Export option "No conversion of expression/instruction contents" is not consequently observed and may even cause errors

[codemanyak]

On code export, the recent versions have not strictly considered and respected the export preference "No conversion of expression/instruction contents" (see #144, User Guide), such that with this option chosen, yet several texts are partially translated (at least tried to), which is bad for users that fill in certain target language code in the diagram elements.
Yet it might sometimes be disputable which transformations are considered "structural" and which ones content-related, think e.g. of the logical inversion of REPEAT loop conditions towards a do ... while loop in the target language or between different FOR loop concepts.
Either way, a meticulous revison is necessary.

[codemanyak]

It seems time now to establish some rules, what parts of the element texts may be translated even in mode "No conversion of the expression/instruction contents" and why. We distinguish between structural information and "content".

• Type definitions, variable declarations, and constant definitions are considered content and should not be transformed but just left as are.
• Generators should not in particular insert inferred type defintions, variable declarations etc. (in suppressed transformatin mode).
• In case of INPUT and OUTPUT, however, where users may configure the keywords (e.g. to be out of their way), we will assume that on using the configured keyword, a keyword translation is intended (while the involved expressions, variable names etc. shall not be translated). This rule may already get tricky, since the keyword translation may result in something type-dependent, e.g. in Oberon or C, though Structorizer cannot infer data types ignoring text content.
• In case of Jump/EXIT keywords (return, leave, exit, throw) we classify them as structural information (particularly with multi-level leave) rather than pure content. The keywords are subject of configuration, again. So the same as with INPUT / OUTPUT should hold: if the configured keywords are used then (and only then) they will be translated.
• FOR loops: Formular-based loop headers will be structurally transformed (this may get tricky with certain loop parameters), whereas free-text FOR loops should be left as are.
• REPEAT: In case the target language has only a do ... while ... loop (or an even more primitive loop construct) as closest equivalent, then the (untouched) loop condition should be negated by means of the target language.
• CALL elements / subroutine headers: They show a fundamental dilemma: If their text is formulated in e.g. shell-like manner (in order to be exported with "No conversion ..." then Structorizer will not be able to link CALLs to called subroutines. Hence a group export or an export with imvolved subroutines will not work such that complete export of an arrangement group may require to export all involvd diagrams individually. If they happen to be linked to existing subroutines, however, then the text will be considered as structurally conform and a syntactic transformation of the call itself (not its arguments) will be performed.

[codemanyak]

With export mode "No conversion ...", the export of a FOR loop header filled in C style (or some other notation not conformous with Structorizer's syntax expectations) like in the above diagram causes errors like the following one on export to Pascal, Oberon, Perl, ksh, bash, PHP, BASIC, and ARM:

Batch export of several arrangement files to bash/ksh and StrukTex with switch -t fails with NullPointerException.

On export to Perl with switch -t (i.e., in mode "No conversion ..."), parentheses around conditions are omitted. As this is a structural syntax aspect, it is to be mended.

By the way, the result of the translation attempt for unrecognized FOR loop headers without mode "No conversion ..." had not been sensible, either (example PHP):

[codemanyak]

Mostly fixed. There are still type definition conversions in Oberon but this may be consolidated later. Batch export with "-t" option now works for all sample arrangements,