CODEWITHSUNDEEP
lisphy
Srv19
Srv19

Reputation: 3618

Why does my hylang program fail at parsing?

I have written a small hylang program that parses a log. However, when i try to evaluate it, i get the following error:

File "", line 8, column 38

        (setv rule (.next irule)))))))
                                   ^ LexException: Ran into a RPAREN where it wasn't expected.

The function in question (also gives an error when evaluated separately) is the following:

(defmain [&rest args]
  (setv inname (get args 1))
  (setv outname (get args 2))
  (with [ifile (open inname 'r')]
    (with [ofile (open outname 'w')]
      (setv tl (Tableline))
      (setv irule (iter (.get-rule tl)))
      (setv rule (.next irule))
      (for [line ifile]
        (setv match (re.match (get rule 0) line))
        (when match
          (for [(, group-num attr-data) (enumerate (get rule 1))]
            (setattr tl (get attr-data 1) (apply (get attr-data 0)
                                                 [(.group match (inc group-num))])))
          (if (. tl ready) (write ofile (str tl)))
          (setv rule (.next irule)))))))

As far as i can tell, it is balanced expression, with all parens in their places. Why does the lexer fails?

The full text of my program is here: pastebin

Upvotes: 1

Views: 107

Answers (2)

Srv19
Srv19

Reputation: 3618

Should have used "w" and "r" instead of 'w' and 'r'

Upvotes: 0

djeis
djeis

Reputation: 286

You need to use double quotes for making strings.

In lisps, the single quote is used for something completely different than making strings- "quoting" the next form. When lisp code is parsed, expressions like 'a are transformed into (quote a). Similarly, '(hello) becomes (quote (hello)). Note that there is only one ' mark, as it always wraps the next expression. The quote form lets you "turn off" evaluation for a single expression. Look up lisp quotation- it's pretty useful, and is important for some of the more powerful features of the language.

Upvotes: 1

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