92 lines
2.1 KiB
Go
92 lines
2.1 KiB
Go
package token
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import "fmt"
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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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OpenParen Type = iota // Denotes the '(' token.
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CloseParen // Denotes the ')' token.
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OpenBrace // Denotes the '{' token.
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CloseBrace // Denotes the '}' token.
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HardBreak // Denotes the ';' token.
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Assign // Denotes the ':=' token.
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Atom // Denotes an alpha-numeric variable.
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Slash // Denotes the '/' token.
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Dot // Denotes the '.' token.
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SoftBreak // Denotes a new-line.
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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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Column int // Where the token begins in the source text.
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Type Type // What type the token is.
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Value string // The value of the token.
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}
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func NewOpenParen(column int) *Token {
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return &Token{Type: OpenParen, Column: column, Value: "("}
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}
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func NewCloseParen(column int) *Token {
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return &Token{Type: CloseParen, Column: column, Value: ")"}
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}
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func NewOpenBrace(column int) *Token {
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return &Token{Type: OpenBrace, Column: column, Value: "{"}
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}
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func NewCloseBrace(column int) *Token {
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return &Token{Type: CloseBrace, Column: column, Value: "}"}
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}
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func NewDot(column int) *Token {
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return &Token{Type: Dot, Column: column, Value: "."}
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}
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func NewHardBreak(column int) *Token {
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return &Token{Type: HardBreak, Column: column, Value: ";"}
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}
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func NewAssign(column int) *Token {
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return &Token{Type: Assign, Column: column, Value: ":="}
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}
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func NewSlash(column int) *Token {
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return &Token{Type: Slash, Column: column, Value: "\\"}
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}
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func NewAtom(name string, column int) *Token {
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return &Token{Type: Atom, Column: column, Value: name}
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}
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func NewSoftBreak(column int) *Token {
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return &Token{Type: SoftBreak, Column: column, Value: "\\n"}
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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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case SoftBreak:
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return "\\n"
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case HardBreak:
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return ";"
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default:
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panic(fmt.Errorf("unknown token type %v", typ))
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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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