Compilation, conditional

We apply common techniques used for conditional compilation to control activation and deactivation of those parts of the specification that implement failure modes. 

From reacting a gas mixture of 1 mole nitrogen to 3 mole hydrogen under the indicated conditions. Compiled from the data of Haber et al. [7], and Larson [8]. Nielson gives more recent and more detailed data for conditions of commercial interest [9]. 

Glacial ice core samples indicate pre-industrial-age levels of atmospheric chlorine at <1 ppb. By the late 20th century, the concentration had reached 3.6 ppb. Continuation of current efforts may return the Earth s atmosphere to <1 ppb levels shortly after year 2100. The following link provides a summary analysis of CEC/HCEC atmospheric conditions compiled by the Canada Chemical Producers Association http //en.wikipedia.org/wiki/ozone layer. 

The two testbench programs of the last chapter have a great deal in common they are functionally identical and only differ in a few details which depend on the use to which the code is to be put. There is an important general rule here which gives the opportunity of demonstrating the value of conditional compilation. 

Use conditional compilation arrange for the compiler to be capable of compiling only certain parts of a given source file depending on the definition of some global symbol(s). 

A particular tool for version control will be outlined later (the RCS, Revision Control System), for the moment we take the opportunity to introduce the conditional compilation facility of a macro processor which is typical of Unix-based systems. 

Of course, our two testbenches are merely that, examples to be discarded as experience is gained with the implementation, and the use of conditional compilation here is rather out-of-place but it docs provide a convenient introduction to the technique and its use. 

With the combined use of RCS and, optionally, the conditional compilation facility of rat 77 (or C) it is never necessary to keep multiple copies of any document. ... 

Traditionally, the C preprocessor has provided three ma-jor features of the C language a simple macro facility, file inclusion, and conditional compilation. 

The hyphenation of UHPLC to MS, carried out generally with electrospray (Table 2.1), requires volatile and low-viscosity solvents to favor the ionic evaporation, as was the case in HPLC-MS, and to keep the pressures low, which is particularly important in UHPLC. These requirements restrict the composition of the mobile phase however, the separation of high number of compounds is still achieved. The conditions compiled in Table 2.1 show that the aqueous phase is generally constituted by water, 0.02-0.2% formic in water, or 2-10 mM ammonium acetate, and methanol or acetonitrile are the solvents chosen for the organic phase, like in conventional LC. The separation has been carried out at a higher temperature than room temperature, up to 50°C [75], to keep viscosity of the solvent low, which reduces the pressure in the chromatograph. 

Various configuration options affect conditional compilation and linking. The programmers are used to make sme that the somce code compiles and links fine with respect to the most common and obvious configurations, but the unforeseen interaction of the less common configuration options might cause linking or even compilation errors. 

In the foregoing sections we became acquainted with the influence of slit width, scan speed, number of data points, etc., on the resolution of the derivatives. Therefore, normalization of conditions is undoubtedly required if characteristic data of the spectrum is to be stored. In practice, the conditions compiled in Table 4-9 have proved to be a success [33]. 

Howeveii some synthesizers may also throw out the assignment of the unknown to S even though it will bie ignored. In this case it may be necessary to resort to conditional compilation of the design. 

The example below demonstrates how the conditional compilation switch can be used to make the synthesizer ignore die assignment of an unknown to A. 

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