Whether an operand/argument is expected AT caret — the gate for the "input expected" marker and
for insert-arming the reference picker at the caret.
True when the character before the caret opens an operand slot (INPUT_EXPECTED_CHAR) AND
nothing after the caret already fills it: the caret is at the end of the text (the classic trailing
case — =A1+|), or the next non-space character still leaves the slot empty
(OPERAND_STILL_MISSING_CHAR) — the mid-formula case a cleared argument leaves behind
(=SUM(|,A1:C3)). A next character that STARTS an operand (=|SUM(A1), =SUM(1,|-2)) means the
slot is taken: the caret is doing text work there, and splicing a reference in would corrupt the
token after it.
(The caller decides what the text IS — a formula, a reference segment; this is the pure caret rule.)
Whether an operand/argument is expected AT
caret— the gate for the "input expected" marker and for insert-arming the reference picker at the caret.True when the character before the caret opens an operand slot (INPUT_EXPECTED_CHAR) AND nothing after the caret already fills it: the caret is at the end of the text (the classic trailing case —
=A1+|), or the next non-space character still leaves the slot empty (OPERAND_STILL_MISSING_CHAR) — the mid-formula case a cleared argument leaves behind (=SUM(|,A1:C3)). A next character that STARTS an operand (=|SUM(A1),=SUM(1,|-2)) means the slot is taken: the caret is doing text work there, and splicing a reference in would corrupt the token after it.(The caller decides what the text IS — a formula, a reference segment; this is the pure caret rule.)