diff options
| -rw-r--r-- | cppawk-include/base.h | 1 | ||||
| -rw-r--r-- | cppawk-include/iter.h | 48 | ||||
| -rw-r--r-- | cppawk-iter.1 | 102 |
3 files changed, 91 insertions, 60 deletions
diff --git a/cppawk-include/base.h b/cppawk-include/base.h index 751da86..4012d95 100644 --- a/cppawk-include/base.h +++ b/cppawk-include/base.h @@ -37,6 +37,7 @@ #define __str(x) # x #define __xstr(x) __str(x) #define __g(name) __xcat(__, __xcat(name, __LINE__)) +#define __gx(name, ext) __xcat(__, __xcat(name, __xcat(ext, __LINE__))) #define __error(...) { printf(__VA_ARGS__); print; exit 1 } diff --git a/cppawk-include/iter.h b/cppawk-include/iter.h index 1ac3ac2..f73fbea 100644 --- a/cppawk-include/iter.h +++ b/cppawk-include/iter.h @@ -244,40 +244,40 @@ function __loop_argmax(a, arga, b, argb) return a > b ? arga : argb; } -#define __am_max __g(amx) -#define __am_min __g(ami) -#define __am_old __g(arg) - -#define __temp_argmax(amx, arg, expr) __am_max, __am_old, -#define __init_argmax(amx, arg, expr) (__am_max = __nil) || (amx = __nil) -#define __test_argmax(amx, arg, expr) 1 -#define __prep_argmax(amx, arg, expr) ((__am_old = __am_max) || 1) && \ - ((__am_max = \ - (__null(__am_max) \ +#define __ami(v) __gx(v, _max) +#define __amx(v) __gx(v, _min) +#define __amo(v) __gx(v, _old) + +#define __temp_argmax(am, arg, expr) __amx(am), __amo(am), +#define __init_argmax(am, arg, expr) (__amx(am) = __nil) || (am = __nil) +#define __test_argmax(am, arg, expr) 1 +#define __prep_argmax(am, arg, expr) ((__amo(am) = __amx(am)) || 1) && \ + ((__amx(am) = \ + (__null(__amx(am)) \ ? expr \ - : __loop_max(__am_max, \ + : __loop_max(__amx(am), \ expr))) || 1) && \ - ((__am_old != __am_max) ? amx = arg : 1) -#define __fini_argmax(amx, arg, expr) 1 -#define __step_argmax(amx, arg, expr) 1 + ((__amo(am) != __amx(am)) ? am = arg : 1) +#define __fini_argmax(am, arg, expr) 1 +#define __step_argmax(am, arg, expr) 1 function __loop_argmin(a, arga, b, argb) { return a < b ? arga : argb; } -#define __temp_argmin(ami, arg, expr) __am_min, __am_old, -#define __init_argmin(ami, arg, expr) (__am_min = __nil) || (ami = __nil) -#define __test_argmin(ami, arg, expr) 1 -#define __prep_argmin(ami, arg, expr) ((__am_old = __am_min) || 1) && \ - ((__am_min = \ - (__null(__am_min) \ +#define __temp_argmin(am, arg, expr) __ami(am), __amo(am), +#define __init_argmin(am, arg, expr) (__ami(am) = __nil) || (am = __nil) +#define __test_argmin(am, arg, expr) 1 +#define __prep_argmin(am, arg, expr) ((__amo(am) = __ami(am)) || 1) && \ + ((__ami(am) = \ + (__null(__ami(am)) \ ? expr \ - : __loop_min(__am_min, \ + : __loop_min(__ami(am), \ expr))) || 1) && \ - ((__am_old != __am_min) ? ami = arg : 1) -#define __fini_argmin(ami, arg, expr) 1 -#define __step_argmin(ami, arg, expr) 1 + ((__amo(am) != __ami(am)) ? am = arg : 1) +#define __fini_argmin(am, arg, expr) 1 +#define __step_argmin(am, arg, expr) 1 #define __temp_while(expr) #define __init_while(expr) 1 diff --git a/cppawk-iter.1 b/cppawk-iter.1 index 531a4a6..d55fb24 100644 --- a/cppawk-iter.1 +++ b/cppawk-iter.1 @@ -86,8 +86,8 @@ iter \- powerful, user-extensible iteration language for Awk summing (\fIvar\fP, \fIexpr\fP) maximizing (\fIvar\fP, \fIexpr\fP) minimizing (\fIvar\fP, \fIexpr\fP) - argmax (\fImaxvar\fP, \fIargvar\fP, \fIexpr\fP) - argmin (\fIminvar\fP, \fIargvar\fP, \fIexpr\fP) + argmax (\fImaxvar\fP, \fIarg\fP, \fIexpr\fP) + argmin (\fIminvar\fP, \fIarg\fP, \fIexpr\fP) \fI// termination control clauses\fP while (\fIexpr\fP) @@ -864,8 +864,8 @@ value indicating that no minimum or maximum had been found. .B Syntax: .ft B - argmax (\fImaxvar\fP, \fIargvar\fP, \fIexpr\fP) - argmin (\fIminvar\fP, \fIargvar\fP, \fIexpr\fP) + argmax (\fImaxvar\fP, \fIarg\fP, \fIexpr\fP) + argmin (\fIminvar\fP, \fIarg\fP, \fIexpr\fP) .ft R .B Description: @@ -874,26 +874,71 @@ The .B argmax and .B argmin -clauses calculate the value of a variable -.I argvar -which maximize or minimizes the value of -.IR expr . +clauses calculate the value of the expression +.I arg +which is observed when the maximum or minimum value of +.I expr +occurs. -This maximum or minimum value appears in +This value of +.I arg +associated with the maximum or minimum value of +.I expr +then appears in .I maxvar or .IR minvar -respectively. +respectively. (The actual maximum or minimum value of +.I expr +is itself not made available.) -The purpose of the -.I argvar -argument is to name the variable that is being maximized -or minimized. It is expected that the +The +.B argmax +and +.B argmin +operations are most useful when +.I arg +and +.I expr +are related, such as +.I expr +being a function of +.IR arg . +For instance +.I expr +might be +.BI sin( x ) +and +.I arg +might be +.IR x . +This is the situation which inspires the term "argmax": +.I arg +is the argument of the .I expr -expression contains -.I argvar -and thus its value is dependent on -.IR argvar . +function. + + +This is not a requirement, though: +.I arg +and +.I expr +might simply be independent properties of the same datum. For example, +.I arg +might be +.BI miles_per_gallon( car ) +and +.I expr +might be +.BI trunk_space( car ) +in which case +.BI argmax( mpg ", miles_per_gallon(" car "), trunk_space(" car )) +will calculate and store into +.I mpg +the miles per gallon value of the car which has the maximum trunk space, +assuming that the loop will step the value of +.I car +through a sequence of different car objects. Like .B minimize @@ -927,13 +972,13 @@ is evaluated. If it is the first iteration, then or .I minvar is set to the value of -.IR argvar . +.IR arg . If it is the second or subsequent iteration, then .B argmax sets .I maxvar to the value of -.I argvar +.I arg if .I expr is higher than the previously seen maximum value of @@ -943,7 +988,7 @@ Likewise, sets .I minvar to the value of -.I argvar +.I arg if .I expr is lower than the previously seen minimum value of @@ -960,21 +1005,6 @@ has a maximum and minimum value, over the range 0 to 3.14159 examined in increments of 0.001. -Note that the variable used as -.IR argvar , -namely -.I x -is made to vary by the use of a -.I range_step -clause. For -.B argmax -and -.B argmin -to be useful, the argument variable has to vary from one iteration -to the next, and the -.I expr -has to be a function of that variable. - .ft B #include <iter.h> |