  We present the first results of an ALMA spectral survey of strong absorption
lines for common interstellar species in the z=0.89 molecular absorber toward
the lensed blazar PKS1830-211. The dataset brings essential information on the
structure and composition of the absorbing gas in the foreground galaxy. In
particular, we find absorption over large velocity intervals (gtrsim 100 km/s)
toward both lensed images of the blazar. This suggests either that the galaxy
inclination is intermediate and that we sample velocity gradients or streaming
motions in the disk plane, that the molecular gas has a large vertical
distribution or extraplanar components, or that the absorber is not a simple
spiral galaxy but might be a merger system. The number of detected species is
now reaching a total of 42 different species plus 14 different rare
isotopologues toward the SW image, and 14 species toward the NE line-of-sight.
The abundances of CH, H2O, HCO+, HCN, and NH3 relative to H2 are found to be
comparable to those in the Galactic diffuse medium. Of all the lines detected
so far toward PKS1830-211, the ground-state line of ortho-water has the deepest
absorption. We argue that ground-state lines of water have the best potential
for detecting diffuse molecular gas in absorption at high redshift.
