Add example for if expressions

README.md

@@ -43,6 +43,13 @@ add2 4
 
 // nested function calls
 add2 (sub4 (mul2 4)) 
+
+// if is an expression that can return a value
+let value = 
+  if a == b then
+    a
+  else
+    b
 ```
 
 ### Declarations

src/grammar.pest

@@ -3,7 +3,7 @@ file = {
 }
 
 statement  =  { (decl | type_decl | expr) ~ TERMINATE }
-decl       =  { "let" ~ #name = ident ~ #args = (ident)* ~ #type = type_annot? ~ "=" ~ expr }
+decl       =  { "let" ~ #name = ident ~ #args = (ident)* ~ #type = type_annot? ~ "=" ~ MLF ~ expr }
 block      =  { "{" ~ MLF ~ block_line ~ MLF ~ "}" }
 block_line = _{ expr | (statement ~ MLF)* }
 

tests/corpus/statements/if-stmt.txt

@@ -12,6 +12,12 @@ if 1 != 1 then {
   a + 1
 }
 
+let value = 
+  if a == b then
+    a
+  else
+    b
+
 ======
 
 (file
@@ -88,5 +94,27 @@ if 1 != 1 then {
       )
     )
   )
+  (statement
+    (decl
+      (ident: "value")
+      (expr
+        (if
+          (expr
+            (infix_expr
+              (ident: "a")
+              (operator: "==")
+              (ident: "b")
+            )
+          )
+          (expr
+            (ident: "a")
+          )
+          (expr
+            (ident: "b")
+          )
+        )
+      )
+    )
+  )
   (EOI: "")
 )