expand() — tailwindcss Function Reference

Architecture documentation for the expand() function in brace-expansion.ts from the tailwindcss codebase.

Function typescript CompilerEngine ModuleResolution calls 3 called by 1

Entity Profile

CompilerEngine→ ModuleResolution→ expand() — tailwindcss Function Reference

Dependency Diagram

graph TD
  1f29c0ee_be09_f644_3fb8_8d80057c5d97["expand()"]
  26086ff1_0d4f_fdb2_3fc4_d0c999f90a8c["parseCss()"]
  26086ff1_0d4f_fdb2_3fc4_d0c999f90a8c -->|calls| 1f29c0ee_be09_f644_3fb8_8d80057c5d97
  18ccf8d0_0754_3385_ba3d_739fd86e9969["isSequence()"]
  1f29c0ee_be09_f644_3fb8_8d80057c5d97 -->|calls| 18ccf8d0_0754_3385_ba3d_739fd86e9969
  86796617_8567_a2d8_d154_f31f20830948["expandSequence()"]
  1f29c0ee_be09_f644_3fb8_8d80057c5d97 -->|calls| 86796617_8567_a2d8_d154_f31f20830948
  2a20ea29_c850_cd61_5600_aeebbe3dda66["segment()"]
  1f29c0ee_be09_f644_3fb8_8d80057c5d97 -->|calls| 2a20ea29_c850_cd61_5600_aeebbe3dda66
  style 1f29c0ee_be09_f644_3fb8_8d80057c5d97 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

packages/tailwindcss/src/utils/brace-expansion.ts lines 5–53

export function expand(pattern: string): string[] {
  let index = pattern.indexOf('{')
  if (index === -1) return [pattern]

  let result: string[] = []
  let pre = pattern.slice(0, index)
  let rest = pattern.slice(index)

  // Find the matching closing brace
  let depth = 0
  let endIndex = rest.lastIndexOf('}')
  for (let i = 0; i < rest.length; i++) {
    let char = rest[i]
    if (char === '{') {
      depth++
    } else if (char === '}') {
      depth--
      if (depth === 0) {
        endIndex = i
        break
      }
    }
  }

  if (endIndex === -1) {
    throw new Error(`The pattern \`${pattern}\` is not balanced.`)
  }

  let inside = rest.slice(1, endIndex)
  let post = rest.slice(endIndex + 1)
  let parts: string[]

  if (isSequence(inside)) {
    parts = expandSequence(inside)
  } else {
    parts = segment(inside, ',')
  }

  parts = parts.flatMap((part) => expand(part))

  let expandedTail = expand(post)

  for (let tail of expandedTail) {
    for (let part of parts) {
      result.push(pre + part + tail)
    }
  }
  return result
}