= SprigX
Brent Saner <bts@square-r00t.net>
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:toc: preamble
:toc2: left
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:toclevels: 7
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:docinfo: shared

[id="wat"]
== What is SprigX?
SprigX are extensions to https://masterminds.github.io/sprig/[the `sprig` library^] (https://pkg.go.dev/github.com/Masterminds/sprig/v3[Go docs^]).

They provide functions that offer more enriched use cases and domain-specific data.

[id="use"]
== How do I Use SprigX?

[%collapsible]
.The same way you would `sprig`!
====
[source,go]
----
package main

import (
	htmlTplLib "html/template"
	txtTplLib "text/template"

	"r00t2.io/goutils/tplx/sprigx"
)

var (
	txtTpl *txtTplLib.Template = txtTplLib.
									New("").
										Funcs(
											sprigx.TxtFuncMap(),
										)
	htmlTpl *htmlTplLib.Template = htmlTplLib.
									New("").
										Funcs(
											sprigx.HtmlFuncMap(),
										)
)
----
====

[%collapsible]
.They can even be combined/used together.
====
[source,go]
----
package main

import (
	"text/template"

	"github.com/Masterminds/sprig/v3"
	"r00t2.io/goutils/tplx/sprigx"
)

var txtTpl *template.Template = template.
									New("").
										Funcs(
											sprigx.TxtFuncMap(),
										).
										Funcs(
											sprig.TxtFuncMap(),
										)
// Or:
/*
var txtTpl *template.Template = template.
									New("").
										Funcs(
											sprig.TxtFuncMap(),
										).
										Funcs(
											sprigx.TxtFuncMap(),
										)
 */
----
====

If a `<template>.FuncMap` is added via `.Funcs()` *after* template parsing, it will override any functions of the same name of a `<template>.FuncMap` *before* parsing.

For example, if both `sprig` and `sprigx` provide a function `foo`:

[%collapsible]
.this will use `foo` from `sprigx`
====
[source,go]
----
package main

import (
	"text/template"

	"github.com/Masterminds/sprig/v3"
	"r00t2.io/goutils/tplx/sprigx"
)

const (
	myTpl string = `{{ "This is an example template string." | foo }}`
)

var (
	tpl *template.Template = template.Must(
								template.
									New("").
										Funcs(sprig.TxtFuncMap()).
										Parse(myTpl),
									).
									Funcs(sprigx.TxtFuncMap())
)
----
====

whereas

[%collapsible]
.this will use `foo` from `sprig`
====
[source,go]
----
package main

import (
	"text/template"

	"github.com/Masterminds/sprig/v3"
	"r00t2.io/goutils/tplx/sprigx"
)

const (
	myTpl string = `{{ "This is an example template string." | foo }}`
)

var (
	tpl *template.Template = template.Must(
								template.
									New("").
										Funcs(sprigx.TxtFuncMap()).
										Parse(myTpl),
									).
									Funcs(sprig.TxtFuncMap())
)
----
====

and a function can even be

[%collapsible]
.explicitly overridden.
====
This would override a function `foo` and `foo2` in `sprigx` from `foo` and `foo2` from `sprig`, but leave all other `sprig` functions untouched.

[source,go]
----
package main

import (
	"text/template"

	"github.com/Masterminds/sprig/v3"
	"r00t2.io/goutils/tplx/sprigx"
)

const (
	myTpl string = `{{ "This is an example template string." | foo }}`
)

var (
	overrideFuncs template.FuncMap = sprig.TxtFuncMap()
	tpl *template.Template = template.Must(
								template.
									New("").
									Funcs(sprigx.TxtFuncMap()).
									Parse(myTpl),
								).
									Funcs(
										template.FuncMap(
											map[string]any{
												"foo": overrideFuncs["foo"],
												"foo2": overrideFuncs["foo2"],
											},
										),
									)
)
----
====

[id="fn"]
== Functions
Expect this list to grow over time, and potentially more frequently than the `sprigx` functions.

[id="fn_sys"]
=== System/OS/Platform

[id="fn_sys_arch"]
==== `sysArch`
Returns the https://pkg.go.dev/runtime#GOARCH[`runtime.GOARCH`^] constant.

[id="fn_sys_numcpu"]
==== `sysNumCpu`
Returns the value from https://pkg.go.dev/runtime#NumCPU[`runtime.NumCPU`^].

