fix: dirty fix for char width

.github/workflows/deno.yml

@@ -26,9 +26,9 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Setup Deno
-        uses: denoland/setup-deno@v1.1.4
+        uses: denoland/setup-deno@v2
         with:
-          deno-version: v1.x
+          deno-version: v2.x
 
       # Uncomment this step to verify the use of 'deno fmt' on each commit.
       - name: Verify formatting

.github/workflows/publish_npm.yml

@@ -11,9 +11,14 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - name: Setup Deno
-        uses: denoland/setup-deno@v1.1.4
+        uses: denoland/setup-deno@v2
         with:
-          deno-version: v1.x
+          deno-version: v2.x
+      # Setup .npmrc file to publish to npm
+      - uses: actions/setup-node@v4
+        with:
+          node-version: "22.x"
+          registry-url: "https://registry.npmjs.org"
       - run: deno run -A scripts/build_npm.ts
       - run: cd npm && npm ci
       - run: cd npm && npm publish --provenance --access public

.zed/tasks.json

@@ -1,9 +1,10 @@
-// Static tasks configuration.
-//
-// Example:
 [
   {
     "label": "Test",
     "command": "deno test"
+  },
+  {
+    "label": "Test - Watch",
+    "command": "deno test --watch"
   }
 ]

deno.json

@@ -1,8 +1,9 @@
 {
   "name": "@textplace/core",
-  "version": "0.1.5",
+  "version": "0.4.1",
   "exports": "./mod.ts",
   "imports": {
-    "@deno/dnt": "jsr:@deno/dnt@^0.41.1"
+    "@deno/dnt": "jsr:@deno/dnt@^0.41.3",
+    "@std/cli": "jsr:@std/cli@^1.0.11"
   }
 }

