Type checking of expressions / functions!

This is a bit of a chonky commit, but it adds in the basics of checking
the types of expressions / function calls / return types. There's still
a lot of work to be done, including:

(1) Adding new core types, and casting between allowed types
    automatically
(2) Picking the corrent output type based on input types (for instance
    float+int == float)
(3) We need much better error reporting, the error messages are really
    vague and unhelpful as-is
(4) We also need to work to ensure that a function with a return type
    actually returns
(5) Possible re-factoring to make stuff less hacky when we have more
    types / structs / arrays / etc.

1 files changed, 10 insertions, 10 deletions

diff --git a/tests/loops.sh b/tests/loops.sh
index 3fea60f..ab0a949 100755
--- a/tests/loops.sh
+++ b/tests/loops.sh
@@ -6,7 +6,7 @@ set -e
 
 echo -n "- While loops: "
 assert_exit_status_stdin 5 <<EOF
-fn main() { 
+fn main(): int { 
     while (1) {
         return 5;
     }
@@ -15,7 +15,7 @@ fn main() {
 EOF
 
 assert_exit_status_stdin 3 <<EOF
-fn main() { 
+fn main(): int { 
     while (0) {
         return 5;
     }
@@ -24,7 +24,7 @@ fn main() {
 EOF
 
 assert_exit_status_stdin 10 <<EOF
-fn main() { 
+fn main(): int { 
     let sum: int = 0;
     while (sum < 10) {
         sum = sum + 1;
@@ -34,7 +34,7 @@ fn main() {
 EOF
 
 assert_exit_status_stdin 55 <<EOF
-fn main() { 
+fn main(): int { 
     let sum: int = 0;
     let N: int = 10;
     let i: int = 0;
@@ -49,7 +49,7 @@ echo " OK"
 
 echo -n "- For loops: "
 assert_exit_status_stdin 5 <<EOF
-fn main() { 
+fn main(): int { 
     for (;;) {
         return 5;
     }
@@ -58,7 +58,7 @@ fn main() {
 EOF
 
 assert_exit_status_stdin 3 <<EOF
-fn main() { 
+fn main(): int { 
     for (;0;) {
         return 5;
     }
@@ -67,7 +67,7 @@ fn main() {
 EOF
 
 assert_exit_status_stdin 55 <<EOF
-fn main() { 
+fn main(): int { 
     let sum: int = 0;
     let i: int;
     for (i = 0; i <= 10; i = i + 1) {
@@ -78,7 +78,7 @@ fn main() {
 EOF
 
 assert_exit_status_stdin 55 <<EOF
-fn main() { 
+fn main(): int { 
     let sum: int = 0;
     let i: int = 0;
     for (; i <= 10; i = i + 1) {
@@ -89,7 +89,7 @@ fn main() {
 EOF
 
 assert_exit_status_stdin 45 <<EOF
-fn main() { 
+fn main(): int { 
     let sum: int = 0;
     let i: int = 0;
     for (;i < 10;) {
@@ -101,7 +101,7 @@ fn main() {
 EOF
 
 assert_exit_status_stdin 55 <<EOF
-fn main() { 
+fn main(): int { 
     let sum: int = 0;
     let i: int = 0;
     for (;;) {