[id="fn_sys_os"]
==== `sysOsName`
Returns the https://pkg.go.dev/runtime#GOOS[`runtime.GOOS`^] constant.

[id="fn_sys_rntm"]
==== `sysRuntime`
This function returns a `map[string]string` of various information from the https://pkg.go.dev/runtime[`runtime` stdlib library^].

Specifically, the following are returned.

[TIP]
====
The value type is a direct link to the `runtime` documentation providing more detail about the associated value.

Because all values are mapped as strings, they can be converted back to their native type via e.g. the https://masterminds.github.io/sprig/conversion.html[Sprig conversion functions^] if necessary.
====

.`sysRuntime` Values
[cols="^.^3m,^.^3",options="header"]
|===
| Key | Value Type

| compiler | https://pkg.go.dev/runtime#Compiler[string^]
| arch | https://pkg.go.dev/runtime#GOARCH[string^]
| os | https://pkg.go.dev/runtime#GOOS[string^]
| maxprocs | https://pkg.go.dev/runtime#GOMAXPROCS[int^] footnote:[For safety concerns, `sprigx` does not allow *setting* `GOMAXPROCS`, this value only contains the *current* `GOMAXPROCS` value.]
| cpu_cnt | https://pkg.go.dev/runtime#NumCPU[int^]
| num_cgo | https://pkg.go.dev/runtime#NumCgoCall[int^]
| num_go | https://pkg.go.dev/runtime#NumGoroutine[int^]
| go_ver | https://pkg.go.dev/runtime#Version[string^]
|===

As a convenience, some of these values also have their own dedicated functions as well:

* <<fn_sys_arch>>
* <<fn_sys_numcpu>>
* <<fn_sys_os>>

[id="fn_path"]
=== Paths

[id="fn_path_gnrc"]
==== Generic
These operate similar to https://pkg.go.dev/path[the `path` stdlib library^] and use a fixed `/` path separator.

[id="fn_path_gnrc_pj"]
===== `pathJoin`
`pathJoin` operates *exactly* like https://pkg.go.dev/path#Join[`path.Join`^] in stdlib.

[WARNING]
====
If you are joining paths in a pipeline, you almost assuredly want <<fn_path_gnrc_ppj>> or <<fn_path_gnrc_pspj>> instead unless you are explicitly *appending* a pipeline result to a path.
====

[source,gotemplate]
----
{{- pathJoin "a" "b" "c" }}
{{- pathJoin "/" "a" "b" "c" }}
{{- pathJoin "/a/b" "c" }}
----

renders as:

[source,text]
----
a/b/c
/a/b/c
/a/b/c
----

[id="fn_path_gnrc_ppj"]
===== `pathPipeJoin`
`pathPipeJoin` operates like <<fn_path_gnrc_pj>> with one deviation: the root/base path is expected to be *last* in the arguments.

This makes it much more suitable for use in template pipelines, as the previous value in a pipeline is passed in as the last element to the next pipe function.

[source,gotemplate]
----
{{- $myBase := "/a" -}}
{{- pathPipeJoin "b" "c" "a" }}
{{- pathPipeJoin "a" "b" "c" "/" }}
{{- $myBase | pathPipeJoin "b" "c" }}
----

renders as:

[source,text]
----
a/b/c
/a/b/c
/a/b/c
----

[id="fn_path_gnrc_psj"]
===== `pathSliceJoin`
`pathSliceJoin` joins a slice of path segment strings (`[]string`) instead of a variadic sequence of strings.

[TIP]
====
The `splitList` function shown below is from the https://masterminds.github.io/sprig/string_slice.html[`sprig` string slice functions^].
====

[source,gotemplate]
----
{{- $myList := "a,b,c" | splitList "," -}}
{{- $myList | pathSliceJoin }}
{{- ("a,b,c" | splitList ",") | pathSliceJoin }}
{{- ("/,a,b,c" | splitList ",") | pathSliceJoin }}
----

renders as:

[source,text]
----
a/b/c
a/b/c
/a/b/c
----

[id="fn_path_gnrc_pspj"]
===== `pathSlicePipeJoin`
`pathSlicePipeJoin` operates like <<fn_path_gnrc_ppj>> in that it is suitable for pipeline use in which the root/base path is passed in from the pipeline, but it is like <<fn_path_gnrc_psj>> in that it then also accepts a slice of path segments (`[]string`) to append to that base path.

