From a976876211ca2507a49319027ef121ba18676543 Mon Sep 17 00:00:00 2001
From: yuyi <yuyi98@163.com>
Date: Thu, 4 Feb 2021 15:18:38 +0800
Subject: [PATCH] v.token: correct some comments, and add some missing comments
 (#8542)

---
 vlib/v/token/token.v | 110 ++++++++++++++++++++++---------------------
 1 file changed, 56 insertions(+), 54 deletions(-)

diff --git a/vlib/v/token/token.v b/vlib/v/token/token.v
index 1142d42562..8ea77f14af 100644
--- a/vlib/v/token/token.v
+++ b/vlib/v/token/token.v
@@ -5,13 +5,13 @@ module token
 
 pub struct Token {
 pub:
-	kind    Kind // the token number/enum; for quick comparisons
+	kind    Kind   // the token number/enum; for quick comparisons
 	lit     string // literal representation of the token
-	line_nr int // the line number in the source where the token occured
+	line_nr int    // the line number in the source where the token occured
 	// name_idx int // name table index for O(1) lookup
-	pos     int // the position of the token in scanner text
-	len     int // length of the literal
-	tidx    int // the index of the token
+	pos  int // the position of the token in scanner text
+	len  int // length of the literal
+	tidx int // the index of the token
 }
 
 pub enum Kind {
@@ -22,31 +22,31 @@ pub enum Kind {
 	string // 'foo'
 	str_inter // 'name=$user.name'
 	chartoken // `A` - rune
-	plus
-	minus
-	mul
-	div
-	mod
+	plus // +
+	minus // -
+	mul // *
+	div // /
+	mod // %
 	xor // ^
 	pipe // |
 	inc // ++
 	dec // --
 	and // &&
-	logical_or
-	not
-	bit_not
-	question
-	comma
-	semicolon
-	colon
+	logical_or // ||
+	not // !
+	bit_not // ~
+	question // ?
+	comma // ,
+	semicolon // ;
+	colon // :
 	arrow // <-
-	amp
-	hash
-	dollar
+	amp // &
+	hash // #
+	dollar // $
 	at // @
 	str_dollar
-	left_shift
-	right_shift
+	left_shift // <<
+	right_shift // >>
 	not_in // !in
 	not_is // !is
 	assign // =
@@ -58,26 +58,26 @@ pub enum Kind {
 	xor_assign // ^=
 	mod_assign // %=
 	or_assign // |=
-	and_assign
-	right_shift_assign
-	left_shift_assign // {}  () []
-	lcbr
-	rcbr
-	lpar
-	rpar
-	lsbr
-	rsbr // == != <= < >= >
-	eq
-	ne
-	gt
-	lt
-	ge
-	le
+	and_assign // &=
+	right_shift_assign // <<=
+	left_shift_assign // >>=
+	lcbr // {
+	rcbr // }
+	lpar // (
+	rpar // )
+	lsbr // [
+	rsbr // ]
+	eq // ==
+	ne // !=
+	gt // >
+	lt // <
+	ge // >=
+	le // <=
 	comment
 	nl
-	dot
-	dotdot
-	ellipsis // keywords
+	dot // .
+	dotdot // ..
+	ellipsis // ...
 	keyword_beg
 	key_as
 	key_asm
@@ -99,7 +99,7 @@ pub enum Kind {
 	key_import
 	key_in
 	key_interface
-	key_is // key_it
+	key_is
 	key_match
 	key_module
 	key_mut
@@ -132,7 +132,7 @@ pub const (
 )
 
 const (
-	nr_tokens     = int(Kind._end_)
+	nr_tokens = int(Kind._end_)
 )
 
 // @FN => will be substituted with the name of the current V function
@@ -174,7 +174,7 @@ pub const (
 fn build_keys() map[string]Kind {
 	mut res := map[string]Kind{}
 	for t in int(Kind.keyword_beg) + 1 .. int(Kind.keyword_end) {
-		key := token_str[t]
+		key := token.token_str[t]
 		res[key] = Kind(t)
 	}
 	return res
@@ -182,7 +182,7 @@ fn build_keys() map[string]Kind {
 
 // TODO remove once we have `enum Kind { name('name') if('if') ... }`
 fn build_token_str() []string {
-	mut s := []string{len: nr_tokens}
+	mut s := []string{len: token.nr_tokens}
 	s[Kind.unknown] = 'unknown'
 	s[Kind.eof] = 'eof'
 	s[Kind.name] = 'name'
@@ -297,11 +297,11 @@ const (
 )
 
 pub const (
-	keywords  = build_keys()
+	keywords = build_keys()
 )
 
 pub fn key_to_token(key string) Kind {
-	return Kind(keywords[key])
+	return Kind(token.keywords[key])
 }
 
 pub fn is_key(key string) bool {
@@ -309,16 +309,17 @@ pub fn is_key(key string) bool {
 }
 
 pub fn is_decl(t Kind) bool {
-	return t in
-		[.key_enum, .key_interface, .key_fn, .key_struct, .key_type, .key_const, .key_pub, .eof]
+	return t in [.key_enum, .key_interface, .key_fn, .key_struct, .key_type, .key_const, .key_pub,
+		.eof,
+	]
 }
 
 pub fn (t Kind) is_assign() bool {
-	return t in assign_tokens
+	return t in token.assign_tokens
 }
 
 pub fn (t Kind) str() string {
-	return token_str[int(t)]
+	return token.token_str[int(t)]
 }
 
 pub fn (t Token) str() string {
@@ -405,7 +406,7 @@ const (
 
 // precedence returns a tokens precedence if defined, otherwise lowest_prec
 pub fn (tok Token) precedence() int {
-	return int(precedences[tok.kind])
+	return int(token.precedences[tok.kind])
 }
 
 // is_scalar returns true if the token is a scalar
@@ -416,7 +417,7 @@ pub fn (tok Token) is_scalar() bool {
 // is_unary returns true if the token can be in a unary expression
 pub fn (tok Token) is_unary() bool {
 	// `+` | `-` | `!` | `~` | `*` | `&` | `<-`
-	return tok.kind in [ .plus, .minus, .not, .bit_not, .mul, .amp, .arrow]
+	return tok.kind in [.plus, .minus, .not, .bit_not, .mul, .amp, .arrow]
 }
 
 pub fn (tok Kind) is_relational() bool {
@@ -433,8 +434,9 @@ pub fn (kind Kind) is_prefix() bool {
 }
 
 pub fn (kind Kind) is_infix() bool {
-	return kind in
-		[.plus, .minus, .mod, .mul, .div, .eq, .ne, .gt, .lt, .key_in, .key_as, .ge, .le, .logical_or, .xor, .not_in, .key_is, .not_is, .and, .dot, .pipe, .amp, .left_shift, .right_shift, .arrow]
+	return kind in [.plus, .minus, .mod, .mul, .div, .eq, .ne, .gt, .lt, .key_in, .key_as, .ge,
+		.le, .logical_or, .xor, .not_in, .key_is, .not_is, .and, .dot, .pipe, .amp, .left_shift,
+		.right_shift, .arrow]
 }
 
 // Pass table.builtin_type_names