fmt: unify struct field align code (#10887)

vlib/v/fmt/align.v

@@ -0,0 +1,56 @@
+// 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.
+module fmt
+
+import math.mathutil
+
+const struct_field_align_threshold = 8
+
+struct AlignInfo {
+mut:
+	line_nr      int
+	max_len      int
+	max_type_len int
+}
+
+struct AddInfoConfig {
+	use_threshold bool
+}
+
+fn (mut infos []AlignInfo) add_new_info(len int, type_len int, line int) {
+	infos << AlignInfo{
+		line_nr: line
+		max_len: len
+		max_type_len: type_len
+	}
+}
+
+[direct_array_access]
+fn (mut infos []AlignInfo) add_info(len int, type_len int, line int, cfg AddInfoConfig) {
+	if infos.len == 0 {
+		infos.add_new_info(len, type_len, line)
+		return
+	}
+	i := infos.len - 1
+	if line - infos[i].line_nr > 1 {
+		infos.add_new_info(len, type_len, line)
+		return
+	}
+	if cfg.use_threshold {
+		len_diff := mathutil.abs(infos[i].max_len - len) +
+			mathutil.abs(infos[i].max_type_len - type_len)
+
+		if len_diff >= fmt.struct_field_align_threshold {
+			infos.add_new_info(len, type_len, line)
+			return
+		}
+	}
+	infos[i].line_nr = line
+	if len > infos[i].max_len {
+		infos[i].max_len = len
+	}
+	if type_len > infos[i].max_type_len {
+		infos[i].max_type_len = type_len
+	}
+}

