-- The Agda standard library
-- Strings

{-# OPTIONS --cubical-compatible --safe #-}

module Data.String where

open import Data.Bool using (true; false; T?)
open import Data.Char as Char using (Char)
open import Function.Base
open import Data.Nat.Base as  using (; _∸_; ⌊_/2⌋; ⌈_/2⌉)
import Data.Nat.Properties as ℕₚ
open import Data.List.Base as List using (List; _∷_; []; [_])
open import Data.List.NonEmpty as NE using (List⁺)
open import Data.List.Extrema ℕₚ.≤-totalOrder
open import Data.List.Relation.Binary.Pointwise using (Pointwise)
open import Data.List.Relation.Binary.Lex.Strict using (Lex-<; Lex-≤)
open import Data.Vec.Base as Vec using (Vec)
open import Data.Char.Base as Char using (Char)
import Data.Char.Properties as Char using (_≟_)
open import Function
open import Relation.Binary using (Rel)
open import Relation.Binary.PropositionalEquality using (_≡_; refl)
open import Relation.Nullary using (does)
open import Relation.Unary using (Pred; Decidable)

open import Data.List.Membership.DecPropositional Char._≟_

-- Re-export contents of base, and decidability of equality

open import Data.String.Base public
open import Data.String.Properties using (_≈?_; _≟_; _<?_; _==_) public

-- Conversion functions

toVec : (s : String)  Vec Char (length s)
toVec s = Vec.fromList (toList s)

fromVec :  {n}  Vec Char n  String
fromVec = fromList  Vec.toList

-- enclose string with parens if it contains a space character
parensIfSpace : String  String
parensIfSpace s with does (' ' ∈? toList s)
... | true  = parens s
... | false = s

-- Splitting strings

wordsBy :  {p} {P : Pred Char p}  Decidable P  String  List String
wordsBy P? = List.map fromList  List.wordsBy P?  toList

words : String  List String
words = wordsBy (T?  Char.isSpace)

-- `words` ignores contiguous whitespace
_ : words " abc  b   "  "abc"  "b"  []
_ = refl

linesBy :  {p} {P : Pred Char p}  Decidable P  String  List String
linesBy P? = List.map fromList  List.linesBy P?  toList

lines : String  List String
lines = linesBy ('\n' Char.≟_)

-- `lines` preserves empty lines
_ : lines "\nabc\n\nb\n\n\n"  ""  "abc"  ""  "b"  ""  ""  []
_ = refl

-- Rectangle

-- Build a rectangular column by:
-- Given a vector of cells and a padding function for each one
-- Compute the max of the widths, and pad the strings accordingly.

rectangle :  {n}  Vec (  String  String) n 
            Vec String n  Vec String n
rectangle pads cells = Vec.zipWith  p c  p width c) pads cells where

  sizes = List.map length (Vec.toList cells)
  width = max 0 sizes

-- Special cases for left, center, and right alignment

rectangleˡ :  {n}  Char  Vec String n  Vec String n
rectangleˡ c = rectangle (Vec.replicate $ padLeft c)

rectangleʳ :  {n}  Char  Vec String n  Vec String n
rectangleʳ c = rectangle (Vec.replicate $ padRight c)

rectangleᶜ :  {n}  Char  Char  Vec String n  Vec String n
rectangleᶜ cₗ cᵣ = rectangle (Vec.replicate $ padBoth cₗ cᵣ)