mirror of https://github.com/janet-lang/janet
56 lines
1.5 KiB
Clojure
56 lines
1.5 KiB
Clojure
# A flexible templater for janet. Compiles
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# templates to janet functions that produce buffers.
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(defn template
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"Compile a template string into a function"
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[source]
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# State for compilation machine
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(def p (parser/new))
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(def forms @[])
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(defn parse-chunk
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"Parse a string and push produced values to forms."
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[chunk]
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(parser/consume p chunk)
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(while (parser/has-more p)
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(array/push forms (parser/produce p)))
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(if (= :error (parser/status p))
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(error (parser/error p))))
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(defn code-chunk
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"Parse all the forms in str and return them
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in a tuple prefixed with 'do."
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[str]
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(parse-chunk str)
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true)
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(defn string-chunk
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"Insert string chunk into parser"
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[str]
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(parser/insert p str)
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(parse-chunk "")
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true)
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# Run peg
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(def grammar
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~{:code-chunk (* "{%" (drop (cmt '(any (if-not "%}" 1)) ,code-chunk)) "%}")
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:main-chunk (drop (cmt '(any (if-not "{%" 1)) ,string-chunk))
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:main (any (+ :code-chunk :main-chunk (error "")))})
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(def parts (peg/match grammar source))
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# Check errors in template and parser
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(unless parts (error "invalid template syntax"))
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(parse-chunk "\n")
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(case (parser/status p)
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:pending (error (string "unfinished parser state " (parser/state p)))
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:error (error (parser/error p)))
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# Make ast from forms
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(def ast ~(fn [&opt params] (default params @{}) (,buffer ,;forms)))
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(def ctor (compile ast (fiber/getenv (fiber/current)) source))
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(if-not (function? ctor)
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(error (string "could not compile template")))
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(ctor))
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