indent_and_wrap: Text utility for Deno

Finds and replaces common indent, hard-wraps text, generates text tables and table-based complex text layouts. Can work on text that contains terminal escape sequences.

Example

Indent

import {indentAndWrap} from 'https://deno.land/x/indent_and_wrap@v0.0.17/mod.ts';

console.log
(	indentAndWrap
    (	`	Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
        `,
        {wrapWidth: 40, indent: '\t'}
    )
);

Result:

        Lorem ipsum dolor sit amet,
        consectetur adipiscing elit, sed do
        eiusmod tempor incididunt ut labore
        et dolore magna aliqua.

Text table

import {textTable, BorderStyle, TextAlign} from 'https://deno.land/x/indent_and_wrap@v0.0.17/mod.ts';

console.log
(	textTable
    (	[	[	{	content: 'Lorem ipsum',
                },
                {	content: 'dolor sit amet,\nconsectetur adipiscing elit,\nsed do',
                    options: {paddingLeft: 1, paddingRight: 1, nowrap: true},
                }
            ],
            [	{	content: 'eiusmod',
                },
                {	content: 'tempor',
                    options: {textAlign: TextAlign.Center},
                }
            ]
        ],
        {borderStyle: BorderStyle.Double, borderColor: 0xDDDDDD}
    )
);

Result:

╔═══════════╦══════════════════════════════╗
║           ║ dolor sit amet,              ║
║Lorem ipsum║ consectetur adipiscing elit, ║
║           ║ sed do                       ║
╠═══════════╬══════════════════════════════╣
║eiusmod    ║            tempor            ║
╚═══════════╩══════════════════════════════╝

Complex layout

import {textTable, TextTable, BorderStyle, TextAlign} from 'https://deno.land/x/indent_and_wrap@v0.0.17/mod.ts';

console.log
(	textTable
    (	[	[	{	content: new TextTable
                    (	[	[	{	content: 'Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.',
                                    options: {maxWidth: 30, textAlign: TextAlign.Right}
                                },
                                {	content: `Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.`,
                                    options: {maxWidth: 33, textAlign: TextAlign.Left, paddingLeft: 3}
                                }
                            ]
                        ],
                        {borderStyle: BorderStyle.None}
                    ),
                    options: {paddingLeft: 3, paddingRight: 3}
                }
            ]
        ],
        {borderStyle: BorderStyle.Solid, borderColor: 0xDDDDDD}
    )
);

Result:

┌──────────────────────────────────────────────────────────────────────┐
│      Lorem ipsum dolor sit amet,    Lorem ipsum dolor sit amet,      │
│     consectetur adipiscing elit,    consectetur adipiscing elit,     │
│            sed do eiusmod tempor    sed do eiusmod tempor            │
│   incididunt ut labore et dolore    incididunt ut labore et dolore   │
│                    magna aliqua.    magna aliqua.                    │
└──────────────────────────────────────────────────────────────────────┘

Exported functions

indentAndWrap() - Indent or unindent and wrap text.
getTextRect() - Calculate dimensions of text rectangle.
findCommonIndent() - Scan text string, and find leading space characters, that are common across all lines.
calcLines() - Count number of lines in text string, and determine column number after the last character.
textTable() - Generate text table.

indentAndWrap()

function indentAndWrap(text: string, options?: IndentAndWrapOptions, knownCommonIndent?: string): string;

type IndentAndWrapOptions =
{	endl?: string;
    indent?: string;
    ignoreFirstIndent?: boolean;
    wrapWidth?: number;
    overflowWrap?: boolean;
    tabWidth?: number;
    tabsToSpaces?: boolean;
    mode?: 'plain' | 'term';
};

This function does:

Replaces new line characters (\n, \r\n or \r) to options.endl, or if it’s not set to \n.
Removes white space at the end of each line.
If options.indent is set, it determines common indent characters across all lines, and replaces them with options.indent string. This can lead to indent increase or decrease. If options.ignoreFirstIndent is set, will look for common indent starting at second line, so the text can be trimmed. If you already know the common indent (e.g. you called findCommonIndent()), you can provide it as knownCommonIndent to save some calculation time. If knownCommonIndent doesn’t match the result of findCommonIndent(), the behavior is undefined.
If options.wrapWidth is set, it inserts options.endl, so there’re no lines longer than options.wrapWidth columns. Columns are calculated with respect to options.tabWidth (default 8). If options.overflowWrap is set, can break long words, that are wider than options.overflowWrap.
If options.tabsToSpaces is set, converts tabs to spaces.

getTextRect()

function getTextRect(text: string, options?: GetTextRectOptions, knownCommonIndent?: string): {nLines: number, nColumns: number};

type GetTextRectOptions =
{	indent?: string;
    ignoreFirstIndent?: boolean;
    wrapWidth?: number;
    overflowWrap?: boolean;
    tabWidth?: number;
    mode?: 'plain' | 'term';
};

This function works the same as indentAndWrap(), but it doesn’t return resulting text, but it returns number of lines and columns the result occupies.

It only counts columns on non-blank lines.

findCommonIndent()

function findCommonIndent(text: string, options?: FindCommonIndentOptions): string;

type FindCommonIndentOptions =
{	ignoreFirstIndent?: boolean;
    mode?: 'plain' | 'term';
};

Scan text string, and find leading space characters, that are common across all lines.

If ignoreFirstIndent is set, then the leading space on the first line is not counted, so the provided text string can be trimmed.

If options.mode is term, then terminal escape sequences (like VT100 color codes) can be part of indent.

This function uses fast algorithm that avoids splitting text to lines array.

calcLines()

function calcLines(text: string, options?: CalcLinesOptions, from=0, to=Number.MAX_SAFE_INTEGER): {nLine: number, nColumn: number};

type CalcLinesOptions =
{	tabWidth?: number;
    mode?: 'plain' | 'term';
};

Count number of lines in text string, and determine column number after the last character.

This function only considers text substring from from to to. Lines and columns counter starts from provided values: nLine and nColumn.

If options.mode is term, skips terminal escape sequences (like VT100 color codes).

textTable()

function textTable(rows: Cell[][], options?: TextTableOptions, nColumn=0): string;

type Cell =
{	content: string|TextTable;
    options?: CellOptions;
};

type TextTableOptions =
{	minWidth?: number;
    maxWidth?: number;
    borderStyle?: BorderStyle;
    borderWidth?: number;
    borderColor?: number | {r: number, g: number, b: number};

    endl?: string;
    tabWidth?: number;
    tabsToSpaces?: boolean;
    mode?: 'plain' | 'term';
};

type CellOptions =
{	textAlign?: TextAlign;
    verticalAlign?: VerticalAlign;
    nowrap?: boolean;
    minWidth?: number;
    maxWidth?: number;
    minHeight?: number;
    paddingTop?: number;
    paddingRight?: number;
    paddingBottom?: number;
    paddingLeft?: number;
    backgroundColor?: number | {r: number, g: number, b: number};
};

const enum BorderStyle
{	NoneNoGap,
    None,
    Solid,
    Double,
    SolidRound,
    Dashed,
}

const enum TextAlign
{	Left,
    Right,
    Center,
    Justify,
}

const enum VerticalAlign
{	Top,
    Middle,
    Bottom,
}

class TextTable
{	constructor(rows: Cell[][], options?: TextTableOptions);
}

Generates text table with or without border. Tables can be nested, and this allows to generate complex layouts.