Refactoring influxql package to enable golint

CHANGELOG.md

@@ -4,14 +4,15 @@
 
 - [#5541](https://github.com/influxdata/influxdb/pull/5541): Client: Support for adding custom TLS Config for HTTP client.
 - [#4299](https://github.com/influxdata/influxdb/pull/4299): Client: Reject uint64 Client.Point.Field values. Thanks @arussellsaw
-- [#5550](https://github.com/influxdata/influxdb/pull/5550): Enabled golint for tsdb/engine/wal.
+- [#5550](https://github.com/influxdata/influxdb/pull/5550): Enabled golint for tsdb/engine/wal. @gabelev
 - [#5419](https://github.com/influxdata/influxdb/pull/5419): Graphite: Support matching tags multiple times Thanks @m4ce
 - [#5598](https://github.com/influxdata/influxdb/pull/5598): Client: Add Ping to v2 client @PSUdaemon
 - [#4125](https://github.com/influxdata/influxdb/pull/4125): Admin UI: Fetch and display server version on connect. Thanks @alexiri!
 - [#5602](https://github.com/influxdata/influxdb/pull/5602): Simplify cluster startup for scripting and deployment
 - [#5562](https://github.com/influxdata/influxdb/pull/5562): Graphite: Support matching fields multiple times (@chrusty)
 - [#5666](https://github.com/influxdata/influxdb/pull/5666): Manage dependencies with gdm
 - [#5512](https://github.com/influxdata/influxdb/pull/5512): HTTP: Add config option to enable HTTP JSON write path which is now disabled by default.
+- [#5336](https://github.com/influxdata/influxdb/pull/5366): Enabled golint for influxql. @gabelev
 
 ### Bugfixes
 

influxql/ast.go

@@ -749,6 +749,7 @@ func (s *AlterRetentionPolicyStatement) RequiredPrivileges() ExecutionPrivileges
 	return ExecutionPrivileges{{Admin: true, Name: "", Privilege: AllPrivileges}}
 }
 
+// FillOption represents different options for aggregate windows.
 type FillOption int
 
 const (
@@ -1406,6 +1407,7 @@ func (s *SelectStatement) validateAggregates(tr targetRequirement) error {
 	return nil
 }
 
+// HasDistinct checks if a select statement contains DISTINCT
 func (s *SelectStatement) HasDistinct() bool {
 	// determine if we have a call named distinct
 	for _, f := range s.Fields {
@@ -1443,6 +1445,7 @@ func (s *SelectStatement) validateDistinct() error {
 	return nil
 }
 
+// HasCountDistinct checks if a select statement contains COUNT and DISTINCT
 func (s *SelectStatement) HasCountDistinct() bool {
 	for _, f := range s.Fields {
 		if c, ok := f.Expr.(*Call); ok {
@@ -1539,7 +1542,7 @@ func (s *SelectStatement) validateDerivative() error {
 	return nil
 }
 
-// GroupByIterval extracts the time interval, if specified.
+// GroupByInterval extracts the time interval, if specified.
 func (s *SelectStatement) GroupByInterval() (time.Duration, error) {
 	// return if we've already pulled it out
 	if s.groupByInterval != 0 {
@@ -2262,7 +2265,7 @@ func (s *ShowRetentionPoliciesStatement) RequiredPrivileges() ExecutionPrivilege
 	return ExecutionPrivileges{{Admin: false, Name: "", Privilege: ReadPrivilege}}
 }
 
-// ShowStats statement displays statistics for a given module.
+// ShowStatsStatement displays statistics for a given module.
 type ShowStatsStatement struct {
 	// Module
 	Module string
@@ -2658,9 +2661,9 @@ func (f *Field) String() string {
 }
 
 // Sort Interface for Fields
-func (f Fields) Len() int           { return len(f) }
-func (f Fields) Less(i, j int) bool { return f[i].Name() < f[j].Name() }
-func (f Fields) Swap(i, j int)      { f[i], f[j] = f[j], f[i] }
+func (a Fields) Len() int           { return len(a) }
+func (a Fields) Less(i, j int) bool { return a[i].Name() < a[j].Name() }
+func (a Fields) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
 
