf = &buf_array[0];
+
 	if (formatting == FLOAT)
 	{
 		if (a > r) a = r;