92 lines
2.3 KiB
Go
92 lines
2.3 KiB
Go
package saccharine
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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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TokenOpenParen Type = iota // Denotes the '(' token.
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TokenCloseParen // Denotes the ')' token.
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TokenOpenBrace // Denotes the '{' token.
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TokenCloseBrace // Denotes the '}' token.
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TokenHardBreak // Denotes the ';' token.
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TokenAssign // Denotes the ':=' token.
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TokenAtom // Denotes an alpha-numeric variable.
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TokenSlash // Denotes the '/' token.
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TokenDot // Denotes the '.' token.
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TokenSoftBreak // 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: TokenOpenParen, Column: column, Value: "("}
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}
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func NewCloseParen(column int) *Token {
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return &Token{Type: TokenCloseParen, Column: column, Value: ")"}
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}
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func NewOpenBrace(column int) *Token {
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return &Token{Type: TokenOpenBrace, Column: column, Value: "{"}
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}
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func NewCloseBrace(column int) *Token {
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return &Token{Type: TokenCloseBrace, Column: column, Value: "}"}
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}
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func NewDot(column int) *Token {
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return &Token{Type: TokenDot, Column: column, Value: "."}
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}
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func NewHardBreak(column int) *Token {
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return &Token{Type: TokenHardBreak, Column: column, Value: ";"}
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}
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func NewAssign(column int) *Token {
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return &Token{Type: TokenAssign, Column: column, Value: ":="}
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}
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func NewSlash(column int) *Token {
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return &Token{Type: TokenSlash, 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: TokenAtom, Column: column, Value: name}
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}
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func NewSoftBreak(column int) *Token {
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return &Token{Type: TokenSoftBreak, 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 TokenOpenParen:
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return "("
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case TokenCloseParen:
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return ")"
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case TokenSlash:
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return "\\"
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case TokenDot:
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return "."
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case TokenAtom:
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return "ATOM"
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case TokenSoftBreak:
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return "\\n"
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case TokenHardBreak:
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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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