For "Querying Data in Staged Files" in Snowflake what does the syntax "=>" mean? - snowflake-cloud-data-platform

Question

In the Snowflake Documentation for "Querying Data in Staged Files" why is the syntax for the "Pattern" & "Format" parameters "=>" instead of "=" whereas for the COPY INTO syntax the "Pattern" & "Format" parameters have "="?
The documentation doesn't mention anything about this difference so I'm confused.
">=" means Greater than or Equal to
"<=" means Less than or Equal to
So, what the hell does "=>" mean?
Link to the documentation for "Querying Data in Staged Files": https://docs.snowflake.com/en/user-guide/querying-stage.html
Link to the documentation for "COPY INTO ": https://docs.snowflake.com/en/sql-reference/sql/copy-into-table.html
Link to the documentation for Snowflake Query Operators: https://docs.snowflake.com/en/sql-reference/operators.html

Answer 1

In general when you define function or stored procedure it will have a specific signature. This signature has to be matched during the routine call.
Example:
CREATE OR REPLACE FUNCTION test(a INT, b TEXT)
RETURNS TEXT
AS
$$
CONCAT(a, ' ', b)
$$;
SHOW FUNCTIONS LIKE 'TEST';
-- TEST(NUMBER, VARCHAR) RETURN VARCHAR
When calling test function argument order has to match its signature("positional notation"):
SELECT test(1, 'b');
-- 1 b
Unfortunately it is not possible to use named parameters for user defined objects and explicitly state the parameters("named notation"):
SELECT test(a => 1, b => 'b');
SELECT test(b => 'b', a => 1);
SELECT test(b => 'b');
Some built-ins constructs however allows to use named parameters => (for instance FLATTEN or staged file clause).
Using FLATTEN as it is easier to produce self-contained example:
FLATTEN( INPUT => <expr> [ , PATH => <constant_expr> ]
[ , OUTER => TRUE | FALSE ]
[ , RECURSIVE => TRUE | FALSE ]
[ , MODE => 'OBJECT' | 'ARRAY' | 'BOTH' ] )
All 3 invocations are correct:
-- no explicit parameters names
SELECT * FROM TABLE(FLATTEN(parse_json('{"a":1, "b":[77,88]}'), 'b')) f;
-- parameters names order: input, path
SELECT * FROM TABLE(FLATTEN(input => parse_json('{"a":1, "b":[77,88]}'), path => 'b')) f;
-- parameters names order: path, input
SELECT * FROM TABLE(FLATTEN(path => 'b', input => parse_json('{"a":1, "b":[77,88]}'))) f;