Go 言語の `++` や `--` は演算子ではない ref: http://qiita.com/spiegel-im-spiegel/items/2c6cf5ff44d816d1be7b

file0.txt

IncDecStmt = Expression ( "++" | "--" ) .

file1.go

package main

import "fmt"

func main() {
    i := 1
    a := i++
    fmt.Println(a)
}

file2.go

package main

import "fmt"

func main() {
    i := 1
    i++
    a := i
    fmt.Println(a)
}

file3.go

package main

import "fmt"

func main() {
    i := 1
    a := i
    i++
    fmt.Println(a)
}

file4.go

package main

import "fmt"

func main() {
    i := 1
    a := i += 1
    fmt.Println(a)
}

file5.txt

Expression = UnaryExpr | Expression binary_op Expression .
UnaryExpr  = PrimaryExpr | unary_op UnaryExpr .

binary_op  = "||" | "&&" | rel_op | add_op | mul_op .
rel_op     = "==" | "!=" | "<" | "<=" | ">" | ">=" .
add_op     = "+" | "-" | "|" | "^" .
mul_op     = "*" | "/" | "%" | "<<" | ">>" | "&" | "&^" .

unary_op   = "+" | "-" | "!" | "^" | "*" | "&" | "<-" .

file6.txt

PrimaryExpr =
    Operand |
    Conversion |
    PrimaryExpr Selector |
    PrimaryExpr Index |
    PrimaryExpr Slice |
    PrimaryExpr TypeAssertion |
    PrimaryExpr Arguments .

Selector       = "." identifier .
Index          = "[" Expression "]" .
Slice          = "[" [ Expression ] ":" [ Expression ] "]" |
                 "[" [ Expression ] ":" Expression ":" Expression "]" .
TypeAssertion  = "." "(" Type ")" .
Arguments      = "(" [ ( ExpressionList | Type [ "," ExpressionList ] ) [ "..." ] [ "," ] ] ")" .