Implement indented code blocks.

7 files changed, 101 insertions, 6 deletions

diff --git a/src/clarktown/correctors.clj b/src/clarktown/correctors.clj
index 6b7cc1c..cd5e7e8 100644
--- a/src/clarktown/correctors.clj
+++ b/src/clarktown/correctors.clj
@@ -1,6 +1,7 @@
 (ns clarktown.correctors
   (:require
     [clarktown.correctors.fenced-code-block :as fenced-code-block]
+    [clarktown.correctors.indented-code-block :as indented-code-block]
     [clarktown.correctors.atx-heading-block :as atx-heading-block]
     [clarktown.correctors.list-block :as list-block]))
 
@@ -10,10 +11,12 @@
   default-block-separation-correctors
   {:newline-above
    [fenced-code-block/newline-above?
+    indented-code-block/newline-above?
     atx-heading-block/newline-above?
     list-block/newline-above?]
    :newline-below
    [fenced-code-block/newline-below?
+    indented-code-block/newline-below?
     atx-heading-block/newline-below?
     list-block/newline-below?]})
 
diff --git a/src/clarktown/correctors/atx_heading_block.clj b/src/clarktown/correctors/atx_heading_block.clj
index 6668700..5a5f713 100644
--- a/src/clarktown/correctors/atx_heading_block.clj
+++ b/src/clarktown/correctors/atx_heading_block.clj
@@ -20,7 +20,7 @@
   there's no empty newline above, we need to create one, and 
   so this function must then return `true`."
   [lines line index]
-  (and (is-atx-heading? (string/trim line))
+  (and (is-atx-heading? line)
        (> index 0)
        (not (= (-> (nth lines (- index 1))
                    string/trim) ""))
diff --git a/src/clarktown/correctors/indented_code_block.clj b/src/clarktown/correctors/indented_code_block.clj
new file mode 100644
index 0000000..47deeb7
--- /dev/null
+++ b/src/clarktown/correctors/indented_code_block.clj
@@ -0,0 +1,57 @@
+(ns clarktown.correctors.indented-code-block
+  (:require
+    [clojure.string :as string]
+    [clarktown.matchers.list-block :as list-block-matcher]))
+
+
+(defn- in-code-block?
+  "Determines whether the current `line` is within a code block."
+  [lines index]
+  (->> (take index lines)
+       (filter #(string/starts-with? (string/trim %) "```"))
+       count
+       odd?))
+
+
+(defn newline-above?
+  "Determines whether there's a need for an empty new line
+  above the `line` at the current `index`. In the case of a
+  code block, which starts with three backticks (```), if there's
+  no empty newline above, we need to create one, and so this
+  function must then return `true`."
+  [lines line index]
+  (let [space-count (count (take-while #{\space} line))
+        not-first? (> index 0)
+        prev-line (when not-first?
+                    (nth lines (- index 1)))
+        space-count-prev-line (count (take-while #{\space} prev-line))]
+    (and (>= space-count 4)
+         not-first?
+         (not (in-code-block? lines index))
+         (not (list-block-matcher/match? line))
+         (not (list-block-matcher/match? prev-line))
+         (not (>= space-count-prev-line 4))
+         (not (= (-> prev-line
+                     string/trim)
+                 "")))))
+
+(defn newline-below?
+  "Determines whether there's a need for an empty new line
+  below the `line` at the current `index`. In the case of a
+  code block, which ends with three backticks (```), if there's
+  no empty newline above, we need to create one, and so this
+  function must then return `true`."
+  [lines line index]
+  (let [space-count (count (take-while #{\space} line))
+        not-last? (< index (- (count lines) 1))
+        next-line (when not-last?
+                    (nth lines (+ index 1)))
+        space-count-next-line (count (take-while #{\space} next-line))]
+    (and (>= space-count 4)
+         not-last?
+         (not (in-code-block? lines index))
+         (not (list-block-matcher/match? line))
+         (not (list-block-matcher/match? next-line))
+         (not (>= space-count-next-line 4))
+         (not (= (-> next-line
+                     string/trim) "")))))
diff --git a/src/clarktown/engine.clj b/src/clarktown/engine.clj
index 5eb22d5..dc07e9f 100644
--- a/src/clarktown/engine.clj
+++ b/src/clarktown/engine.clj
@@ -70,7 +70,7 @@
 
