Non-returning function calls should be followed by semi-colon

[VMatthijs]

Summary:

Currently, non-returning function calls without semi-colon are allowed as statements. This seems like a bug in the parser.

Description:

The requirement that statements end in a semi-colon does not seem to be enforced for non-returning function calls.

Reproducible Steps:

Compile the following model

functions {
  void foo(real x) {
    print("quitting time");
    reject("user-specified rejection");
  }
}
transformed data {
  print("In transformed data");
}
parameters {
  real y;
} 
transformed parameters {
  real v;
  print("In transformed parameters");
  foo(v)
}
model {
  print("In model block.");
  y ~ normal(0,1);
}
generated quantities {
  print("In generated quantities");
}

Current Output:

Compiler does not complain.

Expected Output:

Should throw error as foo(v) is not followed by semi-colon.

Current Version:

v2.18.0

[bob-carpenter]

Yes, definitely a bug. The handling of semicolons is a mess in general.

[VMatthijs]

Note that rstanarm is exploiting this, currently.

[bob-carpenter]

Currently, non-returning function calls without semi-colon are allowed as statements. This seems like a bug in the parser.

Definitely a bug.

Note that rstanarm is exploiting this, currently.

It'll be an easy fix for rstanarm.

[mcol]

Now stanc3 will not compile the example in the description:

Syntax error in 'test.stan', line 16, column 2 to column 8, parsing error:
   -------------------------------------------------
    14:    real v;
    15:    print("In transformed parameters");
    16:    foo(v)
                 ^
    17:  }
    18:  model {
   -------------------------------------------------

Ill-formed phrase. Found expression. There are many options to continue the phrase after this: "~", "[", "]" or an infix or postfix operator.