69 lines
1.2 KiB
Go
69 lines
1.2 KiB
Go
package token
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// All tokens in the pseudo-lambda language.
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type Type int
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const (
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// Denotes the '(' token.
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OpenParen Type = iota
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// Denotes the ')' token.
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CloseParen
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// Denotes an alpha-numeric variable.
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Atom
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// Denotes the '/' token.
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Slash
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// Denotes the '.' token.
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Dot
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)
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// A representation of a token in source code.
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type Token struct {
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// Where the token begins in the source text.
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Index int
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// What type the token is.
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Type Type
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// The value of the token.
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Value string
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}
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func NewOpenParen(index int) *Token {
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return &Token{Type: OpenParen, Index: index, Value: "("}
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}
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func NewCloseParen(index int) *Token {
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return &Token{Type: CloseParen, Index: index, Value: ")"}
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}
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func NewDot(index int) *Token {
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return &Token{Type: Dot, Index: index, Value: "."}
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}
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func NewSlash(index int) *Token {
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return &Token{Type: Slash, Index: index, Value: "\\"}
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}
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func NewAtom(name string, index int) *Token {
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return &Token{Type: Atom, Index: index, Value: name}
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}
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func Name(typ Type) string {
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switch typ {
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case OpenParen:
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return "("
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case CloseParen:
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return ")"
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case Slash:
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return "\\"
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case Dot:
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return "."
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case Atom:
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return "ATOM"
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default:
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return "?"
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}
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}
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func (t Token) Name() string {
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return Name(t.Type)
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}
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