lean4-htt/tests/lean/run/stxMacro.lean
2020-10-09 13:20:04 -07:00

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315 B
Text

new_frontend
-- Macro for the `syntax` category
macro "many " x:stx : stx => `(stx| ($x)*)
syntax "sum! " (many term:max) : term
macro_rules
| `(sum! $xs*) => do
let r ← `(0)
for x in xs do
r ← `($r + $x)
return r
#check sum! 1 2 3
#eval sum! 1 2 3
#check sum!
theorem ex : sum! 1 2 3 = 6 :=
rfl