feat: % support (#8)

README.md

@@ -21,11 +21,13 @@ return {
     -- startVisible = true,
     -- showBlankVirtLine = true,
     -- hints = {
-    --     Caret = { text = "^", prio = 1 },
-    --     Dollar = { text = "$", prio = 1 },
-    --     w = { text = "w", prio = 10 },
-    --     b = { text = "b", prio = 10 },
-    --     e = { text = "e", prio = 10 },
+    --      Caret = { text = "^", prio = 2 },
+    --      Dollar = { text = "$", prio = 1 },
+    --      MatchingPair = { text = "%", prio = 5 },
+    --      Zero = { text = "0", prio = 1 },
+    --      w = { text = "w", prio = 10 },
+    --      b = { text = "b", prio = 9 },
+    --      e = { text = "e", prio = 8 },
     -- },
     -- gutterHints = {
     --     --prio is not currentlt used for gutter hints
@@ -40,8 +42,10 @@ return {
 
 ## ⚙️ Config
 
-- Items can be hidden by settings their priority to 0
-- `lua showBlankVirtLine = false`
+- Items can be hidden by settings their priority to 0, if you want to hide the
+  entire virtual line. Set all elements to `prio = 0` in combination with the
+  below.
+- `showBlankVirtLine = false`
   Setting this option will mean that if a Virtual Line would be blank it wont be
   rendered
 

lua/precognition/horizontal_motions.lua

@@ -3,6 +3,12 @@ local cc = utils.char_classes
 
 local M = {}
 
+local supportedBrackets = {
+    open = { "(", "[", "{" },
+    middle = { nil, nil, nil },
+    close = { ")", "]", "}" },
+}
+
 ---@param str string
 ---@param _cursorcol integer
 ---@param _linelen integer
@@ -138,4 +144,148 @@ function M.prev_word_boundary(str, cursorcol, _linelen)
     return offset + 1
 end
 
+---@param str string
+---@param cursorcol integer
+---@param linelen integer
+---@return Precognition.PlaceLoc
+function M.matching_bracket(str, cursorcol, linelen)
+    local under_cursor = vim.fn.strcharpart(str, cursorcol - 1, 1)
+    local offset = cursorcol
+
+    if
+        not vim.tbl_contains(supportedBrackets.open, under_cursor)
+        and not vim.tbl_contains(supportedBrackets.close, under_cursor)
+    then
+        -- walk until we find a bracket
+        return 0
+    end
+    local idxFound = false
+    local bracketIdx
+    if not idxFound then
+        for i, bracket in ipairs(supportedBrackets.open) do
+            if bracket == under_cursor then
+                bracketIdx = i
+                idxFound = true
+                break
+            end
+        end
+    end
+
+    if not idxFound then
+        for i, bracket in ipairs(supportedBrackets.close) do
+            if bracket == under_cursor then
+                bracketIdx = i
+                idxFound = true
+                break
+            end
+        end
+    end
+
+    if not idxFound then
+        return 0
+    end
+
+    local openBracket = supportedBrackets.open[bracketIdx] or ""
+    local closeBracket = supportedBrackets.close[bracketIdx] or ""
+    local middleBracket = supportedBrackets.middle[bracketIdx] or ""
+
+    if under_cursor == openBracket then
+        local depth = 1
+        offset = offset + 1
+        while offset <= linelen do
+            local char = vim.fn.strcharpart(str, offset - 1, 1)
+            if char == openBracket then
+                depth = depth + 1
+            end
+            if char == closeBracket or char == middleBracket then
+                depth = depth - 1
+                if depth == 0 then
+                    break
+                end
+            end
+            offset = offset + 1
+        end
+    end
+
+    if under_cursor == closeBracket then
+        local depth = 1
+        offset = offset - 2
+        while offset >= 0 do
+            local char = vim.fn.strcharpart(str, offset - 1, 1)
+            if char == closeBracket then
+                depth = depth + 1
+            end
+            if char == openBracket or char == middleBracket then
+                depth = depth - 1
+                if depth == 0 then
+                    break
+                end
+            end
+            offset = offset - 1
+        end
+    end
+
+    if offset < 0 or offset > linelen then
+        return 0
+    end
+    return offset
+end
+
+---@param str string
+---@param cursorcol integer
+---@param linelen integer
+---@return Precognition.PlaceLoc
+function M.matching_comment(str, cursorcol, linelen)
+    local offset = cursorcol
+    local char = vim.fn.strcharpart(str, offset - 1, 1)
+    local next_char = vim.fn.strcharpart(str, (offset - 1) + 1, 1)
+    local prev_char = vim.fn.strcharpart(str, (offset - 1) - 1, 1)
+
+    if (char == "/" and next_char == "*") or (prev_char == "/" and char == "*") then
+        offset = offset + 1
+        while offset <= linelen do
+            char = vim.fn.strcharpart(str, offset - 1, 1)
+            next_char = vim.fn.strcharpart(str, offset, 1)
+            if char == "*" and next_char == "/" then
+                -- return the slash of the closing comment
+                return offset + 1
+            end
+            offset = offset + 1
+        end
+    end
+
+    if (char == "*" and next_char == "/") or (prev_char == "*" and char == "/") then
+        offset = offset - 1
+        while offset >= 0 do
+            char = vim.fn.strcharpart(str, offset - 1, 1)
+            next_char = vim.fn.strcharpart(str, offset, 1)
+            if char == "/" and next_char == "*" then
+                return offset
+            end
+            offset = offset - 1
+        end
+    end
+
+    return 0
+end
+
+---@param str string
+---@param cursorcol integer
+---@param _linelen integer
+---@return function
+function M.matching_pair(str, cursorcol, _linelen)
+    local char = vim.fn.strcharpart(str, cursorcol - 1, 1)
+    if char == "/" or char == "*" then
+        return M.matching_comment
+    end
+
+    if vim.tbl_contains(supportedBrackets.open, char) or vim.tbl_contains(supportedBrackets.close, char) then
+        return M.matching_bracket
+    end
+
+    return function()
+        return 0
+    end
+end
+
 return M

