44 lines
814 B
Go
44 lines
814 B
Go
package parser
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import (
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"code.jmug.me/jmug/interpreter-in-go/pkg/token"
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)
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const (
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_ int = iota
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LOWEST
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EQUALS // ==
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LESSGREATER // > or <
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SUM // +
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PRODUCT // *
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PREFIX // -X or !X
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CALL // myFunction(X)
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INDEX // array[index]
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)
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var precedences = map[token.TokenType]int{
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token.EQ: EQUALS,
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token.NOT_EQ: EQUALS,
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token.GT: LESSGREATER,
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token.LT: LESSGREATER,
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token.PLUS: SUM,
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token.MINUS: SUM,
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token.ASTERISK: PRODUCT,
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token.SLASH: PRODUCT,
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token.LPAREN: CALL,
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token.LBRACKET: INDEX,
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}
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func (p *Parser) peekPrecedence() int {
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if pr, ok := precedences[p.peekToken.Type]; ok {
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return pr
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}
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return LOWEST
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}
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func (p *Parser) curPrecedence() int {
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if pr, ok := precedences[p.curToken.Type]; ok {
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return pr
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}
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return LOWEST
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}
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