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arf/lexer/token.go

171 lines
3.9 KiB
Go

package lexer
import "fmt"
import "github.com/sashakoshka/arf/file"
// TokenKind is an enum represzenting what role a token has.
type TokenKind int
const (
TokenKindNewline TokenKind = iota
TokenKindIndent
TokenKindSeparator
TokenKindPermission
TokenKindReturnDirection
TokenKindInt
TokenKindUInt
TokenKindFloat
TokenKindString
TokenKindRune
TokenKindName
TokenKindColon
TokenKindDot
TokenKindLBracket
TokenKindRBracket
TokenKindLBrace
TokenKindRBrace
TokenKindPlus
TokenKindMinus
TokenKindIncrement
TokenKindDecrement
TokenKindAsterisk
TokenKindSlash
TokenKindAt
TokenKindExclamation
TokenKindPercent
TokenKindTilde
TokenKindLessThan
TokenKindLShift
TokenKindGreaterThan
TokenKindRShift
TokenKindBinaryOr
TokenKindLogicalOr
TokenKindBinaryAnd
TokenKindLogicalAnd
)
// Token represents a single token. It holds its location in the file, as well
// as a value and some semantic information defining the token's role.
type Token struct {
kind TokenKind
location file.Location
value any
}
// Kind returns the semantic role of the token.
func (token Token) Kind () (kind TokenKind) {
return token.kind
}
// Is returns whether or not the token is of kind kind.
func (token Token) Is (kind TokenKind) (match bool) {
return token.kind == kind
}
// Value returns the value of the token. Depending on what kind of token it is,
// this value may be nil.
func (token Token) Value () (value any) {
return token.value
}
// Equals returns whether this token is equal to another token
func (token Token) Equals (testToken Token) (match bool) {
return token == testToken
}
// Location returns the location of the token in its file.
func (token Token) Location () (location file.Location) {
return token.location
}
// Describe generates a textual description of the token to be used in debug
// logs.
func (token Token) Describe () (description string) {
switch token.kind {
case TokenKindNewline:
description += "Newline"
case TokenKindIndent:
description += "Indent"
case TokenKindSeparator:
description += "Separator"
case TokenKindPermission:
description += "Permission"
case TokenKindReturnDirection:
description += "ReturnDirection"
case TokenKindInt:
description += "Int"
case TokenKindUInt:
description += "UInt"
case TokenKindFloat:
description += "Float"
case TokenKindString:
description += "String"
case TokenKindRune:
description += "Rune"
case TokenKindName:
description += "Name"
case TokenKindColon:
description += "Colon"
case TokenKindDot:
description += "Dot"
case TokenKindLBracket:
description += "LBracket"
case TokenKindRBracket:
description += "RBracket"
case TokenKindLBrace:
description += "LBrace"
case TokenKindRBrace:
description += "RBrace"
case TokenKindPlus:
description += "Plus"
case TokenKindMinus:
description += "Minus"
case TokenKindIncrement:
description += "Increment"
case TokenKindDecrement:
description += "Decrement"
case TokenKindAsterisk:
description += "Asterisk"
case TokenKindSlash:
description += "Slash"
case TokenKindAt:
description += "At"
case TokenKindExclamation:
description += "Exclamation"
case TokenKindPercent:
description += "Percent"
case TokenKindTilde:
description += "Tilde"
case TokenKindLessThan:
description += "LessThan"
case TokenKindLShift:
description += "LShift"
case TokenKindGreaterThan:
description += "GreaterThan"
case TokenKindRShift:
description += "RShift"
case TokenKindBinaryOr:
description += "BinaryOr"
case TokenKindLogicalOr:
description += "LogicalOr"
case TokenKindBinaryAnd:
description += "BinaryAnd"
case TokenKindLogicalAnd:
description += "LogicalAnd"
}
if token.value != nil {
description += fmt.Sprint(": ", token.value)
}
return
}