 // Dimensions represents a list of dimensions.
 type Dimensions []*Dimension
@@ -3094,7 +3097,7 @@ func TimeRange(expr Expr) (min, max time.Time) {
 	return
 }
 
-// TimeRange returns the minimum and maximum times, as epoch nano, specified by
+// TimeRangeAsEpochNano returns the minimum and maximum times, as epoch nano, specified by
 // and expression. If there is no lower bound, the start of the epoch is returned
 // for minimum. If there is no higher bound, now is returned for maximum.
 func TimeRangeAsEpochNano(expr Expr) (min, max int64) {
@@ -3721,11 +3724,12 @@ type Valuer interface {
 	Value(key string) (interface{}, bool)
 }
 
-// nowValuer returns only the value for "now()".
+// NowValuer returns only the value for "now()".
 type NowValuer struct {
 	Now time.Time
 }
 
+// Value is a method that returns the value and existence flag for a given key.
 func (v *NowValuer) Value(key string) (interface{}, bool) {
 	if key == "now()" {
 		return v.Now, true

influxql/parser.go

@@ -519,7 +519,7 @@ func (p *Parser) parseUInt64() (uint64, error) {
 // This function assumes the DURATION token has already been consumed.
 func (p *Parser) parseDuration() (time.Duration, error) {
 	tok, pos, lit := p.scanIgnoreWhitespace()
-	if tok != DURATION_VAL && tok != INF {
+	if tok != DURATIONVAL && tok != INF {
 		return 0, newParseError(tokstr(tok, lit), []string{"duration"}, pos)
 	}
 
@@ -1509,7 +1509,7 @@ func (p *Parser) parseCreateDatabaseStatement() (*CreateDatabaseStatement, error
 		stmt.RetentionPolicyDuration = rpDuration
 
 		// Look for "REPLICATION"
-		var rpReplication int = 1 // default is 1
+		var rpReplication = 1 // default is 1
 		if err := p.parseTokens([]Token{REPLICATION}); err != nil {
 			p.unscan()
 		} else {
@@ -2331,7 +2331,7 @@ func (p *Parser) parseUnaryExpr() (Expr, error) {
 		return &NumberLiteral{Val: v}, nil
 	case TRUE, FALSE:
 		return &BooleanLiteral{Val: (tok == TRUE)}, nil
-	case DURATION_VAL:
+	case DURATIONVAL:
 		v, _ := ParseDuration(lit)
 		return &DurationLiteral{Val: v}, nil
 	case MUL:
@@ -2422,7 +2422,7 @@ func (p *Parser) parseResample() (time.Duration, time.Duration, error) {
 	var interval time.Duration
 	if p.parseTokenMaybe(EVERY) {
 		tok, pos, lit := p.scanIgnoreWhitespace()
-		if tok != DURATION_VAL {
+		if tok != DURATIONVAL {
 			return 0, 0, newParseError(tokstr(tok, lit), []string{"duration"}, pos)
 		}
 
@@ -2436,7 +2436,7 @@ func (p *Parser) parseResample() (time.Duration, time.Duration, error) {
 	var maxDuration time.Duration
 	if p.parseTokenMaybe(FOR) {
 		tok, pos, lit := p.scanIgnoreWhitespace()
-		if tok != DURATION_VAL {
+		if tok != DURATIONVAL {
 			return 0, 0, newParseError(tokstr(tok, lit), []string{"duration"}, pos)
 		}
 

influxql/result.go

@@ -22,8 +22,8 @@ func (t *TagSet) AddFilter(key string, filter Expr) {
 	t.Filters = append(t.Filters, filter)
 }
 
-// Rows represents a list of rows that can be sorted consistently by name/tag.
 // Result represents a resultset returned from a single statement.
+// Rows represents a list of rows that can be sorted consistently by name/tag.
 type Result struct {
 	// StatementID is just the statement's position in the query. It's used
 	// to combine statement results if they're being buffered in memory.
@@ -67,6 +67,8 @@ func (r *Result) UnmarshalJSON(b []byte) error {
 	return nil
 }
 