deno.lock

@@ -1,216 +1,121 @@
 {
-  "version": "3",
+  "version": "4",
-  "packages": {
+  "specifiers": {
-    "specifiers": {
+    "jsr:@david/code-block-writer@^13.0.2": "13.0.3",
-      "jsr:@deno/cache-dir@^0.8.0": "jsr:@deno/cache-dir@0.8.0",
+    "jsr:@deno/cache-dir@~0.10.3": "0.10.3",
-      "jsr:@deno/dnt@^0.41.1": "jsr:@deno/dnt@0.41.1",
+    "jsr:@deno/dnt@~0.41.3": "0.41.3",
-      "jsr:@deno/graph@^0.69.7": "jsr:@deno/graph@0.69.10",
+    "jsr:@std/assert@0.223": "0.223.0",
-      "jsr:@std/assert@^0.218.2": "jsr:@std/assert@0.218.2",
+    "jsr:@std/assert@0.226": "0.226.0",
-      "jsr:@std/bytes@^0.218.2": "jsr:@std/bytes@0.218.2",
+    "jsr:@std/bytes@0.223": "0.223.0",
-      "jsr:@std/fmt@^0.218.2": "jsr:@std/fmt@0.218.2",
+    "jsr:@std/cli@^1.0.11": "1.0.11",
-      "jsr:@std/fs@^0.218.2": "jsr:@std/fs@0.218.2",
+    "jsr:@std/fmt@0.223": "0.223.0",
-      "jsr:@std/io@^0.218.2": "jsr:@std/io@0.218.2",
+    "jsr:@std/fmt@1": "1.0.3",
-      "jsr:@std/path@^0.218.2": "jsr:@std/path@0.218.2",
+    "jsr:@std/fs@0.223": "0.223.0",
-      "npm:@ts-morph/bootstrap@0.22": "npm:@ts-morph/bootstrap@0.22.0",
+    "jsr:@std/fs@1": "1.0.6",
-      "npm:code-block-writer@^13.0.1": "npm:code-block-writer@13.0.1"
+    "jsr:@std/fs@~0.229.3": "0.229.3",
+    "jsr:@std/io@0.223": "0.223.0",
+    "jsr:@std/path@0.223": "0.223.0",
+    "jsr:@std/path@1": "1.0.8",
+    "jsr:@std/path@1.0.0-rc.1": "1.0.0-rc.1",
+    "jsr:@std/path@^1.0.8": "1.0.8",
+    "jsr:@std/path@~0.225.2": "0.225.2",
+    "jsr:@ts-morph/bootstrap@0.24": "0.24.0",
+    "jsr:@ts-morph/common@0.24": "0.24.0"
+  },
+  "jsr": {
+    "@david/code-block-writer@13.0.3": {
+      "integrity": "f98c77d320f5957899a61bfb7a9bead7c6d83ad1515daee92dbacc861e13bb7f"
     },
-    "jsr": {
+    "@deno/cache-dir@0.10.3": {
-      "@deno/cache-dir@0.8.0": {
+      "integrity": "eb022f84ecc49c91d9d98131c6e6b118ff63a29e343624d058646b9d50404776",
-        "integrity": "e87e80a404958f6350d903e6238b72afb92468378b0b32111f7a1e4916ac7fe7",
+      "dependencies": [
-        "dependencies": [
+        "jsr:@std/fmt@0.223",
-          "jsr:@deno/graph@^0.69.7",
+        "jsr:@std/fs@0.223",
-          "jsr:@std/fs@^0.218.2",
+        "jsr:@std/io",
-          "jsr:@std/io@^0.218.2"
+        "jsr:@std/path@0.223"
-        ]
+      ]
-      },
-      "@deno/dnt@0.41.1": {
-        "integrity": "8746a773e031ae19ef43d0eece850217b76cf1d0118fdd8e059652d7023d4aff",
-        "dependencies": [
-          "jsr:@deno/cache-dir@^0.8.0",
-          "jsr:@std/fmt@^0.218.2",
-          "jsr:@std/fs@^0.218.2",
-          "jsr:@std/path@^0.218.2",
-          "npm:@ts-morph/bootstrap@0.22",
-          "npm:code-block-writer@^13.0.1"
-        ]
-      },
-      "@deno/graph@0.69.10": {
-        "integrity": "38fe22ac5686f6ece5daeec5a4df65c6314d7d32adcc33f77917a13cfaffa26f"
-      },
-      "@std/assert@0.218.2": {
-        "integrity": "7f0a5a1a8cf86607cd6c2c030584096e1ffad27fc9271429a8cb48cfbdee5eaf"
-      },
-      "@std/bytes@0.218.2": {
-        "integrity": "91fe54b232dcca73856b79a817247f4a651dbb60d51baafafb6408c137241670"
-      },
-      "@std/fmt@0.218.2": {
-        "integrity": "99526449d2505aa758b6cbef81e7dd471d8b28ec0dcb1491d122b284c548788a"
-      },
-      "@std/fs@0.218.2": {
-        "integrity": "dd9431453f7282e8c577cc22c9e6d036055a9a980b5549f887d6012969fabcca",
-        "dependencies": [
-          "jsr:@std/assert@^0.218.2",
-          "jsr:@std/path@^0.218.2"
-        ]
-      },
-      "@std/io@0.218.2": {
-        "integrity": "c64fbfa087b7c9d4d386c5672f291f607d88cb7d44fc299c20c713e345f2785f",
-        "dependencies": [
-          "jsr:@std/bytes@^0.218.2"
-        ]
-      },
-      "@std/path@0.218.2": {
-        "integrity": "b568fd923d9e53ad76d17c513e7310bda8e755a3e825e6289a0ce536404e2662",
-        "dependencies": [
-          "jsr:@std/assert@^0.218.2"
-        ]
-      }
     },
-    "npm": {
+    "@deno/dnt@0.41.3": {
-      "@nodelib/fs.scandir@2.1.5": {
+      "integrity": "b2ef2c8a5111eef86cb5bfcae103d6a2938e8e649e2461634a7befb7fc59d6d2",
-        "integrity": "sha512-vq24Bq3ym5HEQm2NKCr3yXDwjc7vTsEThRDnkp2DK9p1uqLR+DHurm/NOTo0KG7HYHU7eppKZj3MyqYuMBf62g==",
+      "dependencies": [
-        "dependencies": {
+        "jsr:@david/code-block-writer",
-          "@nodelib/fs.stat": "@nodelib/fs.stat@2.0.5",
+        "jsr:@deno/cache-dir",
-          "run-parallel": "run-parallel@1.2.0"
