feat(library/init/data/char): use bool instead of Prop for basic char predicates

library/init/data/char/basic.lean

@@ -65,11 +65,33 @@ lemma ne_of_vne {c d : char} (h : c.val ≠ d.val) : c ≠ d :=
 lemma vne_of_ne {c d : char} (h : c ≠ d) : c.val ≠ d.val :=
 λ h', absurd (eq_of_veq h') h
 
-end char
-
 instance : decidable_eq char :=
 λ i j, decidable_of_decidable_of_iff
   (nat.decidable_eq i.val j.val) ⟨char.eq_of_veq, char.veq_of_eq⟩
 
 instance : inhabited char :=
 ⟨'A'⟩
+
+def is_whitespace (c : char) : bool :=
+c = ' ' || c = '\t' || c = '\n'
+
+def is_upper (c : char) : bool :=
+c.val ≥ 65 && c.val ≤ 90
+
+def is_lower (c : char) : bool :=
+c.val ≥ 97 && c.val ≤ 122
+
+def is_alpha (c : char) : bool :=
+c.is_upper || c.is_lower
+
+def is_digit (c : char) : bool :=
+c.val ≥ 48 && c.val ≤ 57
+
+def is_alphanum (c : char) : bool :=
+c.is_alpha || c.is_digit
+
+def to_lower (c : char) : char :=
+let n := to_nat c in
+if n >= 65 ∧ n <= 90 then of_nat (n + 32) else c
+
+end char

library/init/data/char/classes.lean

@@ -1,57 +0,0 @@
-/-
-Copyright (c) 2017 Microsoft Corporation. All rights reserved.
-Released under Apache 2.0 license as described in the file LICENSE.
-Author: Gabriel Ebner
--/
-prelude
-import .basic .lemmas init.meta init.data.int
-
-namespace char
-
-def is_whitespace (c : char) : Prop :=
-c ∈ [' ', '\t', '\n']
-
-def is_upper (c : char) : Prop :=
-c.val ≥ 65 ∧ c.val ≤ 90
-
-def is_lower (c : char) : Prop :=
-c.val ≥ 97 ∧ c.val ≤ 122
-
-def is_alpha (c : char) : Prop :=
-c.is_upper ∨ c.is_lower
-
-def is_digit (c : char) : Prop :=
-c.val ≥ 48 ∧ c.val ≤ 57
-
-def is_alphanum (c : char) : Prop :=
-c.is_alpha ∨ c.is_digit
-
-def is_punctuation (c : char) : Prop :=
-c ∈ [' ', ',', '.', '?', '!', ';', '-', '\'']
-
-def to_lower (c : char) : char :=
-let n := to_nat c in
-if n >= 65 ∧ n <= 90 then of_nat (n + 32) else c
-
-instance decidable_is_whitespace : decidable_pred is_whitespace :=
-begin intro c, delta is_whitespace, apply_instance end
-
-instance decidable_is_upper : decidable_pred is_upper :=
-begin intro c, delta is_upper, apply_instance end
-
-instance decidable_is_lower : decidable_pred is_lower :=
-begin intro c, delta is_lower, apply_instance end
-
-instance decidable_is_alpha : decidable_pred is_alpha :=
-begin intro c, delta is_alpha, apply_instance end
-
-instance decidable_is_digit : decidable_pred is_digit :=
-begin intro c, delta is_digit, apply_instance end
-
-instance decidable_is_alphanum : decidable_pred is_alphanum :=
-begin intro c, delta is_alphanum, apply_instance end
-
-instance decidable_is_punctuation : decidable_pred is_punctuation :=
-begin intro c, delta is_punctuation, apply_instance end
-
-end char

library/init/data/char/default.lean

@@ -4,4 +4,4 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Leonardo de Moura
 -/
 prelude
-import init.data.char.basic init.data.char.lemmas init.data.char.classes
+import init.data.char.basic init.data.char.lemmas