691acde696
This PR adds the option `pp.parens` (default: false) that causes the pretty printer to eagerly insert parentheses, which can be useful for teaching and for understanding the structure of expressions. For example, it causes `p → q → r` to pretty print as `p → (q → r)`. Any notations with precedence greater than or equal to `maxPrec` do not receive such discretionary parentheses, since this precedence level is considered to be infinity. This option was a feature in the Lean 3 community edition.
56 lines
1.2 KiB
Text
56 lines
1.2 KiB
Text
/-!
|
|
# Tests for the `pp.parens` pretty printing option
|
|
-/
|
|
|
|
set_option pp.parens true
|
|
|
|
/-!
|
|
No parentheses around numeral.
|
|
-/
|
|
/-- info: 1 : Nat -/
|
|
#guard_msgs in #check 1
|
|
|
|
/-!
|
|
No parentheses around variable.
|
|
-/
|
|
/-- info: x : Nat -/
|
|
#guard_msgs in variable (x : Nat) in #check x
|
|
|
|
/-!
|
|
No parentheses around each individual function application.
|
|
-/
|
|
def f (x y z : Nat) : Nat := x + y + z
|
|
/-- info: f 1 2 3 : Nat -/
|
|
#guard_msgs in #check f 1 2 3
|
|
|
|
/-!
|
|
Example arithmetic expressions
|
|
-/
|
|
/-- info: (1 + (2 * 3)) + 4 : Nat -/
|
|
#guard_msgs in #check 1 + 2 * 3 + 4
|
|
/-- info: Nat.add_assoc : ∀ (n m k : Nat), (((n + m) + k) = (n + (m + k))) -/
|
|
#guard_msgs in #check (Nat.add_assoc)
|
|
|
|
/-!
|
|
Implication chains
|
|
-/
|
|
/-- info: p → (q → r) : Prop -/
|
|
#guard_msgs in variable (p q r : Prop) in #check p → q → r
|
|
|
|
/-!
|
|
No parentheses around list literals
|
|
-/
|
|
/-- info: [1, 2, 3] ++ [3, 4, 5] : List Nat -/
|
|
#guard_msgs in #check [1,2,3] ++ [3,4,5]
|
|
|
|
/-!
|
|
Parentheses around body of forall.
|
|
-/
|
|
/-- info: ∀ (p : (Nat → (Nat → Prop))), (p (1 + 2) 3) : Prop -/
|
|
#guard_msgs in #check ∀ (p : Nat → Nat → Prop), p (1 + 2) 3
|
|
|
|
/-!
|
|
Parentheses around branches of `if`.
|
|
-/
|
|
/-- info: if True then (1 + 2) else (2 + 3) : Nat -/
|
|
#guard_msgs in #check if True then 1 + 2 else 2 + 3
|