I‘m new to this so I hope I get it right.
I‘m not exactly new to writing DXL but currently have a performance issue with calling getProperties from a Layout dxl column that is supposed to display outgoing links depending on a module attribute value of type Enum of the linked module.
The code basically works but takes extremely long to complete. Commenting out the getProperties call makes it as fast as it could be.
Yes, the call is written exactly as shown in DXL Ref manual.
Calling the attribute directly, using a module object and dot operator does not work either as it always returns the enums default value but not the actual.
Any ideas welcome...
EDIT added example code below
// couple of declarations snipped
string cond = "Enum selection here" // this is modified from actual code, to show the idea
string linkModName = "*"
ModuleProperties mp
for l in all(o->linkModName) do
{
otherVersion = targetVersion l
otherMod = module(otherVersion)
if (null otherMod || isDeleted otherMod) continue
othero = target l
if (null othero)
{
load(otherVersion,false)
}
getProperties(otherVersion, mp)
sTemp = mp.myAttr
if (sTemp == cond) continue
// further code snipped
}
I'm not 100% sure but I think there is/was a performance issue with module properties in some DOORS versions.
You might want to try the following, i.e. directly get the attribute from the loaded Module
[...]
othero = target l
Module m
if (null othero)
{
m = load(otherVersion,false)
} else {
m = module othero
}
sTemp = m.myAttr
[...]
Caution, I did not test this snippet.
Related
I working on a language similar to ruby called gaiman and I'm using PEG.js to generate the parser.
Do you know if there is a way to implement heredocs with proper indentation?
xxx = <<<END
hello
world
END
the output should be:
"hello
world"
I need this because this code doesn't look very nice:
def foo(arg) {
if arg == "here" then
return <<<END
xxx
xxx
END
end
end
this is a function where the user wants to return:
"xxx
xxx"
I would prefer the code to look like this:
def foo(arg) {
if arg == "here" then
return <<<END
xxx
xxx
END
end
end
If I trim all the lines user will not be able to use a string with leading spaces when he wants. Does anyone know if PEG.js allows this?
I don't have any code yet for heredocs, just want to be sure if something that I want is possible.
EDIT:
So I've tried to implement heredocs and the problem is that PEG doesn't allow back-references.
heredoc = "<<<" marker:[\w]+ "\n" text:[\s\S]+ marker {
return text.join('');
}
It says that the marker is not defined. As for trimming I think I can use location() function
I don't think that's a reasonable expectation for a parser generator; few if any would be equal to the challenge.
For a start, recognising the here-string syntax is inherently context-sensitive, since the end-delimiter must be a precise copy of the delimiter provided after the <<< token. So you would need a custom lexical analyser, and that means that you need a parser generator which allows you to use a custom lexical analyser. (So a parser generator which assumes you want a scannerless parser might not be the optimal choice.)
Recognising the end of the here-string token shouldn't be too difficult, although you can't do it with a single regular expression. My approach would be to use a custom scanning function which breaks the here-string into a series of lines, concatenating them as it goes until it reaches a line containing only the end-delimiter.
Once you've recognised the text of the literal, all you need to normalise the spaces in the way you want is the column number at which the <<< starts. With that, you can trim each line in the string literal. So you only need a lexical scanner which accurately reports token position. Trimming wouldn't normally be done inside the generated lexical scanner; rather, it would be the associated semantic action. (Equally, it could be a semantic action in the grammar. But it's always going to be code that you write.)
When you trim the literal, you'll need to deal with the cases in which it is impossible, because the user has not respected the indentation requirement. And you'll need to do something with tab characters; getting those right probably means that you'll want a lexical scanner which computes visible column positions rather than character offsets.
I don't know if peg.js corresponds with those requirements, since I don't use it. (I did look at the documentation, and failed to see any indication as to how you might incorporate a custom scanner function. But that doesn't mean there isn't a way to do it.) I hope that the discussion above at least lets you check the detailed documentation for the parser generator you want to use, and otherwise find a different parser generator which will work for you in this use case.