+        "jsr:@std/fmt@1",
-        }
+        "jsr:@std/fs@1",
-      },
+        "jsr:@std/path@1",
-      "@nodelib/fs.stat@2.0.5": {
+        "jsr:@ts-morph/bootstrap"
-        "integrity": "sha512-RkhPPp2zrqDAQA/2jNhnztcPAlv64XdhIp7a7454A5ovI7Bukxgt7MX7udwAu3zg1DcpPU0rz3VV1SeaqvY4+A==",
+      ]
-        "dependencies": {}
+    },
-      },
+    "@std/assert@0.223.0": {
-      "@nodelib/fs.walk@1.2.8": {
+      "integrity": "eb8d6d879d76e1cc431205bd346ed4d88dc051c6366365b1af47034b0670be24"
-        "integrity": "sha512-oGB+UxlgWcgQkgwo8GcEGwemoTFt3FIO9ababBmaGwXIoBKZ+GTy0pP185beGg7Llih/NSHSV2XAs1lnznocSg==",
+    },
-        "dependencies": {
+    "@std/assert@0.226.0": {
-          "@nodelib/fs.scandir": "@nodelib/fs.scandir@2.1.5",
+      "integrity": "0dfb5f7c7723c18cec118e080fec76ce15b4c31154b15ad2bd74822603ef75b3"
-          "fastq": "fastq@1.17.1"
+    },
-        }
+    "@std/bytes@0.223.0": {
-      },
+      "integrity": "84b75052cd8680942c397c2631318772b295019098f40aac5c36cead4cba51a8"
-      "@ts-morph/bootstrap@0.22.0": {
+    },
-        "integrity": "sha512-MI5q7pid4swAlE2lcHwHRa6rcjoIMyT6fy8uuZm8BGg7DHGi/H5bQ0GMZzbk3N0r/LfStMdOYPkl+3IwvfIQ2g==",
+    "@std/cli@1.0.11": {
-        "dependencies": {
+      "integrity": "ec219619fdcd31bcf0d8e53bee1e2706ec9a02f70255365a094f69755dadd340"
-          "@ts-morph/common": "@ts-morph/common@0.22.0"
+    },
-        }
+    "@std/fmt@0.223.0": {
-      },
+      "integrity": "6deb37794127dfc7d7bded2586b9fc6f5d50e62a8134846608baf71ffc1a5208"
-      "@ts-morph/common@0.22.0": {
+    },
-        "integrity": "sha512-HqNBuV/oIlMKdkLshXd1zKBqNQCsuPEsgQOkfFQ/eUKjRlwndXW1AjN9LVkBEIukm00gGXSRmfkl0Wv5VXLnlw==",
+    "@std/fmt@1.0.3": {
-        "dependencies": {
+      "integrity": "97765c16aa32245ff4e2204ecf7d8562496a3cb8592340a80e7e554e0bb9149f"
-          "fast-glob": "fast-glob@3.3.2",
+    },
-          "minimatch": "minimatch@9.0.4",
+    "@std/fs@0.223.0": {
-          "mkdirp": "mkdirp@3.0.1",
+      "integrity": "3b4b0550b2c524cbaaa5a9170c90e96cbb7354e837ad1bdaf15fc9df1ae9c31c"
-          "path-browserify": "path-browserify@1.0.1"
+    },
-        }
+    "@std/fs@0.229.3": {
-      },
+      "integrity": "783bca21f24da92e04c3893c9e79653227ab016c48e96b3078377ebd5222e6eb",
-      "balanced-match@1.0.2": {
+      "dependencies": [
-        "integrity": "sha512-3oSeUO0TMV67hN1AmbXsK4yaqU7tjiHlbxRDZOpH0KW9+CeX4bRAaX0Anxt0tx2MrpRpWwQaPwIlISEJhYU5Pw==",
+        "jsr:@std/path@1.0.0-rc.1"
-        "dependencies": {}
+      ]
-      },
+    },
-      "brace-expansion@2.0.1": {
+    "@std/fs@1.0.6": {
-        "integrity": "sha512-XnAIvQ8eM+kC6aULx6wuQiwVsnzsi9d3WxzV3FpWTGA19F621kwdbsAcFKXgKUHZWsy+mY6iL1sHTxWEFCytDA==",
+      "integrity": "42b56e1e41b75583a21d5a37f6a6a27de9f510bcd36c0c85791d685ca0b85fa2",
-        "dependencies": {
+      "dependencies": [
-          "balanced-match": "balanced-match@1.0.2"
+        "jsr:@std/path@^1.0.8"
-        }
+      ]
-      },
+    },
-      "braces@3.0.2": {
+    "@std/io@0.223.0": {
-        "integrity": "sha512-b8um+L1RzM3WDSzvhm6gIz1yfTbBt6YTlcEKAvsmqCZZFw46z626lVj9j1yEPW33H5H+lBQpZMP1k8l+78Ha0A==",
+      "integrity": "2d8c3c2ab3a515619b90da2c6ff5ea7b75a94383259ef4d02116b228393f84f1",
-        "dependencies": {
+      "dependencies": [
-          "fill-range": "fill-range@7.0.1"
+        "jsr:@std/assert@0.223",
-        }
+        "jsr:@std/bytes"
-      },
+      ]
-      "code-block-writer@13.0.1": {
+    },
-        "integrity": "sha512-c5or4P6erEA69TxaxTNcHUNcIn+oyxSRTOWV+pSYF+z4epXqNvwvJ70XPGjPNgue83oAFAPBRQYwpAJ/Hpe/Sg==",
+    "@std/path@0.223.0": {
-        "dependencies": {}
+      "integrity": "593963402d7e6597f5a6e620931661053572c982fc014000459edc1f93cc3989",
-      },
+      "dependencies": [
-      "fast-glob@3.3.2": {
+        "jsr:@std/assert@0.223"
-        "integrity": "sha512-oX2ruAFQwf/Orj8m737Y5adxDQO0LAB7/S5MnxCdTNDd4p6BsyIVsv9JQsATbTSq8KHRpLwIHbVlUNatxd+1Ow==",
+      ]
-        "dependencies": {
+    },
-          "@nodelib/fs.stat": "@nodelib/fs.stat@2.0.5",
+    "@std/path@0.225.2": {
-          "@nodelib/fs.walk": "@nodelib/fs.walk@1.2.8",
+      "integrity": "0f2db41d36b50ef048dcb0399aac720a5348638dd3cb5bf80685bf2a745aa506",
-          "glob-parent": "glob-parent@5.1.2",
+      "dependencies": [
-          "merge2": "merge2@1.4.1",
+        "jsr:@std/assert@0.226"
-          "micromatch": "micromatch@4.0.5"
