rformat

Format R Code

Description

Format R code string according to base R style conventions.

Usage

rformat(code, indent = 4L, line_limit = 80L, wrap = "paren",
        brace_style = "kr", control_braces = FALSE, expand_if = FALSE,
        else_same_line = TRUE, function_space = FALSE, join_else = TRUE)

Arguments

  • code: Character string of R code to format.
  • indent: Indentation per level: integer for spaces (default 4), or character string for literal indent (e.g., "\t\t" for vintage R Core style).
  • line_limit: Maximum line length before wrapping (default 80).
  • wrap: Continuation style for long function signatures: "paren" (default) aligns to opening parenthesis, "fixed" uses 8-space indent.
  • brace_style: Brace placement for function definitions: "kr" (default) puts opening brace on same line as ) {, "allman" puts it on a new line.
  • control_braces: If TRUE, add braces to bare one-line control flow bodies (e.g., if (x) y becomes if (x) { y }). Default FALSE matches R Core source code where 59% of control flow bodies are bare.
  • expand_if: Expand inline if-else to multi-line (default FALSE).
  • else_same_line: If TRUE (default), repair top-level }\nelse (which is a parse error in R) by joining to } else before formatting. When FALSE, unparseable input is returned unchanged with a warning.
  • function_space: If TRUE, add space before ( in function definitions: function (x) instead of function(x). Default FALSE matches 96% of R Core source code.
  • join_else: If TRUE (default), move else to the same line as the preceding }: } else {. Matches R Core source code where 70% use same-line else. When FALSE, }\nelse on separate lines is preserved.

Value

Formatted code as a character string.

Examples

# Basic formatting: spacing around operators
rformat("x<-1+2")

# Add braces to bare control-flow bodies
rformat("if(x>0) y<-1", control_braces = TRUE)

# Expand inline if-else to multi-line
rformat("x <- if (a) b else c", expand_if = TRUE)

# Wrap long function signatures (default: paren-aligned)
long_sig <- paste0(
    "f <- function(alpha, beta, gamma, delta, ",
    "epsilon, zeta, eta) {\n    1\n}")
cat(rformat(long_sig), sep = "\n")

# Wrap with fixed 8-space continuation indent
cat(rformat(long_sig, wrap = "fixed"), sep = "\n")

# Allman brace style
rformat("f <- function(x) { x }", brace_style = "allman")