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Diffstat (limited to 'sys/fmtio/fprfmt.x')
| -rw-r--r-- | sys/fmtio/fprfmt.x | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/sys/fmtio/fprfmt.x b/sys/fmtio/fprfmt.x new file mode 100644 index 00000000..d5e68fb6 --- /dev/null +++ b/sys/fmtio/fprfmt.x @@ -0,0 +1,180 @@ +# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc. + +include <ctype.h> +include <printf.h> + +.help +.nf _________________________________________________________________________ +Process a format descriptor, setting the variables "decpl", "fill_char", +"format_char", and "width" in the fmtio common. Called from PARG_ +to determine the format specification for printing a variable. + +Format: "%[w[.d]]C[n]", where W is the field width, D the number of decimal +places or precision, C the format type character, and N the radix numeral, +for format type FMT_RADIX only. A negative field width signifies left +justification. A leading zero in the W field sets the fill character to the +numeral zero (when right justifying). Default values will be supplied if +any of the fields are omitted. The minimum format is "%C". + +If any of the fields (wdCn) have the value GET_FIELD (= "*") the value of +the field will be taken from the next PARG_ call, rather than from the +format string. This makes it easy to vary the format specification at run +time. For example, "%10.*g" would print a number in G-floating format, +with a constant field width of 10, and with the number of digits of precision +being given by a PARGI call at execution time (followed by a PARG_ call to +pass the value to be printed). +.endhelp ____________________________________________________________________ + +# The following macro marks the position in the FPRFMT procedure (saves the +# code for the needed field), and returns the not done status to PARG_. +# A subsequent call to a PARG_ (with the value of the field we are waiting for +# as argument) causes FPRFMT to be reentered at the point where we left off. + +define (waitfor, if (ival_already_used) { fmt_state = $1; return (NOT_DONE_YET) } ; $1 ival_already_used = true) + +#define (waitfor, if (ival_already_used) { +# fmt_state = $1 +# return (NOT_DONE_YET) +# } +# $1 ival_already_used = true) + +# FPRFMT -- Process a %W.Dn format specification. ALL_DONE is returned when +# the format specification has been fully processed, else NOT_DONE_YET is +# returned, indicating that an additional PARG call is required to complete +# the format (which therefore contained one or more "*" specifiers). + +int procedure fprfmt (ival) + +int ival # argument value (from parg_) +bool ival_already_used # wait for next parg +int ctoi(), stridx() +char ch, chrlwr() +include "fmt.com" + +begin + # This routine functions as a coroutine. If one of the fields in + # the format spec is to be given in a pargi call, an early return + # is taken. The routine is later reentered with the value of the + # needed field, and execution continues at the point it left off. + # (Sorry, I could not think of a simpler way to do it...) + + switch (fmt_state) { # return from "waitfor" + case FMT_START: # initial state + ival_already_used = false + case GET_WIDTH_1: # "%*.dC" + goto GET_WIDTH_1 + case GET_WIDTH_2: # "%-0*.dC" + goto GET_WIDTH_2 + case GET_DECPL: # "%w.*C" + goto GET_DECPL + case GET_FMTCHAR: # "%w.d*" + goto GET_FMTCHAR + case GET_RADIX: # "%w.dr*" + goto GET_RADIX + case GET_OPERAND: # used ival for format + goto GET_OPERAND + } + + # It is not an error if there is no format string. + if (format[ip] == EOS || format[ip] != START_OF_FORMAT) { + width = USE_DEFAULT + decpl = USE_DEFAULT + format_char = USE_DEFAULT + fill_char = ' ' + left_justify = NO + fmt_state = FMT_START + return (ALL_DONE) + } else + ip = ip + 1 # eat the "%" + + if (format[ip] == GET_FIELD) { # "%*.dC" + ip = ip + 1 + waitfor (GET_WIDTH_1) # go get field width... + if (ival < 0) # ...and come back here + left_justify = YES + else + left_justify = NO + + fill_char = ' ' + width = abs (ival) + + } else { # "%-0*.dC" + if (format[ip] == '-') { # left or right justify + left_justify = YES + ip = ip + 1 + } else + left_justify = NO + + fill_char = ' ' # zero or blank fill + if (format[ip] == '0') { + if (IS_DIGIT (format[ip+1]) || format[ip+1] == GET_FIELD) { + fill_char = '0' + ip = ip + 1 + } else + fill_char = ' ' + } + + if (format[ip] == GET_FIELD) { + ip = ip + 1 + waitfor (GET_WIDTH_2) # go get field width... + if (ival < 0) # ... and come back here + left_justify = YES + else + left_justify = NO + width = abs (ival) + + } else if (ctoi (format, ip, width) <= 0) # "%N.dC" + width = USE_DEFAULT + } + + if (width == 0) # make as big as needed + width = USE_DEFAULT + + if (format[ip] == '.') { # get decpl field + ip = ip + 1 + if (format[ip] == GET_FIELD) { # "%w.*C" + ip = ip + 1 + waitfor (GET_DECPL) + decpl = ival + } else if (ctoi (format, ip, decpl) <= 0) # "%w.NC" + decpl = USE_DEFAULT + } else + decpl = USE_DEFAULT + + if (format[ip] == GET_FIELD) { # "%w.d*" + ip = ip + 1 + waitfor (GET_FMTCHAR) + format_char = ival + } else { + format_char = format[ip] # "%w.dC" + ip = ip + 1 + } + + ch = format_char + if (stridx (ch, "bcdefghHmMorstuwxz") <= 0) { + call putline (STDERR, "Warning: Unknown format type char\n") + call fmt_err ("", format, ip-1) + format_char = USE_DEFAULT + + } else if (format_char == FMT_RADIX) { # get radix + ch = chrlwr (format[ip]) + ip = ip + 1 + if (ch == GET_FIELD) { # "%w.dr*" + waitfor (GET_RADIX) + radix = ival + } else if (IS_DIGIT (ch)) { + radix = TO_INTEG (ch) + } else if (IS_LOWER (ch)) { + radix = ch - 'a' + 10 + } else { + radix = DECIMAL + ip = ip - 1 + } + + } else if (format_char == FMT_WHITESPACE || format_char == FMT_TOCOLUMN) + ival_already_used = false # no operand + + waitfor (GET_OPERAND) # used ival for format, + fmt_state = FMT_START # need to get another + return (ALL_DONE) +end |