+      ]
-        }
+    },
-      },
+    "@std/path@1.0.0-rc.1": {
-      "fastq@1.17.1": {
+      "integrity": "b8c00ae2f19106a6bb7cbf1ab9be52aa70de1605daeb2dbdc4f87a7cbaf10ff6"
-        "integrity": "sha512-sRVD3lWVIXWg6By68ZN7vho9a1pQcN/WBFaAAsDDFzlJjvoGx0P8z7V1t72grFJfJhu3YPZBuu25f7Kaw2jN1w==",
+    },
-        "dependencies": {
+    "@std/path@1.0.8": {
-          "reusify": "reusify@1.0.4"
+      "integrity": "548fa456bb6a04d3c1a1e7477986b6cffbce95102d0bb447c67c4ee70e0364be"
-        }
+    },
-      },
+    "@ts-morph/bootstrap@0.24.0": {
-      "fill-range@7.0.1": {
+      "integrity": "a826a2ef7fa8a7c3f1042df2c034d20744d94da2ee32bf29275bcd4dffd3c060",
-        "integrity": "sha512-qOo9F+dMUmC2Lcb4BbVvnKJxTPjCm+RRpe4gDuGrzkL7mEVl/djYSu2OdQ2Pa302N4oqkSg9ir6jaLWJ2USVpQ==",
+      "dependencies": [
-        "dependencies": {
+        "jsr:@ts-morph/common"
-          "to-regex-range": "to-regex-range@5.0.1"
+      ]
-        }
+    },
-      },
+    "@ts-morph/common@0.24.0": {
-      "glob-parent@5.1.2": {
+      "integrity": "12b625b8e562446ba658cdbe9ad77774b4bd96b992ae8bd34c60dbf24d06c1f3",
-        "integrity": "sha512-AOIgSQCepiJYwP3ARnGx+5VnTu2HBYdzbGP45eLw1vr3zB3vZLeyed1sC9hnbcOc9/SrMyM5RPQrkGz4aS9Zow==",
+      "dependencies": [
-        "dependencies": {
+        "jsr:@std/fs@~0.229.3",
-          "is-glob": "is-glob@4.0.3"
+        "jsr:@std/path@~0.225.2"
-        }
+      ]
-      },
-      "is-extglob@2.1.1": {
-        "integrity": "sha512-SbKbANkN603Vi4jEZv49LeVJMn4yGwsbzZworEoyEiutsN3nJYdbO36zfhGJ6QEDpOZIFkDtnq5JRxmvl3jsoQ==",
-        "dependencies": {}
-      },
-      "is-glob@4.0.3": {
-        "integrity": "sha512-xelSayHH36ZgE7ZWhli7pW34hNbNl8Ojv5KVmkJD4hBdD3th8Tfk9vYasLM+mXWOZhFkgZfxhLSnrwRr4elSSg==",
-        "dependencies": {
-          "is-extglob": "is-extglob@2.1.1"
-        }
-      },
-      "is-number@7.0.0": {
-        "integrity": "sha512-41Cifkg6e8TylSpdtTpeLVMqvSBEVzTttHvERD741+pnZ8ANv0004MRL43QKPDlK9cGvNp6NZWZUBlbGXYxxng==",
-        "dependencies": {}
-      },
-      "merge2@1.4.1": {
-        "integrity": "sha512-8q7VEgMJW4J8tcfVPy8g09NcQwZdbwFEqhe/WZkoIzjn/3TGDwtOCYtXGxA3O8tPzpczCCDgv+P2P5y00ZJOOg==",
-        "dependencies": {}
-      },
-      "micromatch@4.0.5": {
-        "integrity": "sha512-DMy+ERcEW2q8Z2Po+WNXuw3c5YaUSFjAO5GsJqfEl7UjvtIuFKO6ZrKvcItdy98dwFI2N1tg3zNIdKaQT+aNdA==",
-        "dependencies": {
-          "braces": "braces@3.0.2",
-          "picomatch": "picomatch@2.3.1"
-        }
-      },
-      "minimatch@9.0.4": {
-        "integrity": "sha512-KqWh+VchfxcMNRAJjj2tnsSJdNbHsVgnkBhTNrW7AjVo6OvLtxw8zfT9oLw1JSohlFzJ8jCoTgaoXvJ+kHt6fw==",
-        "dependencies": {
-          "brace-expansion": "brace-expansion@2.0.1"
-        }
-      },
-      "mkdirp@3.0.1": {
-        "integrity": "sha512-+NsyUUAZDmo6YVHzL/stxSu3t9YS1iljliy3BSDrXJ/dkn1KYdmtZODGGjLcc9XLgVVpH4KshHB8XmZgMhaBXg==",
-        "dependencies": {}
-      },
-      "path-browserify@1.0.1": {
-        "integrity": "sha512-b7uo2UCUOYZcnF/3ID0lulOJi/bafxa1xPe7ZPsammBSpjSWQkjNxlt635YGS2MiR9GjvuXCtz2emr3jbsz98g==",
-        "dependencies": {}
-      },
-      "picomatch@2.3.1": {
-        "integrity": "sha512-JU3teHTNjmE2VCGFzuY8EXzCDVwEqB2a8fsIvwaStHhAWJEeVd1o1QD80CU6+ZdEXXSLbSsuLwJjkCBWqRQUVA==",
-        "dependencies": {}
-      },
-      "queue-microtask@1.2.3": {
-        "integrity": "sha512-NuaNSa6flKT5JaSYQzJok04JzTL1CA6aGhv5rfLW3PgqA+M2ChpZQnAC8h8i4ZFkBS8X5RqkDBHA7r4hej3K9A==",
-        "dependencies": {}
-      },
-      "reusify@1.0.4": {
-        "integrity": "sha512-U9nH88a3fc/ekCF1l0/UP1IosiuIjyTh7hBvXVMHYgVcfGvt897Xguj2UOLDeI5BG2m7/uwyaLVT6fbtCwTyzw==",
-        "dependencies": {}
-      },
-      "run-parallel@1.2.0": {
-        "integrity": "sha512-5l4VyZR86LZ/lDxZTR6jqL8AFE2S0IFLMP26AbjsLVADxHdhB/c0GUsH+y39UfCi3dzz8OlQuPmnaJOMoDHQBA==",
-        "dependencies": {
-          "queue-microtask": "queue-microtask@1.2.3"
-        }
-      },
-      "to-regex-range@5.0.1": {
-        "integrity": "sha512-65P7iz6X5yEr1cwcgvQxbbIw7Uk3gOy5dIdtZ4rDveLqhrdJP+Li/Hx6tyK0NEb+2GCyneCMJiGqrADCSNk8sQ==",
-        "dependencies": {
-          "is-number": "is-number@7.0.0"
-        }
-      }
     }
   },
   "remote": {
@@ -250,7 +155,8 @@
   },
   "workspace": {
     "dependencies": [
-      "jsr:@deno/dnt@^0.41.1"
+      "jsr:@deno/dnt@~0.41.3",
+      "jsr:@std/cli@^1.0.11"
     ]
   }
 }

