codegen

codegen

A small tool to automatically generate code starting from one or more template file(s), and a csv file.

Contents

• Installation
  • Build
  • Get it as a library
• How To
  • Template blocks
  • Including a non-token line in a block
• Usage

Installation

go get github.com/Abathargh/codegen/cmd/codegen

Build

This is how the binaries shipped in the release section are built:

git clone https://github.com/Abathargh/codegen
cd codegen
go test ./...
go build -ldflags "-s -w" ./cmd/codegen/

Pre-compiled binaries are available from the release section.

Get it as a library

# either clone everything and build it
go get github.com/Abathargh/codegen

How To

This tool is able to substitute data from csv files into template files containing tokens in the #n# format, where n is a number greater or equal to 1. You could also use different separators, '#' is the default one.

If you have a template file called templ.c, and a csv called data.csv like these:

#define test_#1# #2#

test,123
test2,456
test3,testing

You may call codegen like this:

codegen -t templ.c -d data.csv 

This is what will be generated:

#define test_test 123
#define test_test2 456
#define test_test3 testing

Template blocks

One or more consecutive lines containing a token make a template block. When the code generation process starts, every line of a template block gets processed together, producing n consecutive blocks each referring to a row od the csv file.

The following template:

package main

func main() {
    test()
}


func test() {
    for  i := 0; i < #2#; i++ {
        #1# := #2# >> 1
    }###
    test2()
}

func test2() {
    // do stuff ...
}

will generate this source code:

package main

func main() {
    test()
}


func test() {
    for  i := 0; i < 123; i++ {
        a := 123 >> 1
    }
    for  i := 0; i < 12; i++ {
        b := 12 >> 1
    }
    for  i := 0; i < 2; i++ {
        c := 2 >> 1
    }
    test2()
}

func test2() {
    // do stuff ...
}

Including a non-token line in a block

In the last example you can see that there was a line containing the closing brace of the for loop, that was escaped with the ### string. This allows for a line that doesn't contain a token to be considered as if it did.

By doing so, you can include a non-token line in a template block: this comes in handy when you have to generate number of loops, functions, ect. in languages that use braces as block delimiters.

Usage

usage: codegen [-h|--help] -t|--template "<value>" [-t|--template "<value>"
               ...] -d|--data "<value>" [-s|--separator "<value>"] [-o|--output
               "<value>" [-o|--output "<value>" ...]]

               Generates files based on templates and csv tables. Template
               files contain tokens in the #n# format, where n is a number and
               # is the default separator. If the passed csv has n columns, the
               application will be able to substitute tokens with the
               corresponding column values, up to a total of n, for each row of
               the csv file.

Arguments:

  -h  --help       Print help information
  -t  --template   a template to process in order to generate code, it should
                   contain tokens in the #n# format, where n is a number and #
                   is the default separator: e.g. #1# #2#
  -d  --data       a csv file that contains the data to substitute the tokens
                   with
  -s  --separator  the separator to use to identify tokens. Default: #
  -o  --output     specifies a file where to save the generated source code.
                   Default: []