permit multiple key-val pairs in `define-meta` (closes #215)

pollen/core.rkt

@@ -21,7 +21,7 @@
 ;; even though this error will happen after macro expansion, when metas are extracted
 ;; empty string will merge with surroundings
 (provide define-meta)
-(define-syntax-rule (define-meta k v) (begin))
+(define-syntax-rule (define-meta k v kv ...) (begin))
 
 (define+provide current-metas (make-parameter #f))
 

pollen/private/main-base.rkt

@@ -3,7 +3,6 @@
                      syntax/strip-context
                      "../setup.rkt"
                      "split-metas.rkt")
-         racket/match
          racket/list
          "to-string.rkt"
          "../pagetree.rkt"
@@ -25,15 +24,15 @@
 
 (define (parse xs-in parser-mode root-proc)
   (define xs (splice (strip-leading-newlines xs-in) (setup:splicing-tag)))
-  (match parser-mode
-    [(== default-mode-pagetree eq?) (decode-pagetree xs)]
-    [(== default-mode-markup eq?) (apply root-proc (remove-voids xs))] 
-    [(== default-mode-markdown eq?)
+  (cond
+    [(eq? parser-mode default-mode-pagetree) (decode-pagetree xs)]
+    [(eq? parser-mode default-mode-markup) (apply root-proc (remove-voids xs))] 
+    [(eq? parser-mode default-mode-markdown)
      (let* ([xs (stringify xs)]
             [xs ((dynamic-require 'markdown 'parse-markdown) xs)]
             [xs (map strip-empty-attrs xs)])
        (apply root-proc xs))]
-    [_ (stringify xs)])) ; preprocessor mode
+    [else (stringify xs)])) ; preprocessor mode
 
 (define-syntax (pollen-module-begin stx)
   (syntax-case stx ()

pollen/private/reader-base.rkt

@@ -4,7 +4,6 @@
          racket/class
          racket/string
          racket/runtime-path
-         racket/match
          setup/getinfo
          sugar/file
          (for-syntax racket/base)
@@ -19,14 +18,15 @@
   ((if (syntax? source-name) syntax-source values) source-name))
 
 (define (infer-parser-mode reader-mode reader-here-path)
-  (match reader-mode
-    [(== default-mode-auto eq?)
-     (match (cond [(get-ext reader-here-path) => string->symbol])
-       [(== (setup:pagetree-source-ext) eq?) default-mode-pagetree]
-       [(== (setup:markup-source-ext) eq?) default-mode-markup]
-       [(== (setup:markdown-source-ext) eq?) default-mode-markdown]
-       [_ default-mode-preproc])]
-    [_ reader-mode]))
+  (cond
+    [(eq? reader-mode default-mode-auto)
+     (let ([val (cond [(get-ext reader-here-path) => string->symbol])])
+       (cond
+         [(eq? val (setup:pagetree-source-ext)) default-mode-pagetree]
+         [(eq? val (setup:markup-source-ext)) default-mode-markup]
+         [(eq? val (setup:markdown-source-ext)) default-mode-markdown]
+         [else default-mode-preproc]))]
+    [else reader-mode]))
 
 (define (custom-read p) (syntax->datum (custom-read-syntax (object-name p) p)))
 
