Package dev.frostlake.functions.scalar

Class JsonNumberNotation

java.lang.Object

dev.frostlake.functions.scalar.JsonNumberNotation

public final class JsonNumberNotation
extends Object

Which JSON numbers belong to the DOUBLE family, decided by HOW THEY WERE WRITTEN.

A number written in scientific notation is a DOUBLE and a number written plainly is not — the rule is the notation itself, with nothing to do with the value: live, PARSE_JSON('[1.0e0]') is [1.0] with TYPEOF DOUBLE while PARSE_JSON('[1.0]') is [1] with TYPEOF INTEGER, and [2e0], [0e0], [1.0E0], [1.0e+0] and [1.0e1] are all DOUBLE too. The sign and magnitude of the exponent never enter into it.

THE NOTATION DOES NOT SURVIVE THE PARSE, which is the whole reason this class exists. A JSON reader hands back a BigDecimal, and 1.0e0 and 1.0 produce the same one — unscaled 10, scale 1. Only a NEGATIVE scale is recoverable afterwards (1e5 keeps scale −5), so everything with a zero or small positive exponent was indistinguishable from its plain spelling and lost the family. The digit-count stand-in that used to cover part of this — more than 15 significant digits reading as double provenance — was measured WRONG in the other direction: live types the plain [1.234567890123456] as DECIMAL.

So the notation is read from the TEXT, in a second streaming pass over the same document that produced the tree, walking the two in lockstep and re-typing each float token written with an exponent. The pass is skipped outright unless the text contains a digit or point followed by an e. Duplicate object keys cannot desynchronise the walk because the reader refuses them outright (a duplicate attribute is a live refusal), so a field is matched by NAME and an element by position.

Method Summary

Modifier and Type	Method	Description
static tools.jackson.databind.JsonNode	applyExponentNotation(tools.jackson.databind.ObjectMapper mapper, String text, tools.jackson.databind.JsonNode tree)	The tree with every float that was WRITTEN with an exponent carried in the DOUBLE family.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

applyExponentNotation

public static tools.jackson.databind.JsonNode applyExponentNotation(tools.jackson.databind.ObjectMapper mapper,
 String text,
 tools.jackson.databind.JsonNode tree)

The tree with every float that was WRITTEN with an exponent carried in the DOUBLE family.

Parameters:

mapper - the mapper whose reader produced tree — the second pass has to read the document under the same leniencies or it will not agree with the first

text - the document exactly as the first pass read it, sentinels and relaxations included

tree - the parsed tree, mutated in place and returned; null is passed through

Returns:

the tree, with exponent-written floats re-typed