Add some notes about problems with extractFunctions().

diff --git a/src/mathed/MathExtern.cpp b/src/mathed/MathExtern.cpp
index d3bf7387532a37ad70507cfca827e139475b301f..2ac732bd7e01462287d8c45c9f926077baf8892a 100644 (file)
--- a/src/mathed/MathExtern.cpp
+++ b/src/mathed/MathExtern.cpp
@@ -537,6 +537,9 @@ void extractDelims(MathData & ar)
 // assume 'extractDelims' ran before
 void extractFunctions(MathData & ar, ExternalMath kind)
 {
+       // FIXME From what I can see, this is quite broken right now, for reasons
+       // I will note below. (RGH)
+
        // we need at least two items...
        if (ar.size() < 2)
                return;
@@ -551,9 +554,26 @@ void extractFunctions(MathData & ar, ExternalMath kind)
                docstring name;
                // is it a function?
                // it certainly is if it is well known...
+
+               // FIXME This will never give us anything. When we get here, *it will
+               // never point at a string, but only at a character. I.e., if we are
+               // working on "sin(x)", then we are seeing:
+               // [char s mathalpha][char i mathalpha][char n mathalpha][delim ( ) [char x mathalpha]]
+               // and of course we will not find the function name "sin" in there, but
+               // rather "n(x)".
+               //
+               // It appears that we original ran extractStrings() before we ran
+               // extractFunctions(), but Andre changed this at f200be55, I think
+               // because this messed up what he was trying to do with "dx" in the
+               // context of integrals.
+               //
+               // This could be fixed by looking at a charSequence instead of just at
+               // the various characters, one by one. But I am not sure I understand
+               // exactly what we are trying to do here. And it involves a lot of
+               // guessing.
                if (!extractFunctionName(*it, name)) {
                        // is this a user defined function?
-                       // it it probably not, if it doesn't have a name.
+                       // probably not, if it doesn't have a name.
                        if (!extractString(*it, name))
                                continue;
                        // it is not if it has no argument
@@ -564,7 +584,7 @@ void extractFunctions(MathData & ar, ExternalMath kind)
                        InsetMathDelim const * del = (*jt)->asDelimInset();
                        if (!del || del->cell(0).size() != 1)
                                continue;
-                       // fall trough into main branch
+                       // fall through into main branch
                }
 
                // do we have an exponent like in