---
name: "smlformat"
section: "1"
platform: "linux"
package: "smlsharp"
version: "4.1.0-1+b1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/smlformat"
---

# smlformat(1)

the pretty printer generator for SML#

## NAME

smlformat - the pretty printer generator for SML#

## SYNOPSIS

**smlformat** \[**--stdout**\|**--output=***file*\] \[**--with-line-directive**\] *filename ...*

## DESCRIPTION

*SMLFormat* generates pretty printing functions for ML types and datatypes. The input file is an SML# program, each type and datatype of which is annotated by formatting comments. The **smlformat** command interprets the definition of types and its formatting comments and inserts formatting functions into the input program. Generated programs can be compiled by the SML# compiler.

When multiple input files are given, each input file is separately read and yields a separate program. By default, the output file name is obtained by appending *.sml* suffix to the input file name.

### OPTIONS

- **--stdout**

  Output the result to the standard output.

- **--output=***filename*

  Output the result to the specified file.

- **--with-line-directive**

  Insert comments about the line number of the input file into the output.

- **--separate=***structureName*

  Output formatters in a separate structure.

## EXAMPLES

The following is a minimal example of an input file *ex.ppg*:

```
(*% *)
datatype intlist = NIL | CONS of int * intlist
fun pretty_intlist x =
    SMLFormat.prettyPrint nil (format_intlist x)
```

where `(*% *)` is the formatting comment of the `intlist` type. By invoking **smlformat**,

```
smlformat ex.ppg
```

it interprets the formatting comment and generates `format_intlist` function of type `intlist -> SMLFormat.format`. In the output file *ex.ppg.sml*, the definition of `format_intlist` is inserted just after the definition of the `intlist` type.

To compile the generated program, you need to write an interface file *ex.ppg.smi* by yourself. In the interface file, the SMLFormat library *smlformat-lib.smi* must be required. The content of *ex.ppg.smi* must be as follows:

```
_require "basis.smi"
_require "smlformat-lib.smi"
datatype intlist = NIL | CONS of int * intlist
val format_intlist : intlist -> SMLFormat.format
val pretty_intlist : intlist -> string
```

## SEE ALSO

*SML# Document*, available at https://www.pllab.riec.tohoku.ac.jp/smlsharp/docs/