Enum TableFunctionForm 

#[non_exhaustive]
pub enum TableFunctionForm {
    PostgreSql,
    DuckDb,
    GoogleSql,
    TSql,
    ClickHouse,
    Snowflake,
    Databricks,
    Unsupported(&'static str),
    Custom(&'static str),
}

Which table-valued function grammar this engine speaks — the routine a query selects FROM, returning columns rather than one value.

The default is TableFunctionForm::PostgreSql, which is what an unlisted dialect has always been handed. Four engines in Razeri’s own set have no table-valued function they can render, and each says so in its own words through TableFunctionForm::Unsupported — because a refusal written once per kind tells a Redshift author about MySQL, and the sentence that helps is the one about their engine.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

PostgreSql

CREATE FUNCTION … RETURNS TABLE(…) / RETURNS SETOF … over a dollar-quoted body — PostgreSQL, Citus, and Razeri’s agnostic renderer.

DuckDb

DuckDB’s table MACRO: CREATE MACRO f(x) AS TABLE SELECT …. There is no RETURNS clause at all, which is why riding the PostgreSQL arm was Parser Error: syntax error at or near "RETURNS".

GoogleSql

GoogleSQL’s CREATE TABLE FUNCTION — BigQuery’s.

TSql

T-SQL’s two shapes: the inline TVF (RETURNS TABLE AS RETURN (…)) and the multi-statement one (RETURNS @t TABLE(…) BEGIN … RETURN END).

ClickHouse

ClickHouse’s parameterized view, addressed with {param:Type}.

Snowflake

Snowflake’s UDTF, including the staged-handler registration.

Databricks

Databricks SQL’s CREATE FUNCTION … RETURNS TABLE … RETURN <query>.

Unsupported(&'static str)

This engine has no table-valued function.

The string is the orientation an author reads — at build time, when Razeri refuses to write the routine, and again in the rendered refusal if anything asks the renderer directly. Write it fix-first: say what this engine offers instead before saying what it lacks, name the artifact: values a designer would reach for, and name the near form if there is one, because a near form the author will find on their own is the thing that costs them a day.

It is prose that lands inside a SQL comment, so it must never spell a complete statement.

Custom(&'static str)

This engine has a table-valued function and spells it in a grammar Razeri does not carry. The string is the grammar’s own name.

Your dialect renders the whole CREATE, through SqlRenderer::render_table_function. It is the opposite claim to Unsupported: the build door writes the routine rather than declining it, because this engine has one.

Implementations

impl TableFunctionForm

pub const fn refusal(self) -> Option<&'static str>

The dialect’s own refusal wording, or None where this engine has the form.

The one accessor both surfaces read — the build door that declines to write the routine, and the renderer that would otherwise emit DDL — so neither one carries a second copy of the words.

Custom answers None here, and that is the whole point of it: an engine whose grammar Razeri cannot spell still has a table-valued function, so the door that asks may I write this at all gets a yes.

pub const fn custom_grammar(self) -> Option<&'static str>

The name of the grammar this dialect renders itself, or None where Razeri renders the function.

Trait Implementations

impl Clone for TableFunctionForm

fn clone(&self) -> TableFunctionForm

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for TableFunctionForm

impl Debug for TableFunctionForm

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for TableFunctionForm

fn default() -> TableFunctionForm

Returns the “default value” for a type.

impl Eq for TableFunctionForm

impl PartialEq for TableFunctionForm

fn eq(&self, other: &TableFunctionForm) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for TableFunctionForm