+// GetProcessor is a Method that returns processor type and index
+// based on the type of expression.
 func GetProcessor(expr Expr, startIndex int) (Processor, int) {
 	switch expr := expr.(type) {
 	case *VarRef:
@@ -91,6 +93,7 @@ func GetProcessor(expr Expr, startIndex int) (Processor, int) {
 	panic("unreachable")
 }
 
+// Processor is a prcessor type returned by GetProcessor
 type Processor func(values []interface{}) interface{}
 
 func newEchoProcessor(index int) Processor {

influxql/scanner.go

@@ -176,6 +176,7 @@ func (s *Scanner) scanString() (tok Token, pos Pos, lit string) {
 	return STRING, pos, lit
 }
 
+// ScanRegex consumes a token to find escapes
 func (s *Scanner) ScanRegex() (tok Token, pos Pos, lit string) {
 	_, pos = s.r.curr()
 
@@ -255,15 +256,15 @@ func (s *Scanner) scanNumber() (tok Token, pos Pos, lit string) {
 		// If the next rune is a duration unit (u,µ,ms,s) then return a duration token
 		if ch0, _ := s.r.read(); ch0 == 'u' || ch0 == 'µ' || ch0 == 's' || ch0 == 'h' || ch0 == 'd' || ch0 == 'w' {
 			_, _ = buf.WriteRune(ch0)
-			return DURATION_VAL, pos, buf.String()
+			return DURATIONVAL, pos, buf.String()
 		} else if ch0 == 'm' {
 			_, _ = buf.WriteRune(ch0)
 			if ch1, _ := s.r.read(); ch1 == 's' {
 				_, _ = buf.WriteRune(ch1)
 			} else {
 				s.r.unread()
 			}
-			return DURATION_VAL, pos, buf.String()
+			return DURATIONVAL, pos, buf.String()
 		}
 		s.r.unread()
 	}
@@ -444,6 +445,7 @@ func (r *reader) curr() (ch rune, pos Pos) {
 // eof is a marker code point to signify that the reader can't read any more.
 const eof = rune(0)
 
+// ScanDelimited reads a delimited set of runes
 func ScanDelimited(r io.RuneScanner, start, end rune, escapes map[rune]rune, escapesPassThru bool) ([]byte, error) {
 	// Scan start delimiter.
 	if ch, _, err := r.ReadRune(); err != nil {

influxql/scanner_test.go

@@ -95,14 +95,14 @@ func TestScanner_Scan(t *testing.T) {
 		{s: `10.3s`, tok: influxql.NUMBER, lit: `10.3`},
 
 		// Durations
-		{s: `10u`, tok: influxql.DURATION_VAL, lit: `10u`},
-		{s: `10µ`, tok: influxql.DURATION_VAL, lit: `10µ`},
-		{s: `10ms`, tok: influxql.DURATION_VAL, lit: `10ms`},
-		{s: `-1s`, tok: influxql.DURATION_VAL, lit: `-1s`},
-		{s: `10m`, tok: influxql.DURATION_VAL, lit: `10m`},
-		{s: `10h`, tok: influxql.DURATION_VAL, lit: `10h`},
-		{s: `10d`, tok: influxql.DURATION_VAL, lit: `10d`},
-		{s: `10w`, tok: influxql.DURATION_VAL, lit: `10w`},
+		{s: `10u`, tok: influxql.DURATIONVAL, lit: `10u`},
+		{s: `10µ`, tok: influxql.DURATIONVAL, lit: `10µ`},
+		{s: `10ms`, tok: influxql.DURATIONVAL, lit: `10ms`},
+		{s: `-1s`, tok: influxql.DURATIONVAL, lit: `-1s`},
+		{s: `10m`, tok: influxql.DURATIONVAL, lit: `10m`},
+		{s: `10h`, tok: influxql.DURATIONVAL, lit: `10h`},
+		{s: `10d`, tok: influxql.DURATIONVAL, lit: `10d`},
+		{s: `10w`, tok: influxql.DURATIONVAL, lit: `10w`},
 		{s: `10x`, tok: influxql.NUMBER, lit: `10`}, // non-duration unit
 
