From c0d9b53004ddfe539bfe76a60b48ce0d05c9c72c Mon Sep 17 00:00:00 2001
From: elkowar <5300871+elkowar@users.noreply.github.com>
Date: Fri, 14 May 2021 11:55:08 +0200
Subject: [PATCH] Add regex replace and function call docs

---
 docs/content/main/expression_language.md | 3 +++
 src/value/attr_value/attr_value_expr.rs  | 9 +++++++++
 2 files changed, 12 insertions(+)

diff --git a/docs/content/main/expression_language.md b/docs/content/main/expression_language.md
index 53b3dd0..cabd73b 100644
--- a/docs/content/main/expression_language.md
+++ b/docs/content/main/expression_language.md
@@ -34,4 +34,7 @@ The expression language supports:
     - strings can contain other expressions again: `'foo {{some_variable}} bar'`
 - json access (`object.field`, `array[12]`, `object["field"]`)
     - for this, the object/array value needs to refer to a variable that contains a valid json string.
+- some function calls:
+    - `round(number, decimal_digits)`: Round a number to the given amount of decimals
+    - `replace(string, regex, replacement)`: Replace matches of a given regex in a string
 
diff --git a/src/value/attr_value/attr_value_expr.rs b/src/value/attr_value/attr_value_expr.rs
index 90320dd..169d522 100644
--- a/src/value/attr_value/attr_value_expr.rs
+++ b/src/value/attr_value/attr_value_expr.rs
@@ -230,6 +230,15 @@ fn call_expr_function(name: &str, args: Vec<PrimVal>) -> Result<PrimVal> {
             }
             _ => Err(anyhow!("Incorrect number of arguments given to {}", name)),
         },
+        "replace" => match args.as_slice() {
+            [string, pattern, replacement] => {
+                let string = string.as_string()?;
+                let pattern = regex::Regex::new(&pattern.as_string()?)?;
+                let replacement = replacement.as_string()?;
+                Ok(PrimVal::from(pattern.replace_all(&string, replacement.replace("$", "$$").replace("\\", "$")).into_owned()))
+            }
+            _ => Err(anyhow!("Incorrect number of arguments given to {}", name)),
+        },
         _ => Err(anyhow!("Unknown function {}", name)),
     }
 }