 
 (defn- remove-excess-newlines
-  "Replaces all occurences of 3 or more concecutive newlines into
+  "Replaces all occurrences of 3 or more consecutive newlines into
   two newlines."
   [markdown]
   (string/replace markdown #"\n{3,}" "\n\n"))
@@ -133,10 +133,8 @@
   [blocks given-parsers given-correctors]
   (for [block blocks]
     (if-let [parser (find-parser-by-block given-parsers block)]
-      (->> (string/trim block)
-           (parse-block-with-known-parser parser given-parsers given-correctors))
-      (->> (string/trim block)
-           (parse-block-with-unknown-parsers given-parsers given-correctors)))))
+      (parse-block-with-known-parser parser given-parsers given-correctors block)
+      (parse-block-with-unknown-parsers given-parsers given-correctors block))))
 
 
 (defn render
diff --git a/src/clarktown/matchers/indented_code_block.clj b/src/clarktown/matchers/indented_code_block.clj
new file mode 100644
index 0000000..b7cf563
--- /dev/null
+++ b/src/clarktown/matchers/indented_code_block.clj
@@ -0,0 +1,10 @@
+(ns clarktown.matchers.indented-code-block
+  (:require
+    [clojure.string :as string]))
+
+
+(defn match?
+  "Determines whether the given block is a indented code block."
+  [block]
+  (->> (string/split-lines block)
+       (every? #(>= (count (take-while #{\space} %)) 4))))
\ No newline at end of file
diff --git a/src/clarktown/parsers.clj b/src/clarktown/parsers.clj
index 0d3b019..8ca27b3 100644
--- a/src/clarktown/parsers.clj
+++ b/src/clarktown/parsers.clj
@@ -10,6 +10,8 @@
     [clarktown.renderers.quote-block]
     [clarktown.matchers.fenced-code-block]
     [clarktown.renderers.fenced-code-block]
+    [clarktown.matchers.indented-code-block]
+    [clarktown.renderers.indented-code-block]
     [clarktown.matchers.list-block]
     [clarktown.renderers.list-block]
     [clarktown.renderers.paragraph-block]
@@ -61,6 +63,13 @@
 
 
 (def
+  ^{:doc "Detects, parses and renders a indented code block."}
+  indented-code-block-parser
+  {:matcher clarktown.matchers.indented-code-block/match?
+   :renderers [clarktown.renderers.indented-code-block/render]})
+
+
+(def
   ^{:doc "Detects, parses and renders a list block."}
   list-block-parser
   {:matcher clarktown.matchers.list-block/match?
@@ -91,5 +100,6 @@
    heading-block-parser
    quote-block-parser
    fenced-code-block-parser
+   indented-code-block-parser
    list-block-parser
    paragraph-block-parser])
diff --git a/src/clarktown/renderers/indented_code_block.clj b/src/clarktown/renderers/indented_code_block.clj
new file mode 100644
index 0000000..b3828ec
--- /dev/null
+++ b/src/clarktown/renderers/indented_code_block.clj
@@ -0,0 +1,17 @@
+(ns clarktown.renderers.indented-code-block
+  (:require
+    [clojure.string :as string]))
+
+
+(defn render
+  "Renders the indented code block."
+  [block _ _]
+  (str
+    "<pre><code>"
+    (-> (->> (string/split-lines block)
+             (map #(subs % 4))
+             (string/join \newline))
+        (string/replace #"&" "&amp;")
+        (string/replace #"<" "&lt;")
+        (string/replace #">" "&gt;"))
+    "</code></pre>"))
\ No newline at end of file