Use standard tokenizations for variable definitions.

This is so that multi-line variable content will be possible one day.

doc/roast.txt

@@ -159,7 +159,7 @@ A note about escaping braces in the context of interpolation. Braced should be
 doubled to escape. So, if we are defining a variable with a JSON value, the
 braces should be doubled so they won't be interpreted as interpolation targets.
 <
-   set payload {{"username": "Sherlock", "password": "Moriarty"}}
+   set payload '{{"username": "Sherlock", "password": "Moriarty"}}'
 >
 Here, the variable `payload` would be set to the following text:
 <

python3/roast_api.py

@@ -31,19 +31,17 @@ def build_request(lines, line_num) -> requests.Request:
             current_template.append(line)
             continue
 
-        if line.startswith('set '):
-            name, value = line[4:].strip().split(None, 1)
-            # Interpolations in variables are applied when the variable is defined.
-            variables[name] = value.format(**variables)
-            continue
-
         parts = tokenize(line)
         if len(parts) < 2:
             continue
 
         head, *rest = parts
 
-        if head == 'alias':
+        if head == 'set':
+            # Interpolations in variables are applied when the variable is defined.
+            variables[rest[0]] = ' '.join(rest[1:]).format(**variables)
+
+        elif head == 'alias':
             # Interpolations in aliases are applied when the alias is used.
             aliases[rest[0]] = ' '.join(rest[1:])
 

python3/test_roast.py

@@ -95,7 +95,7 @@ def test_interpolation_in_headers():
 
 def test_variable_with_json_value():
     req = ra.build_request([
-        'set payload {{"username": "Sherlock", "password": "Moriarty"}}',
+        'set payload \'{{"username": "Sherlock", "password": "Moriarty"}}\'',
         'POST /post <<END',
         '{payload}',
         'END',