Expressions

Operators, precedence, and the two lowerings.

Generated from the language definition for language 1.0.

Expressions

One grammar, two lowerings: a record-local position (a guard, a validation, a browser gate) lowers to JSONLogic; a set-level position (a query, a related list, a rollup, a stat) lowers to a DAL statement. Comparisons do not chain; = is accepted and printed as ==.

Binary operators

Operator	Precedence	JSONLogic	DAL
`or`	1 (or)	`or`	`Or`
`and`	2 (and)	`and`	`And`
`==`	4 (comparison)	`==`	`Eq`
`!=`	4 (comparison)	`!=`	`Ne`
`<`	4 (comparison)	`<`	`Lt`
`<=`	4 (comparison)	`<=`	`Le`
`>`	4 (comparison)	`>`	`Gt`
`>=`	4 (comparison)	`>=`	`Ge`
`like`	4 (comparison)	not available (no pattern match)	`Like`
`+`	5 (additive)	`+`	not available (no arithmetic)
`-`	5 (additive)	`-`	not available (no arithmetic)
`*`	6 (multiplicative)	`*`	not available (no arithmetic)
`/`	6 (multiplicative)	`/`	not available (no arithmetic)

Other forms

not x: logical negation
-x: arithmetic negation
x is null: null test (x is not null for the complement)
x in [a, b]: membership in a list of literals
x in (select …): membership in a subquery (set-level only)
exists (select …): a non-empty subquery (set-level only)
a.b: a field, or one level of ref traversal
this: the current record in a set-level position; this.field reads one of its fields
me: the current user (set-level only)
(x): grouping; parentheses survive round trips where precedence needs them

Functions

Set-level only: JSONLogic has no lower, upper, length or coalesce, and its substr counts from zero where the DAL's counts from one, so a record-local position refuses them rather than promise one meaning in two targets.

Function	Arguments	DAL
`lower`	1	`Lower`
`upper`	1	`Upper`
`coalesce`	2 or more	`Coalesce`
`length`	1	`Length`
`substr`	2 to 3	`Substr`

Aggregates

agg(Entity[.field] [where expr]); in a guard, count(…) op n and sum(…) op n compile to the engine's related-record guards.

Aggregate	DAL
`count`	`Count`
`sum`	`Sum`
`avg`	`Avg`
`min`	`Min`
`max`	`Max`

JSONLogic operators the compiler may emit

A jsonlogic { … } literal may use any of them, and the sugar emits the ones its operators map to.

==, !=, ===, !==, !, !!, <, <=, >, >=, +, -, *, /, %, max, min, merge, in, cat, substr, log, var, missing, missing_some, if, ?:, or, and, map, filter, reduce, all, some, none

DAL vocabulary

Binary operators: Eq, Ne, Lt, Le, Gt, Ge, And, Or, In, NotIn, Like
Unary operators: Not, IsNull, IsNotNull
Functions: Lower, Upper, Coalesce, Length, Substr
Aggregates: Count, Sum, Avg, Min, Max
Built-in sources: jobs (Jobs), event_log (EventLog), fsm_schemas (FsmSchemas)