From 1cc04b1043b501e41c29b5c40c3c4e369c552fc5 Mon Sep 17 00:00:00 2001
From: pgagnidze <pgagnidze@pm.me>
Date: Thu, 1 Jun 2023 02:42:14 +0400
Subject: [PATCH] feat: scan the entire AST to collect function names, instead
 of forward declarations

---
 NOTES.md         |  5 +++--
 ena/compiler.lua | 28 +++++++++++++++-------------
 ena/parser.lua   |  2 +-
 ena/spec/e2e.lua | 20 ++++++++++++++++++++
 4 files changed, 39 insertions(+), 16 deletions(-)

diff --git a/NOTES.md b/NOTES.md
index 48ba282..a0b76d5 100644
--- a/NOTES.md
+++ b/NOTES.md
@@ -61,8 +61,9 @@ Execute the [input.ena](./example/input.ena) for the input program. `input.ena`
 
 Check out the new [sysinfo.ena](./example/sysinfo.ena) program that shows various system informations for Linux and Darwin os.
 
-**Summary of changes:**
-- optional statement separator (;)
+**Summary of modifications:**
+- Optional statement separator (;)
+- Scan the entire AST and collect function names (instead of forward declarations)
 
 ## New Features
 
diff --git a/ena/compiler.lua b/ena/compiler.lua
index ea8ed36..9ba9de4 100644
--- a/ena/compiler.lua
+++ b/ena/compiler.lua
@@ -1,6 +1,7 @@
 local module = {}
 local translator = require "ena.lang.translator"
 local literals = require "ena.lang.literals"
+local pt = require "ena.helper.pt".pt
 local lop = literals.op
 
 local Compiler = {}
@@ -327,19 +328,7 @@ function Compiler:findFirstDuplicateParam(ast)
 end
 
 function Compiler:codeFunction(ast)
-    if not ast.block then
-        if not self.functions[ast.name] then
-            self.functions[ast.name] = {code = {}, forwardDeclaration = true}
-        end
-    end
-    local functionCode = self.functions[ast.name] and self.functions[ast.name].code or {}
-    if #functionCode > 0 and not self.functions[ast.name].forwardDeclaration then
-        error(
-            (self.translate and translator.err.compileErrDuplicateFunctionName or "Duplicate function name") ..
-                ' "' .. ast.name .. '()"'
-        )
-    end
-    self.functions[ast.name] = {code = functionCode, params = ast.params, defaultArgument = ast.defaultArgument}
+    local functionCode = self.functions[ast.name].code
     self.code = functionCode
     self.params = ast.params
     local firstDuplicate = self:findFirstDuplicateParam(ast)
@@ -357,7 +346,20 @@ function Compiler:codeFunction(ast)
     end
 end
 
+function Compiler:collectFunctions(ast)
+    for i = 1, #ast do
+        local functionDeclaration = ast[i]
+        if not self.functions[functionDeclaration.name] then
+            self.functions[functionDeclaration.name] = {code = {}, params = functionDeclaration.params, defaultArgument = functionDeclaration.defaultArgument}
+        else
+            error("Duplicate function name '" .. functionDeclaration.name .. "()'")
+        end
+    end
+end
+
 function Compiler:compile(ast)
+    self:collectFunctions(ast)
+
     for i = 1, #ast do
         self:codeFunction(ast[i])
     end
diff --git a/ena/parser.lua b/ena/parser.lua
index 2b3e889..4b6ddef 100755
--- a/ena/parser.lua
+++ b/ena/parser.lua
@@ -276,7 +276,7 @@ local grammar = {
     funcDec = KW_function * identifier * delim.openFunctionParameterList * funcParams *
         ((op.assign * expression) + Cc({})) *
         delim.closeFunctionParameterList *
-        (blockStatement + sep.statement ^ -1) /
+        blockStatement /
         nodeFunction,
     funcParams = Ct((identifier * (delim.functionParameterSeparator * identifier) ^ 0) ^ -1),
     statementList = statement * (sep.statement ^ -1 * statementList) ^ -1 / nodeStatementSequence,
diff --git a/ena/spec/e2e.lua b/ena/spec/e2e.lua
index 29aa99d..40e934a 100644
--- a/ena/spec/e2e.lua
+++ b/ena/spec/e2e.lua
@@ -512,6 +512,26 @@ function module:testOptionalStatementSeparator()
     )
 end
 
+function module:testFunctionOrdering()
+    lu.assertEquals(
+        self:endToEnd(
+            [[
 
+            function a() {
+                return 1
+            }
+
+            function main() {
+                return a() + b()
+            }
+            
+            function b() {
+                return 2
+            }
+            ]]
+        ),
+        3
+    )
+end
 
 return module