From 5820deb5559dac39b7da8b18e4ef2e5838f41b66 Mon Sep 17 00:00:00 2001
From: Andreas Baumann <mail@andreasbaumann.cc>
Date: Sat, 18 Aug 2018 14:52:01 +0200
Subject: crenshaw: expansion to multi-digit/letter symbols

---
 crenshaw/README    |  3 +++
 crenshaw/main.pas  | 38 ++++++++++++++++++++++++++++----------
 crenshaw/test.prog |  2 +-
 3 files changed, 32 insertions(+), 11 deletions(-)

(limited to 'crenshaw')

diff --git a/crenshaw/README b/crenshaw/README
index 74f0a20..a64a6f5 100644
--- a/crenshaw/README
+++ b/crenshaw/README
@@ -130,3 +130,6 @@ introduces lexing stuff afterwards.
 
 Checking for LF feels hacky.
 
+Mentions now the lexer. The mean reason for a lexer is to keep the
+parser simple, for instance it can work on one lookahead 'character'
+like GREATER_EQUALS instead of individually '>=' and '=>'.
diff --git a/crenshaw/main.pas b/crenshaw/main.pas
index 2ccc9de..fc1224b 100644
--- a/crenshaw/main.pas
+++ b/crenshaw/main.pas
@@ -44,23 +44,40 @@ begin
 	IsDigit := c in ['0'..'9'];
 end;
 
+function IsAlNum(c: char): boolean;
+begin
+	IsAlNum := IsAlpha(c) or IsDigit(c);
+end;
+
 function IsAddop(c: char): boolean;
 begin
    IsAddop := c in ['+', '-'];
 end;
 
-function GetName : char;
+function GetName : string;
+var
+	Token : string;
 begin
+	Token := '';
 	if not IsAlpha(Look) then Expected('Name');
-	GetName := UpCase(Look);
-	GetChar;
+	while IsAlNum(Look) do begin
+		Token := Token + UpCase(Look);
+		GetChar;
+	end;
+	GetName := Token;
 end;
 
-function GetNum : char;
+function GetNum : string;
+var
+	Value : string;
 begin
+	Value := '';
 	if not IsDigit(Look) then Expected('Integer');
-	GetNum := Look;
-	GetChar;
+	while IsDigit(Look) do begin
+		Value := Value + Look;
+		GetChar;
+	end;
+	GetNum := Value;
 end;
 
 procedure Emit(s : string);
@@ -87,11 +104,11 @@ type
 var
 	nof_symbols : integer;
 	symbols : array[0..26] of record
-		name : char;
+		name : string;
 		sym_type : symbolType;
 	end;
 
-procedure RememberName(name : char; sym_type : symbolType);
+procedure RememberName(name : string; sym_type : symbolType);
 var
 	i : integer;
 	found : boolean;
@@ -110,7 +127,7 @@ begin
 end;
 
 procedure Ident;
-var name : char;
+var name : string;
 begin
 	name := GetName;
 	if Look = '(' then begin
@@ -202,7 +219,8 @@ begin
 end;
 
 procedure Assignment;
-var name : char;
+var
+	name : string;
 begin
 	name := GetName;
 	RememberName(name, variableType);
diff --git a/crenshaw/test.prog b/crenshaw/test.prog
index 3636437..e19b072 100644
--- a/crenshaw/test.prog
+++ b/crenshaw/test.prog
@@ -1 +1 @@
-x=(4+4)*3/2-3+a-b*f()
+x=(4+4+12)*3/2-3+a-b*func1()
-- 
cgit v1.2.3-54-g00ecf