From 9bf03c52be41d24988b9876f21cdef1b96fb2eec Mon Sep 17 00:00:00 2001
From: Lephe <sebastien.michelland@protonmail.com>
Date: Sun, 6 Oct 2019 10:57:58 +0200
Subject: [PATCH] allow <sign><function> atoms

---
 fx92.py                 |  5 ++++-
 fx92/lexer.py           | 20 ++++++++++++++------
 fx92/parser.py          | 12 +++++++++---
 tests.py                |  4 +++-
 tests/function-atom.out |  4 ++++
 tests/function-atom.txt |  4 ++++
 6 files changed, 38 insertions(+), 11 deletions(-)
 create mode 100644 tests/function-atom.out
 create mode 100644 tests/function-atom.txt

diff --git a/fx92.py b/fx92.py
index 0618ea1..8c06154 100755
--- a/fx92.py
+++ b/fx92.py
@@ -93,7 +93,10 @@ def main():
     ast = parser.parse_program()
     ast = ast.simplify()
 
-    print_ast(ast, lang="ast")
+    # Parser debug mode, print the AST
+    if debug == "parser":
+        print_ast(ast, lang="ast")
+        return 0
 
     with Window(width=192, height=47, scale=scale, quiet=quiet) as w:
         ctx = Context(w)
diff --git a/fx92/lexer.py b/fx92/lexer.py
index 7057d6a..40e646d 100644
--- a/fx92/lexer.py
+++ b/fx92/lexer.py
@@ -301,9 +301,10 @@ class TextLexer(LexerBase):
         r"PRINT|STYLE|WAIT|REPEAT_END|REPEAT|WHILE_END|WHILE|IF_END|ELSE|"
         r"IFELSE_END|IFELSE|IF",
         re.IGNORECASE)
-
     RE_CONST = re.compile(
         r"([0-9]+(?:\.[0-9]+)?(?:[eE][0-9]+)?)(%?)")
+    RE_FUN = re.compile(
+        r"([a-zA-Z]+)\(")
 
     def __init__(self, code):
         """Initialize the lexer with text code."""
@@ -384,6 +385,13 @@ class TextLexer(LexerBase):
             self.pending_param = True
             return Token(T.CONST, f)
 
+        # Functions
+        m = re.match(self.RE_FUN, c)
+        if m is not None:
+            self.code = c[len(m[0]):]
+            self.pending_param = True
+            return Token(T.FUN, m[1])
+
         # Variables
         if c[0] in "MABCDEFxXyY":
             var = c[0].lower() if c[0] in "xXyY" else c[0]
@@ -391,11 +399,6 @@ class TextLexer(LexerBase):
             self.pending_param = True
             return Token(T.VAR, c[0])
 
-        # If nothing can be found, raise an exception
-        s = c.split(maxsplit=1)
-        err = s[0]
-        self.code = s[1] if len(s) > 1 else ""
-
         # Comments
         if c[0] == "#":
             splits = c.split('\n', maxsplit=1)
@@ -404,6 +407,11 @@ class TextLexer(LexerBase):
             self.position -= 1
             return self.lex()
 
+        # If nothing can be found, raise an exception
+        s = c.split(maxsplit=1)
+        err = s[0]
+        self.code = s[1] if len(s) > 1 else ""
+
         raise Exception("Lexical error near '{}'".format(err))
 
     def at_end(self):
diff --git a/fx92/parser.py b/fx92/parser.py
index 9438c59..39f7dde 100644
--- a/fx92/parser.py
+++ b/fx92/parser.py
@@ -215,10 +215,16 @@ class Parser:
     # atom -> const (VAR | "(" expr ")")* | (VAR | "(" expr ")")+
     def atom(self):
         factors = []
-        lat = self.la.type
 
-        # Case of constants
-        if lat == T.PLUS or lat == T.MINUS or lat == T.CONST:
+        # Initial sign
+        if self.la.type == T.PLUS:
+            self.expect(T.PLUS)
+        elif self.la.type == T.MINUS:
+            self.expect(T.MINUS)
+            factors.append(Node(N.CONST, -1))
+
+        # Optional constant
+        if self.la.type == T.CONST:
             factors.append(self.const())
 
         while 1:
diff --git a/tests.py b/tests.py
index c5ce8aa..4674ffe 100755
--- a/tests.py
+++ b/tests.py
@@ -27,12 +27,14 @@ def runtest(program, refout=None, refimg=None):
     success = True
 
     if refout is not None:
-        with open(refout, "r") as fp:
+        with open(refout, "rb") as fp:
             refout = fp.read()
         if st.stdout == refout:
             print("  Output is correct.")
         else:
             print("  -> Output is incorrect!")
+            print("  ref:", repr(refout))
+            print("  out:", repr(st.stdout))
             success = False
 
     if refimg is not None:
diff --git a/tests/function-atom.out b/tests/function-atom.out
new file mode 100644
index 0000000..4672473
--- /dev/null
+++ b/tests/function-atom.out
@@ -0,0 +1,4 @@
+-2.0
+1.0
+1.0
+-1.0
diff --git a/tests/function-atom.txt b/tests/function-atom.txt
new file mode 100644
index 0000000..57f00f3
--- /dev/null
+++ b/tests/function-atom.txt
@@ -0,0 +1,4 @@
+print -2cos(0)
+print 1cos(0)
+print +cos(0)
+print -cos(0)