 		// Keywords

influxql/token.go

@@ -7,28 +7,29 @@ import (
 // Token is a lexical token of the InfluxQL language.
 type Token int
 
+// These are a comprehensive list of InfluxQL language tokens.
 const (
-	// Special tokens
+	// ILLEGAL Token, EOF, WS are Special InfluxQL tokens.
 	ILLEGAL Token = iota
 	EOF
 	WS
 
-	literal_beg
-	// Literals
-	IDENT        // main
-	NUMBER       // 12345.67
-	DURATION_VAL // 13h
-	STRING       // "abc"
-	BADSTRING    // "abc
-	BADESCAPE    // \q
-	TRUE         // true
-	FALSE        // false
-	REGEX        // Regular expressions
-	BADREGEX     // `.*
-	literal_end
+	literalBeg
+	// IDENT and the following are InfluxQL literal tokens.
+	IDENT       // main
+	NUMBER      // 12345.67
+	DURATIONVAL // 13h
+	STRING      // "abc"
+	BADSTRING   // "abc
+	BADESCAPE   // \q
+	TRUE        // true
+	FALSE       // false
+	REGEX       // Regular expressions
+	BADREGEX    // `.*
+	literalEnd
 
-	operator_beg
-	// Operators
+	operatorBeg
+	// ADD and the following are InfluxQL Operators
 	ADD // +
 	SUB // -
 	MUL // *
@@ -45,7 +46,7 @@ const (
 	LTE      // <=
 	GT       // >
 	GTE      // >=
-	operator_end
+	operatorEnd
 
 	LPAREN    // (
 	RPAREN    // )
@@ -54,8 +55,8 @@ const (
 	SEMICOLON // ;
 	DOT       // .
 
-	keyword_beg
-	// Keywords
+	keywordBeg
+	// ALL and the following are InfluxQL Keywords
 	ALL
 	ALTER
 	ANY
@@ -137,23 +138,23 @@ const (
 	WHERE
 	WITH
 	WRITE
-	keyword_end
+	keywordEnd
 )
 
 var tokens = [...]string{
 	ILLEGAL: "ILLEGAL",
 	EOF:     "EOF",
 	WS:      "WS",
 
-	IDENT:        "IDENT",
-	NUMBER:       "NUMBER",
-	DURATION_VAL: "DURATION_VAL",
-	STRING:       "STRING",
-	BADSTRING:    "BADSTRING",
-	BADESCAPE:    "BADESCAPE",
-	TRUE:         "TRUE",
-	FALSE:        "FALSE",
-	REGEX:        "REGEX",
+	IDENT:       "IDENT",
+	NUMBER:      "NUMBER",
+	DURATIONVAL: "DURATIONVAL",
+	STRING:      "STRING",
+	BADSTRING:   "BADSTRING",
+	BADESCAPE:   "BADESCAPE",
+	TRUE:        "TRUE",
+	FALSE:       "FALSE",
+	REGEX:       "REGEX",
 
 	ADD: "+",
 	SUB: "-",
@@ -266,7 +267,7 @@ var keywords map[string]Token
 
 func init() {
 	keywords = make(map[string]Token)
-	for tok := keyword_beg + 1; tok < keyword_end; tok++ {
+	for tok := keywordBeg + 1; tok < keywordEnd; tok++ {
 		keywords[strings.ToLower(tokens[tok])] = tok
 	}
 	for _, tok := range []Token{AND, OR} {
@@ -302,7 +303,7 @@ func (tok Token) Precedence() int {
 }
 
 // isOperator returns true for operator tokens.
-func (tok Token) isOperator() bool { return tok > operator_beg && tok < operator_end }
+func (tok Token) isOperator() bool { return tok > operatorBeg && tok < operatorEnd }
 
 // tokstr returns a literal if provided, otherwise returns the token string.
 func tokstr(tok Token, lit string) string {