Here is the implementation of heredocs in Peggy successor to PEG.js that is not maintained anymore. This code was based on the GitHub issue.
heredoc = "<<<" begin:marker "\n" text:($any_char+ "\n")+ _ end:marker (
&{ return begin === end; }
/ '' { error(`Expected matched marker "${begin}", but marker "${end}" was found`); }
) {
const loc = location();
const min = loc.start.column - 1;
const re = new RegExp(`\\s{${min}}`);
return text.map(line => {
return line[0].replace(re, '');
}).join('\n');
}
any_char = (!"\n" .)
marker_char = (!" " !"\n" .)
marker "Marker" = $marker_char+
_ "whitespace"
= [ \t\n\r]* { return []; }
EDIT: above didn't work with another piece of code after heredoc, here is better grammar:
{ let heredoc_begin = null; }
heredoc = "<<<" beginMarker "\n" text:content endMarker {
const loc = location();
const min = loc.start.column - 1;
const re = new RegExp(`^\\s{${min}}`, 'mg');
return {
type: 'Literal',
value: text.replace(re, '')
};
}
__ = (!"\n" !" " .)
marker 'Marker' = $__+
beginMarker = m:marker { heredoc_begin = m; }
endMarker = "\n" " "* end:marker &{ return heredoc_begin === end; }
content = $(!endMarker .)*
I'm using the Analysis Wizard to create a LayoutDXL column which should list attributes (e.g. AbsoluteNumber) for each existing In-link in my current module. In one particular DOORS module, the resulting DXL code displays each of these attributes twice. This doesn't happen in other modules.
I did notice that the offending module doesn't have a defined set of LinkModules (as seen in File/ModuleProperties). Could that be causing some sort of loopback?
Update:
I've discovered that somehow the DXL code "thinks" there are two versions of a defined LinkModule, i.e. "Current" and "Baseline X" . These each link to different baseline numbers in the target DOORS module. I don't know how to fix that.
For reference, here's the DXL code generated with the Wizard. This is DOORS 9.6.1.11
// DXL generated by DOORS traceability wizard on 12 February 2019.
// Wizard version 2.0, DOORS version 9.6.1.11
pragma runLim, 0
string limitModules[1] = {"[serial number redacted]"}
void showIn(Object o, int depth) {
Link l
LinkRef lr
ModName_ otherMod = null
Module linkMod = null
ModuleVersion otherVersion = null
Object othero
string disp = null
string s = null
string plain, plainDisp
int plainTextLen
int count
bool doneOne = false
string linkModName = "*"
for lr in all(o<-linkModName) do {
otherMod = module (sourceVersion lr)
if (!null otherMod) {
if ((!isDeleted otherMod) && (null data(sourceVersion lr))) {
if (!equal(getItem otherMod, (itemFromID limitModules[depth-1]))) continue
load((sourceVersion lr),false)
}
}
}
for l in all(o<-linkModName) do {
otherVersion = sourceVersion l
otherMod = module(otherVersion)
if (null otherMod || isDeleted otherMod) continue
if (!equal(getItem otherMod, (itemFromID limitModules[depth-1]))) continue
othero = source l
if (null othero) {
load(otherVersion,false)
}
othero = source l
if (null othero) continue
if (isDeleted othero) continue
doneOne = true
if (depth == 1) {
s = probeRichAttr_(othero,"Absolute Number", false)
if (s == "")
displayRich("\\pard " " ")
else
displayRich("\\pard " s)
s = probeRichAttr_(othero,"Object Heading", false)
if (s == "")
displayRich("\\pard " " ")
else
displayRich("\\pard " s)
}
}
}
showIn(obj,1)
I've seen the situation where objects DID have two links between them, this is possible with different link modules (Object 1 of Module A SATISFIES Object 2 of Module B and Object 1 of Module A REFINES Object 2 of Module B). While there may be reasons for such a situation, most often this is caused by a "link move" script that was not used correctly.
You should augment your code by displaying the name of the link module as well (variable linkModName). Perhaps this shows the reason for your observation
I have the following situation.
I want to count in Module 1, how many objects are having links in links from Module 3.
example:
Module 1 Obj1 <- Module 2 Obj1 <- Module 3.Obj1
Module 1 Obj2 <- Module 2 Obj1 <- Module 3.Obj1
Module 1 Obj3 <- Module 2 Obj1 <- Module 3.Obj1
Module 1 Obj4 <- Module 2 Obj1
Module 1 Obj5 <- Module 2 Obj1
The count should return 3, in the above case.
