diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/ccwl.skb | 76 | ||||
| -rw-r--r-- | doc/dictionary | 8 | ||||
| -rw-r--r-- | doc/spell-check-text.txt | 1 | ||||
| -rw-r--r-- | doc/spell-check-workflow-1.scm | 5 | ||||
| -rw-r--r-- | doc/spell-check-workflow-2.scm | 7 | ||||
| -rw-r--r-- | doc/spell-check.scm | 32 |
6 files changed, 128 insertions, 1 deletions
diff --git a/doc/ccwl.skb b/doc/ccwl.skb index c460ab4..5efd709 100644 --- a/doc/ccwl.skb +++ b/doc/ccwl.skb @@ -247,7 +247,81 @@ following output.]) (p [The MD5, SHA1 and SHA256 checksums are in the files ,(file "112be1054505027982e64d56b0879049c12737c6"), ,(file "d2f19c786fcd3feb329004c8747803fba581a02d") and -,(file "0d2eaa5619c14b43326101200d0f27b0d8a1a4b1") respectively.])))) +,(file "0d2eaa5619c14b43326101200d0f27b0d8a1a4b1") respectively.]))) + + (section :title [Let's write a spell check workflow] + (p [Finally, let's put together a complex workflow to understand +how everything fits together. The workflow we will be attempting is a +spell check workflow inspired by the founders of Unix,(footnote +["UNIX: Making Computers Easier to Use" has a ,(ref +:url "https://www.youtube.com/watch?v=XvDZLjaCJuw?t=315" +:text "section where Brian Kernighan writes a spell check system using +pipes")]) and by dgsh,(footnote [dgsh, a shell supporting general +directed graph pipelines, has a ,(ref +:url "https://www.spinellis.gr/sw/dgsh/#spell-highlight" :text "spell +check example").]). The workflow is pictured below. Let's start by +coding each of the steps required by the workflow.]) + + (image :file "doc/spell-check.png") + + (p [The first command, ,(code "split-words"), splits up the +input text into words, one per line. It does this by invoking the +,(command "tr") command to replace anything that is not an alphabetic +character with a newline. In addition, it uses the +,(code "--squeeze-repeats") flag to prevent blank lines from appearing +in its output. Notice that no type is specified for the input +,(code "text"). When no type is specified, ccwl assumes a +,(code "File") type.] + (scheme-source-form "doc/spell-check.scm" "\\(define split-words")) + + (p [We want our spell check to be case-insensitive. So, we +downcase all words. This is achieved using another invocation of the +,(command "tr") command.] + (scheme-source-form "doc/spell-check.scm" "\\(define downcase")) + + (p [For easy comparison against a dictionary, we want both our +words and our dictionary sorted and deduplicated. We achieve this by +invoking the ,(command "sort") command with the ,(code "--unique") +flag.] + (scheme-source-form "doc/spell-check.scm" "\\(define sort")) + + (p [Finally, we compare the sorted word list with the sorted +dictionary to identify the misspellings. We do this using the +,(command "comm") command.] + (scheme-source-form "doc/spell-check.scm" + "\\(define find-misspellings")) + + (p [Now, let's wire up the workflow. First, we assemble the +,(code "split-words")-,(code "downcase")-,(code "sort-words") arm of +the workflow. This arm is just a linear chain that can be assembled +using ,(code "pipe"). We will need to invoke the ,(code "sort") +command twice in our workflow. To distinguish the two invocations, CWL +requires us to specify a unique step id for each invocation. We do +this using the second element, ,(code "(sort-words)"). To avoid name +conflicts, we also need to rename the output of the ,(code "sort") +command. The last step, +,(source-ref "ccwl/ccwl.scm" "\\(\\(rename" (code "rename")), a +special ccwl construct that, is used to achieve this. In this case, it +renames the ,(code "sorted") output of the ,(code "sort") command into +,(code "sorted-words").] + (scheme-source "doc/spell-check-workflow-1.scm")) + + (p [Next, we assemble the ,(code "split-dictionary") arm of the +workflow. This arm is just a single step. Then, we connect up both the +arms using a ,(code "tee"). Here too, we have a step id and renaming +of intermediate inputs/outputs.] + (scheme-source "doc/spell-check-workflow-2.scm")) + + (p [And finally, we use the outputs of both the arms of the +workflow together in the ,(code "find-misspellings") step.] + (scheme-source-form "doc/spell-check.scm" "\\(workflow")) + + (p [The complete workflow is as follows.] + (scheme-source "doc/spell-check.scm")) + + (p [When compiled and run with a text file and a dictionary, the +misspelt words appear at the output.] + (prog :line #f (source :file "doc/spell-check.out"))))) (chapter :title [Cookbook] (section :title [Reuse external CWL workflows] diff --git a/doc/dictionary b/doc/dictionary new file mode 100644 index 0000000..71df044 --- /dev/null +++ b/doc/dictionary @@ -0,0 +1,8 @@ +brown +dog +fox +jumps +lazy +over +quick +the
\ No newline at end of file diff --git a/doc/spell-check-text.txt b/doc/spell-check-text.txt new file mode 100644 index 0000000..a116b9a --- /dev/null +++ b/doc/spell-check-text.txt @@ -0,0 +1 @@ +The quick brown fox jumps over the laazy dog. diff --git a/doc/spell-check-workflow-1.scm b/doc/spell-check-workflow-1.scm new file mode 100644 index 0000000..0a82900 --- /dev/null +++ b/doc/spell-check-workflow-1.scm @@ -0,0 +1,5 @@ +(workflow (text-file) + (pipe (split-words #:text text-file) + (downcase #:words words) + (sort (sort-words) #:words downcased-words) + (rename #:sorted-words sorted))) diff --git a/doc/spell-check-workflow-2.scm b/doc/spell-check-workflow-2.scm new file mode 100644 index 0000000..15b380f --- /dev/null +++ b/doc/spell-check-workflow-2.scm @@ -0,0 +1,7 @@ +(workflow (text-file dictionary) + (tee (pipe (split-words #:text text-file) + (downcase #:words words) + (sort (sort-words) #:words downcased-words) + (rename #:sorted-words sorted)) + (pipe (sort (sort-dictionary) #:words dictionary) + (rename #:sorted-dictionary sorted)))) diff --git a/doc/spell-check.scm b/doc/spell-check.scm new file mode 100644 index 0000000..1f05154 --- /dev/null +++ b/doc/spell-check.scm @@ -0,0 +1,32 @@ +(define split-words + (command #:inputs text + #:run "tr" "--complement" "--squeeze-repeats" "A-Za-z" "\\n" + #:stdin text + #:outputs (words #:type stdout))) + +(define downcase + (command #:inputs words + #:run "tr" "A-Z" "a-z" + #:stdin words + #:outputs (downcased-words #:type stdout))) + +(define sort + (command #:inputs words + #:run "sort" "--unique" + #:stdin words + #:outputs (sorted #:type stdout))) + +(define find-misspellings + (command #:inputs words dictionary + #:run "comm" "-23" words dictionary + #:outputs (misspellings #:type stdout))) + +(workflow (text-file dictionary) + (pipe (tee (pipe (split-words #:text text-file) + (downcase #:words words) + (sort (sort-words) #:words downcased-words) + (rename #:sorted-words sorted)) + (pipe (sort (sort-dictionary) #:words dictionary) + (rename #:sorted-dictionary sorted))) + (find-misspellings #:words sorted-words + #:dictionary sorted-dictionary))) |