logic/board.ts

@@ -9,15 +9,7 @@ import { applyChange, createSection } from "./section.ts";
 import type { BoardChange } from "../types/change.ts";
 
 export function createBoard(config: BoardConfig): BoardData {
-  const sections: SectionData[][] = Array(config.ySections)
+  return { config, sections: [] };
-    .fill(0)
-    .map((_, sy) =>
-      Array(config.xSections)
-        .fill(0)
-        .map((_, sx) => createSection({ sx, sy }, config))
-    );
-
-  return { config, sections };
 }
 
 export function locateSection(
@@ -30,9 +22,38 @@ export function locateSection(
   };
 }
 
+/**
+ * Get a section from board.
+ *
+ * If the section does not exist yet, it will be created and (optionally) added to `board`.
+ */
+export function getSectionOnBoard(
+  { sx, sy }: SectionPosition,
+  board: BoardData,
+  options: {
+    /**
+     * Whether the section data is only used for reading.
+     *
+     * If `true`, this function will return an empty section configured with default values, but will not add it to the board data to save storage.
+     */
+    readOnly: boolean;
+  } = { readOnly: false },
+): SectionData {
+  let section: SectionData;
+  if (!board.sections[sy] && !options.readOnly) board.sections[sy] = [];
+
+  if (!board.sections[sy]?.[sx]) {
+    section = createSection({ sx, sy }, board.config);
+    if (!options.readOnly) board.sections[sy][sx] = section;
+  } else {
+    section = board.sections[sy][sx];
+  }
+  return section;
+}
+
 export function applyChangeOnBoard(change: BoardChange, board: BoardData) {
-  const { sx, sy } = locateSection(change, board.config);
+  const sPos = locateSection(change, board.config);
-  const section = board.sections[sy][sx];
+  const section = getSectionOnBoard(sPos, board);
   applyChange(change, section);
 }
 
@@ -40,16 +61,16 @@ export function renderFullBoard(data: BoardData): FullBoard {
   const totalLineCount = data.config.sectionHeight * data.config.ySections;
   const lineLength = data.config.sectionWidth * data.config.xSections;
 
-  const chLines: string[] = Array(totalLineCount);
+  const chLines: string[][] = Array(totalLineCount);
-  const colorLines: string[] = Array(totalLineCount);
+  const colorLines: string[][] = Array(totalLineCount);
-  const bgColorLines: string[] = Array(totalLineCount);
+  const bgColorLines: string[][] = Array(totalLineCount);
-  const widthLines: string[] = Array(totalLineCount);
+  const widthLines: number[][] = Array(totalLineCount);
 
   for (let y = 0; y < totalLineCount; y++) {
-    let chLine = "";
+    const chLine: string[] = [];
-    let colorLine = "";
+    const colorLine: string[] = [];
-    let bgColorLine = "";
+    const bgColorLine: string[] = [];
-    let widthLine = "";
+    const widthLine: number[] = [];
 
     let charsToSkip = 0;
 
@@ -59,8 +80,8 @@ export function renderFullBoard(data: BoardData): FullBoard {
         continue;
       }
 
-      const { sx, sy } = locateSection({ x, y }, data.config);
+      const sPos = locateSection({ x, y }, data.config);
-      const section = data.sections[sy][sx];
+      const section = getSectionOnBoard(sPos, data, { readOnly: true });
       const xInSection = x % data.config.sectionWidth;
       const yInSection = y % data.config.sectionHeight;
 
@@ -69,10 +90,10 @@ export function renderFullBoard(data: BoardData): FullBoard {
       const cBg = section.bgColor[yInSection][xInSection];
       const cWd = section.width[yInSection][xInSection];
 
-      chLine += cCh;
+      chLine.push(cCh);
-      colorLine += cCo;
+      colorLine.push(cCo);
-      bgColorLine += cBg;
+      bgColorLine.push(cBg);
-      widthLine += cWd.toString();
+      widthLine.push(cWd);
       charsToSkip += cWd - 1;
     }
 
