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, 18 insertions, 18 deletions

diff --git a/tests/variables.sh b/tests/variables.sh
index ffa66c3..93e9bd8 100755
--- a/tests/variables.sh
+++ b/tests/variables.sh
@@ -5,12 +5,12 @@
 set -e
 
 echo -n "- One variable: "
-assert_exit_status 'fn main() { let x: int; x = 45; return x; }' 45
-assert_exit_status 'fn main() { let x: int = 45; return x; }' 45
-assert_exit_status 'fn main() { let x: int = 45; return x+x; }' 90
+assert_exit_status 'fn main(): int { let x: int; x = 45; return x; }' 45
+assert_exit_status 'fn main(): int { let x: int = 45; return x; }' 45
+assert_exit_status 'fn main(): int { let x: int = 45; return x+x; }' 90
 
 assert_exit_status_stdin 5 <<EOF
-fn main() {
+fn main(): int {
     let x: int;
     x = 3;
     x = 5;
@@ -19,7 +19,7 @@ fn main() {
 EOF
 
 assert_exit_status_stdin 5 <<EOF
-fn main() {
+fn main(): int {
     let x: int = 3;
     x = x + x - 1;
     return x;
@@ -30,7 +30,7 @@ echo " OK"
 
 echo -n "- Multiple variable: "
 assert_exit_status_stdin 2 <<EOF
-fn main() {
+fn main(): int {
     let x: int = 1;
     let y: int = x + x;
     return y;
@@ -38,7 +38,7 @@ fn main() {
 EOF
 
 assert_exit_status_stdin 23 <<EOF
-fn main() {
+fn main(): int {
     let x: int = 1;
     let y: int = x + x;
     let z: int = y + y;
@@ -49,7 +49,7 @@ fn main() {
 EOF
 
 assert_exit_status_stdin 2 <<EOF
-fn main() {
+fn main(): int {
     let x: int = 1;
     let y: int = x + x;
     y = y + x;
@@ -59,7 +59,7 @@ fn main() {
 EOF
 
 assert_exit_status_stdin 18 <<EOF
-fn main() {
+fn main(): int {
     let x: int = 5;
     let y: int;
     let z: int = (y = x + 3) + 2;
@@ -71,7 +71,7 @@ echo " OK"
 echo -n "- Global variables: "
 assert_exit_status_stdin 18 <<EOF
 let g: int;
-fn main() {
+fn main(): int {
     g = 18;
     return g;
 }
@@ -80,7 +80,7 @@ EOF
 assert_exit_status_stdin 18 <<EOF
 let g: int;
 let h: int;
-fn main() {
+fn main(): int {
     g = 18;
     h = g + g;
     return h - g;
@@ -96,7 +96,7 @@ fn test() {
     h = g + g;
 }
 
-fn main() {
+fn main(): int {
     test();
     return h - g;
 }
@@ -105,7 +105,7 @@ EOF
 assert_compile_failure_stdin <<EOF
 let g: int = 0;
 
-fn main() {
+fn main(): int {
     return g;
 }
 EOF
@@ -113,7 +113,7 @@ echo " OK"
 
 echo -n "- Nested Blocks: "
 assert_exit_status_stdin 3 <<EOF
-fn main() {
+fn main(): int {
     let x: int = 1;
     {
         let y: int = 3;
@@ -216,7 +216,7 @@ echo " OK"
 
 echo -n "- Conditionals w/ blocks: "
 assert_exit_status_stdin 3 <<EOF
-fn main() {
+fn main(): int {
     let x: int = 1;
     if (x == 1) {
         let y: int = 3;
@@ -227,7 +227,7 @@ fn main() {
 EOF
 
 assert_exit_status_stdin 1 <<EOF
-fn main() {
+fn main(): int {
     let x: int = 1;
     if (x != 1) {
         let y: int = 3;
@@ -238,7 +238,7 @@ fn main() {
 EOF
 
 assert_exit_status_stdin 5 <<EOF
-fn main() {
+fn main(): int {
     let x: int = 1;
     if (x != 1) {
         let y: int = 3;
@@ -252,7 +252,7 @@ fn main() {
 EOF
 
 assert_compile_failure_stdin <<EOF
-fn main() {
+fn main(): int {
     let x: int = 1;
     if (x != 1) {
         let y: int = 3;