st: Problem with -infix- with if qualifiers and strings?

[Jorge Eduardo Pérez Pérez <jorge_perez@brown.edu>]

Dear Statalist.

I have noticed weird behavior regarding -infix- and data where the
variable type may change per line. -infix- is not reading the dataset
properly.

Here's an example. My dataset is:

10ABC
20321
10ZYX
20654

If I try to read the lines that start with 10 and the remainder as a
string, everything works:

. clear

. infix type 1-2 str text 3-5 if type==10 using test.txt
(2 observations read)

. list

     +-------------+
     | type   text |
     |-------------|
  1. |   10    ABC |
  2. |   10    ZYX |
     +-------------+

But if I try to read the lines that start with 20, where the remainder
is a number, Stata seems to be trying to read the lines that start
with 10 as well, producing a "cannot be read" message and , worse,
dropping observations from my data!

. clear

. infix type 1-2 number 3-5 if type==20 using test.txt
'ABC' cannot be read as a number for number[1]
'ZYX' cannot be read as a number for number[2]
(1 observations read)

. list

     +---------------+
     | type   number |
     |---------------|
  1. |   20      321 |
     +---------------+

I have replicated this in both Stata 12.1, Windows 7 and 13.1 on
Windows 8. Can someone replicate to see if this is a bug, or am I
missing something? In the meantime I will read my variables as strings
and destring afterwards.

Thanks!

--------------------------------------------
Jorge Eduardo Pérez Pérez
Graduate Student
Department of Economics
Brown University

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