@@ -85,9 +106,9 @@ export function renderFullBoard(data: BoardData): FullBoard {
   return {
     w: lineLength,
     h: totalLineCount,
-    ch: chLines.join("\n"),
+    ch: chLines.flat(),
-    color: colorLines.join("\n"),
+    color: colorLines.flat(),
-    bg_color: bgColorLines.join("\n"),
+    bg_color: bgColorLines.flat(),
-    width: widthLines.join("\n"),
+    width: widthLines.flat(),
   };
 }

logic/character.ts

@@ -1,7 +1,6 @@
+import { unicodeWidth } from "@std/cli/unicode-width";
+
 const segmenter = new Intl.Segmenter("en", { granularity: "grapheme" });
-const cjkRegex =
-  /[\p{Unified_Ideograph}\u30A0-\u30FF\u3040-\u309F\u31F0-\u31FF]/u;
-const printableASCIIRegex = /^[\x20-\x7E]$/;
 
 export function getCharacterWidth(ch: string): number {
   const segments = [...segmenter.segment(ch)];
@@ -11,11 +10,6 @@ export function getCharacterWidth(ch: string): number {
     );
   }
 
-  const matchesASCII = ch.match(printableASCIIRegex);
+  // TODO: Properly fix this.
-  const matchesCJK = ch.match(cjkRegex);
+  return Math.min(unicodeWidth(ch), 2);
-
-  if (!matchesASCII && !matchesCJK) throw new Error(`Invalid character: ${ch}`);
-
-  // TODO: Support Emojis.
-  return matchesCJK ? 2 : 1;
 }

logic/section.ts

@@ -16,17 +16,17 @@ export function createSection(
   const offsetX = sx * boardConfig.sectionWidth;
   const offsetY = sy * boardConfig.sectionHeight;
 
-  const ch: string[][] = Array(boardConfig.sectionHeight).fill(
+  const ch: string[][] = Array(boardConfig.sectionHeight).fill([]).map(() =>
-    Array(boardConfig.sectionWidth).fill(boardConfig.defaultCh),
+    Array(boardConfig.sectionWidth).fill(boardConfig.defaultCh)
   );
-  const color: string[][] = Array(boardConfig.sectionHeight).fill(
+  const color: string[][] = Array(boardConfig.sectionHeight).fill([]).map(() =>
-    Array(boardConfig.sectionWidth).fill(boardConfig.defaultColor),
+    Array(boardConfig.sectionWidth).fill(boardConfig.defaultColor)
   );
-  const bgColor: string[][] = Array(boardConfig.sectionHeight).fill(
+  const bgColor: string[][] = Array(boardConfig.sectionHeight).fill([]).map(
-    Array(boardConfig.sectionWidth).fill(boardConfig.defaultBgColor),
+    () => Array(boardConfig.sectionWidth).fill(boardConfig.defaultBgColor),
   );
-  const width: number[][] = Array(boardConfig.sectionHeight).fill(
+  const width: number[][] = Array(boardConfig.sectionHeight).fill([]).map(() =>
-    Array(boardConfig.sectionWidth).fill(boardConfig.defaultWidth),
+    Array(boardConfig.sectionWidth).fill(boardConfig.defaultWidth)
   );
 
   return { offsetX, offsetY, ch, color, bgColor, width };
@@ -44,7 +44,7 @@ export function applyChange(change: BoardChange, section: SectionData) {
 
   if (change.ch) {
     const chWidth = getCharacterWidth(change.ch);
-    const xCharacterOffset = xInSection % 2;
+    const xCharacterOffset = xInSection % chWidth;
     const offsetAdjustedXInSection = xInSection - xCharacterOffset;
     section.ch[yInSection][offsetAdjustedXInSection] = change.ch;
     section.width[yInSection][offsetAdjustedXInSection] = chWidth;

tests/board.test.ts

@@ -3,7 +3,11 @@ import {
   assertEquals,
 } from "https://deno.land/std@0.224.0/assert/mod.ts";
 
-import { createBoard, renderFullBoard } from "../logic/board.ts";
+import {
+  createBoard,
+  getSectionOnBoard,
+  renderFullBoard,
+} from "../logic/board.ts";
 import type { BoardData } from "../types/board.ts";
 import { checkFullBoard } from "./checkFullBoard.ts";
 import { locateSection } from "../logic/board.ts";
@@ -14,8 +18,8 @@ Deno.test("board", async (t) => {
 
   await t.step("createBoard", () => {
     board = createBoard({
-      xSections: 2,
+      xSections: 3,
-      ySections: 2,
+      ySections: 3,
       sectionWidth: 4,
       sectionHeight: 3,
       defaultCh: " ",
@@ -24,17 +28,8 @@ Deno.test("board", async (t) => {
       defaultWidth: 1,
     });
 
