Add function call support

src/grammar.pest

@@ -3,8 +3,11 @@ file = { "hello world" }
 statement = { decl }
 decl      = { "let" ~ #name = ident ~ #args = (ident)* ~ "=" ~ expr }
 
-expr       =  { infix_expr | term }
+expr       =  { infix_expr | call_expr | term }
 term       = _{ ident | literal | "(" ~ expr ~ ")" }
+call_expr  =  {
+    #name = ident ~ #args = (term)+
+}
 infix_expr =  {
     #lhs = term ~ operator ~ #rhs = expr
 }

src/test/expressions.rs

@@ -81,3 +81,36 @@ fn it_parses_multiple_operations() {
         ])
     ]);
 }
+
+#[test]
+fn it_parses_calls() {
+    parses_to!(parser: SnekParser, input: "print a", rule: Rule::expr, tokens: [
+        expr(0, 7, [
+            call_expr(0, 7, [
+                ident(0, 5),
+                ident(6, 7),
+            ])
+        ])
+    ]);
+    parses_to!(parser: SnekParser, input: "print (1 + 1) a", rule: Rule::expr, tokens: [
+        expr(0, 15, [
+            call_expr(0, 15, [
+                ident(0, 5),
+                expr(7, 12, [
+                    infix_expr(7, 12, [
+                        literal(7, 8, [
+                            integer(7, 8)
+                        ]),
+                        operator(9, 10),
+                        expr(11, 12, [
+                            literal(11, 12, [
+                                integer(11, 12)
+                            ]),
+                        ])
+                    ])
+                ]),
+                ident(14, 15)
+            ])
+        ])
+    ]);
+}

src/test/mod.rs

@@ -1,4 +1,4 @@
-mod infix_expressions;
+mod expressions;
 mod literals;
 mod statements;
 

src/test/statements.rs

@@ -3,7 +3,7 @@ use pest::{consumes_to, parses_to};
 use crate::{Rule, SnekParser};
 
 #[test]
-fn it_parses_assignments() {
+fn it_parses_plain_assignments() {
     parses_to!(parser: SnekParser, input: "let a = 1", rule: Rule::statement, tokens: [
         statement(0, 9, [
             decl(0, 9, [
@@ -17,3 +17,26 @@ fn it_parses_assignments() {
         ])
     ]);
 }
+
+#[test]
+fn it_parses_assignments_with_args() {
+    parses_to!(parser: SnekParser, input: "let add a = a + 1", rule: Rule::statement, tokens: [
+        statement(0, 17, [
+            decl(0, 17, [
+                ident(4, 7),
+                ident(8, 9),
+                expr(12, 17, [
+                    infix_expr(12, 17, [
+                        ident(12, 13),
+                        operator(14, 15),
+                        expr(16, 17, [
+                            literal(16, 17, [
+                                integer(16, 17)
+                            ])
+                        ])
+                    ])
+                ])
+            ])
+        ])
+    ]);
+}