Numeric Property Definitions
Live Document: http://goo.gl/KIMTs
We provide a crisp and useful definition of Numeric_Type=Decimal. However we have not provided a crisp and useful definition of the other two types: Numeric_Type=Digit and Numeric_Type=Numeric. We’ve also drifted away from the (few) characterizations that we had in the text. This issue was raised in the UTC last time, so I spent some time looking at the current contents, and what would make a coherent definition.
Put the following proposal up for public review, targeted at Unicode 6.2.1.
1. Add the following definitions
(The underlined examples would be changed from current properties.)
Characters used in a positional decimal systems, which standard base-10 radix systems with contiguous digits 0..9, and are most-significant-digit first (backingstore order). These are coextensive by definition with General_Category=Decimal_Number.
Rationale: This is simply a formulation of conditions that we already have.
Variants of positional decimal characters (Numeric_Type=Decimal) or sequences thereof. These include super/subscripts, enclosed, or decorated by the addition of characters such as parentheses, dots, or commas.
U+2080 ( ₀ ) SUBSCRIPT ZERO
U+2460 ( ① ) CIRCLED DIGIT ONE
U+2469 ( ⑩ ) CIRCLED NUMBER TEN
Rationale: This provides a cohesive, useful definition, and does not break series of related numbers like circled Western numbers, or include non-decimal numbers like Ethiopic:
Characters with numeric value, but that are neither Decimal nor Digit.
U+2150 ( ⅐ ) VULGAR FRACTION ONE SEVENTH
U+2160 ( Ⅰ ) ROMAN NUMERAL ONE
U+1369 ( ፩ ) ETHIOPIC DIGIT ONE
U+1372 ( ፲ ) ETHIOPIC NUMBER TEN
U+0D72 ( ൲ ) MALAYALAM NUMBER ONE THOUSAND
U+3021 ( 〡 ) HANGZHOU NUMERAL ONE
2. Change NT properties for certain characters, consistent with the above.
A. from Numeric_Type=Digit to Numeric_Type=Numeric
U+10E60 ( 𐹠 ) RUMI DIGIT ONE...U+10E68 ( 𐹨 ) RUMI DIGIT NINE
U+11052 ( 𑁒 ) BRAHMI NUMBER ONE…U+1105A ( 𑁚 ) BRAHMI NUMBER NINE
U+1369 ( ፩ ) ETHIOPIC DIGIT ONE...U+1371 ( ፱ ) ETHIOPIC DIGIT NINE
U+10A40 ( 𐩀 ) KHAROSHTHI DIGIT ONE...U+10A43 ( 𐩃 ) KHAROSHTHI DIGIT FOUR
U+19DA ( ᧚ ) NEW TAI LUE THAM DIGIT ONE
B. from Numeric_Type=Numeric to Numeric_Type=Digit
U+2469 ( ⑩ ) CIRCLED NUMBER TEN...U+2473 ( ⑳ ) CIRCLED NUMBER TWENTY
U+247D ( ⑽ ) PARENTHESIZED NUMBER TEN...U+2487 ( ⒇ ) PARENTHESIZED NUMBER TWENTY
U+2491 ( ⒑ ) NUMBER TEN FULL STOP...U+249B ( ⒛ ) NUMBER TWENTY FULL STOP
U+277F ( ❿ ) DINGBAT NEGATIVE CIRCLED NUMBER TEN
U+24EB ( ⓫ ) NEGATIVE CIRCLED NUMBER ELEVEN...U+24F4 ( ⓴ ) NEGATIVE CIRCLED NUMBER TWENTY
U+3251 ( ㉑ ) CIRCLED NUMBER TWENTY ONE...U+32BF ( ㊿ ) CIRCLED NUMBER FIFTY
U+3248 ( ㉈ ) CIRCLED NUMBER TEN ON BLACK SQUARE...U+324F ( ㉏ ) CIRCLED NUMBER EIGHTY ON BLACK SQUARE
U+24FE ( ⓾ ) DOUBLE CIRCLED NUMBER TEN
U+2789 ( ➉ ) DINGBAT CIRCLED SANS-SERIF NUMBER TEN
U+2793 ( ➓ ) DINGBAT NEGATIVE CIRCLED SANS-SERIF NUMBER TEN
Current contents, for comparison
Numeric_Type=Decimal & General_Category=Decimal_Number