-    assertEquals(board.sections.length, 2);
+    // Sections are created on demand.
-    assertEquals(board.sections[0].length, 2);
+    assertEquals(board.sections.length, 0);
-    assertEquals(board.sections[0][0].offsetX, 0);
-    assertEquals(board.sections[0][0].offsetY, 0);
-    assertEquals(board.sections[0][1].offsetX, 4);
-    assertEquals(board.sections[0][1].offsetY, 0);
-    assertEquals(board.sections[1].length, 2);
-    assertEquals(board.sections[1][0].offsetX, 0);
-    assertEquals(board.sections[1][0].offsetY, 3);
-    assertEquals(board.sections[1][1].offsetX, 4);
-    assertEquals(board.sections[1][1].offsetY, 3);
   });
 
   await t.step("locateSection", () => {
@@ -56,11 +51,12 @@ Deno.test("board", async (t) => {
     applyChangeOnBoard({ x: 4, y: 0, ch: "B" }, board);
     applyChangeOnBoard({ x: 0, y: 3, ch: "C" }, board);
     applyChangeOnBoard({ x: 4, y: 3, ch: "D" }, board);
+    applyChangeOnBoard({ x: 5, y: 3, ch: "E" }, board);
 
     assertEquals(board.sections[0][0].ch[0][0], "A");
     assertEquals(board.sections[0][1].ch[0][0], "B");
     assertEquals(board.sections[1][0].ch[0][0], "C");
-    assertEquals(board.sections[1][1].ch[0][0], "D");
+    assertEquals(board.sections[1][1].ch[0], ["D", "E", " ", " "]);
 
     applyChangeOnBoard({ x: 0, y: 1, ch: "你" }, board);
     applyChangeOnBoard({ x: 4, y: 2, ch: "好" }, board);
@@ -70,7 +66,46 @@ Deno.test("board", async (t) => {
     assertEquals(board.sections[0][0].ch[1][0], "你");
     assertEquals(board.sections[0][1].ch[2][0], "好");
     assertEquals(board.sections[1][0].ch[1][0], "嗎");
-    assertEquals(board.sections[1][1].ch[2][0], "嘛");
+    assertEquals(board.sections[1][1].ch[1], ["嘛", " ", " ", " "]);
+
+    applyChangeOnBoard({ x: 5, y: 4, ch: "啊" }, board);
+    assertEquals(board.sections[1][1].ch[1], ["啊", " ", " ", " "]);
+  });
+
+  await t.step("getSectionOnBoard: existing section", () => {
+    assert(board);
+
+    const section = getSectionOnBoard({ sx: 1, sy: 1 }, board, {
+      readOnly: true,
+    });
+    assertEquals(section.ch[0], ["D", "E", " ", " "]);
+    assertEquals(section.color[0][0], "F");
+    assertEquals(section.bgColor[0][0], "0");
+    assertEquals(section.width[0], [1, 1, 1, 1]);
+  });
+
+  await t.step("getSectionOnBoard: non-existing row", () => {
+    assert(board);
+
+    const section = getSectionOnBoard({ sx: 1, sy: 2 }, board, {
+      readOnly: true,
+    });
+    assertEquals(section.ch[0][0], " ");
+    assertEquals(section.color[0][0], "F");
+    assertEquals(section.bgColor[0][0], "0");
+    assertEquals(section.width[0][0], 1);
+  });
+
+  await t.step("getSectionOnBoard: non-existing section", () => {
+    assert(board);
+
+    const section = getSectionOnBoard({ sx: 2, sy: 1 }, board, {
+      readOnly: true,
+    });
+    assertEquals(section.ch[0][0], " ");
+    assertEquals(section.color[0][0], "F");
+    assertEquals(section.bgColor[0][0], "0");
+    assertEquals(section.width[0][0], 1);
   });
 
   await t.step("renderFullBoard", () => {
@@ -79,4 +114,11 @@ Deno.test("board", async (t) => {
     const rendered = renderFullBoard(board);
     checkFullBoard(rendered);
   });
+
+  await t.step("on-demand creation: only changed sections are saved", () => {
+    assert(board);
+
+    assertEquals(board.sections[2], undefined);
+    assertEquals(board.sections[0][2], undefined);
+  });
 });

tests/character.test.ts

@@ -26,14 +26,18 @@ Deno.test("getCharacterWidth CJK", () => {
   assertEquals(getCharacterWidth("グ"), 2);
   assertEquals(getCharacterWidth("ソ"), 2);
 
-  assertThrows(() => getCharacterWidth("？"));
+  assertEquals(getCharacterWidth("？"), 2);
-  assertThrows(() => getCharacterWidth("！"));
+  assertEquals(getCharacterWidth("！"), 2);
   assertThrows(() => getCharacterWidth("你好"));
   assertThrows(() => getCharacterWidth("ヨスガノ"));
 });
 
+Deno.test("getCharacterWidth Emoji", () => {
+  assertEquals(getCharacterWidth("👋"), 2);
+  assertEquals(getCharacterWidth("🌲️"), 2);
+  assertEquals(getCharacterWidth("👨‍👩‍👧‍👦"), 2);
+});
+
 Deno.test("getCharacterWidth previously faulty cases", () => {
   assertEquals(getCharacterWidth("𤲶"), 2);
-
-  assertThrows(() => getCharacterWidth("𤲶"[0]));
 });

tests/checkFullBoard.ts

@@ -1,8 +1,8 @@
 import { getCharacterWidth } from "../logic/character.ts";
 import type { FullBoard } from "../types/board.ts";
 