lua/precognition/init.lua

@@ -14,6 +14,8 @@ local M = {}
 ---@field w Precognition.HintOpts
 ---@field e Precognition.HintOpts
 ---@field b Precognition.HintOpts
+---@field Zero Precognition.HintOpts
+---@field MatchingPair Precognition.HintOpts
 ---@field Caret Precognition.HintOpts
 ---@field Dollar Precognition.HintOpts
 
@@ -39,8 +41,10 @@ local M = {}
 ---@field w Precognition.PlaceLoc
 ---@field e Precognition.PlaceLoc
 ---@field b Precognition.PlaceLoc
+---@field Zero Precognition.PlaceLoc
 ---@field Caret Precognition.PlaceLoc
 ---@field Dollar Precognition.PlaceLoc
+---@field MatchingPair Precognition.PlaceLoc
 
 ---@class (exact) Precognition.GutterHints
 ---@field G Precognition.PlaceLoc
@@ -50,8 +54,10 @@ local M = {}
 
 ---@type Precognition.HintConfig
 local defaultHintConfig = {
-    Caret = { text = "^", prio = 1 },
+    Caret = { text = "^", prio = 2 },
     Dollar = { text = "$", prio = 1 },
+    MatchingPair = { text = "%", prio = 5 },
+    Zero = { text = "0", prio = 1 },
     w = { text = "w", prio = 10 },
     b = { text = "b", prio = 9 },
     e = { text = "e", prio = 8 },
@@ -210,7 +216,9 @@ local function display_marks()
         w = hm.next_word_boundary(cur_line, cursorcol, line_len),
         e = hm.end_of_word(cur_line, cursorcol, line_len),
         b = hm.prev_word_boundary(cur_line, cursorcol, line_len),
+        MatchingPair = hm.matching_pair(cur_line, cursorcol, line_len)(cur_line, cursorcol, line_len),
         Dollar = hm.line_end(cur_line, cursorcol, line_len),
+        Zero = 1,
     }
 
     local virt_line = build_virt_line(virtual_line_marks, line_len)

tests/precognition/horizontal_motions_spec.lua

@@ -144,6 +144,93 @@ describe("boundaries", function()
     end)
 end)
 
