format: revise numeric handling.

There are a number of issues, such as left adjustment not
working and such. This needs a better treatment from the
requirements level, through to a set of test cases.

* stream.c (max, min): Macros macros added, in their usual
form.
(vformat_num): Implement new rules which suppress the zero and
space characters used in place of a sign if they overflow the
field width.
(formatv): Clamp integer precision field to width - 1 for
integers, for consistency with floating-point handling.
For floating-point values under ~a and ~s, do not force
the second stage precision to width - 1; only clamp it
if it is greater.

* format.tl: Numerous new tests.

* txr.1: Significant redocumenting of this area. The handling
of numbers is described as a two stage process, clarifying the
changing role of "precision" in the two stages.

1 files changed, 96 insertions, 5 deletions

diff --git a/tests/018/format.tl b/tests/018/format.tl
index 6c58d45b..1b161936 100644
--- a/tests/018/format.tl
+++ b/tests/018/format.tl
@@ -24,16 +24,107 @@
   (fmt "~4,03x" #xaf) " 0af"
   (fmt "~-4,03X" #xaf) "0AF ")
 
-(mtest
-  (fmt "~8,02f" 12) " 0012.00"
-  (fmt "~8,+02f" 12) "+0012.00"
-  (fmt "~8,-02f" 12) "00012.00")
-
 (test
   (fmt "~x" (sha256 "abc"))
   "ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad")
 
 (mtest
+  (fmt "~8,02f"   12) " 0012.00"
+  (fmt "~8,+02f"  12) "+0012.00"
+  (fmt "~8,-02f"  12) "00012.00"
+  (fmt "~8, 02f"  12) " 0012.00"
+  (fmt "~8,-02f" -12) "-0012.00"
+  (fmt "~6,02f"   12)   " 12.00"
+  (fmt "~6,+02f"  12)   "+12.00"
+  (fmt "~6,-02f"  12)   "012.00"
+  (fmt "~6,- 2f"  12)   " 12.00"
+  (fmt "~6,-02f" -12)   "-12.00"
+  (fmt "~5,02f"   12)    "12.00"
+  (fmt "~5,+02f"  12)   "+12.00"
+  (fmt "~5,-02f"  12)    "12.00"
+  (fmt "~5,- 2f"  12)    "12.00"
+  (fmt "~5,-02f" -12)   "-12.00")
+
+(mtest
+  (fmt "~<8,02f"   12) "0012.00 "
+  (fmt "~<8,+02f"  12) "+0012.00"
+  (fmt "~<8,-02f"  12) "00012.00"
+  (fmt "~<8, 02f"  12) " 0012.00"
+  (fmt "~<8,-02f" -12) "-0012.00"
+  (fmt "~<6,02f"   12)   "12.00 "
+  (fmt "~<6,+02f"  12)   "+12.00"
+  (fmt "~<6,-02f"  12)   "012.00"
+  (fmt "~<6,- 2f"  12)   " 12.00"
+  (fmt "~<6,-02f" -12)   "-12.00"
+  (fmt "~<5,02f"   12)    "12.00"
+  (fmt "~<5,+02f"  12)   "+12.00"
+  (fmt "~<5,-02f"  12)    "12.00"
+  (fmt "~<5,- 2f"  12)    "12.00"
+  (fmt "~<5,-02f" -12)   "-12.00")
+
+(mtest
+  (fmt "~<8,2a"    12)   "12      "
+  (fmt "~<8,02a"   12)   "12      "
+  (fmt "~<8,+02a"  12)   "+12     "
+  (fmt "~<8,-02a"  12)   "012     "
+  (fmt "~<8, 02a"  12)   " 12     "
+  (fmt "~<8,2a"    12.0) "12      "
+  (fmt "~<8,02a"   12.0) "12      "
+  (fmt "~<8,+02a"  12.0) "+12     "
+  (fmt "~<8,-02a"  12.0) "012     "
+  (fmt "~<8, 02a"  12.0) " 12     "
+  (fmt "~<8,4a"    12.0) "  12    "
+  (fmt "~<8,04a"   12.0) "0012    "
+  (fmt "~<8,+04a"  12.0) "+0012   "
+  (fmt "~<8,-04a"  12.0) "00012   "
+  (fmt "~<8, 04a"  12.0) " 0012   "
+  (fmt "~<8,8a"    12.0) "     12 "
+  (fmt "~<8,08a"   12.0) "0000012 "
+  (fmt "~<8,+08a"  12.0) "+0000012"
+  (fmt "~<8,-08a"  12.0) "00000012"
+  (fmt "~<8, 08a"  12.0) " 0000012")
+
+(mtest
+  (fmt "~,04a" 1) "0001"
+  (fmt "~,4a" 1) "   1"
+  (fmt "~4,a" 1) "   1"
+  (fmt "~<8,a" 1) "1       "
+  (fmt "~<8,0a" 1) "1       "
+  (fmt "~<8,4a" 1) "   1    "
+  (fmt "~<8,04a" 1) "0001    "
+  (fmt "~<8,+04a" 1) "+0001   "
+  (fmt "~<,4a" 1) "   1")
+
+(mtest
+  (fmt "~,04a" 1) "0001"
+  (fmt "~,4a" 1) "   1"
+  (fmt "~4,a" 1) "   1"
+  (fmt "~<8,a" 1) "1       "
+  (fmt "~<8,0a" 1) "1       "
+  (fmt "~<8,4a" 1) "   1    "
+  (fmt "~<8,04a" 1) "0001    "
+  (fmt "~<8,+04a" 1) "+0001   "
+  (fmt "~<,4a" 1) "   1")
+
+(mtest
+  (fmt "~e"   1.2e13)     "1.200e13"
+  (fmt "~,2e" 1.2e13)      "1.20e13"
+  (fmt "~,0e" 1.2e13)         "1e13"
+  (fmt "~8,0e" 1.2e13)    "    1e13"
+  (fmt "~8,00e" 1.2e13)   " 0001e13"
+  (fmt "~8,-0e" 1.2e13)   "   01e13"
+  (fmt "~8,-00e" 1.2e13)  "00001e13"
+  (fmt "~8, 00e" 1.2e13)  " 0001e13"
+  (fmt "~8,+00e" 1.2e13)  "+0001e13"
+  (fmt "~8,+00e" -1.2e13) "-0001e13"
+  (fmt "~8,00e" -1.2e13)  "-0001e13"
+  (fmt "~<8,0e" 1.2e13)   "   1e13 "
+  (fmt "~<8,00e" 1.2e13)  "0001e13 "
+  (fmt "~<8,-0e" 1.2e13)  "   01e13"
+  (fmt "~<8,-00e" 1.2e13) "00001e13"
+  (fmt "~<8,+00e" 1.2e13) "+0001e13")
+
+(mtest
   (pic "") ""
   (pic "~") :error
   (pic "~z") :error