Create retext plugin: Numbers

[danielgolden]

Requirements

When a user breaks one of these rules, provide feedback (See one core docs):

Basics

• Always write numbers as numerals (3 not three)
• Use commas for numbers with 4 or more digits
• Round large numbers if helpful: If absolute numerical accuracy is less important than giving customers a sense of the number, it’s OK to round them to something like 1k (for 1,012) or 324.5 million (for 324,501,082). Use your best judgment with this one.
• Never write whole numbers with a decimal place and a trailing zero (2 not 2.0)
• Abbreviate thousand with a lowercase k with no space between the the last number and the letter: 50k.

Decimals and fractions

• Write fractional values in decimal form.
• Round fractional numbers 2 decimal places to the right.
• Include a leading 0 in decimal numbers less than 1.

Money

• Omit the trailing decimal and 0s for whole dollar amounts.
• Place the appropriate currency symbol before the dollar amount with no spaces.
• When including currency with a price, the currency comes at the end with a space between it and the dollar amount.

Percentages

• Use the % symbol with no space between the number and symbol.
• For fractional values in decimal form, always include a leading zero.

EXCEPTION - When pinpoint accuracy is necessary, as with Synthetics data, you can use use up to three decimal places in percentages.

Phone numbers

• Separate numbers with hyphens only (no parentheses, nor spaces between numers)