Merge pull request #161 from hairyhenderson/regexp-funcs

Adding regexp support

1 files changed, 70 insertions, 0 deletions

diff --git a/docs/content/functions/regexp.md b/docs/content/functions/regexp.md
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+---
+title: regexp functions
+menu:
+  main:
+    parent: functions
+---
+
+## `regexp.Replace`
+
+Replaces matches of a regular expression with the replacement string. The syntax
+of the regular expressions accepted is [Go's `regexp` syntax](https://golang.org/pkg/regexp/syntax/#hdr-Syntax),
+and is the same general syntax used by Perl, Python, and other languages.
+
+### Usage
+
+```go
+regexp.Replace expression replacement input
+```
+```go
+input | regexp.Replace expression replacement
+```
+
+### Arguments
+
+| name   | description |
+|--------|-------|
+| `expression` | The regular expression string |
+| `replacement` | The replacement string |
+| `input` | the input string to operate on |
+
+### Examples
+
+```console
+$ gomplate -i '{{ regexp.Replace "(foo)bar" "$1" "foobar"}}'
+foo
+```
+
+```console
+$ gomplate -i '{{ regexp.Replace "(?P<first>[a-zA-Z]+) (?P<last>[a-zA-Z]+)" "${last}, ${first}" "Alan Turing"}}'
+Turing, Alan
+```
+
+## `regexp.Match`
+
+Returns `true` if a given regular expression matches a given input string.
+
+This returns a boolean which can be used in an `if` condition, for example.
+
+### Usage
+
+```go
+regexp.Match expression input
+```
+```go
+input | regexp.Match expression
+```
+
+### Arguments
+
+| name   | description |
+|--------|-------|
+| `expression` | the regular expression to match |
+| `input` | the input string to test |
+
+### Examples
+
+```console
+$ gomplate -i '{{ if (.Env.USER | regexp.Match `^h`) }}username ({{.Env.USER}}) starts with h!{{end}}'
+username (hairyhenderson) starts with h!
+```