用Go语言实现的语法分析器(syntax analyzer)

    package main
     
    import (
    "bufio"
    "fmt"
    "log"
    "os"
    "strconv"
    "strings"
    )
     
    type TokenType int
     
    const (
    tkEOI TokenType = iota
    tkMul
    tkDiv
    tkMod
    tkAdd
    tkSub
    tkNegate
    tkNot
    tkLss
    tkLeq
    tkGtr
    tkGeq
    tkEql
    tkNeq
    tkAssign
    tkAnd
    tkOr
    tkIf
    tkElse
    tkWhile
    tkPrint
    tkPutc
    tkLparen
    tkRparen
    tkLbrace
    tkRbrace
    tkSemi
    tkComma
    tkIdent
    tkInteger
    tkString
    )
     
    type NodeType int
     
    const (
    ndIde