Things that does not work

OpenModelica v.1.4.2

 In simulation code:

• Limited error checking in numerical solver.
• No dynamic selection of states (in index reduction)
• Only possible to run with DASSL numerical solver.
• If equations does not work. Workaround: use if-expressions instead.

In translation to flat Modelica:

• Lookup through extends of packages, e.g. extends Modelica.Constants; is terribly slow. Also lookup of unqualified imports, e.g. import Modelica.Constants.*; has this problem. Workaround: use fully qualified names or qualified or named imports. e.g. import Modelica.Constants.PI;
• der(expression) is not supported. Only der(variable) works. Workaround: expand your expression by hand. e.g. der(x*y) => x*der(y)+der(x)*y
• Inner/Outer
• Some excotic cases with Modifications, especially with redeclare.
• Final element modification not checked against.
• Constraining type on redeclarations
• Restrictions on redeclarations (subtype etc.)
• Derivatives of functions, using annotations.
• Components of function type not implemented.
• When clauses in algorithms.
• Restrictions on connections.
• The following operators in 3.4.2 have not been implemented:
  smooth terminate delay  
• The following operators in 3.4.3 have not been implemented:
  ndims matrix outerProduct linspace product symmetric cross skew 
• Reduction expressions,
• Slice operation. Partly works but the resulting component names are sometimes messed up.
• Output parameters of functions, enable attribute, etc.

• Array construction (3.4.4.1). Using array(... for ...) syntax. Partially implemented. Left to do:
  - Constant evaluation and/or optimization. Could be implemented as function calls with index as argument. Or array can be unrolled and indexed, or if constant value can be calculated and indexed. Array should then be cached.
  - Automatic type conversion of element type, e.g. (Real[]) a[5] = {(Integer)3 for ...} fails.
  - Handle multiple iterators
• Array constructors with iterators. Using {expr for i in ...} syntax.
• Deduction of ranges (3.3.3.1). It is allowed to leave out "in range" in loops. e.g. for i loop ... end for; according to specification.
• Multiple loop ranges, e.g.: for i in 1:5, j in 1:3 loop a[i,j]=i*j; end for;
• Constant evaluation of record constructors for hierarchical records.
• Constant evaluation of dot ('.') operator.