Add basic type system with only integers

This commit adds static typing with signed and unsigned integers of 8,
16, 32 and 64 bits.

1 files changed, 42 insertions, 14 deletions

diff --git a/expression.go b/expression.go
index 76cb16b..d042ebf 100644
--- a/expression.go
+++ b/expression.go
@@ -5,7 +5,6 @@
 package main
 
 import (
-	"fmt"
 	"io"
 )
 
@@ -63,19 +62,6 @@ func (p *paramExpr) markExpr() {}
 
 func (p *paramExpr) line() int { return p.ln }
 
-func (p *paramExpr) String() string {
-	if p == nil {
-		return ""
-	}
-
-	s := fmt.Sprintf("%s %%%s", p.typ, p.name)
-	if p.next != nil {
-		s += p.next.String()
-	}
-
-	return s
-}
-
 type externFuncExpr struct {
 	name       string
 	params     *signatureExpr
@@ -247,6 +233,7 @@ func (r *remAssignStmt) line() int { return r.ln }
 type exprExpr interface {
 	expression
 	markExprExpr()
+	cerType() cerType
 	generate(io.Writer) (string, error)
 }
 
@@ -262,6 +249,8 @@ func (e *equalityExpr) markExprExpr() {}
 
 func (e *equalityExpr) line() int { return e.ln }
 
+func (e *equalityExpr) cerType() cerType { return e.lhs.cerType() }
+
 type equalityRhs struct {
 	op    equalityOp
 	value *comparisonExpr
@@ -279,6 +268,8 @@ func (c *comparisonExpr) markExprExpr() {}
 
 func (c *comparisonExpr) line() int { return c.ln }
 
+func (c *comparisonExpr) cerType() cerType { return c.lhs.cerType() }
+
 type comparisonRhs struct {
 	op    comparisonOp
 	value *termExpr
@@ -296,6 +287,8 @@ func (t *termExpr) markExprExpr() {}
 
 func (t *termExpr) line() int { return t.ln }
 
+func (t *termExpr) cerType() cerType { return t.lhs.cerType() }
+
 type termRhs struct {
 	op    shiftOp
 	value *numeralExpr
@@ -313,6 +306,8 @@ func (n *numeralExpr) markExprExpr() {}
 
 func (n *numeralExpr) line() int { return n.ln }
 
+func (n *numeralExpr) cerType() cerType { return n.lhs.cerType() }
+
 type numeralRhs struct {
 	op    addSubOp
 	value *factorExpr
@@ -330,6 +325,8 @@ func (f *factorExpr) markExprExpr() {}
 
 func (f *factorExpr) line() int { return f.ln }
 
+func (f *factorExpr) cerType() cerType { return f.lhs.cerType() }
+
 type factorRhs struct {
 	op    mulDivOp
 	value *unaryExpr
@@ -347,6 +344,8 @@ func (u *unaryExpr) markExprExpr() {}
 
 func (u *unaryExpr) line() int { return u.ln }
 
+func (u *unaryExpr) cerType() cerType { return u.value.cerType() }
+
 type primaryExpr interface {
 	exprExpr
 	markPrimaryExpr()
@@ -372,6 +371,8 @@ func (s *stringExpr) markLiteralExpr() {}
 
 func (s *stringExpr) line() int { return s.ln }
 
+func (s *stringExpr) cerType() cerType { return nil } // TODO: string type
+
 type numberExpr struct {
 	typ string
 	s   string
@@ -388,6 +389,8 @@ func (n *numberExpr) markLiteralExpr() {}
 
 func (n *numberExpr) line() int { return n.ln }
 
+func (n *numberExpr) cerType() cerType { return resolveType(n.typ) }
+
 type groupingExpr struct {
 	inner exprExpr
 	ln    int
@@ -401,9 +404,12 @@ func (g *groupingExpr) markPrimaryExpr() {}
 
 func (g *groupingExpr) line() int { return g.ln }
 
+func (g *groupingExpr) cerType() cerType { return g.inner.cerType() }
+
 type callExpr struct {
 	funcName string
 	args     *argument
+	numArgs  int
 	ln       int
 }
 
@@ -415,6 +421,15 @@ func (c *callExpr) markPrimaryExpr() {}
 
 func (c *callExpr) line() int { return c.ln }
 
+func (c *callExpr) cerType() cerType {
+	ok, _ := isDeclared(c.funcName, true)
+	if !ok {
+		return nil
+	}
+
+	return funcs[c.funcName].returnType
+}
+
 type argument struct {
 	value exprExpr
 	next  *argument
@@ -432,3 +447,16 @@ func (v *varExpr) markExprExpr() {}
 func (v *varExpr) markPrimaryExpr() {}
 
 func (v *varExpr) line() int { return v.ln }
+
+func (v *varExpr) cerType() cerType {
+	ok, mutable := isDeclared(v.name, false)
+	if !ok {
+		return nil
+	}
+
+	if mutable {
+		return localMuts[currentFunc][v.name].typ
+	}
+
+	return localConsts[currentFunc][v.name].typ
+}