+describe("matching_pair returns the correction function", function()
+    it("returns the correct function for the given character", function()
+        local test_string = "()[]{}/*"
+        eq(hm.matching_pair(test_string, 1, #test_string), hm.matching_bracket)
+        eq(hm.matching_pair(test_string, 2, #test_string), hm.matching_bracket)
+        eq(hm.matching_pair(test_string, 3, #test_string), hm.matching_bracket)
+        eq(hm.matching_pair(test_string, 4, #test_string), hm.matching_bracket)
+        eq(hm.matching_pair(test_string, 5, #test_string), hm.matching_bracket)
+        eq(hm.matching_pair(test_string, 6, #test_string), hm.matching_bracket)
+        eq(hm.matching_pair(test_string, 7, #test_string), hm.matching_comment)
+        eq(hm.matching_pair(test_string, 8, #test_string), hm.matching_comment)
+    end)
+
+    it("returns a function that returns 0 for other characters", function()
+        local test_string = "abcdefghijklmnopqrstuvwxyz!@#$%^&*_+-=,.<>?|\\~`"
+        for i = 1, #test_string do
+            local func = hm.matching_pair(test_string, i, #test_string)
+            eq(0, func(test_string, i, #test_string))
+        end
+    end)
+end)
+
+describe("matching brackets", function()
+    it("if cursor is over a bracket it can find the pair", function()
+        eq(9, hm.matching_bracket("abc (efg)", 5, 9))
+        eq(0, hm.matching_bracket("abc (efg)", 6, 9))
+        eq(0, hm.matching_bracket("abc (efg)", 7, 9))
+        eq(0, hm.matching_bracket("abc (efg)", 8, 9))
+        eq(5, hm.matching_bracket("abc (efg)", 9, 9))
+    end)
+
+    it("if cursor is over a square bracket it can find the pair", function()
+        eq(9, hm.matching_bracket("abc [efg]", 5, 9))
+        eq(0, hm.matching_bracket("abc [efg]", 6, 9))
+        eq(0, hm.matching_bracket("abc [efg]", 7, 9))
+        eq(0, hm.matching_bracket("abc [efg]", 8, 9))
+        eq(5, hm.matching_bracket("abc [efg]", 9, 9))
+    end)
+
+    it("if cursor is over a curly bracket it can find the pair", function()
+        eq(9, hm.matching_bracket("abc {efg}", 5, 9))
+        eq(0, hm.matching_bracket("abc {efg}", 6, 9))
+        eq(0, hm.matching_bracket("abc {efg}", 7, 9))
+        eq(0, hm.matching_bracket("abc {efg}", 8, 9))
+        eq(5, hm.matching_bracket("abc {efg}", 9, 9))
+    end)
+
+    it("nested brackets find the correct pair", function()
+        eq(19, hm.matching_bracket("abc (efg [hij] klm)", 5, 19))
+        eq(0, hm.matching_bracket("abc (efg [hij] klm)", 6, 19))
+        eq(14, hm.matching_bracket("abc (efg [hij] klm)", 10, 19))
+        eq(10, hm.matching_bracket("abc (efg [hij] klm)", 14, 19))
+        eq(0, hm.matching_bracket("abc (efg [hij] klm)", 15, 19))
+        eq(5, hm.matching_bracket("abc (efg [hij] klm)", 19, 19))
+    end)
+
+    it("nested brackets of the same type find the correct pair", function()
+        eq(19, hm.matching_bracket("abc (efg (hij) klm)", 5, 19))
+        eq(0, hm.matching_bracket("abc (efg (hij) klm)", 6, 19))
+        eq(14, hm.matching_bracket("abc (efg (hij) klm)", 10, 19))
+        eq(10, hm.matching_bracket("abc (efg (hij) klm)", 14, 19))
+        eq(0, hm.matching_bracket("abc (efg (hij) klm)", 15, 19))
+        eq(5, hm.matching_bracket("abc (efg (hij) klm)", 19, 19))
+    end)
+
+    it("if cursor is over an unclosed bracket it returns 0", function()
+        eq(0, hm.matching_bracket("abc (efg", 5, 8))
+        eq(0, hm.matching_bracket("abc [efg", 5, 8))
+        eq(0, hm.matching_bracket("abc {efg", 5, 8))
+    end)
+end)
+
+describe("matching comments", function()
+    it("if cursor is over a comment it can find the pair", function()
+        eq(11, hm.matching_comment("abc /*efg*/", 5, 11))
+        eq(11, hm.matching_comment("abc /*efg*/", 6, 11))
+        eq(0, hm.matching_comment("abc /*efg*/", 7, 11))
+        eq(5, hm.matching_comment("abc /*efg*/", 10, 11))
+        eq(5, hm.matching_comment("abc /*efg*/", 11, 11))
+    end)
+
+    it("if cursor is over an unclosed comment it returns 0", function()
+        eq(0, hm.matching_comment("abc /*efg", 5, 9))
+        eq(0, hm.matching_comment("abc /*efg", 6, 9))
+    end)
+end)
+
 describe("edge case", function()
     it("can handle empty strings", function()
         eq(0, hm.next_word_boundary("", 1, 0))