-function isCorrectWidth(cWdRaw: string, cCh: string): boolean {
+function isCorrectWidth(cWd: number, cCh: string): boolean {
-  return getCharacterWidth(cCh).toString() === cWdRaw;
+  return getCharacterWidth(cCh) === cWd;
 }
 
 function isValidColor(color: string): boolean {
@@ -24,8 +24,7 @@ export function checkFullBoard(board: FullBoard) {
     const cCh = ch[i];
     const cCo = board.color[i];
     const cBg = board.bg_color[i];
-    const cWdRaw = board.width[i];
+    const cWd = board.width[i];
-    const cWd = parseInt(cWdRaw);
 
     const printSituation = () => {
       console.error(
@@ -40,7 +39,7 @@ export function checkFullBoard(board: FullBoard) {
         "cBg:",
         JSON.stringify(cBg),
         "cWd:",
-        JSON.stringify(cWdRaw),
+        JSON.stringify(cWd),
       );
       console.error("ch:      ", chLine);
       console.error("color:   ", colorLine);
@@ -48,33 +47,9 @@ export function checkFullBoard(board: FullBoard) {
       console.error("width:   ", widthLine);
     };
 
-    if (cCh === "\n") {
+    if (typeof cCh !== "string") {
-      if (cCo !== "\n" || cBg !== "\n" || cWdRaw !== "\n") {
+      printSituation();
-        printSituation();
+      throw new Error("cCh is not string");
-        throw new Error("cCh is newline while at least one other field aren't");
-      }
-
-      if (colorLine.length !== board.w) {
-        printSituation();
-        throw new Error("color line length error");
-      }
-      if (bgColorLine.length !== board.w) {
-        printSituation();
-        throw new Error("bg color line length error");
-      }
-      if (widthLine.length !== board.w) {
-        printSituation();
-        throw new Error("width line length error");
-      }
-
-      chLine = "";
-      colorLine = "";
-      bgColorLine = "";
-      widthLine = "";
-      lines++;
-      unsafeCurrentOffset += cCh.length;
-
-      continue;
     }
 
     if (!isValidColor(cCo) || !isValidColor(cBg)) {
@@ -82,7 +57,7 @@ export function checkFullBoard(board: FullBoard) {
       throw new Error("cCo or cBg is not valid");
     }
 
-    if (!isCorrectWidth(cWdRaw, cCh)) {
+    if (!isCorrectWidth(cWd, cCh)) {
       printSituation();
       throw new Error("cWd is wrong");
     }
@@ -90,9 +65,17 @@ export function checkFullBoard(board: FullBoard) {
     chLine += cCh;
     colorLine += cCo.padEnd(cWd);
     bgColorLine += cBg.padEnd(cWd);
-    widthLine += cWdRaw.padEnd(cWd);
+    widthLine += String(cWd).padEnd(cWd);
     unsafeCurrentOffset += cCh.length;
+
+    if (colorLine.length === board.w) {
+      lines++;
+      chLine = "";
+      colorLine = "";
+      bgColorLine = "";
+      widthLine = "";
+    }
   }
 
-  if (lines + 1 !== board.h) throw new Error("board height error");
+  if (lines !== board.h) throw new Error("board height error");
 }

tests/section.test.ts

@@ -90,27 +90,33 @@ Deno.test("section", async (t) => {
     assert(section);
 
     applyChange({ x: 0, y: 0, ch: "t" }, section);
-    assertEquals(section.ch[0][0], "t");
+    assertEquals(section.ch[0], ["t", " ", " ", " "]);
-    assertEquals(section.ch[0][1], " ");
+    assertEquals(section.ch[1], [" ", " ", " ", " "]);
-    assertEquals(section.width[0][0], 1);
+    assertEquals(section.width[0], [1, 1, 1, 1]);
+  });
+
+  await t.step("applyChange 1-width at odd position", () => {
+    assert(section);
+
+    applyChange({ x: 1, y: 0, ch: "t" }, section);
+    assertEquals(section.ch[0], ["t", "t", " ", " "]);
+    assertEquals(section.width[0], [1, 1, 1, 1]);
   });
 
   await t.step("applyChange 2-width at a correct position", () => {
     assert(section);
 
     applyChange({ x: 0, y: 0, ch: "あ" }, section);
-    assertEquals(section.ch[0][0], "あ");
+    assertEquals(section.ch[0], ["あ", "t", " ", " "]);
-    assertEquals(section.ch[0][1], " ");
+    assertEquals(section.width[0], [2, 1, 1, 1]);
-    assertEquals(section.width[0][0], 2);
   });
 
   await t.step("applyChange 2-width at an alternate position", () => {
     assert(section);
 
     applyChange({ x: 1, y: 0, ch: "あ" }, section);
-    assertEquals(section.ch[0][0], "あ");
+    assertEquals(section.ch[0], ["あ", "t", " ", " "]);
-    assertEquals(section.ch[0][1], " ");
+    assertEquals(section.width[0], [2, 1, 1, 1]);
-    assertEquals(section.width[0][0], 2);
   });
 
   await t.step("applyChange incorrect section", () => {

types/board.ts

@@ -11,14 +11,14 @@ export interface FullBoard {
   /** The total height of the board, in `ch`. */
   h: number;
 
-  /** Compact string of characters on board. */
+  /** Compact array of characters on board. */
-  ch: string;
+  ch: string[];
-  /** Compact string of color, for each character. */
+  /** Compact array of color, for each character. */
-  color: string;
+  color: string[];
-  /** Compact string of background color, for each character. */
+  /** Compact array of background color, for each character. */
-  bg_color: string;
+  bg_color: string[];
-  /** Compact string of width indicator for each character. */
+  /** Compact array of width indicator for each character. */
-  width: string;
+  width: number[];
 }
 
 /**