vlib/v/fmt/struct.v

@@ -7,88 +7,6 @@ import math.mathutil as mu
 import strings
 import v.ast
 
-const (
-	threshold_to_align_struct = 8
-)
-
-struct StructFieldAlignInfo {
-mut:
-	first_line   int
-	last_line    int
-	max_type_len int
-	max_len      int
-}
-
-fn (mut list []StructFieldAlignInfo) add_new_info(len int, type_len int, line int) {
-	list << StructFieldAlignInfo{
-		first_line: line
-		last_line: line
-		max_type_len: type_len
-		max_len: len
-	}
-}
-
-[direct_array_access]
-fn (mut list []StructFieldAlignInfo) add_info(len int, type_len int, line int) {
-	if list.len == 0 {
-		list.add_new_info(len, type_len, line)
-		return
-	}
-	i := list.len - 1
-	if line - list[i].last_line > 1 {
-		list.add_new_info(len, type_len, line)
-		return
-	}
-	list[i].last_line = line
-	if len > list[i].max_len {
-		list[i].max_len = len
-	}
-	if type_len > list[i].max_type_len {
-		list[i].max_type_len = type_len
-	}
-}
-
-struct CommentAndExprAlignInfo {
-mut:
-	max_attrs_len int
-	max_type_len  int
-	first_line    int
-	last_line     int
-}
-
-fn (mut list []CommentAndExprAlignInfo) add_new_info(attrs_len int, type_len int, line int) {
-	list << CommentAndExprAlignInfo{
-		max_attrs_len: attrs_len
-		max_type_len: type_len
-		first_line: line
-		last_line: line
-	}
-}
-
-fn (mut list []CommentAndExprAlignInfo) add_info(attrs_len int, type_len int, line int) {
-	if list.len == 0 {
-		list.add_new_info(attrs_len, type_len, line)
-		return
-	}
-	i := list.len - 1
-	if line - list[i].last_line > 1 {
-		list.add_new_info(attrs_len, type_len, line)
-		return
-	}
-	d_len := mu.abs(list[i].max_attrs_len - attrs_len) + mu.abs(list[i].max_type_len - type_len)
-	if !(d_len < fmt.threshold_to_align_struct) {
-		list.add_new_info(attrs_len, type_len, line)
-		return
-	}
-	list[i].last_line = line
-	if attrs_len > list[i].max_attrs_len {
-		list[i].max_attrs_len = attrs_len
-	}
-	if type_len > list[i].max_type_len {
-		list[i].max_type_len = type_len
-	}
-}
-
 pub fn (mut f Fmt) struct_decl(node ast.StructDecl) {
 	f.attrs(node.attrs)
 	if node.is_pub {
@@ -113,9 +31,9 @@ pub fn (mut f Fmt) struct_decl(node ast.StructDecl) {
 		return
 	}
 	f.writeln(' {')
-	mut field_aligns := []StructFieldAlignInfo{}
+	mut field_aligns := []AlignInfo{}
-	mut comment_aligns := []CommentAndExprAlignInfo{}
+	mut comment_aligns := []AlignInfo{}
-	mut default_expr_aligns := []CommentAndExprAlignInfo{}
+	mut default_expr_aligns := []AlignInfo{}
 	mut field_types := []string{cap: node.fields.len}
 	for i, field in node.fields {
 		ft := f.no_cur_mod(f.table.type_to_str_using_aliases(field.typ, f.mod2alias))
@@ -126,7 +44,8 @@ pub fn (mut f Fmt) struct_decl(node ast.StructDecl) {
 		for comment in field.comments {
 			if comment.pos.pos >= end_pos {
 				if comment.pos.line_nr == field.pos.line_nr {
-					comment_aligns.add_info(attrs_len, field_types[i].len, comment.pos.line_nr)
+					comment_aligns.add_info(attrs_len, field_types[i].len, comment.pos.line_nr,
+						use_threshold: true)
 				}
 				continue
 			}
@@ -136,7 +55,8 @@ pub fn (mut f Fmt) struct_decl(node ast.StructDecl) {
 		}
 		field_aligns.add_info(comments_len + field.name.len, ft.len, field.pos.line_nr)
 		if field.has_default_expr {
-			default_expr_aligns.add_info(attrs_len, field_types[i].len, field.pos.line_nr)
+			default_expr_aligns.add_info(attrs_len, field_types[i].len, field.pos.line_nr,
+				use_threshold: true)
 		}
 	}
 	for embed in node.embeds {
@@ -194,7 +114,7 @@ pub fn (mut f Fmt) struct_decl(node ast.StructDecl) {
 		f.comments(between_comments, iembed: true, has_nl: false)
 		comments_len := f.line_len - before_len
 		mut field_align := field_aligns[field_align_i]
-		if field_align.last_line < field.pos.line_nr {
+		if field_align.line_nr < field.pos.line_nr {
 			field_align_i++
 			field_align = field_aligns[field_align_i]
 		}
@@ -209,11 +129,11 @@ pub fn (mut f Fmt) struct_decl(node ast.StructDecl) {
 		}
 		if field.has_default_expr {
 			mut align := default_expr_aligns[default_expr_align_i]
-			if align.last_line < field.pos.line_nr {
+			if align.line_nr < field.pos.line_nr {
 				default_expr_align_i++
 				align = default_expr_aligns[default_expr_align_i]
 			}
-			pad_len := align.max_attrs_len - attrs_len + align.max_type_len - field_types[i].len
+			pad_len := align.max_len - attrs_len + align.max_type_len - field_types[i].len
 			f.write(strings.repeat(` `, pad_len))
 			f.write(' = ')
 			if !expr_is_single_line(field.default_expr) {
@@ -233,11 +153,11 @@ pub fn (mut f Fmt) struct_decl(node ast.StructDecl) {
 			} else {
 				if !field.has_default_expr {
 					mut align := comment_aligns[comment_align_i]
-					if align.last_line < field.pos.line_nr {
+					if align.line_nr < field.pos.line_nr {
 						comment_align_i++
 						align = comment_aligns[comment_align_i]
 					}
-					pad_len := align.max_attrs_len - attrs_len + align.max_type_len - field_types[i].len
+					pad_len := align.max_len - attrs_len + align.max_type_len - field_types[i].len
 					f.write(strings.repeat(` `, pad_len))
 				}
 				f.write(' ')

vlib/v/fmt/tests/array_init_comment_ending_keep.vv

@@ -14,7 +14,7 @@ const (
 			},
 			]
 		}
-		// TODO(bradfitz): users have reported seeing this in the
+		// (bradfitz): users have reported seeing this in the
 		// wild, but do browsers handle it? RFC 6265 just says "don't
 		// do that" (section 3) and then never mentions header folding
 		// again.

vlib/v/fmt/tests/nested_map_type_keep.vv

@@ -1,6 +1,5 @@
 import v.ast
 
-// TODO fix `fn foo(my_map map[string]map[string]int) []ast.FnDecl {`
 fn foo(my_map map[string]map[string]int) int {
 	return 0
 }

vlib/v/fmt/tests/struct_init_with_comments_keep.vv

@@ -2,7 +2,7 @@ module abcde
 
 pub struct Builder {
 pub mut:
-	// TODO
+	// inline before field
 	buf          []byte
 	str_calls    int
 	len          int