@@ -88,12 +88,16 @@
          (hash-ref! command-char-cache maybe-source-path (λ () (setup:command-char maybe-source-path))))
        (case key
          [(color-lexer)
-          (match (dynamic-require 'syntax-color/scribble-lexer 'make-scribble-inside-lexer (λ () #false))
-            [(? procedure? make-lexer) (make-lexer #:command-char my-command-char)]
-            [_ default])]
+          (define maybe-lexer
+            (dynamic-require 'syntax-color/scribble-lexer 'make-scribble-inside-lexer (λ () #false)))
+          (cond
+            [(procedure? maybe-lexer) (maybe-lexer #:command-char my-command-char)]
+            [else default])]
          [(drracket:toolbar-buttons)
-          (match (dynamic-require 'pollen/private/drracket-buttons 'make-drracket-buttons (λ () #false))
-            [(? procedure? make-buttons) (make-buttons my-command-char)])])]
+          (define maybe-button-maker
+            (dynamic-require 'pollen/private/drracket-buttons 'make-drracket-buttons (λ () #false)))
+          (when (procedure? maybe-button-maker)
+            (maybe-button-maker my-command-char))])]
       [(drracket:indentation)
        (λ (text pos)
          (define line-idx (send text position-line pos))
@@ -114,12 +118,12 @@
        (list (list "Pollen sources" (string-join filter-strings ";")))]
       [(drracket:default-extension)
        (symbol->string
-        (match mode
-          [(== default-mode-auto eq?) (setup:preproc-source-ext)]
-          [(== default-mode-preproc eq?) (setup:preproc-source-ext)]
-          [(== default-mode-markdown eq?) (setup:markdown-source-ext)]
-          [(== default-mode-markup eq?) (setup:markup-source-ext)]
-          [(== default-mode-pagetree eq?) (setup:pagetree-source-ext)]))]
+        (cond
+          [(eq? mode default-mode-auto) (setup:preproc-source-ext)]
+          [(eq? mode default-mode-preproc) (setup:preproc-source-ext)]
+          [(eq? mode default-mode-markdown) (setup:markdown-source-ext)]
+          [(eq? mode default-mode-markup) (setup:markup-source-ext)]
+          [(eq? mode default-mode-pagetree) (setup:pagetree-source-ext)]))]
       [else default])))
 
 (define-syntax-rule (reader-module-begin mode . _)

pollen/private/split-metas.rkt

@@ -7,10 +7,16 @@
   (apply hasheq
          (let loop ([x ((if (syntax? x) syntax->datum values) x)])
            (match x
-             [(list (== meta-key eq?) key val)
+             [(list (== meta-key eq?) kvs ...)
+              (unless (>= (length kvs) 2)
+                  (raise-argument-error meta-key "at least one key-value pair" kvs))
+              (unless (even? (length kvs))
+                  (raise-argument-error meta-key "equal number of keys and values" kvs))
+              (for ([(key idx) (in-indexed kvs)]
+                    #:when (even? idx))
                 (unless (symbol? key)
-                (raise-argument-error meta-key "valid meta key" key))
-              (list key val)]
+                  (raise-argument-error meta-key "valid meta key" key)))
+              kvs]
              [(? list? xs) (append-map loop xs)]
              [_ null]))))
 
@@ -19,6 +25,7 @@
   (check-equal? (split-metas 'root) (hasheq))
   (check-equal? (split-metas '(root)) (hasheq))
   (check-exn exn:fail:contract? (λ () (split-metas '(root (define-meta 42 "bar")))))
+  (check-exn exn:fail:contract? (λ () (split-metas '(root (define-meta foo "bar" zim)))))
   (check-equal? (split-metas '(root (div #:kw #f (define-meta foo "bar") "hi") "zim" (define-meta foo "boing") "zam")) '#hasheq((foo . "boing")))
   (check-equal? (split-metas '(root (div #:kw #f (define-meta foo 'bar) "hi") "zim" (define-meta foo 'boing) "zam")) '#hasheq((foo . 'boing)))
   (check-equal? (split-metas #'(root (define-meta dog "Roxy") (define-meta dog "Lex"))) '#hasheq((dog . "Lex")))

pollen/private/ts.rktd

@@ -1 +1 @@
-1581033338
+1581271696

pollen/scribblings/command.scrbl

@@ -661,6 +661,32 @@ The title is ◊(select-from-metas 'title metas)
 @repl-output{'(root "The title is " "Conclusion to " (em "Infinity War"))}
 
 
+To save a few keystrokes, you can consolidate multiple key–value pairs into one @racket[define-meta] form. So this:
+
+@codeblock{
+#lang pollen
+◊(define-meta dog "Roxy")
+◊(define-meta cat "Chopper")
+◊(define-meta ape "Koko") 
+}
+
+Is the same as this:
+
+@codeblock{
+#lang pollen
+◊(define-meta dog "Roxy"
+              cat "Chopper"
+              ape "Koko")
+}
+
+In both cases, the resulting metas look like this:
+
+@terminal{
+> metas
+'#hasheq((ape . "Koko") (cat . "Chopper") (dog . "Roxy") (here-path . "unsaved editor"))
+}
+
+
 @subsubsection{Retrieving metas}
 
 The @id{metas} hashtable is available immediately within the body of your source file. You can use @racket[select] to get values out of @id{metas}.