Start your engines! APP and TeX duke it out / Part 1
It seemed to me a comparison of output from the APP Styler and TeX-based formatting engines would be helpful, so I did some testing, as described below. METHODOLOGY I copiedthe sample document from the 6.0 distributed axdocbook doctype andlengthened the first chapter. I copiedaxdocbook.style from the same directory. Ituses the APP engine.For TeX output,I exported a FOSI from the Styler stylesheet. The stylesheet's default output is one column, ragged right, no hyphenation. I also tested ragged right with hyphenation, and justification with hyphenation. Default hyphenation settings were used. Note thatwith out-of-the-box APP Styler, all word spaces are 0.25em (according to the documentation). However, variable word spacing can be supported with APP source edits. I copied the source edits inArbortext Editor\samples\APP\textProperties\textPropertiesPropertySets.style, andtested both fixed and variable word spacing with APP Styler. By default, the TeX engine uses word spacing information from the font in effect. If desired,minimum, preferred, and maximumword space values can be specifiedin the FOSI Wordsp category to support fixed or variable word spacing.In addition, theHyphencategory'szone characteristiccan be specified to influence the "raggedness" of ragged output. However, I testedonlythe default TeX spacing without FOSI changes. After testing one-column output, I tried two columns.Since the vertical space between paragraphs has minimal stretch, I specified unbalanced columns.I also changed 12/12 to 10/12 because 12pt is too large for two columns, and would make line-breaking more difficult. I also tried downsizing the APP source edits for variable word spacing, which were specified in points rather than ems, but it made no difference in the line breaks. To produce formatted output, I used 6.0 Print Composer. PDF files are attached. They can also be viewed at my website atFormatting Comparison Results. NOTES - Changing Alignmentin Stylerto justified for all para elements did not justify para elements in itemized lists (including lists in table cells), and the generated FOSI had the same problem. The FOSI was easily fixed with a Textbrk category, but correcting this in Styler appeared to be more complicated. So I didn't change APP Styler or the generated FOSI. Consequently,paragraphs in itemized listsare not justified. - I did not evaluate the Index output because the formatting is wrong to start with. Leader dots are not used in indexes. - It seemed to take longer to open a file associated with APP, so I tested opening documents with ~50 and ~100 pages and found that opening a file with an associated APP Styler print stylesheet took about twice as long as opening the same document with an associated FOSI print stylesheet. JUDGE FOR YOURSELFKeepin mind the formatting specs in the Styler stylesheet are less than ideal (for example,12/12 is too tight for a 37-pica line length). Also, you need to overlook Styler shortcomings (for example, lastline quadding cannot be specified without a source edit). Compare the two outputs side by side. Whaddya think?
To my typesetter's eye, the TeX output is superior for many reasons, as discussed below. First, let's get out the loupe. NO LIGATURES IN APP STYLER Ligatures are automatic with TeX, but ligatures do not appear in the APP Styler output. (Ligatures generally go unnoticed; however, even a mechanic might notice the black splotch in the word "difficult" in Times New Roman.) TheStyler Users Guideindicates ligatures are available only with an associated APP template. NO EXTRA SENTENCE SPACING IN APPThe TeX output shows extra space after a sentence (aka "French spacing"), which is the TeX-based engine's default. APP does not support this and uses regular word spacing at the end of sentences. Note that extra sentence spacing can be turned off for the TeX engine with one short line of FOSI code. continued in Part 2