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liquid/scanner.rl

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2017-06-25 18:36:28 +02:00
package main
import "strconv"
%% machine lexer;
func ScanExpression(data string) ([]Token, error) {
cs, p, pe, eof := 0, 0, len(data), len(data)
var (ts, te, act int)
_ = act
tokens := make([]Token, 0)
%%{
action Ident {tokens = append(tokens, Token{IdentifierType, data[ts:te], nil})}
action Number {
n, err := strconv.ParseFloat(data[ts:te], 64)
if err != nil {
panic(err)
}
tokens = append(tokens, Token{ValueType, "", n})
}
action Relation {tokens = append(tokens, Token{RelationType, data[ts:te], nil})}
ident = (alpha | '_') . (alnum | '_')* ;
number = '-'? (digit+ ('.' digit*)?) ;
main := |*
ident => Ident;
number => Number;
("==" | "!=" | ">" | ">" | ">=" | "<=") => Relation;
("and" | "or" | "contains") => Relation;
space+;
*|;
write init;
write exec;
}%%
return tokens, nil
}
%% write data;