support output-path attribute

quad/quad/scribblings/quad.scrbl

@@ -106,7 +106,7 @@ quadwriter: wrote PDF to /Users/Desktop/test.pdf
 Congratulations — you just made your first PDF. If you want to have a look, either open the file manually, or enter this command on the REPL, which will open the PDF in your default viewer:
 
 @terminal{
-> (view-result)
+> (view-output)
 }
 
 Next, on the REPL enter this:
@@ -121,7 +121,7 @@ You will see the actual input to Quadwriter, which is called a @tech{Q-expressio
 '(q () (q ((page-margin-left "120") (page-margin-top "80") (page-margin-bottom "120") (font-family "text") (line-height "17")) (q ((keep-first-lines "2") (keep-last-lines "3") (font-size-adjust "100%") (character-tracking "0") (hyphenate "true") (display "g49598")) "Brennan and Dale like fancy sauce.")))
 }
 
-In the demos that follow, the input language will change slightly. But the PDF will be rendered the same way (by running the source file) and you can always look at @racket[doc] or use @racket[view-result].
+In the demos that follow, the input language will change slightly. But the PDF will be rendered the same way (by running the source file) and you can always look at @racket[doc] or use @racket[view-output].
 
 
 @subsection{Quadwriter & Markdown}
@@ -447,7 +447,7 @@ The @tech{Q-expression} @racketresult['#,para-break]. Used to denote the start o
 @defthing[section-break qexpr?]{
 The @tech{Q-expression} @racketresult['#,section-break]. Used to denote the start of a new section.
 
-A section is a contiguous series of pages. Each section has its own @secref{Page-level_attributes}. A document without any explicit section breaks still has one section (that includes all the pages).
+A section is a contiguous series of pages. Each section has its own @secref{Section-level_attributes}. A document without any explicit section breaks still has one section (that includes all the pages).
 }
 
 
@@ -457,8 +457,20 @@ These are the attributes that can be used inside a @tech{Q-expression} passed to
 
 A @deftech{dimension string} represents a distance in the plane. If unitless, it is treated as points (where 1 point = 1/72 of an inch). If the number has @racket[in], @racket[cm], or @racket[mm] as a suffix, it is treated as inches, centimeters, or millimeters respectively.
 
+@subsubsection{Document-level attributes}
+
+Attributes that can only be set once for the whole document.
+
+
+@defthing[#:kind "attribute" output-path symbol?]{
+Output path for the rendered PDF. Default is the name of the source file with its extension changed to @racket[.pdf]. For instance, @racket["my-source.rkt"] would become @racket["my-source.pdf"]. Unsaved source files are rendered as @racket["untitled.pdf"].
+}
+
+
+@subsubsection{Section-level attributes}
+
+Attributes that can be set for each section.
 
-@subsubsection{Page-level attributes}
 
 @deftogether[(@defthing[#:kind "attribute" page-size symbol?]
               @defthing[#:kind "attribute" page-orientation symbol?])]{
@@ -737,7 +749,7 @@ A @deftech{named color} is a hex color with a pre-existing name.
 @subsection{Utility}
 
 @defproc[
-(view-result)
+(view-output)
 void?]{
 On the REPL, after running a @racketmodname[quadwriter] dialect and generating a PDF, this function will open the PDF.
 }

quad/quadwriter/lang-helper.rkt

@@ -32,8 +32,8 @@
              [_ (loop kw-val-pairs)]))]
         ;; reverse in case of multiple values with same keyword, latest takes precedence (by becoming first)
         [else (reverse (for/list ([(kw val) (in-dict kw-val-pairs)])
-                                 (list (string->symbol (string-trim (keyword->string kw) "#:"))
-                                       (format "~a" val))))])))
+                         (list (string->symbol (string-trim (keyword->string kw) "#:"))
+                               (format "~a" val))))])))
   (strip-context
    (with-syntax ([PATH-STRING path-string]
                  [((ATTR-NAME ATTR-VAL) ...) kw-attrs]
@@ -51,30 +51,36 @@
       (syntax-case stx ()
         [(_ PATH-STRING ATTRS . EXPRS)
          (with-syntax ([DOC (datum->syntax #'PATH-STRING 'doc)]
-                       [VIEW-RESULT (datum->syntax #'PATH-STRING 'view-result)])
+                       [VIEW-OUTPUT (datum->syntax #'PATH-STRING 'view-output)])
            #'(#%module-begin
-              (provide DOC VIEW-RESULT)
-              (define DOC `(q ATTRS ,(DOC-PROC (list . EXPRS))))
-              (define pdf-path (path-string->pdf-path 'PATH-STRING))
-              (define (VIEW-RESULT)
+              (provide DOC VIEW-OUTPUT)
+              (define attrs (let ([h (make-hasheq)])
+                              (for ([kvlist (in-list 'ATTRS)])
+                                (apply hash-set! h kvlist))
+                              h))
+              (define pdf-path (hash-ref! attrs 'output-path (λ () (path-string->pdf-path 'PATH-STRING))))
+              (define DOC `(q ,(for/list ([(k v) (in-hash attrs)])
+                                 (list k v))
+                              ,(DOC-PROC (list . EXPRS))))
+              (define (VIEW-OUTPUT)
                 (define open-string
                   (case (system-type 'os)
                     [(macosx) "open '~a'"]
                     [(windows) "start '~a'"]
                     [(unix) "xdg-open '~a' &> /dev/null"]
-                    [else (error "Don't know how to open PDF file.")]))
+                    [else (error "Unknown platform. Don't know how to view PDF.")]))
                 (when (file-exists? pdf-path)
                   (void (system (format open-string pdf-path)))))
               (module+ main
                 (with-logging-to-port
-                 (current-output-port)
-                 (λ () (with-logging-to-port
-                        (current-output-port)
-                        (λ () (render-pdf DOC pdf-path PATH-STRING))
-                        #:logger quadwriter-logger
-                        'debug))
-                 #:logger quad-logger
-                 'debug))))]))))
+                    (current-output-port)
+                  (λ () (with-logging-to-port
+                            (current-output-port)
+                          (λ () (render-pdf DOC pdf-path PATH-STRING))
+                          #:logger quadwriter-logger
+                          'debug))
+                  #:logger quad-logger
+                  'debug))))]))))
 
 (define (path-string->pdf-path path-string)
   (match (format "~a" path-string)
@@ -122,7 +128,7 @@
            (or
             (for/first ([pos (in-range line-start-pos line-end-pos)]
                         #:unless (char-blank? (send text get-character pos)))
-                       pos)
+              pos)
             line-start-pos))
          (- first-vis-pos line-start-pos))]      
       [else default])))