[TIP]
====
The `splitList` function shown below is from the https://masterminds.github.io/sprig/string_slice.html[`sprig` string slice functions^].
====

[source,gotemplate]
----
{{- $myBase := "/a" -}}
{{- $myList := "b,c,d" | splitList "." -}}
{{- pathSlicePipeJoin $myList $myBase }}
{{- $myBase | pathSlicePipeJoin $myList }}
----

renders as:

[source,text]
----
/a/b/c
/a/b/c
----

[id="fn_path_gnrc_psubj"]
===== `pathSubJoin`
`pathSubJoin` operates like <<fn_path_gnrc_pj>> but it expects an explicit root/base path.

The pipeline-friendly equivalent of this is <<fn_path_gnrc_ppj>>.

[source,gotemplate]
----
{{- pathSubJoin "/a/b" "c" }}
{{- pathSubJoin "/" "a" "b" "c" }}
{{- "c" | pathSubJoin "/" "a" "b" }}
----

renders as:

[source,text]
----
/a/b/c
/a/b/c
/a/b/c
----

[id="fn_path_os"]
==== OS/Platform-Tailored
These operate similar to https://pkg.go.dev/path/filepath[the `path/filepath` stdlib library^], and use the OS-specific https://pkg.go.dev/os#PathSeparator[`os.PathSeparator`^].

[WARNING]
====
Take special note of the oddness around specifying Windows paths and drive letters in e.g. <<fn_path_os_pj>>!

It is recommended to make use of <<fn_sys_os>> to conditionally format path bases/roots if needed.
====

[id="fn_path_os_pj"]
===== `osPathJoin`
`osPathJoin` operates *exactly* like https://pkg.go.dev/path/filepath#Join[`path/filepath.Join`^] in stdlib.

[WARNING]
====
If you are joining paths in a pipeline, you almost assuredly want <<fn_path_os_ppj>> or <<fn_path_os_pspj>> instead unless you are explicitly *appending* a pipeline result to a path.
====

[source,gotemplate]
----
{{- osPathJoin "a" "b" "c" }}
{{- osPathJoin "/" "a" "b" "c" }}
{{- osPathJoin "C:\\" "a" "b" "c" }}
{{- osPathJoin "C:" "a" "b" "c" }}
----

renders as:

[cols="^.^2,.^4a",options="header"]
|===
| OS ^| Result

| Windows | [source,text]
----
a\b\c
\a\b\c
\a\b\c
C:\a\b\c
C:a\b\c
----
| Others (e.g. Linux, macOS) | [source,text]
----
a/b/c
/a/b/c
C:\/a/b/c
C:/a/b/c
----
|===

[id="fn_path_os_ppj"]
===== `osPathPipeJoin`
`osPathPipeJoin` operates like <<fn_path_gnrc_ppj>> (except using OS-specific path separators).

This makes it much more suitable for use in template pipelines, as the previous value in a pipeline is passed in as the last element to the next pipe function.

[source,gotemplate]
----
{{- $myBase := "/a" -}}
{{- osPathPipeJoin "b" "c" "a" }}
{{- osPathPipeJoin "a" "b" "c" "/" }}
{{- $myBase | osPathPipeJoin "b" "c" }}
----

renders as:

[cols="^.^2,.^4a",options="header"]
|===
| OS ^| Result

| Windows | [source,text]
----
a\b\c
\a\b\c
\a\b\c
----
| Others (e.g. Linux, macOS) | [source,text]
----
a/b/c
/a/b/c
/a/b/c
----
|===

[id="fn_path_ossep"]
===== `osPathSep`
`osPathSep` returns the https://pkg.go.dev/os#PathSeparator[`os.PathSeparator`^] for this OS.

[source,gotemplate]
----
{{- osPathSep }}
----

renders as:

[cols="^.^2,.^4a",options="header"]
|===
| OS ^| Result

| Windows | [source,text]
----
\
----
| Others (e.g. Linux, macOS) | [source,text]
----
/
----
|===

[id="fn_path_os_psj"]
===== `osPathSliceJoin`
`osPathSliceJoin` operates like <<fn_path_gnrc_psj>> but with OS-specific path separators.

