lean4-htt/src/Lean/Data/Position.lean
2020-10-29 16:42:22 -07:00

83 lines
2.6 KiB
Text

/-
Copyright (c) 2018 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Authors: Leonardo de Moura, Sebastian Ullrich
-/
import Lean.Data.Format
namespace Lean
structure Position :=
(line : Nat)
(column : Nat)
namespace Position
instance : DecidableEq Position :=
fun ⟨l₁, c₁⟩ ⟨l₂, c₂⟩ =>
if h₁ : l₁ = l₂ then
if h₂ : c₁ = c₂ then
isTrue $ by subst h₁; subst h₂; rfl
else
isFalse fun contra => Position.noConfusion contra (fun e₁ e₂ => absurd e₂ h₂)
else
isFalse fun contra => Position.noConfusion contra (fun e₁ e₂ => absurd e₁ h₁)
protected def lt : Position → Position → Bool
| ⟨l₁, c₁⟩, ⟨l₂, c₂⟩ => (l₁, c₁) < (l₂, c₂)
instance : ToFormat Position :=
⟨fun ⟨l, c⟩ => "⟨" ++ fmt l ++ ", " ++ fmt c ++ "⟩"⟩
instance : ToString Position :=
⟨fun ⟨l, c⟩ => "⟨" ++ toString l ++ ", " ++ toString c ++ "⟩"⟩
instance : Inhabited Position := ⟨⟨1, 0⟩⟩
end Position
structure FileMap :=
(source : String)
(positions : Array String.Pos)
(lines : Array Nat)
namespace FileMap
instance : Inhabited FileMap :=
⟨{ source := "", positions := #[], lines := #[] }⟩
partial def ofString (s : String) : FileMap :=
let rec loop (i : String.Pos) (line : Nat) (ps : Array String.Pos) (lines : Array Nat) : FileMap :=
if s.atEnd i then { source := s, positions := ps.push i, lines := lines.push line }
else
let c := s.get i;
let i := s.next i;
if c == '\n' then loop i (line+1) (ps.push i) (lines.push (line+1))
else loop i line ps lines
loop 0 1 (#[0]) (#[1])
partial def toPosition (fmap : FileMap) (pos : String.Pos) : Position :=
match fmap with
| { source := str, positions := ps, lines := lines } =>
if ps.size >= 2 && pos <= ps.back then
let rec toColumn (i : String.Pos) (c : Nat) : Nat :=
if i == pos || str.atEnd i then c
else toColumn (str.next i) (c+1)
let rec loop (b e : Nat) :=
let posB := ps[b]
if e == b + 1 then { line := lines.get! b, column := toColumn posB 0 }
else
let m := (b + e) / 2;
let posM := ps.get! m;
if pos == posM then { line := lines.get! m, column := 0 }
else if pos > posM then loop m e
else loop b m
loop 0 (ps.size -1)
else
-- Some systems like the delaborator use synthetic positions without an input file,
-- which would violate `toPositionAux`'s invariant
⟨1, pos⟩
end FileMap
end Lean
def String.toFileMap (s : String) : Lean.FileMap :=
Lean.FileMap.ofString s