Is it possible via DXL to follow a link, and then follow another link?
(not using the Wizard or DXL attributes)
Most important for me: knowing if somebody else did this and it's possible to do.
Please try the following DXL from within the module that has the incoming links. Before running the code:
make sure that you open the 'Edit DXL' window from the relevant module
set the string values assigned to global constant STR_LINK_MOD_FULLNAME (line 17) to the full pathname of the link module whose links you are interested in
set the string values assigned to global constant STR_SRC_MOD_FULLNAME (line 18) to the full pathname of the source formal module (Module 3, in your example) whose links you are interested in
You shouldn't need to change anything else to make it work.
N.B. I have not considered the implications of analysing links in all link modules by using the string "*" in place of a specific link module name in line 17 (see point 2, above).
I also haven't gone out of my way to explain the code, though I have tried to be nice and tidy up after myself where DOORS and DXL require it. Please feel free to reply with any questions on what I have done.
Kind regards,
Richard
//<CheckObjectInNestedLink.dxl>
/*
*/
///////////////
// Sanity check
if (null (current Module))
{
print "ERROR: this script must be run from a Formal Module."
}
///////////////////
// Global Constants
const string STR_LINK_MOD_FULLNAME = "/New Family Car Project/Admin/Satisfies" // the fullName of a single link module - results of using "*" have not been considered/tested
const string STR_SRC_MOD_FULLNAME = "/New Family Car Project/Architecture/Architectural Design" // The fullName of the desired source Formal Module
///////////////////
// Global Variables
Module modSource = null
Object objTarget = null
Object objSource = null
Link lkIn = null
Skip skLinkedMods = create()
Skip skObjsWithDesiredSource = create()
int intNoOfLinked = 0
//////////////////////
// Auxiliary Functions
void closeSourceMods ()
{
Module srcMod
for srcMod in skLinkedMods do
{
close(srcMod)
}
}
void openSourceMods (Object objWithLinks)
{
ModName_ srcModRef
Module srcMod
for srcModRef in (objWithLinks <- STR_LINK_MOD_FULLNAME) do
{
srcMod = read(fullName(srcModRef), false)
put(skLinkedMods, srcMod, srcMod)
}
}
void recurseFollowInLinks (Object objWithLinks)
{
openSourceMods(objWithLinks)
for lkIn in objWithLinks <- STR_LINK_MOD_FULLNAME do
{
openSourceMods(objWithLinks)
objSource = source(lkIn)
string strSrcModName = fullName(module(objSource))
if (strSrcModName == STR_SRC_MOD_FULLNAME)
{
bool blNewEntry = put(skObjsWithDesiredSource, objTarget, objTarget)
if (blNewEntry)
{
intNoOfLinked++
}
//print "put(skObjsWithDesiredSource, " identifier(objTarget) ", " identifier(objTarget) ")\n"
}
recurseFollowInLinks(objSource)
}
}
void checkObjectInNestedLink (Module modThis, string strSourceModuleFullname, string strLinkModuleFullName)
{
intNoOfLinked = 0
for objTarget in modThis do
{
recurseFollowInLinks(objTarget)
}
print "The following " intNoOfLinked " objects have direct or indirect links of type " STR_LINK_MOD_FULLNAME " from formal module " STR_SRC_MOD_FULLNAME ":\n"
for objTarget in skObjsWithDesiredSource do
{
print identifier(objTarget)
print "\n"
}
}
///////////////
// Main Program
checkObjectInNestedLink ((current Module), STR_SRC_MOD_FULLNAME, STR_LINK_MOD_FULLNAME)
closeSourceMods()
delete(skLinkedMods)
delete(skObjsWithDesiredSource)
I'm using ANTLR4 to generate a Lexer for some JavaScript preprocessor (basically it tokenizes a javascript file and extracts every string literal).
I used a grammar originally made for Antlr3, and imported the relevant parts (only the lexer rules) for v4.
I have just one single issue remaining: I don't know how to handle corner cases for RegEx literals, like this:
log(Math.round(v * 100) / 100 + ' msec/sample');
The / 100 + ' msec/ is interpreted as a RegEx literal, because the lexer rule is always active.
What I would like is to incorporate this logic (C# code. I would need JavaScript, but simply I don't know how to adapt it):
/// <summary>
/// Indicates whether regular expression (yields true) or division expression recognition (false) in the lexer is enabled.