[TIP]
====
The `splitList` function shown below is from the https://masterminds.github.io/sprig/string_slice.html[`sprig` string slice functions^].
====

[source,gotemplate]
----
{{- $myList := "a,b,c" | splitList "," -}}
{{- $myList | osPathSliceJoin }}
{{- ("a,b,c" | splitList ",") | osPathSliceJoin }}
{{- ("/,a,b,c" | splitList ",") | osPathSliceJoin }}
----

renders as:

[cols="^.^2,.^4a",options="header"]
|===
| OS ^| Result

| Windows | [source,text]
----
a\b\c
a\b\c
\a\b\c
----
| Others (e.g. Linux, macOS) | [source,text]
----
a/b/c
a/b/c
/a/b/c
----
|===

[id="fn_path_os_pspj"]
===== `osPathSlicePipeJoin`
`osPathSlicePipeJoin` operates like <<fn_path_gnrc_pspj>> but with OS-specific separators.

[TIP]
====
The `splitList` function shown below is from the https://masterminds.github.io/sprig/string_slice.html[`sprig` string slice functions^].
====

[source,gotemplate]
----
{{- $myBase := "/a" -}}
{{- $myList := "b,c,d" | splitList "." -}}
{{- osPathSlicePipeJoin $myList $myBase }}
{{- $myBase | osPathSlicePipeJoin $myList }}
----

renders as:

[cols="^.^2,.^4a",options="header"]
|===
| OS ^| Result

| Windows | [source,text]
----
\a\b\c\d
\a\b\c\d
----
| Others (e.g. Linux, macOS) | [source,text]
----
/a/b/c/d
/a/b/c/d
----
|===

[id="fn_path_os_psubj"]
===== `osPathSubJoin`
`osPathSubJoin` operates like <<fn_path_gnrc_psubj>> but with OS-specific separators.

The pipeline-friendly equivalent of this is <<fn_path_os_ppj>>.

[source,gotemplate]
----
{{- osPathSubJoin "/a/b" "c" }}
{{- osPathSubJoin "/" "a" "b" "c" }}
{{- "c" | osPathSubJoin "/" "a" "b" }}
----

renders as:

[cols="^.^2,.^4a",options="header"]
|===
| OS ^| Result

| Windows | [source,text]
----
\a\b\c
\a\b\c
\a\b\c
----
| Others (e.g. Linux, macOS) | [source,text]
----
/a/b/c
/a/b/c
/a/b/c
----
|===

[id="fn_str"]
=== Strings

[id="fn_str_extindent"]
==== `extIndent`
`extIndent` allows for a MUCH more flexible indenter than the `sprig` `indent` function.

It works with both Windows (`\r\n`) and POSIX (`\n`) linebreaks.

[TIP]
====
If `<indentString>` is set to `\n` and `<levels>` is always set to `1`, this function can even be used to doubelspace text!
====

It has quite a few arguments, however:

[source,gotemplate]
----
{{ extIndent <levels> <skipFirst> <skipEmpty> <skipWhitespace> <indentString> <input> }}
----

Where:

* `<levels>`: The level of indentation for the text. If less than or equal to `0`, `extIndent` just returns `<input>` as-is and NO-OPs otherwise.
* `<skipFirst>`: If true, skip indenting the first line. This is particularly handy if you like to visually align your function calls in your templates.
* `<skipEmpty>`: If true, do not add an indent to *empty* lines (where an "empty line" means "only has a linebreak").
* `<skipWhitespace>`: If true, do not add an indent to lines that *only* consist of whitespace (spaces, tabs, etc.) and a linebreak.
* `<indentString>`: The string to use as the "indent character". This can be any string, such as `" "`, `"\t"`, `"."`, `"|"`, `"=="` etc.
* `<input>`: The text to be indented. Because it is the last argument, `extIndent` works with pipelined text as well.

[id="fn_dbg"]
=== Debugging

[id="fn_dbg_dump"]
==== `dump`
The `dump` function calls https://pkg.go.dev/github.com/davecgh/go-spew/spew#Sdump[the `Sdump` function^] from https://github.com/davecgh/go-spew[`go-spew`] (https://pkg.go.dev/github.com/davecgh/go-spew/spew[`github.com/davecgh/go-spew/spew`^]) for whatever object(s) is/are passed to it.