/// These are mutual exclusive and the decision which is active in the lexer is based on the previous on channel token.
/// When the previous token can be identified as a possible left operand for a division this results in false, otherwise true.
/// </summary>
private bool AreRegularExpressionsEnabled
{
get
{
if (Last == null)
{
return true;
}
switch (Last.Type)
{
// identifier
case Identifier:
// literals
case NULL:
case TRUE:
case FALSE:
case THIS:
case OctalIntegerLiteral:
case DecimalLiteral:
case HexIntegerLiteral:
case StringLiteral:
// member access ending
case RBRACK:
// function call or nested expression ending
case RPAREN:
return false;
// otherwise OK
default:
return true;
}
}
}
This rule was present in the old grammar as an inline predicate, like this:
RegularExpressionLiteral
: { AreRegularExpressionsEnabled }?=> DIV RegularExpressionFirstChar RegularExpressionChar* DIV IdentifierPart*
;
But I don't know how to use this technique in ANTLR4.
In the ANTLR4 book, there are some suggestions about solving this kind of problems at the parser level (chapter 12.2 - context sensitive lexical problems), but I don't want to use a parser. I want just to extract all the tokens, leave everything untouched except for the string literals, and keep the parsing out of my way.
Any suggestion would be really appreciated, thanks!
I'm posting here the final solution, developed adapting the existing one to the new syntax of ANTLR4, and addressing the differences in JavaScript syntax.
I'm posting just the relevant parts, to give a clue to someone else about a working strategy.
The rule was edited as follows:
RegularExpressionLiteral
: DIV {this.isRegExEnabled()}? RegularExpressionFirstChar RegularExpressionChar* DIV IdentifierPart*
;
The function isRegExEnabled is defined in a #members section on top of the lexer grammar, as follows:
#members {
EcmaScriptLexer.prototype.nextToken = function() {
var result = antlr4.Lexer.prototype.nextToken.call(this, arguments);
if (result.channel !== antlr4.Lexer.HIDDEN) {
this._Last = result;
}
return result;
}
EcmaScriptLexer.prototype.isRegExEnabled = function() {
var la = this._Last ? this._Last.type : null;
return la !== EcmaScriptLexer.Identifier &&
la !== EcmaScriptLexer.NULL &&
la !== EcmaScriptLexer.TRUE &&
la !== EcmaScriptLexer.FALSE &&
la !== EcmaScriptLexer.THIS &&
la !== EcmaScriptLexer.OctalIntegerLiteral &&
la !== EcmaScriptLexer.DecimalLiteral &&
la !== EcmaScriptLexer.HexIntegerLiteral &&
la !== EcmaScriptLexer.StringLiteral &&
la !== EcmaScriptLexer.RBRACK &&
la !== EcmaScriptLexer.RPAREN;
}}
As you can see, two functions are defined, one is an override of lexer's nextToken method, which wraps the existing nextToken and saves the last non-comment-or-whitespace token for reference. Then, the semantic predicate invokes isRegExEnabled checking if the last significative token is compatible with the presence of RegEx literals. If it's not, it returns false.
Thanks to Lucas Trzesniewski for the comment: it pointed me in the right direction, and to Patrick Hulsmeijer for the original work on v3.
I am a little confused by the Scala parser combinators.
I'm using a custom implementation of Reader to directly read a list of tokens:
private class Token_Reader(tokens: List[Token], val pos: Token_Pos) extends Reader
{
def first = if(atEnd) null else tokens.head
def rest = if(atEnd) this else new Token_Reader(tokens.tail, new Token_Pos(pos.p + 1))
def atEnd = tokens.isEmpty
}
What puzzles me is that atEnd seems to be completely ignored by the actual parsers, resulting in an infinite loop / infinite recursion when using */rep.
I don't know that it will fix this issue, but in the Reader implementations I see in the Scala source, the first method returns an end of file character rather than null when at the end. And I believe it's generally good to avoid nulls...
For example, in CharSequenceReader it looks like
/** Returns the first element of the reader, or EofCh if reader is at its end
*/
def first =
if (offset < source.length) source.charAt(offset) else EofCh
And this character is defined in the companion object:
object CharSequenceReader {
final val EofCh = '\032'
}